Equal length headers is mostly about making beautiful music to our ears. Take a v12 equal lenght headers vs non equal lenght and my point is proven. 💪👊🇺🇸 🎶 🎵
I find this interesting but does it apply to a V12 engine? The firing order on V12s are all opposing so you won't encounter the issue talked about in the video. I'm really interested if any people looked into if V12 engines lose power with equal length headers.
Dude I hope your video blows up soon. You have so much good information in there and you explained it so well. I've seen other videos on TH-cam looking up what's the difference and yada yada. But I have not seen a video explaining what you're explaining here. Thanks 👍
Header science can get crazy really quickly. To keep it simple a fella can just add an X pipe and enjoy the results. Or go deep into building a properly tuned 180 degree header and enjoy the biggest result.
if you have the packaging space for an X and 180 headers. You can get an X to fit but its too steep of an angle it'll negate any gain youd be tryin to get. It all comes down to flow based on the path of least resistance. But here again, engine masters did the header bash test and it gained 1-2hp via their dyno and keeping the conditions and variables to a minimum. Again, 1-2hp, you'll only care about that if youre trying for dyno-queen flex numbers. But it also shows even as a negative 1-2hp loss isnt going to change much. you can easily gain/lose more than that depending on the weather at the track.
The absolute best bet would be 180-degree tri-y headers where the 4 resultant secondaries are plumbed sequentially/radially into a 4-1 collector. 1-3/4 into 2-inch secondaries into a 4-inch final collector should do the trick.
This explains why changing the firing order to 18436527, (swapping 2 and 7 with the necessary cam) makes 5+ hp without any other mods. Thanks for the video!
Right. This is something I've wondered about for a while. While Equal Length Headers are nice, they only really make sense on equal firing order engines. Flat plane V8s, inline 4s etc. For cross plane, yes, a slightly offset length header makes sense. I would love to hear someone make some of those one day. This is why the other option is 180 degree headers, but those are way more convoluted.
Lots of people see the terms but don't understand exactly what n why. Great job explaining it!! Also, you make a good point, But... Unequal length headers are generally that way due to design (fitment) restrictions. In equal length tubes, I think even the 5-7 pulses are still working. As long as the 5 pulse is in the collector and past the 7 opening, it'll draw vacuum and be ok. I could be wrong, but I've never heard a manufacturer claim being 'tuned' in an unequal length format. I'd think that although clearly imperfect, equal length tubes are having a notable, worthwhile effect ,or else nobody would bother.
@@newguysgarage6802 thanks!!! I grew up into cars reading E-berg, Uncle Tony, etc, in Mopar mags, and Vizard is certainly Mr Knowledge!!! Will def go watch this! Im kinda "stuck" in a slant six resto, so Im not doing any performance fun stuff for the near future, but its always good to learn somthing!!!
Great explanation. I do feel there are multiple factors depending on the application that can very what is desired. I agree with you on open headers with maybe an 12-18" extension to the collector. Adding an x pipe mostly alleviates the overloaded collector you previously mentioned, but getting the proper distance to the crossover is also critical to getting it all right. In general, uneven headers broadens the torque curve (better application for street) where "tuned" equal length is more of a peaked torque curve tailored to a specific rpm range. I built custom equal length headers for my race truck and gained 8hp over the unequal length headers previously installed. Each primary tube was within 1" of the desired length and also running an x pipe at 12" from the end of the collector.
The headers don't scavenge at the collector, not across any kind of wide range anyway. The collectors and the pulse timing are still important, though for different reasons. The scavenging is largely done in the first few inches of pipe and the exhaust port, mostly from inertia of the exhaust. The blowdown pulse (when the exhaust valve opens its super high pressure in there, half the mass of the exhaust can be out the valve before *bottom* dead centre) is what kills scavenging, and it's what collector grouping and lengths should be about. The collector itself can also pay a large part in overall pressure in the primary pipes. Generally the smaller the collector choke the better it functions as an anti reversion valve and the less restrictive the less the blowdown pulse gets turned around and goes up the wrong pipe. There's a point where pipes and collectors chokes are too small, but it's generally a lot smaller than people think.
I appreciate that 😁 Just a guy sharing the things ive figured out so hopefully it can help out some people out! And hopefully make it make sense along the way 😅
you should really be emphasizing this mainly applies to cross plane cranks, most inline and flat plain engines would still benefit. cross plane would even still benefit if you do an 8-1 collector.
Uhm NO. Equal length headers make it so that each cylinder gets the same signal. So you can tune the engine easier. During the exhaust stroke, the pulse leaving the cylinder will actually pull a vacuum, if you tune that vacuum just right you can actually start the intake flow BEFORE the piston hits TDC. If you want the pulse to even out, consider 4-2-1 headers. If you have unequal length headers - one cylinder will go lean when others are rich. Makes fine tuning impossible - basically you'll have to run on the rich side and leave horsepower on the table as it were. As for cylinder to cylinder cross talk - you can control that with merge collectors. Depends on how strong the signal you want and how sharp. Don't believe me - run it on a dyno - tuning the carb AND ignition timing between runs. write down the settings so you can redo the test.
So david vizard has a couple of videos about this on his channel. Although this issue applies particularly to V-layout engines. There’s also a whole other factor to header length besides the firing order; the angle of the V also takes part in calculating the correct lengths.
Angel of the V really? Interesting! Ill have to run back through his stuff again because i dont quit remember it fully but that dose ring a bell now that you mentioned it 😁
How many sets of headers have you actually tested on dyno's?? I have had at least a half dozen sets of headers I built tested on the dyno, every set so far has made more torque and HP than the unequal sets they were compared to, some as much as 45 HP. Until the time comes that I see unequal length headers producing better results on the dyno and track I will keep building equal length headers for my customers. I hope that the headers on that engine you use as an example are not the headers you are talking about, I wouldn't expect a $200 set of big box store headers to produce good results on anything. Please do let us know the type of numbers you have seen on the dyno, I hope this video isn't all just theory.
You are correct but i think you should have mentioned that this is due to inherent firing order of v8s which causes issues. Naturally balanced engines like i6 and v12s are perfect for ELH. The sound they produce is also f1 like ☠️
No No No. The point of equal length header is that each cylinder sees the same 'signal' ... One cylinder doesn't scavange from the other..... When the pulse goes down the exhaust, it has momentum. When the piston reaches TDC on the exhaust stroke, the piston no longer pushes exhaust out. However, the exhaust pulse has momentum and it pulls a vacuum behind it.... See pressure measurements at the exhaust ports of a single cylinder - and you will see the exhaust pressure go negative. At 8000rpm, the pulse moves about 90 inches when the engine turns 90 degrees. Bottom line, the exhaust valve is closed long before any adjacent cylinder's pulse gets near it. Stick with equal length - just make sure you don't go too big on primary tubes. Use the collector to tune how hard the reverse pulse hits. You can soften and stretch to give you power over wider rpm, or narrow, to give more power at a more limited rpm range.
See how small the primaries are on that header. Thats how small they need to be no matter how much power you want. Modern headers are way too big and therefore lose power. We have tested hundreds of them and smaller primaries is always better. Always!
Exhaust gasses are faster than the valve too lol When the valve is closed the Exhaust pulse is still traveling down the tube creating that low pressure "vacuum" pocket behind it.
I have a Camaro with a 383sbc and i want to give it a dual sidepipe only at the driver side. So just run 2 tubes in front of the left rear wheel from the collectors, so the right side will obviously be a bit longer, my question is , will it loose power that way? Or does it not matter after the collectors? Would i be better off running both sides into just a single pipe and then making the turn?
I have an in-line six cylinder engine, and I am designing an unequal headers, the firing order 1 - 5 - 3 - 6- 2- 4 it’s a Nissan tb 48, it’s going to be a true duel exhaust , so therefore two manifolds will be available, first manifold will have its primary tubes on 1 5 3 and the second one will be 6 2 4, I am doing this to get the scavenging. I want to avoid the pulses from hitting each other. What’s the ideal situation to get the most of it, is it fine I just make the headers tube for cylinder one the shortest after wards slightly taller for cylinder 5 then a bit taller for cylinder 3? I don’t have any special equipment to measure the pulses I am just using common sense
If the firing order is 1-5-3-6-2-4 then wouldn't it make more sense to have the two manifolds be 1-2-3 and 4-5-6? That would evenly spread the pulses out to were equal length would work for both manifolds. I wouldn't do duals all the way back though, i would join the two manifolds with a Y pipe into a single all the way back a little after the two collectors. I have a video on that too! 🙂 th-cam.com/video/a_nF8Y4DQ3g/w-d-xo.html
Yeah, uh no. Not according to dyno testing - which is where the significance of equal length primary tubes (for racing purposes) came from. Once an entire exhaust system is placed behind a set of headers, by and large the gains from the headers themselves are significantly diminished, at that point back pressure, and the use of X pipes as a means to propagate exhaust flow became as significant if not more so than the headers themselves.
Yeah, in both banks the two cylinders that fire close together need a sort of delay. I think in this example, making the runners for 7 and 8 twice as long as 5 and 4 respectively should do the trick given how the other two cylinders on that bank fire 180 degrees apart compared to the two "close" cylinders firing 90 apart. Just double the dwell time for one of the cylinders as you're good.
Done correctly yes they will make power... now since youre looking for that high end power, you'll lose in the low end. All depends on how you want to tilt the curve before and after 5252rpm. Long tubes and equal length are for high revving platforms that you'll be at or above 5252, so you'll want that. Down low, you'll lose BUT if you're running the correct converter and rear gear it'll flash past that because you won't be launching at below 3500rpm anyways at the drag strip. nor in between shifts will it drop below the power curve Ay bit of power you might lose or gain can easily be negated by a hot track day, bad track prep, wrong tire pressure, tune, and many many many other variables.
I never saw this as an overload issue, as much as a scavenging problem. Both banks have a pair of cylinders doing everything 90 degrees from each other. 8/4 and 5/7, or if you have a 4/7 swap cam, the issue moves to 4/2 and 7/3. The second exhaust pulse causes a flow loss [during overlap] of the first cylinder blowing down, as its wave looks like backpressure [or a wrong length collector]. Shorten the first and lengthen the second to adjust time of arrival and stop blending pulses, effectively. A dual plane crank begs for it.
Well, I think a firing order implies that there aren't cylinders going off at exactly the same time, but I get your point if that's correct for most V8s. On Shorties it's also about being able to pass emissions, which is why a lot of enthusiasts choose them in addition to improving the sound. Most engines can be tuned to pass emissions on most setups, so I would say just cause the firing order to go off at the interval you want and it's problem solved! You pass emissions, you get better sound and you get better power - Voila! We're not necessarily at the mercy of any particular design with the advent of modern-day tuning.
How do they affect sound? Especially on flatplane v8s, because I think Ferraris use equal length and the gt350 used unequal length. Both flatplane but sound wildly different. How is that explained?
Firing order will change sound, And you only hear the exhaust sound after it exists the end of the exhaust so anything you do to lengthen or shorten that distance will affect sound 🙂
@@newguysgarage6802 what’s the firing order on a ford voodoo v8 vs literally any ferrari v8 (non Maserati)? Also thanks for the explanation, wouldn’t have known firing order affected the sound
......well ford had a bunch of different firing orders 😅 And im not really familiar with Ferraris but i bet you could find out that stuff with a google search 😁
@@fadedsoul23 Ford's Voodoo flat plane uses a very different firing order than a normal even firing flat plane. They did it literally just to maintain an "American muscle" sound. Driving 4 Answers did a great video on this.
No the actual tube length tuning will be the same. The goal is to have each pulse enter the collector one at a time so that the collector has a constant steady pull on all the tubes. Easy to say but hard in reality to do, so as long as you have a good collector length (18" at least) that should help the collector keep a good signal on the tubes. Now all 8 into one i would think you would want a bigger collector diameter like 3.5" to accept all of that exhaust (mabey even a 4" if your motor is verry stout!) Dose that make sense? Collector length helps the handicapped tube lengths
@@newguysgarage6802 cool. It's 4 3/4 inch very stout methanol dry sump. I start racing after Christmas. Manning River Taree Aus. Love ýour channel mate
Great topic. The other drawback of equeal length headers is the unequeal bends in the pipes making flow eneven throughout. I have often wondered if equeal bends and a collector that has each pipe the same length into the collector creating a internal enequeal pipe length into the collector... hard to explain in words, so picture a longer collector with the pipes staggered in lengths to mathematically create equeal pipe lengths and firing order pulsing to get the biggest bang for your buck.
@newguysgarage6802 Just checked out the Tri Y you mentioned... not exactly what my thoughs are. Picture a collector and from the flange to the pipes, inside is staggered exits of pipes within the collector. I will draw a picture later and send it to you.
You are correct. The issue now would be to figure out which tube is the correct length, for desired results. There will be 2 per side that would need to be shorter, and one longer. David Vizard also covers this on his channel, and the results are impressive.
True, but almost every Chevy (and same firing order engines) headers I see, even expensive ones, it looks like the #5 tube is at least as long as #7. They even put bends in #5 to make it unnecessarily longer. I don't get why, especially on $800+ headers!
@mikewillett5076 being expensive doesn't usually mean they are also quality and better performing lol They are looking for key words "equal length" just to make people think they are super trick so they will buy them 😅
@@newguysgarage6802 . That's true. But you mean even companies like Hooker with their Super Competition and others don't make them unequal for the 5/7 issue? I looked at pics of a lot of the them and haven't seen any where the 5 is obviously shorter than the 7. Of course it can be hard to tell by eyeballing them in a photo if they're close. Thanks
@@mikewillett5076 it is easier for them to just make the tubes whatever length is required to make them fit under the hood of any specific modle car they are made for too. Headers can already be a tight fit let alone with one pipe noticeably longer that the other ones to try and deal with 😅
@@newguysgarage6802 . Yep. But I've seen where they could've made one shorter or longer no problem. Eh, long tubes are still better than shorties or manifolds. Thanks a lot for replying, too many channels "abandon their posts". Lol
@@newguysgarage6802 Alright, thanks. Also.... what generally is the power increase from the entirely custom, properly made exhaust? Google says up to 5%, but you seem to know a lot so I'd rather as you too
A good exhaust can make or brake your power in a big way! Might even be more important than the intake side for making power. th-cam.com/video/AxGa6byZyOw/w-d-xo.html I will refer you to David Vizard. He is a legend! Watch some of his stuff and you will have your mind blown 😁
You do have a point, but I think you need to be a bit more clear about this is only for crossplane v8's but is still the best option for all other engines.
Equal length headers is mostly about making beautiful music to our ears. Take a v12 equal lenght headers vs non equal lenght and my point is proven. 💪👊🇺🇸 🎶 🎵
I find this interesting but does it apply to a V12 engine? The firing order on V12s are all opposing so you won't encounter the issue talked about in the video. I'm really interested if any people looked into if V12 engines lose power with equal length headers.
If the firing order is semetrical on both sides then equal length headers would be the right choicec😁
Dude I hope your video blows up soon. You have so much good information in there and you explained it so well. I've seen other videos on TH-cam looking up what's the difference and yada yada. But I have not seen a video explaining what you're explaining here. Thanks 👍
Thank you! 😀
I appreciate that 😁
Header science can get crazy really quickly.
To keep it simple a fella can just add an X pipe and enjoy the results.
Or go deep into building a properly tuned 180 degree header and enjoy the biggest result.
if you have the packaging space for an X and 180 headers. You can get an X to fit but its too steep of an angle it'll negate any gain youd be tryin to get. It all comes down to flow based on the path of least resistance. But here again, engine masters did the header bash test and it gained 1-2hp via their dyno and keeping the conditions and variables to a minimum. Again, 1-2hp, you'll only care about that if youre trying for dyno-queen flex numbers. But it also shows even as a negative 1-2hp loss isnt going to change much. you can easily gain/lose more than that depending on the weather at the track.
The absolute best bet would be 180-degree tri-y headers where the 4 resultant secondaries are plumbed sequentially/radially into a 4-1 collector. 1-3/4 into 2-inch secondaries into a 4-inch final collector should do the trick.
This explains why changing the firing order to 18436527, (swapping 2 and 7 with the necessary cam) makes 5+ hp without any other mods.
Thanks for the video!
No problem! Thanks for watching 😁
Right. This is something I've wondered about for a while. While Equal Length Headers are nice, they only really make sense on equal firing order engines. Flat plane V8s, inline 4s etc. For cross plane, yes, a slightly offset length header makes sense. I would love to hear someone make some of those one day. This is why the other option is 180 degree headers, but those are way more convoluted.
Lots of people see the terms but don't understand exactly what n why. Great job explaining it!! Also, you make a good point, But... Unequal length headers are generally that way due to design (fitment) restrictions. In equal length tubes, I think even the 5-7 pulses are still working. As long as the 5 pulse is in the collector and past the 7 opening, it'll draw vacuum and be ok. I could be wrong, but I've never heard a manufacturer claim being 'tuned' in an unequal length format. I'd think that although clearly imperfect, equal length tubes are having a notable, worthwhile effect ,or else nobody would bother.
th-cam.com/video/f72BMpmoGMY/w-d-xo.html
Here is a link to one of david vizards videos were he explains it in a more technical sense 😀
@@newguysgarage6802 thanks!!! I grew up into cars reading E-berg, Uncle Tony, etc, in Mopar mags, and Vizard is certainly Mr Knowledge!!! Will def go watch this! Im kinda "stuck" in a slant six resto, so Im not doing any performance fun stuff for the near future, but its always good to learn somthing!!!
You are welcome 😁
Great explanation. I do feel there are multiple factors depending on the application that can very what is desired.
I agree with you on open headers with maybe an 12-18" extension to the collector. Adding an x pipe mostly alleviates the overloaded collector you previously mentioned, but getting the proper distance to the crossover is also critical to getting it all right.
In general, uneven headers broadens the torque curve (better application for street) where "tuned" equal length is more of a peaked torque curve tailored to a specific rpm range.
I built custom equal length headers for my race truck and gained 8hp over the unequal length headers previously installed. Each primary tube was within 1" of the desired length and also running an x pipe at 12" from the end of the collector.
The headers don't scavenge at the collector, not across any kind of wide range anyway. The collectors and the pulse timing are still important, though for different reasons.
The scavenging is largely done in the first few inches of pipe and the exhaust port, mostly from inertia of the exhaust. The blowdown pulse (when the exhaust valve opens its super high pressure in there, half the mass of the exhaust can be out the valve before *bottom* dead centre) is what kills scavenging, and it's what collector grouping and lengths should be about.
The collector itself can also pay a large part in overall pressure in the primary pipes. Generally the smaller the collector choke the better it functions as an anti reversion valve and the less restrictive the less the blowdown pulse gets turned around and goes up the wrong pipe. There's a point where pipes and collectors chokes are too small, but it's generally a lot smaller than people think.
This only applies to cross-plane crankshaft V8's.
That’s why a linear, firing order collector is to be made for mid-engine vehicles.
IIRC the theoretical ideal scavenge setup involves sending the center two cylinders on each side over to the other collector.
I think Doug’s still sells crossover headers. I’d love to see a back to back dyno comparison. Off to search Richard Holdners channel 😂
U deserved subs Thanks bro
@@vrcarvlog3037 thanks for watching! 😁
I’ve learned more on this channel in two videos than I did years of training at Yodeling University (seriously, great video. Really enjoy these. 👍👍👍)
I appreciate that 😁
Just a guy sharing the things ive figured out so hopefully it can help out some people out!
And hopefully make it make sense along the way 😅
you should really be emphasizing this mainly applies to cross plane cranks, most inline and flat plain engines would still benefit. cross plane would even still benefit if you do an 8-1 collector.
Uhm NO. Equal length headers make it so that each cylinder gets the same signal. So you can tune the engine easier. During the exhaust stroke, the pulse leaving the cylinder will actually pull a vacuum, if you tune that vacuum just right you can actually start the intake flow BEFORE the piston hits TDC.
If you want the pulse to even out, consider 4-2-1 headers.
If you have unequal length headers - one cylinder will go lean when others are rich. Makes fine tuning impossible - basically you'll have to run on the rich side and leave horsepower on the table as it were.
As for cylinder to cylinder cross talk - you can control that with merge collectors. Depends on how strong the signal you want and how sharp.
Don't believe me - run it on a dyno - tuning the carb AND ignition timing between runs. write down the settings so you can redo the test.
So david vizard has a couple of videos about this on his channel. Although this issue applies particularly to V-layout engines. There’s also a whole other factor to header length besides the firing order; the angle of the V also takes part in calculating the correct lengths.
Angel of the V really?
Interesting! Ill have to run back through his stuff again because i dont quit remember it fully but that dose ring a bell now that you mentioned it 😁
How many sets of headers have you actually tested on dyno's?? I have had at least a half dozen sets of headers I built tested on the dyno, every set so far has made more torque and HP than the unequal sets they were compared to, some as much as 45 HP. Until the time comes that I see unequal length headers producing better results on the dyno and track I will keep building equal length headers for my customers. I hope that the headers on that engine you use as an example are not the headers you are talking about, I wouldn't expect a $200 set of big box store headers to produce good results on anything. Please do let us know the type of numbers you have seen on the dyno, I hope this video isn't all just theory.
You are correct but i think you should have mentioned that this is due to inherent firing order of v8s which causes issues. Naturally balanced engines like i6 and v12s are perfect for ELH. The sound they produce is also f1 like ☠️
True!
99% of my world is old school V8's so I didnt really think to cover anything else 😅
No No No. The point of equal length header is that each cylinder sees the same 'signal' ... One cylinder doesn't scavange from the other..... When the pulse goes down the exhaust, it has momentum. When the piston reaches TDC on the exhaust stroke, the piston no longer pushes exhaust out. However, the exhaust pulse has momentum and it pulls a vacuum behind it.... See pressure measurements at the exhaust ports of a single cylinder - and you will see the exhaust pressure go negative.
At 8000rpm, the pulse moves about 90 inches when the engine turns 90 degrees. Bottom line, the exhaust valve is closed long before any adjacent cylinder's pulse gets near it.
Stick with equal length - just make sure you don't go too big on primary tubes.
Use the collector to tune how hard the reverse pulse hits. You can soften and stretch to give you power over wider rpm, or narrow, to give more power at a more limited rpm range.
Sorry but inline fours and non cross plane v8s make more power with equal length
See how small the primaries are on that header. Thats how small they need to be no matter how much power you want. Modern headers are way too big and therefore lose power. We have tested hundreds of them and smaller primaries is always better. Always!
You have no idea. It’s obvious you have never pulled heads off and spun a motor over
ahhh, this makes a lot of sense why chevys sound like shit then
Considering the fact that the valve opens and closes about 60 times a second at 6000 rpm hmmm 🤔 just thinking bro
Exhaust gasses are faster than the valve too lol
When the valve is closed the Exhaust pulse is still traveling down the tube creating that low pressure "vacuum" pocket behind it.
I have a Camaro with a 383sbc and i want to give it a dual sidepipe only at the driver side. So just run 2 tubes in front of the left rear wheel from the collectors, so the right side will obviously be a bit longer, my question is , will it loose power that way? Or does it not matter after the collectors? Would i be better off running both sides into just a single pipe and then making the turn?
@@quirinm. I would run them into a good size single after the headers, single will scavenge better than dual pipes and is less weight.
@@newguysgarage6802 thanks
I have an in-line six cylinder engine, and I am designing an unequal headers, the firing order 1 - 5 - 3 - 6- 2- 4 it’s a Nissan tb 48, it’s going to be a true duel exhaust , so therefore two manifolds will be available, first manifold will have its primary tubes on 1 5 3 and the second one will be 6 2 4, I am doing this to get the scavenging.
I want to avoid the pulses from hitting each other.
What’s the ideal situation to get the most of it, is it fine I just make the headers tube for cylinder one the shortest after wards slightly taller for cylinder 5 then a bit taller for cylinder 3? I don’t have any special equipment to measure the pulses I am just using common sense
If the firing order is 1-5-3-6-2-4 then wouldn't it make more sense to have the two manifolds be 1-2-3 and 4-5-6? That would evenly spread the pulses out to were equal length would work for both manifolds.
I wouldn't do duals all the way back though, i would join the two manifolds with a Y pipe into a single all the way back a little after the two collectors.
I have a video on that too! 🙂
th-cam.com/video/a_nF8Y4DQ3g/w-d-xo.html
I would love to hear a six-cylinder engine with UeL headers!
Yeah, uh no.
Not according to dyno testing - which is where the significance of equal length primary tubes (for racing purposes) came from.
Once an entire exhaust system is placed behind a set of headers, by and large the gains from the headers themselves are significantly diminished, at that point back pressure, and the use of X pipes as a means to propagate exhaust flow became as significant if not more so than the headers themselves.
th-cam.com/video/AxGa6byZyOw/w-d-xo.html
You want to talk about dynos here is your guy.......he litterally wrote the books legends read lol 😆
Yeah, in both banks the two cylinders that fire close together need a sort of delay. I think in this example, making the runners for 7 and 8 twice as long as 5 and 4 respectively should do the trick given how the other two cylinders on that bank fire 180 degrees apart compared to the two "close" cylinders firing 90 apart. Just double the dwell time for one of the cylinders as you're good.
What does it sound like
Done correctly yes they will make power... now since youre looking for that high end power, you'll lose in the low end. All depends on how you want to tilt the curve before and after 5252rpm. Long tubes and equal length are for high revving platforms that you'll be at or above 5252, so you'll want that. Down low, you'll lose BUT if you're running the correct converter and rear gear it'll flash past that because you won't be launching at below 3500rpm anyways at the drag strip. nor in between shifts will it drop below the power curve
Ay bit of power you might lose or gain can easily be negated by a hot track day, bad track prep, wrong tire pressure, tune, and many many many other variables.
I never saw this as an overload issue, as much as a scavenging problem. Both banks have a pair of cylinders doing everything 90 degrees from each other. 8/4 and 5/7, or if you have a 4/7 swap cam, the issue moves to 4/2 and 7/3. The second exhaust pulse causes a flow loss [during overlap] of the first cylinder blowing down, as its wave looks like backpressure [or a wrong length collector]. Shorten the first and lengthen the second to adjust time of arrival and stop blending pulses, effectively. A dual plane crank begs for it.
"Tuned length" headers are supposedly what you really want.
@@____MC____ yes they are lol 😆
Well, I think a firing order implies that there aren't cylinders going off at exactly the same time, but I get your point if that's correct for most V8s. On Shorties it's also about being able to pass emissions, which is why a lot of enthusiasts choose them in addition to improving the sound.
Most engines can be tuned to pass emissions on most setups, so I would say just cause the firing order to go off at the interval you want and it's problem solved! You pass emissions, you get better sound and you get better power - Voila! We're not necessarily at the mercy of any particular design with the advent of modern-day tuning.
How do you determine the difference in length that is required?
Math way above my pay grade 😅😂
Interesting. David Vizard says basically the same thing.
The guy is a legend! 😁
missinfo, only applies to V8's often older school americans ones, also a 4-2-1 setup is overall better for most applications
How do they affect sound? Especially on flatplane v8s, because I think Ferraris use equal length and the gt350 used unequal length. Both flatplane but sound wildly different. How is that explained?
Firing order will change sound,
And you only hear the exhaust sound after it exists the end of the exhaust so anything you do to lengthen or shorten that distance will affect sound 🙂
@@newguysgarage6802 what’s the firing order on a ford voodoo v8 vs literally any ferrari v8 (non Maserati)? Also thanks for the explanation, wouldn’t have known firing order affected the sound
......well ford had a bunch of different firing orders 😅
And im not really familiar with Ferraris but i bet you could find out that stuff with a google search 😁
@@newguysgarage6802 I shall do some research, thanks man
@@fadedsoul23 Ford's Voodoo flat plane uses a very different firing order than a normal even firing flat plane. They did it literally just to maintain an "American muscle" sound.
Driving 4 Answers did a great video on this.
Hey, noob hear, could anybody explain if the same applies to inline 6 engines? I am a bit confused .
My boat has 8 in to 1 sbc. Is Is this going to be different
No the actual tube length tuning will be the same.
The goal is to have each pulse enter the collector one at a time so that the collector has a constant steady pull on all the tubes.
Easy to say but hard in reality to do, so as long as you have a good collector length (18" at least) that should help the collector keep a good signal on the tubes.
Now all 8 into one i would think you would want a bigger collector diameter like 3.5" to accept all of that exhaust (mabey even a 4" if your motor is verry stout!)
Dose that make sense?
Collector length helps the handicapped tube lengths
@@newguysgarage6802 cool. It's 4 3/4 inch very stout methanol dry sump. I start racing after Christmas. Manning River Taree Aus. Love ýour channel mate
Perfect!
Sounds awsome 😀
Thank you for watching!
make a video on inline 6 bmw firing order with equal lengths. would it benefit ?
Cragars in the living room... I trust this guy! 😂😂😂
Great topic. The other drawback of equeal length headers is the unequeal bends in the pipes making flow eneven throughout. I have often wondered if equeal bends and a collector that has each pipe the same length into the collector creating a internal enequeal pipe length into the collector... hard to explain in words, so picture a longer collector with the pipes staggered in lengths to mathematically create equeal pipe lengths and firing order pulsing to get the biggest bang for your buck.
Tri-Y headers is the key 😃
@newguysgarage6802 Just checked out the Tri Y you mentioned... not exactly what my thoughs are. Picture a collector and from the flange to the pipes, inside is staggered exits of pipes within the collector. I will draw a picture later and send it to you.
@user-yq6zd6be5y i see what you are talking about, that would probably work out 😁
So if you have a 4-7 swap camshaft that trades the firing order cylinders 4 and 7, would the equal length headers be beneficial then?
Yes it is beneficial, but still doesn't fully fix the pulses at the collector 🙂
Equal length is for Flatplane Cranks v8 and inline engines.
Which never really applies to us hot rodders lol 😆
but I have TRI Y's 🤪
So if most drag cars have eight stub headers maybe cars should have eight individual tailpipes.🤣
Eight stub headers?
@@newguysgarage6802 think he's talking about zoomie headers like dragsters have.
th-cam.com/video/1CzGFoXwrfo/w-d-xo.html
Oh i see lol 😆
Well you would need to build the right kind of engine for them to be usable 😁
You are correct. The issue now would be to figure out which tube is the correct length, for desired results. There will be 2 per side that would need to be shorter, and one longer. David Vizard also covers this on his channel, and the results are impressive.
True, but almost every Chevy (and same firing order engines) headers I see, even expensive ones, it looks like the #5 tube is at least as long as #7. They even put bends in #5 to make it unnecessarily longer. I don't get why, especially on $800+ headers!
@mikewillett5076 being expensive doesn't usually mean they are also quality and better performing lol
They are looking for key words "equal length" just to make people think they are super trick so they will buy them 😅
@@newguysgarage6802 . That's true. But you mean even companies like Hooker with their Super Competition and others don't make them unequal for the 5/7 issue? I looked at pics of a lot of the them and haven't seen any where the 5 is obviously shorter than the 7. Of course it can be hard to tell by eyeballing them in a photo if they're close. Thanks
@@mikewillett5076 it is easier for them to just make the tubes whatever length is required to make them fit under the hood of any specific modle car they are made for too.
Headers can already be a tight fit let alone with one pipe noticeably longer that the other ones to try and deal with 😅
@@newguysgarage6802 . Yep. But I've seen where they could've made one shorter or longer no problem. Eh, long tubes are still better than shorties or manifolds. Thanks a lot for replying, too many channels "abandon their posts". Lol
How can I know what's my engine's firing order? Not really a V8, most likely will be inline 3 or 4
Google is your friend on that one lol 😆
@@newguysgarage6802 Alright, thanks. Also.... what generally is the power increase from the entirely custom, properly made exhaust? Google says up to 5%, but you seem to know a lot so I'd rather as you too
A good exhaust can make or brake your power in a big way!
Might even be more important than the intake side for making power.
th-cam.com/video/AxGa6byZyOw/w-d-xo.html
I will refer you to David Vizard.
He is a legend! Watch some of his stuff and you will have your mind blown 😁
@@newguysgarage6802 Thanks a lot! Gonna watch now :)
Yes it 'dose' matter
Dang it!
I do that every time 😅🤣😂
@@newguysgarage6802 🤣
There fixed it!
I like this one better anyway so thanks 😅😂
@@newguysgarage6802 Np
You do have a point, but I think you need to be a bit more clear about this is only for crossplane v8's but is still the best option for all other engines.
There are other engines that have two cylinders firing right next to eachother other than just v8's lol