I love your real world mentality vs channels that just mess around with big dollar equipment that's unaccessible to most of us vs several junkyard based engines and repurposed or budget add ons, I absolutely love the other guy builds, please do even more! I watch all your content keep up the great work!
I've recently found your channel and find it educational to say the least. Dispels the myths. This is from an old school 67 year old gear head with his first LS. ( SS truck LQ9)
Your the best engine guy on here so simple to understand best explanations iv heard I'll be sending a lot of people here who think 1000hp turbo will give them 1000hp at the wheels on a stock engine
@@richardholdener1727 thank you for all your work.. I'll come help with the wrenching when your in So-Cal ... I'd like to see the same turbo with 3 different hot sides.. see how it would effect the curve.. which one would be better for the street with the backpressure that's not too crazy
you are correct. Smaller turbo makes boost at lower rpm and better for torque but runs out of breath up top in the higher rpm's, bigger turbo doesn't light off until higher rpm's but when it does come on pulls like a freight train up top. An engine with a smaller cam would probably be better with a smaller turbo and bigger cam should have bigger turbo. It's all a balancing act where you have to choose components based on what sort of rpm range you want the engine to make the power at.
Hey man, new sub here. I’ve only seen about three of your videos so far but damn SUCH GREAT STUFF!!! So awesome to get real world data and see comparisons that average joe’s actually build! I know it’s different strokes for different folks and the high end stuff is cool to watch on TH-cam but some of us are junkyard dogs trying to make power as cheap as possible hahah I’ll be watching all your stuff now. Thanks for what you do brother.
What would have been really interesting was advancing the cam in the larger turbo to see if you could recover the low end torque to match the smaller turbo at what cost to peak horsepower.
@@richardharris492 Not really. Same wheel just different AR housing. The Housing AR size is a big driver on back pressure. A housing swap is quick and relatively cheap compared to a wheel (cartridge) change so is something that someone might consider doing. I think it would be a great test to perform.
Super informative presentation, thx for for your work. Also no the way you did it with the bleed valve illustrated the differences in turbos better and the back pressure chart was cool
I'd like to hear/see more about back pressure. You mention a point where you start to worry about back pressure. Explain that. When is back pressure a problem and how does that problem manifest itself? In videos I hear it mentioned but never explained.
Ok we need more people here for the 4.7L Dodge test!!! So here with me!!! But definitely need to know about the turbos and how do you size them so awesome video
Great test! At some future point it will be really interesting to see a back to back comparison of different exhaust housings on the same turbo. Suspect it will be a bit like the LSA cam test.
A neat test would be to see what power each of these turbos would make on the same test motor maxed out. Put 25-30# spring in the wastegate and let them eat on race gas. That will really show the difference in the hotsides and back pressures.
There is that combination thing again.....power desired, intended usage, money available. I have never built a 600 hp engine, there is no way I would try turbo, without a dyno, can't afford to just blow it up......good demonstration.
Double the air and double the fuel gives you double your original bang. Big hotside impellers need a lot of wind to get started spinning. Before they start really spinning it's basically just in the way. Size your turbo to be on boost at the rpms you see most often.
Great work Richard love what you do. thx for helping the fellow man as you do. as mentioned above back to back rear housing change would be interesting with spool rpm being a consideration. something else that might be interesting for the viewers is b2b different design turbine impeller of the same diameter. thx again
One issue that should be looked at is whether or not it is worth spending the extra money on dual ceramic ball bearings or does the traditional film layer/journal style better suits your needs? Not everyone needs pricey ball style bearings. Most people don't even know how to run them correctly. They flood the bearings with the wrong type of motor oil, which will hinder the balls from spinning in the races. Ball bearings actually need very little "race" oil. A fine mist is what high-quality bearings are designed to work with. They need just enough to keep them cool and from making metal to metal contact with their surroundings. Many times film layers/journals are superior to balls if it is going to have a super high shaft speed(small turbos) and only a hydro-dynamic layer can cope or the engine is going to get street use. Research before dropping $2500 bucks on a turbo when a $900 dollar unit might meet all your goals and even last longer, in some cases. There are some really good companies here, in the U.S. who make their own niche' turbos. There are some really smart guys here in America ready to help you with one phone call. Try getting genius-level answers when calling an overseas manufacturer. If you are watching Mr. Holdener's videos, take notes. His experience is invaluable.
I assume a 2:1 drive psi to boost psi ratio always equates to more responsiveness, but at what point do reach diminishing returns? A 1:1 ratio is probably more ideal, but is also more lazy down low? I’ve heard so many horror stories about toasting exhaust valves from excessive drive pressure, and how you have to have inconel valves. What’s your opinion on ideal drive pressure at max boost while also having response for a street car?
So I'm not Richard, but did a lot of work in Turbo Vipers and a very well known, record-holding 911 turbo. In my viewpoint, traditional turbos (I'll until recently) would drive like an OE application with max target EBR of 2 (and tuning needs to watch EGTs), had a good mix of power and streetability around 1.3-1.5, and became very racecar at 0.8-1. These days, I feel like a very power-capable turbo can be made to make power everywhere without needing to go to 2... More like 1.5-1.7. A perfectly streetable turbo is now in the 1.1-1.3 range, and race applications are well under 1. Some of what we see here is the issue with manifolding 8 cylinders into one turbo. You just can't use the exhaust energy that efficiently versus a well designed twin system. Puts you very much in my "traditional" category.
@@corystansbury this is why I would love a test like this with the same turbo s475 but with a nice turbo header hot side and see the backpreasure comparison. I want 700 wheel and still be a fun street car with a head cam fuel system 5.3 or 5.7 this looks like the setup with an ar change or headers on the hot side.
That was great information Richard especially on the 6 LT. Still like to see more on the 455 Buick with cam, intake, heads and compression, thanks again Richard.
what would be the difference if say u took the 480 hot side and put it on the 475 and see what that would do for responsiveness? so like the difference between a top end drag car or a street car that stays mid range n stop n go so responsiveness would be top priority then ..... im upgrading from a journal bearing to a dual ceramic ball bearing turbo for response n hopefully better power as i kept hot side at .63 and upped compressor from a 57 i think i was to a 60 so i should see more response and more boost going on bearing response differences .... love your vids bro super informative ... peace n love fam keep it rad stay safe and build on bro l8z
Would have liked to see a 4.8 and a 6.0 and then two turbos. 1 a s475 with a 1.32 AR and the other a s475 with a .96 or 1.0 AR. That way you see what the hot side change is vs engine size.
Is it possible to run a quick spool valve that chases boost pressure for example { 8 LB of boost @ 12 LB of back psi } { 16 LB of boost @ 24 LB of back psi } { 28 LB of boost @ 28 LB of back psi } This would be achieved by using a quick spool valves on a twin scroll housing With an actuator spring psi of 29.4 PSI { atmospheric psi 14.7 x 2 = 29.4 } To avoid choke flow
Hey Richard, been enjoying your videos for a while now. As soon as i saw this title an idea poped into my head for the junkyard guys. Would you consider getting a bunch of popular junkyard turbos together an testing then out? Hx35w, twins maybe? duramax turbos? Semi turbo (lol exhaust) im sure theres more but itd be sweet if it sparked an idea to test out some low buck junk again!
That’s an comparison I’d like to see , a junkyard turbo shootout.! I’ve got a home brew setup: Its a 5 ton deck carrier with HX35 huffing a blow through on 427 tall deck . 10 psi is where I’ve capped with big a increase in usable power .
I've been watching alot of your videos and I absolutely love them! I'm learning alot! I live in South Dakota and I want to build a sbc or ls twin turbo with a blow through style fuel injection from Holley for my 4x4 squarebody chevy pickup. I want this to be daily driven year around summer and winter. Is this a bad idea or I guess any do's, dont's, or advice on the extreme cold in winter for doing a twin turbo blow through fuel injection build? Also I would love to see you do a beginners guide to tuning a boosted engine for both fuel injection and carbureted engines to get a beginner like myself on the right path and not make instant junk.
Nice videos. Keep up all the great work. The reason one turbo makes more hp per psi on the same setup is because of where it is on the compressor efficiency map. As it becomes less efficient, it starts generating more heat and less airflow, thus reduced power. And it depends on the application. There is always a limit to how much octane, boost and timing you can get into a motor. Lowering the compression will allow you to run more boost and timing without detonation. If you exceed the turbo's efficiency map it can no longer produce enough air to keep up with the boost required. Thus is falls off.
@@richardholdener1727 I would rather drop the compression and run higher boost and make more horsepower than run a high compression na motor that makes great power off boost with limited boost due to getting into detonation
For those running older motors and only looking for say 50% power improvement ie. 7-8 lbs of boost, I find that pressure ratio (1.5) well below the most efficient boost level of every compressor map out there.
Great test! AR trst would be great too. One that I’ve really been dying to see some results from are a twin scroll turbo on a properly divided twin scroll manifold (perhaps easier on a 6?). Lots of info about this 10 years ago, and now you don’t hear too much, yet all the OEMs use them? Great job keeping us entertained while stuck at home.
Richard, Looking at your graphs, at around 5,800-5,900 both turbos are producing the same boost, with the larger turbo making ~20-30hp more. Is this a result of the lower back pressure of the larger turbo, and does the larger compressor wheel have any part to play? If it’s purely a function of the back pressure, is there some sort of formula that you can apply to work out how much Torque you would need to sacrifice to drive the differential back pressure over boost pressure? Thanks!
Hi from Australia Richard, I love your vids. I have a 2014 Jeep SRT 6.4l SBE with 25k miles, I am working on a rear mount turbo system and am going single turbo. trying to pick the best hot side size for response for a peek power of around 750 crank HP, around 8 PSI (street use). I was looking at CS racing 7875 or pulsar turbo G42 1450 Which is a perfect clone of Garrets g42 1450 turbo. any advise on hot side wheel size would be much appreciated. Keep these vids coming! I have learnt so much from you. you simplify things so well. you have given me the confidence to do my own set up. Love your enthusiasm.... Glen Z.
Great info! Thank you for sharing. I can see that you are a shoot out kind of guy. How about another cam shootout? 5.3L LS with these three Elgin cams, vs a GM LQ4, E-1838-P, E-1839-P, and E-1840-P. Now I know this is difficult to do on the dyno, but would like to see the difference down low as well as up top. Thanks again for providing great information for all of us.
How does AR affect a compound setup? I realize those aren't super common on the gas engine side but for diesels they are super common. In the end I suppose it is still similar in that the more restrictive hot sides are more responsive but limit overall production which is probably why some guys go with large singles over compound setups to lower the backpressure.
when a test about oil pump and how much hp we can have when we "decompress" the block, how many hp can give oil pump sistem or exhaust sistem? also a question, if i boost an na engine, i should increase the oil pressure or i leave the same? when an oli pump upgrade have sense?
Does it not seem like maybe your wastegate could be undersized? You can see where the gate opens at 4700 (475) and 5100 (480) and they seem to not bypass as much exhaust flow as needed to keep a flat boost curve after wastegate opens. Just a thought.
Isn't that where looking at the compressor maps come into play? Figuring out the efficiency of the turbos at the power levels you're looking for. Now, obviously the compressor map isn't going to help you choose a hotside, but it's definitely needed when selecting what turbo to use for your power goals. I'm in the process of selecting a turbo for a twin charging application on a 4.6 2v modular and it's looking like I'm going to need an s488 for the power levels I'm wanting at the boost levels I'll be looking for. It will be feeding through an intercooled m122 supercharger. Most people when twincharging make the mistake of not selecting a big enough primary to support their goals at the boost level that the primary will be running at and then they get frustrated when they can't make the top end power they were expecting. Maybe you could do a twincharging test to showcase how choosing the primary is so important in a twincharging compound boost setup.
I do love these tests. However, I do wish the comparisons were more apples to apples. In this case I would have liked to see an electronic boost control used because I think the top end difference would have been a lot less drastic. Just my opinion.
Thanks Richard, what do you think about the variable vane turbos that Porsche is using in their cars that give great response in the lower rpm and fantastic power in the upper rpm range. Great video keep em coming.
Drive double boost seems really bad. Curious if you went to twin 75's how would the power compare? Also what if you went a way bigger AR? Could you make the same power with half the boost if you got the back pressure more close to 1-1?
If you changed your boost control, say to Dominator with co2,could you raise your lower rpm boost? Then maybe lower the pressure at higher rpm, so it doesn't built too much?
I'd like to see you compare a late 80's Ford 2.3 liter turbo engine (aka Mustang SVO) to the current 2.3 Ecoboost engine. 1st stock, then ported head, bigger (roller) cam, then finally with bigger turbo. With video please. Sounds good to me. BTW, I'm sure we've crossed paths while I was at Travis back in the day.
I have a question I have a big block Chevy ho 502 Factory rating 450 horsepower 550 ft lb of torque I was looking at a 475 Turbo 78/75 with a Air1 .25 Hearthside I'm not after major horsepower I'm looking to increase the bottom in pulling under 4,500 RPM so I'm looking for a turbo that will come in somewhere surround I would say 18 to 2000 RPM increase the low-end torque of the big lock to help pull or for off-road applications truck is used as a daily driver toy mod off-road and towing vehicle would you recommend a s475 is the air 1.25 ok if not what do you recommend I'm only looking to make about 9 pounds 9 and a half pounds Max boost at any given time probably even more likely around 8 thank you for your time
If you’re drag racing in Florida and then move to Denver for a race, would you downsize the hot side of the turbo because of the higher elevation? I know racers have issues with spooling I’m thinner air and after watching this I was thinking that a smaller hot side would help speed up spooling, Do I misunderstand this? Thanks!
Awesome video! Got a video idea. Could you do a test on a centrifugal blower where you pulley way down to try and bring on boost harder and just use a watsegate to vent any extra boost up top? I always wondered if that would work. Would probably run into belt slip early but I'm not sure
You always talk about the right ring gap. What is the right ring gap for turbo or how do you find that out? I have a 5.3 ls engine wanting to run 600-800hp. 0.020- 0.025 is what I've come up with. Any help would be greatly appreciated
Richard. im gonna put a turbo on my stock 06 series 3 3800 v6. I just wanted to get your recomendation on what size turbo would be quick spooling and efficent on my stock series 3 3800'. im shooting for around 400hp at thr wheels or as close as I can get. this is a budget setup so Ive been looking at some of the ebay turbos as I plan on just having a littel fun with this setup then build a more serious engine build over the winter.
Thanks for taking the time to answer my question I really appreciate it. I've used a gt35 before on a 4g63t but it was a much more of a track oriented build. And it worked great.
I wonder if a smaller header and crossover pipe diameter on the hot side would help spool the s480 quicker? Or would it just raise the back pressure? Maybe that would be a good topic for another test.
Do you have the availability of showing different hot size piping on these? 2 vs 2.25 vs 2.5 and maybe 3 showing power difference and where they are in the curve and what happens to lower end boost.
Good test and data. That said, it would have been so easy to also do a matched boost run for more data. A more complex effort but also interesting would be a matched backpressure test.
What motor was in the 1 lt 100hp pic? Was that a 3cyl sprint? Intrested in info on your tests on the little stuff, even a mototcycle or draw thro if you have done it. Got my turbo car goin again with a 355 and s475 with a fairly big cam and guess what, it rips up top nut no bottom end power haha just like how the cam is na
Richard like I said in my previous comment a big engine does not produce more 'back pressure' compared to a small engine at same HP level , yes the boost to back pressure will way more on the bigger motor but the actual back pressure should be close . Can actually prove my theory if you go look at your VSracing turbo vs Borg, @ 6500 rpm the 4.8 produces about 20 psi of back pressure and makes 800 hp . In this video same turbo on the 6.0 its produces about 875hp @6500rpm and about 22-23 psi of back pressure. Yes the boost to back pressure ratio is way off on the bigger motor but it proved my point that back pressure( exhaust gas volume) is a function of HP not displacement.
Good stuff man great info as always I kno how to work on cars but dont kno everything you got real fill in the big gaps I have especially on turbo stuff
Love the content. I have a question can you make 1000hp on 91 octane fuel only? You said you mixed 91 and higher octane mix. Is it even possible to run double atmospheres with 91octane only safely. Thanks keep up the great info and content
This is another super informative video. Thanks! I wonder though, when a different size engine (like 4.8 vs 6.0, like you were using as examples) makes the same power, isn’t the hot side flow the same? Lbs/min airflow in would have to equal lbs/min out, seems like. The little engine would take longer to get there, but the resulting flow should be the same-or not? Would pinning the waste gates closed with CO2 affect the way the boost comes in? Is there a solution using variable A/R, like a diesel turbo? Is there a way to get the back pressure curve you showed on the BBC with twin eBay turbos on the little LS? Inquiring minds...
I thought pound for pound flow was a good measure when looking for junk yard diesel turbos to use on a gas engine. I figured that my gas engine will run half the boost and double the rpm of the diesel so it all works out. But it turns out that it's not about matching mass flow but matching volume flow. So a 7.5L gas engine that turns to 5000rpm will need a turbo from a 15L diesel that turns to 2500rpm.
I thoroughly enjoy your channel. You address all the crazy thoughts I have during the day while wrenching. Have you tried building a compound turbo setup for an LS? I'm an LS guy but run compounds on my cummins. It always seems to be in the powerband while towing. Just a thought and it would be cool to see a setup that holds 14 psi of boost from 3500 rpms. Keep up the great work.
I am deciding which turbo to order. I am seeing conflicting info everywhere. Turbo size and drivability being my concern. LC9 /799 heads with a stage 1 or 2 truck cam (all cams are turbo cams) . My issue I want to feel my turbo when I’m driving. Too big and I will never be in boost. Too small and I will run out of boost. @ Richard Holdener I know you are busy but could you please advise?
For the billet wheel, ball bearing, twin scroll testing, an engine dyno might not be the best way to test it. A brake dyno will make the results almost irrelevant. The only way it would be worth doing is if you could load the engine at an rpm lower than the boost threshold and have the the rpm/s at something wild like 1200 or 2k. I doubt the engine dyno you have can hold a v8 that low, it would be like 1500rpm, or have the rpm escalating that fast. You might be able to do it with a really small engine to cut the torque at load in and a really big turbo. If you had something like a b16 and loaded it at 2500 and ran it out to 8500 it gives you a huge sweep and you can test boost response if you can have the rpm/s fast enough... The thing is as soon as the boost comes in and pounds the torque out, the dyno will slam the door to keep the engine acceleration consistent and make the torque spike worse, not better. You almost need to test this with an inertial dyno, the brake fusses with turbos.
Hey Richard, thanks again for taking your time to make these aWESOME videos ! I tried the ebay turbos on a 355, make 1335, with a blow through carb(CSU) but after 30+ dyno pulls,the seal let go,(smokey as heck) but they made big power, have you had good luck with these turbos lasting /
Richard! What is AR an what's the difference between 1.00 ar and 1.25 ar ? Looking to do a rear mount turbo on ly6 street car. So power down low and mid rpm is more important.
Lots of info out there online, but basically put.. smaller AR is more restrictive and more responsive but can potentially limit power, larger AR is less restrictive and less responsive but can allow for more power on top end
@@joelstevensz06 going for the stealth turbo look myself, not looking on building a race car for the track. Just a fun street car, to surprise people on the street!
I love your real world mentality vs channels that just mess around with big dollar equipment that's unaccessible to most of us vs several junkyard based engines and repurposed or budget add ons, I absolutely love the other guy builds, please do even more! I watch all your content keep up the great work!
agree 100%!
Good stuff as usual. I got rid of my 4.2L Trailblazer btw.
I love it when you talk combinations. So many people don’t understand how important getting the right parts that work together is.
This was a great test! I was surprised a little bit by how high the back pressure was on the S480. Really killer test Richard.
I've recently found your channel and find it educational to say the least. Dispels the myths.
This is from an old school 67 year old gear head with his first LS. ( SS truck LQ9)
Excellent video. Your explanations of boost vs HP vs displacement were very enlightening.
Love your videos, I'm trying to pick a turbo now and find the right balance and you are helping a ton!
Your the best engine guy on here so simple to understand best explanations iv heard I'll be sending a lot of people here who think 1000hp turbo will give them 1000hp at the wheels on a stock engine
Run hard, it absolutely can. If it's an efficient motor, it can make well above the turbos rating.
I’ve been waiting for this vid. Thanks Richard! Pls keep up the great work. 👍
Thanks, will do!
@@richardholdener1727 thank you for all your work.. I'll come help with the wrenching when your in So-Cal ... I'd like to see the same turbo with 3 different hot sides.. see how it would effect the curve.. which one would be better for the street with the backpressure that's not too crazy
Good info honestly never put that much thought to the hot side. Thank you!
This turbo comparison, reminds me of cams. Smaller cam, more responsive down low. Not as powerful. Large cam, fall off down low, more power up top!
you are correct. Smaller turbo makes boost at lower rpm and better for torque but runs out of breath up top in the higher rpm's, bigger turbo doesn't light off until higher rpm's but when it does come on pulls like a freight train up top. An engine with a smaller cam would probably be better with a smaller turbo and bigger cam should have bigger turbo. It's all a balancing act where you have to choose components based on what sort of rpm range you want the engine to make the power at.
@@GnarshredProductions I think that is the opposite of what Richard holdener was talking about in his b-tec video
But I want something for nothing!! :) is funny how much guys scrutinize parts like this when it makes so little difference for most...
Hey man, new sub here. I’ve only seen about three of your videos so far but damn SUCH GREAT STUFF!!!
So awesome to get real world data and see comparisons that average joe’s actually build!
I know it’s different strokes for different folks and the high end stuff is cool to watch on TH-cam but some of us are junkyard dogs trying to make power as cheap as possible hahah
I’ll be watching all your stuff now. Thanks for what you do brother.
welcome, check out the junkyard stuff-plenty of videos on cheap stuff
What would have been really interesting was advancing the cam in the larger turbo to see if you could recover the low end torque to match the smaller turbo at what cost to peak horsepower.
Why not just bolt different hot side housings (AR) to the same turbo? That would really make your point.
Yes size the compressor for power and turbine ar for efficiency
@@bill2178 finely some one gets it.
we can do an AR test
I think he means changing hot side wheel more so than AR size
@@richardharris492 Not really. Same wheel just different AR housing. The Housing AR size is a big driver on back pressure. A housing swap is quick and relatively cheap compared to a wheel (cartridge) change so is something that someone might consider doing. I think it would be a great test to perform.
Super informative presentation, thx for for your work. Also no the way you did it with the bleed valve illustrated the differences in turbos better and the back pressure chart was cool
I'd like to hear/see more about back pressure.
You mention a point where you start to worry about back pressure.
Explain that. When is back pressure a problem and how does that problem manifest itself?
In videos I hear it mentioned but never explained.
Ok we need more people here for the 4.7L Dodge test!!! So here with me!!!
But definitely need to know about the turbos and how do you size them so awesome video
I think you might be the only one
It would be cool to see this ran again changing both hot sides larger hot side on 475, and smaller on 480.
Couldn't have said it better myself, no fairy dust marketing! Flow is what it is, if it flows it goes doesn't have to be magic.
Great test!
At some future point it will be really interesting to see a back to back comparison of different exhaust housings on the same turbo. Suspect it will be a bit like the LSA cam test.
Did you mention the exhaust AR size for both turbo? If you did I just missed it. Great video as always.
A neat test would be to see what power each of these turbos would make on the same test motor maxed out. Put 25-30# spring in the wastegate and let them eat on race gas. That will really show the difference in the hotsides and back pressures.
There is that combination thing again.....power desired, intended usage, money available. I have never built a 600 hp engine, there is no way I would try turbo, without a dyno, can't afford to just blow it up......good demonstration.
thats 1000+ hp turbo...
Double the air and double the fuel gives you double your original bang. Big hotside impellers need a lot of wind to get started spinning. Before they start really spinning it's basically just in the way. Size your turbo to be on boost at the rpms you see most often.
on the extreme side of things I'm still waiting to see you feed a SC with a turbo, maybe even twin snails into a slug. Keep up the good work, cheers
You should take a look at Banks power. Gale has done many of these “super turbo” combinations. Granted it’s on diesel but most of it ports over.
that is happening
Great work Richard love what you do. thx for helping the fellow man as you do. as mentioned above back to back rear housing change would be interesting with spool rpm being a consideration. something else that might be interesting for the viewers is b2b different design turbine impeller of the same diameter. thx again
One issue that should be looked at is whether or not it is worth spending the extra money on dual ceramic ball bearings or does the traditional film layer/journal style better suits your needs? Not everyone needs pricey ball style bearings. Most people don't even know how to run them correctly. They flood the bearings with the wrong type of motor oil, which will hinder the balls from spinning in the races. Ball bearings actually need very little "race" oil. A fine mist is what high-quality bearings are designed to work with. They need just enough to keep them cool and from making metal to metal contact with their surroundings. Many times film layers/journals are superior to balls if it is going to have a super high shaft speed(small turbos) and only a hydro-dynamic layer can cope or the engine is going to get street use. Research before dropping $2500 bucks on a turbo when a $900 dollar unit might meet all your goals and even last longer, in some cases. There are some really good companies here, in the U.S. who make their own niche' turbos. There are some really smart guys here in America ready to help you with one phone call. Try getting genius-level answers when calling an overseas manufacturer. If you are watching Mr. Holdener's videos, take notes. His experience is invaluable.
Great video on lots of information so I can get the right turbo for my tow truck
Another great video exactly what I was looking for thanks
I assume a 2:1 drive psi to boost psi ratio always equates to more responsiveness, but at what point do reach diminishing returns? A 1:1 ratio is probably more ideal, but is also more lazy down low? I’ve heard so many horror stories about toasting exhaust valves from excessive drive pressure, and how you have to have inconel valves. What’s your opinion on ideal drive pressure at max boost while also having response for a street car?
So I'm not Richard, but did a lot of work in Turbo Vipers and a very well known, record-holding 911 turbo. In my viewpoint, traditional turbos (I'll until recently) would drive like an OE application with max target EBR of 2 (and tuning needs to watch EGTs), had a good mix of power and streetability around 1.3-1.5, and became very racecar at 0.8-1. These days, I feel like a very power-capable turbo can be made to make power everywhere without needing to go to 2... More like 1.5-1.7. A perfectly streetable turbo is now in the 1.1-1.3 range, and race applications are well under 1.
Some of what we see here is the issue with manifolding 8 cylinders into one turbo. You just can't use the exhaust energy that efficiently versus a well designed twin system. Puts you very much in my "traditional" category.
@@corystansbury this is why I would love a test like this with the same turbo s475 but with a nice turbo header hot side and see the backpreasure comparison. I want 700 wheel and still be a fun street car with a head cam fuel system 5.3 or 5.7 this looks like the setup with an ar change or headers on the hot side.
back pressure is only 1 part of the response equation-and something you look at after you have done everything you can to improve na power production
Richard Holderner, I love how people insult you then they say, " I'd love to see blah blah blah" You can't win Rich. Thanks for videos.
If you run a similar test again, you should put a 1.58 exhaust housing on the S480 and record the difference in back pressure.
Please do a vid with compound induction. With turbos and with turbo and super charger. Thank you
THOSE VIDEOS ARE ALREADY UP ON THE CHANNEL-TURBO/TURBO AND TURBO/BLOWER
That was great information Richard especially on the 6 LT. Still like to see more on the 455 Buick with cam, intake, heads and compression, thanks again Richard.
what would be the difference if say u took the 480 hot side and put it on the 475 and see what that would do for responsiveness? so like the difference between a top end drag car or a street car that stays mid range n stop n go so responsiveness would be top priority then ..... im upgrading from a journal bearing to a dual ceramic ball bearing turbo for response n hopefully better power as i kept hot side at .63 and upped compressor from a 57 i think i was to a 60 so i should see more response and more boost going on bearing response differences .... love your vids bro super informative ... peace n love fam keep it rad stay safe and build on bro l8z
Great test . It was interesting to see the results of both turbos at the same boost setting.
More backpressure also equals more heat. More hot exhaust gas left in cyl. Less cold charge air filling the cyl
What size wheel and housing were used on each? You just said “smaller vs larger” but never specified actual sizes
Would have liked to see a 4.8 and a 6.0 and then two turbos. 1 a s475 with a 1.32 AR and the other a s475 with a .96 or 1.0 AR.
That way you see what the hot side change is vs engine size.
What about comparing twin turbo set up to beat both down load and up top?
Is it possible to run a quick spool valve that chases boost pressure
for example
{ 8 LB of boost @ 12 LB of back psi }
{ 16 LB of boost @ 24 LB of back psi }
{ 28 LB of boost @ 28 LB of back psi }
This would be achieved by
using a quick spool valves on a twin scroll housing
With an actuator spring psi of 29.4 PSI
{ atmospheric psi 14.7 x 2 = 29.4 }
To avoid choke flow
Hey Richard, been enjoying your videos for a while now. As soon as i saw this title an idea poped into my head for the junkyard guys. Would you consider getting a bunch of popular junkyard turbos together an testing then out? Hx35w, twins maybe? duramax turbos? Semi turbo (lol exhaust) im sure theres more but itd be sweet if it sparked an idea to test out some low buck junk again!
I like this idea. Also, I'd like to see how turbos from diesel engines work on gasoline engines.
That’s an comparison I’d like to see , a junkyard turbo shootout.!
I’ve got a home brew setup: Its a 5 ton deck carrier with HX35 huffing a blow through on 427 tall deck . 10 psi is where I’ve capped with big a increase in usable power .
those are hard to find sometimes
I've been watching alot of your videos and I absolutely love them! I'm learning alot! I live in South Dakota and I want to build a sbc or ls twin turbo with a blow through style fuel injection from Holley for my 4x4 squarebody chevy pickup. I want this to be daily driven year around summer and winter. Is this a bad idea or I guess any do's, dont's, or advice on the extreme cold in winter for doing a twin turbo blow through fuel injection build? Also I would love to see you do a beginners guide to tuning a boosted engine for both fuel injection and carbureted engines to get a beginner like myself on the right path and not make instant junk.
Nice videos. Keep up all the great work. The reason one turbo makes more hp per psi on the same setup is because of where it is on the compressor efficiency map. As it becomes less efficient, it starts generating more heat and less airflow, thus reduced power. And it depends on the application. There is always a limit to how much octane, boost and timing you can get into a motor. Lowering the compression will allow you to run more boost and timing without detonation. If you exceed the turbo's efficiency map it can no longer produce enough air to keep up with the boost required. Thus is falls off.
the amount of power a turbo supplies is a function of the na power much more than the map position
@@richardholdener1727 I would rather drop the compression and run higher boost and make more horsepower than run a high compression na motor that makes great power off boost with limited boost due to getting into detonation
For those running older motors and only looking for say 50% power improvement ie. 7-8 lbs of boost, I find that pressure ratio (1.5) well below the most efficient boost level of every compressor map out there.
Great test! AR trst would be great too.
One that I’ve really been dying to see some results from are a twin scroll turbo on a properly divided twin scroll manifold (perhaps easier on a 6?). Lots of info about this 10 years ago, and now you don’t hear too much, yet all the OEMs use them?
Great job keeping us entertained while stuck at home.
Richard, Looking at your graphs, at around 5,800-5,900 both turbos are producing the same boost, with the larger turbo making ~20-30hp more. Is this a result of the lower back pressure of the larger turbo, and does the larger compressor wheel have any part to play?
If it’s purely a function of the back pressure, is there some sort of formula that you can apply to work out how much Torque you would need to sacrifice to drive the differential back pressure over boost pressure?
Thanks!
I don't have that formula
I want to see what happens when you use a turbo w/ the 75's compressor specs and the 80's turbine specs
I have a severe case of ADD and I am trying so so hard to keep up with what you're telling me and it's just not working
Thanks for your input.. Very helpful for a beginner
Hi from Australia Richard, I love your vids. I have a 2014 Jeep SRT 6.4l SBE with 25k miles, I am working on a rear mount turbo system and am going single turbo. trying to pick the best hot side size for response for a peek power of around 750 crank HP, around 8 PSI (street use). I was looking at CS racing 7875 or pulsar turbo G42 1450 Which is a perfect clone of Garrets g42 1450 turbo. any advise on hot side wheel size would be much appreciated.
Keep these vids coming! I have learnt so much from you. you simplify things so well. you have given me the confidence to do my own set up.
Love your enthusiasm....
Glen Z.
I KNOW THE GEN 2 VS RACING 7875 WORKS WELL
As always you have a way of simplifying a problem so a dummy like me can understand it. Kind of like eating the elephant, one bite at a time.
Great info! Thank you for sharing.
I can see that you are a shoot out kind of guy. How about another cam shootout?
5.3L LS with these three Elgin cams, vs a GM LQ4, E-1838-P, E-1839-P, and E-1840-P.
Now I know this is difficult to do on the dyno, but would like to see the difference down low as well as up top.
Thanks again for providing great information for all of us.
Spot on information.. huge help to my future build
How does AR affect a compound setup? I realize those aren't super common on the gas engine side but for diesels they are super common. In the end I suppose it is still similar in that the more restrictive hot sides are more responsive but limit overall production which is probably why some guys go with large singles over compound setups to lower the backpressure.
when a test about oil pump and how much hp we can have when we "decompress" the block, how many hp can give oil pump sistem or exhaust sistem? also a question, if i boost an na engine, i should increase the oil pressure or i leave the same? when an oli pump upgrade have sense?
I'm thinking about back pressure against the back side of the in and ex valves and spring rate that would be needed at seat and lower lifts.
Does it not seem like maybe your wastegate could be undersized? You can see where the gate opens at 4700 (475) and 5100 (480) and they seem to not bypass as much exhaust flow as needed to keep a flat boost curve after wastegate opens. Just a thought.
Or is your correlation of backpressure to boost responsible for what I'm seeing in the boost curve with a rise in boost after the gate opens?
we have two gates-no problem with gates-its back pressure/boost changing the opening
@@richardholdener1727 thanks so much for your reply.
What effect would long-tube headers have if the turbo(s) were mounted on them instead of on shorter "turbo" headers?
not dramatic
Isn't that where looking at the compressor maps come into play? Figuring out the efficiency of the turbos at the power levels you're looking for. Now, obviously the compressor map isn't going to help you choose a hotside, but it's definitely needed when selecting what turbo to use for your power goals.
I'm in the process of selecting a turbo for a twin charging application on a 4.6 2v modular and it's looking like I'm going to need an s488 for the power levels I'm wanting at the boost levels I'll be looking for.
It will be feeding through an intercooled m122 supercharger. Most people when twincharging make the mistake of not selecting a big enough primary to support their goals at the boost level that the primary will be running at and then they get frustrated when they can't make the top end power they were expecting.
Maybe you could do a twincharging test to showcase how choosing the primary is so important in a twincharging compound boost setup.
the map is looking at a small thing--the general turbo size and max capacity is the big thing you look at first
We are the Borg ~ love the Star Trek TNG reference
welcome to the collective
@@richardholdener1727 I have been assimilated. And I love it.
Have you ever done a comparison of different hot-sides on the same turbo on the same motor?
Great videos, very informative!
I do love these tests. However, I do wish the comparisons were more apples to apples. In this case I would have liked to see an electronic boost control used because I think the top end difference would have been a lot less drastic. Just my opinion.
Dumb question but why do LS guys flock to Borg Warner turbos instead of another manufacturer like Garrett?
oH WHERE oH WHERE IS THE VS racing turbo with the Elgin -1840P cam ? Richard please 😁 great video anyway
Thanks Richard, what do you think about the variable vane turbos that Porsche is using in their cars that give great response in the lower rpm and fantastic power in the upper rpm range. Great video keep em coming.
What turbo would you recommend to provide 6 pounds boost on a 454 peanut port engine with an RV cam in my tow rig?
Running a 1.2 A/R on the S475 would be a useful comparison for impact on backpressure and response v power
Drive double boost seems really bad. Curious if you went to twin 75's how would the power compare? Also what if you went a way bigger AR? Could you make the same power with half the boost if you got the back pressure more close to 1-1?
If you changed your boost control, say to Dominator with co2,could you raise your lower rpm boost? Then maybe lower the pressure at higher rpm, so it doesn't built too much?
I'd like to see you compare a late 80's Ford 2.3 liter turbo engine (aka Mustang SVO) to the current 2.3 Ecoboost engine. 1st stock, then ported head, bigger (roller) cam, then finally with bigger turbo. With video please. Sounds good to me.
BTW, I'm sure we've crossed paths while I was at Travis back in the day.
I have a question I have a big block Chevy ho 502 Factory rating 450 horsepower 550 ft lb of torque I was looking at a 475 Turbo 78/75 with a Air1 .25 Hearthside I'm not after major horsepower I'm looking to increase the bottom in pulling under 4,500 RPM so I'm looking for a turbo that will come in somewhere surround I would say 18 to 2000 RPM increase the low-end torque of the big lock to help pull or for off-road applications truck is used as a daily driver toy mod off-road and towing vehicle would you recommend a s475 is the air 1.25 ok if not what do you recommend I'm only looking to make about 9 pounds 9 and a half pounds Max boost at any given time probably even more likely around 8 thank you for your time
that turbo will do what you want on that motor
If you’re drag racing in Florida and then move to Denver for a race, would you downsize the hot side of the turbo because of the higher elevation? I know racers have issues with spooling I’m thinner air and after watching this I was thinking that a smaller hot side would help speed up spooling, Do I misunderstand this? Thanks!
you need to worry about over speeding the turbo at high elevation
Awesome video! Got a video idea. Could you do a test on a centrifugal blower where you pulley way down to try and bring on boost harder and just use a watsegate to vent any extra boost up top? I always wondered if that would work. Would probably run into belt slip early but I'm not sure
it does work
You always talk about the right ring gap. What is the right ring gap for turbo or how do you find that out? I have a 5.3 ls engine wanting to run 600-800hp. 0.020- 0.025 is what I've come up with. Any help would be greatly appreciated
I run .007 per 1 inch of bore size
@@richardholdener1727 thanks for the quick response. I love your videos. Hope you and your family have a happy Thanksgiving
Richard. im gonna put a turbo on my stock 06 series 3 3800 v6. I just wanted to get your recomendation on what size turbo would be quick spooling and efficent on my stock series 3 3800'. im shooting for around 400hp at thr wheels or as close as I can get. this is a budget setup so Ive been looking at some of the ebay turbos as I plan on just having a littel fun with this setup then build a more serious engine build over the winter.
a GT35 size from ebay would be cheap and effective
Thanks for taking the time to answer my question I really appreciate it. I've used a gt35 before on a 4g63t but it was a much more of a track oriented build. And it worked great.
how do you set up a turbo system or possibly twins for low end towing power on an 8.1 chevrolet engine with 340 hp starting.
Thank you very much..... I kinda knew most of this before, but now I can see it in my mind. This was a big help............................thanks
I wonder if a smaller header and crossover pipe diameter on the hot side would help spool the s480 quicker? Or would it just raise the back pressure? Maybe that would be a good topic for another test.
I wish you would put the turbo specs!
Do you have the availability of showing different hot size piping on these? 2 vs 2.25 vs 2.5 and maybe 3 showing power difference and where they are in the curve and what happens to lower end boost.
doubt it will change anything
Good test and data. That said, it would have been so easy to also do a matched boost run for more data. A more complex effort but also interesting would be a matched backpressure test.
What motor was in the 1 lt 100hp pic? Was that a 3cyl sprint? Intrested in info on your tests on the little stuff, even a mototcycle or draw thro if you have done it. Got my turbo car goin again with a 355 and s475 with a fairly big cam and guess what, it rips up top nut no bottom end power haha just like how the cam is na
IT WAS A TURBO SPRINT-one of my favorite cars
Cool, how much power did you get out of it? 100 is good for those, would feel pretty fast i bet
How about a old 2.5 Chrysler with a turbo im looking to build one but no clue where to start
I have a 2.2 and 2.5 going up on the dyno soon
Richard like I said in my previous comment a big engine does not produce more 'back pressure' compared to a small engine at same HP level , yes the boost to back pressure will way more on the bigger motor but the actual back pressure should be close .
Can actually prove my theory if you go look at your VSracing turbo vs Borg, @ 6500 rpm the 4.8 produces about 20 psi of back pressure and makes 800 hp . In this video same turbo on the 6.0 its produces about 875hp @6500rpm and about 22-23 psi of back pressure. Yes the boost to back pressure ratio is way off on the bigger motor but it proved my point that back pressure( exhaust gas volume) is a function of HP not displacement.
Good stuff man great info as always I kno how to work on cars but dont kno everything you got real fill in the big gaps I have especially on turbo stuff
My gess is if you ran them at the same boost level the one with the least back pressure would make more power but only buy 5 or so hp.
Love the content. I have a question can you make 1000hp on 91 octane fuel only? You said you mixed 91 and higher octane mix. Is it even possible to run double atmospheres with 91octane only safely. Thanks keep up the great info and content
I HAVEN'T
Can you add the turbo ar specs to the description?
This is another super informative video. Thanks! I wonder though, when a different size engine (like 4.8 vs 6.0, like you were using as examples) makes the same power, isn’t the hot side flow the same? Lbs/min airflow in would have to equal lbs/min out, seems like. The little engine would take longer to get there, but the resulting flow should be the same-or not? Would pinning the waste gates closed with CO2 affect the way the boost comes in? Is there a solution using variable A/R, like a diesel turbo? Is there a way to get the back pressure curve you showed on the BBC with twin eBay turbos on the little LS? Inquiring minds...
I thought pound for pound flow was a good measure when looking for junk yard diesel turbos to use on a gas engine. I figured that my gas engine will run half the boost and double the rpm of the diesel so it all works out. But it turns out that it's not about matching mass flow but matching volume flow. So a 7.5L gas engine that turns to 5000rpm will need a turbo from a 15L diesel that turns to 2500rpm.
How does a small hot side with big cold side affect the HP and Tq curves compared to a big hot side with a small cold side?
I thoroughly enjoy your channel. You address all the crazy thoughts I have during the day while wrenching. Have you tried building a compound turbo setup for an LS? I'm an LS guy but run compounds on my cummins. It always seems to be in the powerband while towing. Just a thought and it would be cool to see a setup that holds 14 psi of boost from 3500 rpms. Keep up the great work.
I'm thinking of using a G42-1450 on a GM 525HP crate engine. 12psi from down low is the goal. Would love to get Richards take on this.
@@Dodgevair I was thinking the same turbo on a 408 stroker
I am deciding which turbo to order. I am seeing conflicting info everywhere. Turbo size and drivability being my concern. LC9 /799 heads with a stage 1 or 2 truck cam (all cams are turbo cams) . My issue I want to feel my turbo when I’m driving. Too big and I will never be in boost. Too small and I will run out of boost. @ Richard Holdener I know you are busy but could you please advise?
For the billet wheel, ball bearing, twin scroll testing, an engine dyno might not be the best way to test it. A brake dyno will make the results almost irrelevant. The only way it would be worth doing is if you could load the engine at an rpm lower than the boost threshold and have the the rpm/s at something wild like 1200 or 2k. I doubt the engine dyno you have can hold a v8 that low, it would be like 1500rpm, or have the rpm escalating that fast.
You might be able to do it with a really small engine to cut the torque at load in and a really big turbo. If you had something like a b16 and loaded it at 2500 and ran it out to 8500 it gives you a huge sweep and you can test boost response if you can have the rpm/s fast enough... The thing is as soon as the boost comes in and pounds the torque out, the dyno will slam the door to keep the engine acceleration consistent and make the torque spike worse, not better.
You almost need to test this with an inertial dyno, the brake fusses with turbos.
Or do it on the road with a data logger. You can always extrapolate HP from numbers.
@@DodgyBrothersEngineering Some people are building test sleds, just for that purpose.
I have a 6.0 lq4 4l80e.....862 heads btr stage3 truck cam 110lsa.what would be the best turbo for less back pressure and more boost down low. Thanks.
what power level
@@richardholdener1727 600hp with stock internals other than cam and springs
Thank you Mr. Holdener.
I'd like to see this same test done with twin turbo setups. And please explain to people that boost doesn't add between the two.
Hey Richard, thanks again for taking your time to make these aWESOME videos ! I tried the ebay turbos on a 355, make 1335, with a blow through carb(CSU) but after 30+ dyno pulls,the seal let go,(smokey as heck) but they made big power, have you had good luck with these turbos lasting /
Richard! What is AR an what's the difference between 1.00 ar and 1.25 ar ? Looking to do a rear mount turbo on ly6 street car. So power down low and mid rpm is more important.
Lots of info out there online, but basically put.. smaller AR is more restrictive and more responsive but can potentially limit power, larger AR is less restrictive and less responsive but can allow for more power on top end
@@jaredp551 thanks for the info!
Looking at doing the same but on a 08 ly6 2500 for towin ggv and stealth turbo
@@hondatech5000 thank you for your opinion!
@@joelstevensz06 going for the stealth turbo look myself, not looking on building a race car for the track. Just a fun street car, to surprise people on the street!
I'm assuming that the results we're on race fuel if so what we're the results on pump gas
e85