I saw a test on Nick's Garage with a bone stock 2 four barrel 1970 426 Hemi. The factory rated this engine at 425 Horsepower. On the dyno with factory exhaust manifolds, the 1970 426 Hemi made 500 HP.. By adding only headers, the 426 Hemi made 550 Horsepower.
i have a doubt, why it makes 433 hp almost bone stock on the dyno more than the gm numbers of 364 hp advertises?, is it because of open exhaust, the cam swap, or because of running without accesories, or the efi custom pcm?
all of that-GM tests and certifies the power output of their stock motors differently-with all accs, full exhaust, fuel air intake, run at 200 degrees with the factory tune
Hi Richard, for my 06 Z71 I can only find exhaust systems that use the original style gm cross over to passenger side. Even the long tube types use it. It seems that this would cause unequal flow or is it negligible? Mild cam and cai so far. Thanks!
My work delivery truck is an Isuzu NPR-HD with a well-maintained beast of an LY6. Whether it's 1 stop or 10... all deliveries get done before 2 every day :)
I can answer this question before I even watch your dyno results; the answer is it depends. There are literally some engines that don’t pickup any power at all from aftermarket headers. This being the result of an engine that A) isn’t flow restricted on the exhaust side of things and/or B) has a decent factory setup that promotes scavenging. As far as boosted applications from what I’ve seen over the years it matters far more what is in front of the compressor wheel than what feeds the turbine wheel. More often than not I’ve changed boost pressure more with inlet piping than the exhaust setup, and typically see changes in spool rate with exhaust modifications rather than changes in overall total boost pressure. When I have seen gains on built NA engines from header changes, it’s not usually from flow it’s from the effects of scavenging. I know this because I rarely see a power difference from a change in primary diameter, and I have literally bashed and bent/Pryed on headers to make them fit off the wall swap applications to the point where I 100% know I diminished the inner diameter of the tube somewhat, and power did not change.
I have a 5.3 Ls out of a 2010 chevy Silverado putting it in a 1997 s10 single cab pickup will I be able to use the manifolds that came on the 5.3 in the s10
You are so right. That is why I watch these engine experts like Richard. They actually teach you what's going on and why it's good or bad, not just hyperbole from something that someone said 50 years ago and it's been repeated as truth ever since.
@@1967davethewave I don't even understand that statement Scavenging is a natural occurrence is going to happen and what you want is to promote better Scavenging I don't know anything about this fifty-year-old whatever nonsense you're talking about building power has always been about math before computers came out you have to be able to literally write down the equation for horsepower
Got your clips out of order there, you put the supercharged comparison before the cammed comparison, but the narration was opposite. Not a big deal, still a great video.
Another very nice test Richard, I was looking for such a test for sometime already 🙂 it really helps people to make a smart investment when upgrading their Engines and also helps to understand how to maximize the advantage of Long Tube Headers even further. Great test. Thanks again Richard.
I don’t like how you change components up like adding a cam or valve springs. Can’t you just do a straight up comparison with a stock engine? Some of us just want to know if long tubes will benefit us without mechanical upgrades.
@@krisjones1286 I just read that article. Search for Everthing you need to know about hooker small block chevy manifolds. They say if your over 550 hp use headers if your after every last hp.
thank you for doing these types of really detailed analyisis...im in love with the content.!> dude..make a video of you shredding a car or truck some where...we need to see you drive some wild vehicles..q>>!>q>>!>q>!q
The LS manifolds are good enough and dont go threw header gaskets . Every time I had headers I kept burning out gaskets . If your on the street I would manifolds and headers on the track.
@@rustinpenner5661 yes indeed, also Coated headers are the way to go, and in most applications, wrap all nearby wiring, even if it's several inches from the tubes. Another thing is plug wires sure do catch alot of abuse, of course there is remedies for that too.
A few questions sir' 1. can i put a small turbo on my stock 94 4x4 gmc suburban so i can get a bit more power out of it.2. and will it basically bolt on. 3 or would i be better off rebuilding this very good running no oil leaking stock 5.7 350 chevy 210 HP motor using Vortech heads, cam, Timing chain, 2.0 intake, headers into my 2 1/2'' flow masters. it runs great for what it is but once i added the 4'' lift kit and 35'' tires its sluggish up hills or when towing. it has 373 gears. thank you
What about in a turbo application? Long tube headers vs stock. I imagine it wont affect the output as much because the turbo itself is a restriction? 🧐
In theory, a turbo should like equal length runners with runner lenght being a compromise between response and scavenging (so, most stock and street applications short or even no runners, racing medium to long) but I've never seen different primary tube lengths tested to confirm this.
I'm curious about the LS1/LS6 (C5 Corvette) manifolds versus the newer log style exhaust manifolds. The C5 Vette manifolds almost look like headers but are cast of course.
I tune the combination with each change. If run in closed loop, the ECU can adjust to the specified AF target, but I don't do this at WOT-only part throttle.
I can save you a bunch of time. Good long tube headers give marginal performance upgrades over MODERN stock mans. But of course you want them because they look cool and they offer a better exhaust note. Thats all sorry if that disappoints you but that is the truth.
I know that the old style SBC is no longer a go-to power plant, but it would have been interesting to compare that generation’s stock log style exhaust manifolds to long tube headers. Sure there would be a much more impressive gains with the headers.
Are long tubes worth the extra expense and hassle on a mild 5.0ho in a sn95 or any other fox mustang? I've heard even tho the factory shorty's are pretty bad that aftermarket shorty's are still offer meager improvements unless it's a heavy breather then any extra flow will be a appreciated improvement
I was running 40 ifr, 72 primary jet on my ls swapped obs with stock cast headers. When I installed 1 3/4 headers, I had to lean out the jets to 35 ifr and 65 primary jet , so yes theres a big scavenging effect with longtube headers, I had to jet down because of how rich it was with tubes , just an fyi
what I learned was they don't offer up enough performance advantage to go through the hassle of installing them on your car unless the engine is already out. I know, that's an unpopular opinion here.
Have you done a tri-y vs 4-1 comparison? There's probably bugger all difference between them in reality but there seems to be two distinct camps claiming one is better than the other.
So what is the real theory about the size the exhaust to amount of horse power cause now when you add a super charger now your going to be second hand guessing what to pick out for a exhaust.
In the 70s, one of the best ways to get power was headers and free-flowing exhaust. Since the 2000s engines have improved so much that there just isn't much difference. Your results are about what I'd expect. For example: my 2003 GMC LQ4 has cast manifolds that are essentially short tube headers that feed into a 4" exhaust system.
I have a 2002 Avalanche, stock 5.3, and I added a Whipple SC that makes 6 psi boost. I put long tube headers on it and they were nothing but trouble. First, the headers for the truck do not have tubes that lay neat and tidy like his dyno headers. They have tubes that loop upward and make contact with the LS ign wires, forcing you to solve that problem. Then they make access the spark plugs more difficult. And they have a clearance issue with the 4x4 front pinion. And they crowd the starter, making it more prone to heat failure and more difficult to change out when it fails. They were not worth it. I now have a little more cam in it, very mild, stock idle with .050" more lift than stock. The 706 heads have been CNC ported and the chambers polished & cc'd, still the same Whipple SC. I now have the stock exhaust manifolds back on and I will install a good performance exhaust system behind the stock manifolds. I am looking forward to fewer under-hood problems and I don't mind if there is a small HP penalty. The engine runs well, BUT unfortunately I can't drive it right now because the engine has to come back apart ... apparently Comp Cams has sold me a bad set of lifters and they clack like mad after the engine warms up. Quiet on cold start but excessive lash noise gradually comes in as it warms past 180 degrees.
Very true! malaise era cars had the worst exhaust systems ever just a plain dual exhaust system begins at 20 or more even a better air filter would add a few hopefully you would be lucky enough to have a four barrel.
@@bigboreracing356 I'm 63, retired, and I put ~ $30K into a frame-off restoration on the truck since 3 years ago. No regrets, it's been fun but the next time the engine comes apart it's getting stock GM lifters instead of Comp Cams. When you grow up you might rethink stamping emojis all over what you write.
I feel like my 1 3/4 longtubes are the right package for my boosted and cammed gen 2 LT1. When it eventually gets some AFR heads, a larger cam and a smaller pulley it'll be time for 1 7/8 longtubes.
100% spot on, the longer the cam duration the bigger the potential gains from the header. Especially noticeable on a street driven motor at low RPM, with the Wrong cam 😆
Hey Richard, I'm curious about your thoughts on job security as things are trending towards electric vehicles. Do you know if what you do will still be allowed in the future? I love engines and want to keep them alive as long as possible but I worry about their place in the world moving forward. Do you think they'll still allow gasoline powered vehicles but with a tax so that only the wealthy can collect them?
Funny, for me every set of headers I've put on were worth it. I even fabricated headers for my camaro one bend at a time because of the unusual motor swap.
Since GM pioneered their modern casting practices, factory manifolds have been outflowing most shorty headers since the LS6. I'm not surprised to see them hold up well, in comparison to full length primaries... especially given how most of today's full length headers have junk collectors.
@Richard Holdener - what you meant to say is "[bench] flow is not [necessarily] what makes power...". Had you said that, you'd be correct. As stated, however, it's quite wrong. Flow is literally what makes power. The power of any internal combustion engine is most closely related to its flow rate. Better scavenging IS LITERALLY better flow. It is an increase in volumetric efficiency, caused by the low pressure left behind by exhaust pulses. True, you you can have a header that "flows well" on the bench, but is crap for your engine... but that's because the bench doesn't "flow" like your engine, and your engine isn't "flowing" as well with those particular headers. All other parameters kept relatively the same (fuel, compression, timing, bore, stroke, etc...), scavenging increases horsepower because you are decreasing resistance through the exhaust stroke, and increasing volumetric efficiency as the piston slows to TDC and transitions into the intake phase.
A video on working out matching header pipe sizes to the motor would be good. A K series Honda won’t need 1 7/8” header pipes but does say a mid sized motor like the 3800??
Hey Richard, I may have missed it, but on the Supercharged LS. Was there a difference in boost numbers with the different headers, everything else being the same? I was curious if there mightve been a restriction there. 🤔
I'd be curious how the home made pass side turbo manifold/header is compared to the Hooker Blackheart stuff. Toss in a comparison between a log or Fahler Speed style manifold and everyone will see what is worth doing.
the Holley turbo system is somewhat restrictive (the merge point) after the cross over. A different design with more flow will add power and drop back pressure
Are the Hooker 8502HKR's with 2.5" collector about the same power wise as the stock manifolds you show? Do the bigger openings on the Hookers help? I have fitment issues and longtubes won't work with my project. I have a 6.0 with ls3 heads, and a 219/228 cam with .604 intake and .604 exhaust 112 +4. Would I gain anything much with the Hooker manifolds? Your experience can probably help me. Thanks!
Question. Could you theoretically increase horsepower on a supercharged engine by decreasing the blower pulley diameter, then tune it by scaling the fuel injectors linearly with the percentage increase of the supercharger rpm? Basically tune the vehicle without involving the ecm
@@richardholdener1727 Thanks for the reply! There’s enough equipment over here for me to simulate what the change in airflow will be, so thanks for the heads up there! I’m gonna give it a shot! I have a 10% overdrive pulley for a 2.4L IHI twin screw supercharger on a 6.2L v8 engine. I’m assuming 11.4% bigger injectors is close enough to make up for it. My next question would be if the clutched pulley on the blower will give me trouble. I think it’s a niche situation at that point, so I’ll have to test it myself.
Have you done a similar comparison on a mild cammed 5.7 hemi? I have 2010 rt awd charger and those headers are $1800 a pair. Just wondering if they are worth it? Was planning to preventatively do lifters next spring with a mild cam.
My stock Pontiac exhaust manifolds can care less...Anything was better than that 180 hp! 800 is a hell of a difference (cam, heads, pistons, ring gap, rods, crank, fuel injection, 7875 Vs, e85)...Modified factory Y pipe, swollen up to 3” feeding into a single 3’ long 3” down pipe
Just don’t buy cheap thin wall headers. Early 2000’s I installed Hedman 2 piece long tube headers on a 1983 F150 with the 300-6 and 4 speed. The starter was complete trapped by the tubes and the amount of heat radiating into the engine bay was immense. Either buy good thick metal headers or wrap them or get them ceramic coated. The EFI 300-6 started with the 1987 F150 and I found them to be much more reliable than the carbed ones that were a hassle to keep running good.
one trick most miss with the carbed 300's were the carb was two piece and would still run pretty well if the two large phillips screws that join the parts together were a bit loose.used to use an offset screwdriver to tighten mine regularly , made a difference.
I have always seen substantial gains across the entire rev range when upgrading from cast to long tube headers on my Buick L27 V6 engines, typically 18-20kW gain on a stock engine. I also found I am completely knock limited on cast manifolds to a max of 22º peak WOT timing where I can get to MBT of 28-29º without being knock limited once I go to long tube headers. I use the pacemaker headers here in Australia and they have tubes about 700-850mm long depending if you get the street or competition headers.
@@richardholdener1727 Not really. I ran E85 on a stock engine with cast manifolds mainly to test the knock limits of E85 and found MBT was 23, 24ishº virtually as stock, stock is 22º The headers changed the point of MBT. Oh and as for the E85 I saw no knock even to 40º. With ULP it would knock only about 2º past the factory settings with cast manifolds. So the factory cast manifolds were knock limited and MBT pretty much. With headers the MBT moved up and the knock limit moved up even more which gave much more safety margin, therefore no longer knock limited allowing MBT to be well enough below the knock limit. It would seem with these combos they behave very differently.
@@3800S1 I'd wager a big bet it's going to vary based on the engine - particularly the header design. Stock LS headers flow & scavenge very well, while I've seen many other engines that had headers that were huge restrictions. I certainly wouldn't think an original 1954 SBC would come close to 10lb-ft of a modern race header. Turbo guys consistently have made >1000hp (750kW) to the wheels with stock LS truck headers - and have track times that indicate it's not just a bunch of high-reading dynos.
Guys who love classic exhaust manifolds like Pontiac Ram Air, 426 Hemi or LS6 Chevy will argue endlessly that the manifolds are superior to long tube headers and that headers are only for high rpms. I learned a long time ago about the benefits of long tube headers at almost every rpm range but especially low and midrange due to the increased scavaging effect. Guys like Richard who have tested every possible combination and their only goal is what makes the best power, not what pulls at our heart strings, show every time that nothing beats a long tube header for making power. If you want trouble free operation, long life and easy fit then cast iron manifolds might be the way to go, but if you want to squeeze every bit of horsepower out of the engine then nothing can replace the long tubes!
The Chrysler max wedge exhaust manifolds are really close to a header. Nicks Garage did a dyno test with them versus regular manifolds and I think they were 30hp better and less than 10hp off the long tube headers.
@@bcbloc02 I saw that test too. And you can tell by looking at them they are good units. Pontiac had some Super Duty manifolds in the early 1960's that looked like cast long tube headers and they were made from aluminum to boot. I bet they were pretty good too but I've never seen a test on them.
I love that you show the dyno results in the graph and not just top numbers. I'm really curious how short, medium, and long tube headers compare throughout the rpm range since everyone else only shows numbers and I prefer the low to mid rpm range for 2 builds I have going. A Jeep YJ and a daily driver 56 Bel Air, both getting 5.3 LS swaps.
You make great videos, Richard. That said, it may help to make a comparison list, in addition to the graphs. For instance....... Stock manifold Hp Hp w/LTs 415hp 432 Don't have room on phone screen to elaborate. You provide great info, but there's so much, it's hard to keep it all straight. But I'm subscribed, and I like 👍 👌!
Yeah the editing is quite good already but the numbers that flash on the screen could just be placed somewhere on the screen for a short while as they are discussed, like the cam specs listed, and also especially in the dyno charts I would like to see the gains/losses posted as a number somewhere on the screen, so we don't have to go count bars and guess. Engine Masters (motortrend) on TH-cam did some really nice editing on their dyno videos, a full screen break down with the gains posted and each runs maximum numbers.
I really like this test. Basically I have a lq9 with a stock ls3 topend and a small custom cam which is 228 231 620 lift or something really close. Runs decent, but was dynoed in 2nd gear instead of 3rd. Only managed 395wheel but did have the wrong valve springs from the eBay seller who built the heads. Almost dropped multiple valves.
I once had a 92 Mustang LX with JBA 1 1/2 inch shorties, K&N filter and silencer removed, Flowmasters, and bumped up timing. It ran decent while still pretty stock and reliable. Then I drove an 88-89 convertible with long tubes and possibly a larger throttle body. I think the cats were also missing. That car ran really strong. I didn’t see much else over stock. Led me to believe the long tubes worked better than the shorties.
This is exactly what I needed to see. I picked up a set of 1 7/8 headers for CHEAP for my 6.2. They won't fit currently but it's an easy modification for them to work. The problem is then I'm left with a set of nice stainless headers that only fit a 03+ crown vic when I pull them off to go turbo.I was planning on running manifolds until I sort any bugs out of my l92 (with tsp stage 1 LS3 225/230 .629"/615" 114) swap before building the turbo buuuut cheap is cheap.
@@P71ScrewHead I've been down that road with the 4.6 in other crown vics and I was always disappointed. I hope you have a converter and gears on order too. I'm very excited to finally make real power with the 6.2 LS swap.
@@ianm432 Oh yeah, i know what you mean, modding the 2v is more for the love of the 2v than for huge power gains..lol If anyone really wants great amounts of power, everyone'd build big blocks, that'll be my next build, a 632ci BBC/BBF over 800hp n/a.. With power adder looking at over 2k hp.. Edit: forgot to mention that yeah, getting 3.73s n might hold off on a converter for future mod..
@@chipcurrey653 ok but isn’t the exhaust pressure dependent on how efficient the turbo is? As in, how little a restriction the turbo becomes as to be as close to a 1:1 ratio in exhaust pressure? Maybe I’m confused
@@richardholdener1727 i know that a shorter turbo manifold will have a better response so will the effects of turbo spool have more gains than scavenging or is it that since scavenging is only initiated by the exhaust pulse exiting to a higher volume area and triggering a reflecting wave, that turbos negate scavenging all together???
I've got an example of full tube headers, lightly ported heads, and a stock 2 barrel intake. This is 9n my 1970 Mercury Cougar, 2 barrel Windsor. I had a valve job done to them and at the same time I hogged out the EGR bumps from the exhaust ports, blended the bowls and port matched the openings. Put a set of Hooked Super Comp headers on it with dual exhaust to the back. I couldn't afford a new carb and intake set up at the time so I ran what the factory sent. The set up was scavenging so much the engine developed a bad lean mis at 50 MPH and got worse from there. I was only 2 miles from home to figure that out. So off comes the top off the carb and I figured to drill out the main jets 0.010" to start. Much better! I still had a hard time coming off the line, like not enough timing. Tipped in 5 degrees on the distributor and now she comes alive! Not an LS story but relatable. A few little things can make a big difference without spending a lot of money. Good video BTW.
I would love to see a comparison between different sizes of longtube headers. 1 5/8 vs 1 3/4 vs 1 7/8 on a stock 350 or ls 5.3l, although it might be hard to find a 1 5/8 for an ls. And the difference between similar headers with cheap vs proper collector.
Dead giveaway as to the easy big power LS engines make compared to traditional SBC is the lack of 1-5/8" header size!! They don't do anything for the LS motors, except-MAYBE-the 4.8L....
@@milojanis4901 Agreed. I at one time had found a comparison... but damn if I can't find it now. Results being I have 1 7/8 long tubes on my 6.2 Denali.
@@milojanis4901 yeah, I think the 4.8 would be the only ls to utilize the 1 5/8 headers but I think the exhaust port is bigger that 1 5/8 anyways so it probably wouldn't be any better than stock.
@@HioSSilver1999 I have a 5.3l with a BTR torque cam and I went with the 1 3/4 on it but it is my daily driver too. I think if I went with a stage 3 cam or wilder then the 1 7/8 would probably be better.
Richard, I realize that 99% of folks could care less about cast iron exhaust manifolds. And I realize that Cast iron exhaust manifolds kill power substantially, especially in the upper rpm ranges. I have a set of cnc'ed and ported (by Brzezinski) corvette ram horns and wonder just how much power they are capable of making over 3000 rpm, but... I cant find any dyno numbers anywhere. I would really be interested in what it would take to make 450 to 475hp with these manifolds. Thanks for reading, Jim
Nobody makes cams, heads, intake aftermarket performance parts for them, maybe headers, but they aren't known for their toughness, it was designed for the 99 Jeep Grand Cherokee, as a lightweight, torque biased V8. Their internals are weak.
Sport bikes are a good example of this Most every performance sport bike has like has a 4 and a one collector. Harley's use a 2 in the one that offers the same scavenging effect to up the performance versus a straight pipe.
Curious as to how shorty headers would compare. Although I imagine that it would be somewhere in between the stock exhaust manifold and the long tube headers, just don't have concrete information or a way to test my hypothesis.
Years back, In an S10 SBC swap, I started out with factory manifolds (the little logs that went over the plugs, passenger side angle output, drivers side straight dump) and at the time, there were no long tube headers available, so I went with what everyone else was doing, the Headman shorty headers and WHAT A MISTAKE. For the little bit gained above 4500 RPM, too much was lost everywhere below. I will never buy shorty headers for anything ever again.
This concept that Richard pushes of being "flow restricted" is flawed. I understand why he does it, it's simplifies things for the average person but it masks the true physics of what's going on here. The engine is a pump, any type of inlet or outlet appendage is going to reduce air flow through the pump as it's a restriction. Might not be a major issue but it's still a factor. Pumping losses from the exhaust system don't go away under any circumstances.
Whenever I hear that bass line, I know I'm in store to learn a thing or two about a thing or two.
in this case a thing or 3
Richard knows a thing or two because he's seen a thing or two.
@@krazykraka777 Westech Performance, bum ba bum bum bum ba bum
😂
A thing or two a day keeps a thing or two at bay
those LS factory manifolds actually look like really nice quality castings. Sure makes the old kinked and ugly factory manifolds of the past look bad.
Would love to see heat proof coating on stock manifold or wrapped headers with heat proof coated combustion chambers could do for efficiency.
The lower RPM seems to gain more with headers when you have a cam. I've noticed that a lot of engines run cooler when they go to longtubes.
Good to know. Makes it worth it. I have a LQ4 block, with a cam. Doing speed engineering long tubes.
I saw a test on Nick's Garage with a bone stock 2 four barrel 1970 426 Hemi. The factory rated this engine at 425 Horsepower. On the dyno with factory exhaust manifolds, the 1970 426 Hemi made 500 HP.. By adding only headers, the 426 Hemi made 550 Horsepower.
That’s 50 hp dude if you want to be totally stock appearing the 50 hp loss from the stock cast manifolds vs the headers is not bad at all
i have a doubt, why it makes 433 hp almost bone stock on the dyno more than the gm numbers of 364 hp advertises?, is it because of open exhaust, the cam swap, or because of running without accesories, or the efi custom pcm?
all of that-GM tests and certifies the power output of their stock motors differently-with all accs, full exhaust, fuel air intake, run at 200 degrees with the factory tune
Hi Richard, for my 06 Z71 I can only find exhaust systems that use the original style gm cross over to passenger side. Even the long tube types use it. It seems that this would cause unequal flow or is it negligible? Mild cam and cai so far. Thanks!
My work delivery truck is an Isuzu NPR-HD with a well-maintained beast of an LY6. Whether it's 1 stop or 10... all deliveries get done before 2 every day :)
You should do a test on crossover pipes x,h,y
And the effects it has on the power band
Scavenging
8-1 collector too. Sounds amazing
Yes I'd like to see this. I don't know the size limitations in the dyno room. I would atleast like richard to make a comment on this.
Engine Masters did a H and X pipe test I think
Please revisit it!!!
Love to see you do it
I can answer this question before I even watch your dyno results; the answer is it depends. There are literally some engines that don’t pickup any power at all from aftermarket headers. This being the result of an engine that A) isn’t flow restricted on the exhaust side of things and/or B) has a decent factory setup that promotes scavenging. As far as boosted applications from what I’ve seen over the years it matters far more what is in front of the compressor wheel than what feeds the turbine wheel. More often than not I’ve changed boost pressure more with inlet piping than the exhaust setup, and typically see changes in spool rate with exhaust modifications rather than changes in overall total boost pressure. When I have seen gains on built NA engines from header changes, it’s not usually from flow it’s from the effects of scavenging. I know this because I rarely see a power difference from a change in primary diameter, and I have literally bashed and bent/Pryed on headers to make them fit off the wall swap applications to the point where I 100% know I diminished the inner diameter of the tube somewhat, and power did not change.
I have a 5.3 Ls out of a 2010 chevy Silverado putting it in a 1997 s10 single cab pickup will I be able to use the manifolds that came on the 5.3 in the s10
Next do 180⁰ headers
Those are some fing pretty good factory manifolds, kinda short tube headers,
Yeah, and imagine the headaches they would save on a lot of swap installs!!
You always have to factor in the Scavenging effect a lot of people don't realize or even know how it works
You are so right. That is why I watch these engine experts like Richard. They actually teach you what's going on and why it's good or bad, not just hyperbole from something that someone said 50 years ago and it's been repeated as truth ever since.
but would it be better with an x pipe here rather than the divorced headers?
@@1967davethewave I don't even understand that statement Scavenging is a natural occurrence is going to happen and what you want is to promote better Scavenging I don't know anything about this fifty-year-old whatever nonsense you're talking about building power has always been about math before computers came out you have to be able to literally write down the equation for horsepower
@@1flynlow to be honest with you bro you're you're talking about a full on exhaust system we're even the size of the collector makes a difference
@@rogerowens5669 What? I agree with you and you call my statement nonsense? Are you off your meds today?
Got your clips out of order there, you put the supercharged comparison before the cammed comparison, but the narration was opposite. Not a big deal, still a great video.
My bad
I love how smooth ls charts are I test 350 crate motors for a living and they don’t come anywhere near that smooth no matter the combination
Another very nice test Richard, I was looking for such a test for sometime already 🙂 it really helps people to make a smart investment when upgrading their Engines and also helps to understand how to maximize the advantage of Long Tube Headers even further. Great test. Thanks again Richard.
Does anyone know if long tube headers would fit in a 66 belair/impala?
How about a test between stock exhaust manifolds and Extrude hone exhaust manifolds
X pipe vs y pipe vs h pipe no muffler
I think Engine Masters did that
I just got a Holden VF v8 (Chevy SS) with an l77. This is relevant to me. Excellent
I’d love a detailed build on that supercharged crate engine 😮
Wow not as much of a difference as I thought there would be. The scavenging effect down low was a surprise.
I don’t like how you change components up like adding a cam or valve springs. Can’t you just do a straight up comparison with a stock engine? Some of us just want to know if long tubes will benefit us without mechanical upgrades.
Now I'd like to see a test Stock exhaust manifolds VS holley cast iron manifolds VS headers. With and without cam.
Didn't motortend do just that?
@@krisjones1286 I just read that article. Search for Everthing you need to know about hooker small block chevy manifolds. They say if your over 550 hp use headers if your after every last hp.
The worst things about this guys videos is when they end.
I would love to see this test between manifolds vs shorty vs long tube headers at part throttle freeway cruise. A fuel consumption test.
Now do an over plug log style SBC manifolds versus long tubes! Lol I bet the gains would be much more dramatic. Those manifolds were/are awful.
And hooker cast iron manifolds VS stock VS headers
@@venturahwy76 yes!! Good call
thank you for doing these types of really detailed analyisis...im in love with the content.!>
dude..make a video of you shredding a car or truck some where...we need to see you drive some wild vehicles..q>>!>q>>!>q>!q
The LS manifolds are good enough and dont go threw header gaskets . Every time I had headers I kept burning out gaskets . If your on the street I would manifolds and headers on the track.
try Percys next time, never had one leak in years on multiple vehicles
31 lb ft of torque difference is enuf for me to put up with headers...
I agree, also burning up starters isnt worth the trouble. Sure you can wrap it but not worth it for me on the street anyway.
@@coupe50h never had the starter issue... Maybe depends on the application
@@rustinpenner5661 yes indeed, also Coated headers are the way to go, and in most applications, wrap all nearby wiring, even if it's several inches from the tubes.
Another thing is plug wires sure do catch alot of abuse, of course there is remedies for that too.
How about a 6.0 with Truck Norris NSR cam?
A few questions sir' 1. can i put a small turbo on my stock 94 4x4 gmc suburban so i can get a bit more power out of it.2. and will it basically bolt on. 3 or would i be better off rebuilding this very good running no oil leaking stock 5.7 350 chevy 210 HP motor using Vortech heads, cam, Timing chain, 2.0 intake, headers into my 2 1/2'' flow masters. it runs great for what it is but once i added the 4'' lift kit and 35'' tires its sluggish up hills or when towing. it has 373 gears. thank you
you can add boost if you can tune it
Have you ever done a h pipe vs x pipe testing ??
EM did that I believe
What about in a turbo application? Long tube headers vs stock. I imagine it wont affect the output as much because the turbo itself is a restriction? 🧐
Shorties always shorties.
I think he covered this in a video somewhere
@@evanc6110 I dont think he has because he said in a livestream recently that he wanted to test ut
In theory, a turbo should like equal length runners with runner lenght being a compromise between response and scavenging (so, most stock and street applications short or even no runners, racing medium to long) but I've never seen different primary tube lengths tested to confirm this.
@@177SCmaro yeah but one you build enough back pressure, it wont actually matter what the tubes are. At least thats what I think
I'm curious about the LS1/LS6 (C5 Corvette) manifolds versus the newer log style exhaust manifolds. The C5 Vette manifolds almost look like headers but are cast of course.
they are short-long tubes work much better
hey Rich how often you have to add fuel after you do longtubes or does sometimes the ECU adjust itself?
I tune the combination with each change. If run in closed loop, the ECU can adjust to the specified AF target, but I don't do this at WOT-only part throttle.
I can save you a bunch of time. Good long tube headers give marginal performance upgrades over MODERN stock mans. But of course you want them because they look cool and they offer a better exhaust note. Thats all sorry if that disappoints you but that is the truth.
THE DYNO TELLS US THE TRUTH
I watch your stuff religiously So stock lq4 with gutted cats and stock manifolds base be a lot lower I'm assuming right due to compression right
compression change is very minimal
I know that the old style SBC is no longer a go-to power plant, but it would have been interesting to compare that generation’s stock log style exhaust manifolds to long tube headers. Sure there would be a much more impressive gains with the headers.
Or a test with the new Hooker cast iron manifolds for the SBC.
done that many times-same type of gains
It's similar. They've done that comparison often. 0
Are long tubes worth the extra expense and hassle on a mild 5.0ho in a sn95 or any other fox mustang? I've heard even tho the factory shorty's are pretty bad that aftermarket shorty's are still offer meager improvements unless it's a heavy breather then any extra flow will be a appreciated improvement
shorty headers offer very little power
Now try an 8 to 1 header
Please add Hooker Manifolds to a test like this
I was running 40 ifr, 72 primary jet on my ls swapped obs with stock cast headers. When I installed 1 3/4 headers, I had to lean out the jets to 35 ifr and 65 primary jet , so yes theres a big scavenging effect with longtube headers, I had to jet down because of how rich it was with tubes , just an fyi
Personally I blame squirrels
what I learned was they don't offer up enough performance advantage to go through the hassle of installing them on your car unless the engine is already out. I know, that's an unpopular opinion here.
Have you done a tri-y vs 4-1 comparison? There's probably bugger all difference between them in reality but there seems to be two distinct camps claiming one is better than the other.
I would literally do anything to buy one of your old Ls based engine’s
go to the junkyard-that is where I get all of mine
Another video just like this with a Gen V engine would be money
So what is the real theory about the size the exhaust to amount of horse power cause now when you add a super charger now your going to be second hand guessing what to pick out for a exhaust.
same header works with boost
What brand and size longtube headers were used in the stock cam comparison of this video?
1 3/4 QTP
In the 70s, one of the best ways to get power was headers and free-flowing exhaust. Since the 2000s engines have improved so much that there just isn't much difference. Your results are about what I'd expect. For example: my 2003 GMC LQ4 has cast manifolds that are essentially short tube headers that feed into a 4" exhaust system.
I agree!! It's not worth the wasted money, time and headaches buying/using fancy headers to gain a couple of horsepower!!
I have a 2002 Avalanche, stock 5.3, and I added a Whipple SC that makes 6 psi boost. I put long tube headers on it and they were nothing but trouble. First, the headers for the truck do not have tubes that lay neat and tidy like his dyno headers. They have tubes that loop upward and make contact with the LS ign wires, forcing you to solve that problem. Then they make access the spark plugs more difficult. And they have a clearance issue with the 4x4 front pinion. And they crowd the starter, making it more prone to heat failure and more difficult to change out when it fails. They were not worth it.
I now have a little more cam in it, very mild, stock idle with .050" more lift than stock. The 706 heads have been CNC ported and the chambers polished & cc'd, still the same Whipple SC. I now have the stock exhaust manifolds back on and I will install a good performance exhaust system behind the stock manifolds. I am looking forward to fewer under-hood problems and I don't mind if there is a small HP penalty.
The engine runs well, BUT unfortunately I can't drive it right now because the engine has to come back apart ... apparently Comp Cams has sold me a bad set of lifters and they clack like mad after the engine warms up. Quiet on cold start but excessive lash noise gradually comes in as it warms past 180 degrees.
Very true! malaise era cars had the worst exhaust systems ever just a plain dual exhaust system begins at 20 or more even a better air filter would add a few hopefully you would be lucky enough to have a four barrel.
@@bigboreracing356 I'm 63, retired, and I put ~ $30K into a frame-off restoration on the truck since 3 years ago. No regrets, it's been fun but the next time the engine comes apart it's getting stock GM lifters instead of Comp Cams. When you grow up you might rethink stamping emojis all over what you write.
@@bigboreracing356 I never would have guessed.
I feel like my 1 3/4 longtubes are the right package for my boosted and cammed gen 2 LT1. When it eventually gets some AFR heads, a larger cam and a smaller pulley it'll be time for 1 7/8 longtubes.
Go 2 inch
@@FXIIBeaver go 3 inch
@@1flynlow they make 3 inch headers? Does that even fit anything not custom fabbed for it.
@@1flynlow Go 12 inch!
@@Anarchy-Is-Liberty anything over 7 inches is overkill.
Maybe you covered it in one of the previous videos, have you tried a long tube headder vs stock on high comp motor?
same kind of results
100% spot on, the longer the cam duration the bigger the potential gains from the header. Especially noticeable on a street driven motor at low RPM, with the Wrong cam 😆
Hey Richard, I'm curious about your thoughts on job security as things are trending towards electric vehicles. Do you know if what you do will still be allowed in the future? I love engines and want to keep them alive as long as possible but I worry about their place in the world moving forward. Do you think they'll still allow gasoline powered vehicles but with a tax so that only the wealthy can collect them?
that would be along way off and I can install a Kenne Bell Boost a Pump on an EV Too! PS-I've also sun hybrid vehicles at Bonneville
I’m always interested in this topic because I’ve never met a set of headers worth the trouble.
Funny, for me every set of headers I've put on were worth it. I even fabricated headers for my camaro one bend at a time because of the unusual motor swap.
what do you have, a 4cy motor?? lol.. Longtube headers always win..
Really? Headers were definitely my favorite mod that I've done to my truck. Huge difference!
@@P71ScrewHead hahah and even on a 4cyl gains are abundant, especially in the midrange
@@randyschmidt19 for sure man, never seen an engine not benefit from longtubes..
Since GM pioneered their modern casting practices, factory manifolds have been outflowing most shorty headers since the LS6. I'm not surprised to see them hold up well, in comparison to full length primaries... especially given how most of today's full length headers have junk collectors.
flow is not what makes power on the headers vs manifolds-that would be scavenging
@Richard Holdener - what you meant to say is "[bench] flow is not [necessarily] what makes power...".
Had you said that, you'd be correct. As stated, however, it's quite wrong. Flow is literally what makes power. The power of any internal combustion engine is most closely related to its flow rate. Better scavenging IS LITERALLY better flow. It is an increase in volumetric efficiency, caused by the low pressure left behind by exhaust pulses. True, you you can have a header that "flows well" on the bench, but is crap for your engine... but that's because the bench doesn't "flow" like your engine, and your engine isn't "flowing" as well with those particular headers.
All other parameters kept relatively the same (fuel, compression, timing, bore, stroke, etc...), scavenging increases horsepower because you are decreasing resistance through the exhaust stroke, and increasing volumetric efficiency as the piston slows to TDC and transitions into the intake phase.
A video on working out matching header pipe sizes to the motor would be good.
A K series Honda won’t need 1 7/8” header pipes but does say a mid sized motor like the 3800??
Per piston the K24 would be flowing and revving much more.
Hey Richard, I may have missed it, but on the Supercharged LS. Was there a difference in boost numbers with the different headers, everything else being the same? I was curious if there mightve been a restriction there. 🤔
I'd be curious how the home made pass side turbo manifold/header is compared to the Hooker Blackheart stuff. Toss in a comparison between a log or Fahler Speed style manifold and everyone will see what is worth doing.
I'm quite sure it would make not much of a difference unless you're making way over 1000hp .
the Holley turbo system is somewhat restrictive (the merge point) after the cross over. A different design with more flow will add power and drop back pressure
Are the Hooker 8502HKR's with 2.5" collector about the same power wise as the stock manifolds you show? Do the bigger openings on the Hookers help? I have fitment issues and longtubes won't work with my project. I have a 6.0 with ls3 heads, and a 219/228 cam with .604 intake and .604 exhaust 112 +4. Would I gain anything much with the Hooker manifolds? Your experience can probably help me. Thanks!
minor gains
@@richardholdener1727 Thanks for the information and all the work you do!
Question. Could you theoretically increase horsepower on a supercharged engine by decreasing the blower pulley diameter, then tune it by scaling the fuel injectors linearly with the percentage increase of the supercharger rpm?
Basically tune the vehicle without involving the ecm
if you knew the change in airflow and AF for both sides of the equation and both were linear (might not be the case)
@@richardholdener1727 Thanks for the reply!
There’s enough equipment over here for me to simulate what the change in airflow will be, so thanks for the heads up there!
I’m gonna give it a shot! I have a 10% overdrive pulley for a 2.4L IHI twin screw supercharger on a 6.2L v8 engine. I’m assuming 11.4% bigger injectors is close enough to make up for it.
My next question would be if the clutched pulley on the blower will give me trouble. I think it’s a niche situation at that point, so I’ll have to test it myself.
What size headers are used on the NA motor tests here? 1 3/4 or 1 7/8?
they both work
Have you done a similar comparison on a mild cammed 5.7 hemi? I have 2010 rt awd charger and those headers are $1800 a pair. Just wondering if they are worth it? Was planning to preventatively do lifters next spring with a mild cam.
Headers and a tune can get you about 20-30hp, for the awd, it could be more, but the sound and responsiveness is great
My stock Pontiac exhaust manifolds can care less...Anything was better than that 180 hp! 800 is a hell of a difference (cam, heads, pistons, ring gap, rods, crank, fuel injection, 7875 Vs, e85)...Modified factory Y pipe, swollen up to 3” feeding into a single 3’ long 3” down pipe
Just don’t buy cheap thin wall headers. Early 2000’s I installed Hedman 2 piece long tube headers on a 1983 F150 with the 300-6 and 4 speed. The starter was complete trapped by the tubes and the amount of heat radiating into the engine bay was immense. Either buy good thick metal headers or wrap them or get them ceramic coated. The EFI 300-6 started with the 1987 F150 and I found them to be much more reliable than the carbed ones that were a hassle to keep running good.
one trick most miss with the carbed 300's were the carb was two piece and would still run pretty well if the two large phillips screws that join the parts together were a bit loose.used to use an offset screwdriver to tighten mine regularly , made a difference.
I had lots of trouble with those carbs. I’d rather have a 2 barrel or small 4 barrel or else EFI.
I have always seen substantial gains across the entire rev range when upgrading from cast to long tube headers on my Buick L27 V6 engines, typically 18-20kW gain on a stock engine. I also found I am completely knock limited on cast manifolds to a max of 22º peak WOT timing where I can get to MBT of 28-29º without being knock limited once I go to long tube headers. I use the pacemaker headers here in Australia and they have tubes about 700-850mm long depending if you get the street or competition headers.
IS THE CHANGE IN POWER FROM THE TIMING?
@@richardholdener1727 Not really. I ran E85 on a stock engine with cast manifolds mainly to test the knock limits of E85 and found MBT was 23, 24ishº virtually as stock, stock is 22º The headers changed the point of MBT. Oh and as for the E85 I saw no knock even to 40º. With ULP it would knock only about 2º past the factory settings with cast manifolds. So the factory cast manifolds were knock limited and MBT pretty much. With headers the MBT moved up and the knock limit moved up even more which gave much more safety margin, therefore no longer knock limited allowing MBT to be well enough below the knock limit.
It would seem with these combos they behave very differently.
@@3800S1 I'd wager a big bet it's going to vary based on the engine - particularly the header design. Stock LS headers flow & scavenge very well, while I've seen many other engines that had headers that were huge restrictions. I certainly wouldn't think an original 1954 SBC would come close to 10lb-ft of a modern race header.
Turbo guys consistently have made >1000hp (750kW) to the wheels with stock LS truck headers - and have track times that indicate it's not just a bunch of high-reading dynos.
If each test had a set of catalytic converters on it, how different do you think the results would be. Would the cats kill the scavenging?
SCAVENGING STILL WORKS
What stage cam would this be 212/218 duration and 114 lobe separation
Ok guys what did we learn from this little adventure?... Doing this trumps all uncoolness into supreme coolness! Love it! Peace..
Guys who love classic exhaust manifolds like Pontiac Ram Air, 426 Hemi or LS6 Chevy will argue endlessly that the manifolds are superior to long tube headers and that headers are only for high rpms. I learned a long time ago about the benefits of long tube headers at almost every rpm range but especially low and midrange due to the increased scavaging effect. Guys like Richard who have tested every possible combination and their only goal is what makes the best power, not what pulls at our heart strings, show every time that nothing beats a long tube header for making power. If you want trouble free operation, long life and easy fit then cast iron manifolds might be the way to go, but if you want to squeeze every bit of horsepower out of the engine then nothing can replace the long tubes!
Long tube headers also sound awesome.
i agree, never will i prefer stock over longtubes, never..
The Chrysler max wedge exhaust manifolds are really close to a header. Nicks Garage did a dyno test with them versus regular manifolds and I think they were 30hp better and less than 10hp off the long tube headers.
@@bcbloc02 I saw that test too. And you can tell by looking at them they are good units. Pontiac had some Super Duty manifolds in the early 1960's that looked like cast long tube headers and they were made from aluminum to boot. I bet they were pretty good too but I've never seen a test on them.
I love that you show the dyno results in the graph and not just top numbers. I'm really curious how short, medium, and long tube headers compare throughout the rpm range since everyone else only shows numbers and I prefer the low to mid rpm range for 2 builds I have going. A Jeep YJ and a daily driver 56 Bel Air, both getting 5.3 LS swaps.
LONG TUBES ARE BETTER EVERYWHERE
@@richardholdener1727 They'll definitely fit in the Jeep. There may be clearance issues on the Bel Air lol
You make great videos, Richard. That said, it may help to make a comparison list, in addition to the graphs. For instance.......
Stock manifold Hp Hp w/LTs
415hp 432
Don't have room on phone screen to elaborate. You provide great info, but there's so much, it's hard to keep it all straight. But I'm subscribed, and I like 👍 👌!
Yeah the editing is quite good already but the numbers that flash on the screen could just be placed somewhere on the screen for a short while as they are discussed, like the cam specs listed, and also especially in the dyno charts I would like to see the gains/losses posted as a number somewhere on the screen, so we don't have to go count bars and guess. Engine Masters (motortrend) on TH-cam did some really nice editing on their dyno videos, a full screen break down with the gains posted and each runs maximum numbers.
300hp 1.4l turbo chevy sonic ? 😿
I really like this test. Basically I have a lq9 with a stock ls3 topend and a small custom cam which is 228 231 620 lift or something really close. Runs decent, but was dynoed in 2nd gear instead of 3rd. Only managed 395wheel but did have the wrong valve springs from the eBay seller who built the heads. Almost dropped multiple valves.
also test in 3rd gear
@@richardholdener1727 I wish the tuner did, was declined because I had 2:73s and he was scared the driveshaft would fly out 😞
Is there a need for back pressure, like in a scenario in a stock-ish vehicle, in a stop and go environment?
BACK PRESSURE IS ALWAYS BAD
@@richardholdener1727 Thank You!
Think of it as a restriction and as return pressure (to the engine, not from)
I once had a 92 Mustang LX with JBA 1 1/2 inch shorties, K&N filter and silencer removed, Flowmasters, and bumped up timing. It ran decent while still pretty stock and reliable. Then I drove an 88-89 convertible with long tubes and possibly a larger throttle body. I think the cats were also missing. That car ran really strong. I didn’t see much else over stock. Led me to believe the long tubes worked better than the shorties.
On the 5.0 mustang the long tube would help alot. The intake ports were poor and the scavenging would help fill the cylinder on the overlap.
I tested 1 7/8 vs 2 on my SS. Gained nothing at or below peak but did gain in the overrev. NA LS3.
I learnted somethin new, AGAIN. 😎🤙 Appreciate it R.H. saving me money on the daily!
This is exactly what I needed to see. I picked up a set of 1 7/8 headers for CHEAP for my 6.2. They won't fit currently but it's an easy modification for them to work. The problem is then I'm left with a set of nice stainless headers that only fit a 03+ crown vic when I pull them off to go turbo.I was planning on running manifolds until I sort any bugs out of my l92 (with tsp stage 1 LS3 225/230 .629"/615" 114) swap before building the turbo buuuut cheap is cheap.
i have an 09 P71 that i'm about to put Maximizer/OBX headers on, gonna be sweet.. Oh, n cams n other bolt ons..
@@P71ScrewHead I've been down that road with the 4.6 in other crown vics and I was always disappointed. I hope you have a converter and gears on order too. I'm very excited to finally make real power with the 6.2 LS swap.
@@ianm432 Oh yeah, i know what you mean, modding the 2v is more for the love of the 2v than for huge power gains..lol If anyone really wants great amounts of power, everyone'd build big blocks, that'll be my next build, a 632ci BBC/BBF over 800hp n/a.. With power adder looking at over 2k hp.. Edit: forgot to mention that yeah, getting 3.73s n might hold off on a converter for future mod..
@@P71ScrewHead absolutely do not skip the converter. It was the best mod I ever did on my 2011. Better than the 5spd swap on my 2003
@@ianm432 what stall did you go with?? i have looked into a 2800 stall tho..
I wonder what is the limit - if any - to the length of the headers, is there a point where they become too long and drop power.
This is a testament to the stock manifolds! I'll think I'll pass on my stock 5.3.
Hey Richard!!! What about long vs short turbo manifolds? I know it sounds very silly but would the scavenging still be in effect??
No that is covered in corky bell's book maximum boost...doesn't work the same because there is high pressure in the exhaust
@@chipcurrey653 ok but isn’t the exhaust pressure dependent on how efficient the turbo is? As in, how little a restriction the turbo becomes as to be as close to a 1:1 ratio in exhaust pressure? Maybe I’m confused
that's not why
@@richardholdener1727 i realize that I may be confused so please explain. Love your videos!
@@richardholdener1727 i know that a shorter turbo manifold will have a better response so will the effects of turbo spool have more gains than scavenging or is it that since scavenging is only initiated by the exhaust pulse exiting to a higher volume area and triggering a reflecting wave, that turbos negate scavenging all together???
Why don't u take it past 6,300? Is there a problem after that?
WE TOOK IT TO 7000 LATER
@@richardholdener1727 what's the highest you have had a ls
I've got an example of full tube headers, lightly ported heads, and a stock 2 barrel intake.
This is 9n my 1970 Mercury Cougar, 2 barrel Windsor.
I had a valve job done to them and at the same time I hogged out the EGR bumps from the exhaust ports, blended the bowls and port matched the openings. Put a set of Hooked Super Comp headers on it with dual exhaust to the back. I couldn't afford a new carb and intake set up at the time so I ran what the factory sent.
The set up was scavenging so much the engine developed a bad lean mis at 50 MPH and got worse from there.
I was only 2 miles from home to figure that out. So off comes the top off the carb and I figured to drill out the main jets 0.010" to start. Much better! I still had a hard time coming off the line, like not enough timing. Tipped in 5 degrees on the distributor and now she comes alive! Not an LS story but relatable. A few little things can make a big difference without spending a lot of money.
Good video BTW.
What about tri y?
Ly6 should be like the l77 just iron not aluminum right? Be safe team.
Might have to grab a set of Header for my Hemi Ram and 6.1 Challenger, good stuff
Love how u get down to brass tacks! Now try to get the Koenigsegg free valve to have precise control of the valves!
I would love to see a comparison between different sizes of longtube headers. 1 5/8 vs 1 3/4 vs 1 7/8 on a stock 350 or ls 5.3l, although it might be hard to find a 1 5/8 for an ls.
And the difference between similar headers with cheap vs proper collector.
Dead giveaway as to the easy big power LS engines make compared to traditional SBC is the lack of 1-5/8" header size!! They don't do anything for the LS motors, except-MAYBE-the 4.8L....
@@milojanis4901 Agreed. I at one time had found a comparison... but damn if I can't find it now. Results being I have 1 7/8 long tubes on my 6.2 Denali.
1 7/8 for my 6.0 2500hd seems to work very well. Only ls i would put 1 3/4 on is a 5.3. And even then 1 7/8 might be better.
@@milojanis4901 yeah, I think the 4.8 would be the only ls to utilize the 1 5/8 headers but I think the exhaust port is bigger that 1 5/8 anyways so it probably wouldn't be any better than stock.
@@HioSSilver1999 I have a 5.3l with a BTR torque cam and I went with the 1 3/4 on it but it is my daily driver too. I think if I went with a stage 3 cam or wilder then the 1 7/8 would probably be better.
Have you done a test to compare stock manifolds with boost vs headers with boost?
you don't need headers below 1000 hp
@@richardholdener1727 so what you’re saying is, In this application. Manifolds won’t become a restriction until 1000hp.
I didn't say that-I said you can easily make 1000 hp without the headaches that go with headers.
Nice video but not one dyno run we can see? It'd be nice to hear it run.
if you listen-there was dyno noise
@@richardholdener1727 again, you're providing great info so don't think I'm trolling. I'd just like to see some full dyno runs.
First comment
I'm one of the other guys but you can't deny the beauty of the LS.
Richard, I realize that 99% of folks could care less about cast iron exhaust manifolds. And I realize that Cast iron exhaust manifolds kill power substantially, especially in the upper rpm ranges. I have a set of cnc'ed and ported (by Brzezinski) corvette ram horns and wonder just how much power they are capable of making over 3000 rpm, but... I cant find any dyno numbers anywhere. I would really be interested in what it would take to make 450 to 475hp with these manifolds. Thanks for reading, Jim
STOCK MANIFOLDS TYPICALLY LOSE MORE POWER IN THE LOWER RPM RANGES, WHERE THEY LACK SCAVENGING, THE PORTED RAMS MIGHT FLOW WELL UP TOP
I would like something on another Other Guys engine. Dodge 4.7l v8. Plenty of those in Ram, Dakota, and Durangos.
Nobody makes cams, heads, intake aftermarket performance parts for them, maybe headers, but they aren't known for their toughness, it was designed for the 99 Jeep Grand Cherokee, as a lightweight, torque biased V8. Their internals are weak.
Sport bikes are a good example of this Most every performance sport bike has like has a 4 and a one collector. Harley's use a 2 in the one that offers the same scavenging effect to up the performance versus a straight pipe.
*4 into 1
*2 into 1
Curious as to how shorty headers would compare. Although I imagine that it would be somewhere in between the stock exhaust manifold and the long tube headers, just don't have concrete information or a way to test my hypothesis.
PLEASE SEE THE SHORTY VS LONG TUBE VIDEO-THE SHORTY HEADERS DON'T WORK VERY WELL
Years back, In an S10 SBC swap, I started out with factory manifolds (the little logs that went over the plugs, passenger side angle output, drivers side straight dump) and at the time, there were no long tube headers available, so I went with what everyone else was doing, the Headman shorty headers and WHAT A MISTAKE. For the little bit gained above 4500 RPM, too much was lost everywhere below. I will never buy shorty headers for anything ever again.
This concept that Richard pushes of being "flow restricted" is flawed. I understand why he does it, it's simplifies things for the average person but it masks the true physics of what's going on here.
The engine is a pump, any type of inlet or outlet appendage is going to reduce air flow through the pump as it's a restriction. Might not be a major issue but it's still a factor. Pumping losses from the exhaust system don't go away under any circumstances.
What's the difference between better flow and better scavenging effect? Doesn't better scavenging equal better flow?
flow is not the same as pressure wave
How does fuel pressure effect everything. e85, 12.5:1 6.0l . 40psi vs 50psi vs 60psi ?
very little as long a AF remains constant