Compound Turbocharging

[DrifterProdigy85]

I was on Supraforums and started looking at this and its insane on the spool you can get with a big turbo. Makes lag like non existant. Below are pics of how the setup is done. The dyno graph is of a non turbo 2jz, the 2jz with a 76mm, and the 2jz with the SC50 and 76mm. Its insane how much faster the tq is being made.

[Emperor_Tha]

also known as staged turbo.

I always wanted to do it with my t28+t25 combo but I have no welding skills. Plus to get one customized cost a arm and a leg.

[DrifterProdigy85]

I really wanna do this using a 2871R and my 67mm. I think id make full boost around 4krpm.

[jbracy7]

isnt that just a twin turbo setup

[DrifterProdigy85]

Twin Turbo would be where the turbos run on seperate exhaust runners and merge the boost together. This setup is totally different. The little turbo actually spools up, pulling air from the big turbo making that spool faster.

[jr_ss]

I would think it would work better if the small turbo's compressor outlet went to the larger turbo's inlet... Rather than having it split and take 3 runners to boost the small one and 3 to boost the large one. Although, the small turbo may end up as a restriction for the larger turbo in the end result, not allowing it to flow enough air for the large turbo to breath efficiently.

However, I believe this would only work on a larger displacement and more than 4 cyl engine. I think it's a waste to do such a thing on a 4cyl engine, it would take significantly more time to spool than it's worth and would work better on the larger engines.

[jbracy7]

that sounds like a lot of plumbing for 70-65lb-ft 1000rpm sooner

[DrifterProdigy85]

You guys arent looking at how this works. The engine spools the small turbo. As the small turbo spools it creates the airflow to the engine which turns into exhaust. The more airflow the engine sees, the more exhaust its letting out. This extra exhaust flow is whats going through the small turbo and spooling the big turbo. Its making the big turbo spool up nearly the same as the small turbo giving you a huge jump in tq.

So just an off the wall example, I take my T67 and use a 2871R as the small turbo. As the 2871R spools, its providing the engine with the airflow needed to create enough exhaust flow to spool the T67 along with it. So i could essentially have the T67 spooled up @ 4krpm or so. I made 380tq @ 6krpm before where i could make 380tq @ 4krpm with the compound. Now for a street car on 93 octane, that would make for one hell of a powerband.

[spanishricer]

You already know my opinion on this silliness.

Just get rid of the T67 and buy a better turbo.

[DrifterProdigy85]

its not silliness, your just too ignorant to open your mind to it.

[jr_ss]

This is silliness on a 4cyl...

Besides, that picture with the intake piping is all wrong. Why would you feed the smaller turbo's compressor housing, with the larger turbo's compressor housing? That's just retarded, it should be the other way around.

[DrifterProdigy85]

Engine size doesnt make a difference except for what turbo sizes you need to run. Your trying to look at it as the compressor is spooling the turbo. It doesnt work that way. This isnt a supercharger. Turbo needs exhaust velocity. Spooling up the small turbo gets the engines exhaust velocity high enough at lower rpm to spool the big turbo. The intake pipe is setup like that so the discharge of the big turbo goes into the small turbo and is pushed out into the engine. The small turbo is considered the High Pressure Turbo since its being forced air instead of trying to pull it.

http://www.youtube.com/watch?v...edded

[spanishricer]

its not silliness, your just too ignorant to open your mind to it.

No, it's silly because...

A) It's not cost efficient.

B) You're basing your theoretical gains to a 2.0 4-cyl motor on the numbers put down from a 3.0L inline-6. There should be small print at the bottom of the dyno plot that states, " Results may vary."

C) One year from now, you still won't have a compounded turbo setup underneath your hood, and in all likelihood, will have forgotten about it entirely.

[DrifterProdigy85]

If you dont think it works then just stop posting. Your wasting time in my thread. So far ive only posted up the reasons why it does work and you just come on here saying it wont ever be done. If it doesnt get done by me, it will be done by someone else. So many people were skeptical of the twin scroll s*** when that came out and now everyone thinks its the best thing since sliced bread. You just dont believe it cause it hasnt been done. Take your negativity and waste some posts elsewhere. At least im trying to show everyone what new ideas are out there.

[DrifterProdigy85]

Everyone understand the Supra is using a 950hp rated turbo and getting it to hit full at 4krpm. Thats super impressive for a 3.0L Engine. Theres no doubt in my mind that you can take a 700hp turbo and do the exact same thing on a 2.0L. You just have to match up your turbo sizes to run effeciently with each other. At least make an account on Supraforums.com and read there thread in the Dyno Tuning section before being so skeptical.
Modified by DrifterProdigy85 at 10:58 PM 6/7/2009

[boro drift]

I think compound turbocharging is a great idea. With the the right turbos, it will work on any engine. The compressors need to be matched carefully, or the secondary turbo can blow the compressor off the primary turbo,(I mean clear off!!).

[V8slayr]

Not sure why everbody's hating, but it sounds like a badass setup to me. I don't fully understand exactly what is going on w/ all the piping but it seems like it would work very well. I would be interested to see what would happen on a 4 cylinder. What confuses me is that the big turbo compressor discharge feeds to the small turbo's intake. I can't see how the big turbo wouldn't overwork the smaller one. But also, there is a wastegate between the big and small turbo and i'd imagine that when that wastegate opens it relieves alot of the pressure from the smaller one and at that point the big turbo is doing most/all of the work. Anyway, it is a hell of a setup and I'd like to see if somebody has the balls to try it on a SR

[wrxratd]

Lots of haterade in this thread. Try some of those same repsonses in a diesel forum where compound turbocharging is used ALOT with great success and you'll get educated in a helluva hurry. How does 150psi on a cummins sound? Yeah, it's like that. This one IS set up right. Outlet of primary feeds inlet of the secondary. Why is it setup like that? I'm not sure truth be told, but as most of you guru's say, SEARCH NOOB. It's on wiki or google somewhere i'm sure. Compound turbocharging is no "dumber" than turbocharging in the first place. Whats so stupid about turbocharging a turbocharger? The only thing better than lots of power is more power than that even sooner. And that's exactly what you get with this. The wastegate for the larger turbo is straight underneath it, but on a diesel, they usually don't even use a wastegate for the larger turbo. It's called a free-floating turbine and they just let it buck as they usually use a turbo so large that it'll never over spin. There are downfalls to this setup however, being: cost, complexity, weight, added underhood heat. But honestly, anybody that ISN'T impressed by this, please, explain WHY!?!?!?!

[Emperor_Tha]

Would make more sense if it had two intake piping instead of the outlet pipe going to the second turbo inlet.

[jr_ss]

Engine size doesnt make a difference except for what turbo sizes you need to run. Your trying to look at it as the compressor is spooling the turbo. It doesnt work that way. This isnt a supercharger. Turbo needs exhaust velocity. Spooling up the small turbo gets the engines exhaust velocity high enough at lower rpm to spool the big turbo. The intake pipe is setup like that so the discharge of the big turbo goes into the small turbo and is pushed out into the engine. The small turbo is considered the High Pressure Turbo since its being forced air instead of trying to pull it.

http://www.youtube.com/watch?v...edded

Regaurdless of my opinion, it is interesting. I don't foresee it happening on an SR anytime soon, let alone in an S-chassis, simply because there isn't any room there, not to mention our engines just can't handle huge power unless built to the max with the best parts money can buy. And lets face it, the majority of 240 owners aren't wiping their asses with 100's, let alone 20's. This definitely isn't something for a street car. But perhaps it will be done. I just don't see the point of wasting the time, effort, and money to spool a large turbo 1-1.5k rpms sooner.

[jbracy7]

wouldnt better tuning and a better turbo net the same results

[DrifterProdigy85]

wouldnt better tuning and a better turbo net the same results

Not really cause it depends on how much power your after. I want close to 700hp when im all done so it takes a big turbo to get that. Only way to make it spool faster than it does now is by spraying nitrous, putting it on a larger engine, or doing this compound setup. Being i dont wanna fill bottles and i already have an SR built by Mazworx, the compound setup would be the way to go to have alot of fun. It should give a huge jump in tq than before since the 67mm will be making way more boost at earlier rpm. How much tq is really gonna depend on the cam setup too.

[wrxratd]

Would make more sense if it had two intake piping instead of the outlet pipe going to the second turbo inlet.

No, because then you wouldn't get the compounded boost that is created with this setup, and the larger one would back-spool the smaller one and it would run like crap, if it ran at all on boost. Trust me, it's right. Or don't trust me and do some research, you will find however that it's right, and if you want big power with less lag, it's either this or a vnt setup, which can be just as complex to make it work right.

[jbracy7]

ok how about the kkk-turbo that opens and closes the inlet of the turbo for faster spool,more power sooner

[hugogos22]

I dont really post much any more but this thread caught my eye. You dont really need to have a large frame turbo like a 40R or 42R to make 700HP. You should take a look at billet turbos turbo like the PTE 6765 that have made 820 AWHP on 4G63. The PTE 6262 has made 780 AWHP. These turbos are the same size as my old 35R and have made that power on a T3 Flange. These turbos spool like a 35R but make the power of a 42R. Why worry about a 1000RPM of spool? If you drag race get a stand alone and launch on a two step. If you like to roll race on the street down shift and brake boost.

[cody180sx]

edit: for post 240

AMS was working on this kind of set up on there castrol syntec challenge but didn't have time to prefect it about mid-video you can see it http://www.amsperformance.com/top_shop.php

[DrifterProdigy85]

I dont really post much any more but this thread caught my eye. You dont really need to have a large frame turbo like a 40R or 42R to make 700HP. You should take a look at billet turbos turbo like the PTE 6765 that have made 820 AWHP on 4G63. The PTE 6262 has made 780 AWHP. These turbos are the same size as my old 35R and have made that power on a T3 Flange. These turbos spool like a 35R but make the power of a 42R. Why worry about a 1000RPM of spool? If you drag race get a stand alone and launch on a two step. If you like to roll race on the street down shift and brake boost.

Power comes from the flow rate of the turbo. For 700+hp, you need something that flows 70+ lbs/min. AWD dyno numbers are always horribly inflated. Real numbers lye in there mph at the track which i hardly ever see matching numbers for an AWD car. The EVO and STI are the only cars ive ever seen put down 700+awhp on a GT35R. The turbo only flows 62 lbs/min or something. Everybody else barely gets over 600-650whp with them. And thats with 2 wheels. Graph out the compressor map and you'll see how unrealistic 700whp is on one. Expecially with AWD. 700awhp is like 800rwhp. Its way too unbelievable. I have a 2 step for drag racing it launches pretty hard doing that but lets say you wanna go from a roll @ 45mph. That would put me in 2nd gear at around 4k-4500rpm which even brake boosting doesnt build but maybe 8-10psi at that point. Brake boosting only works if your in the turbos powerband.

[hugogos22]

This is Damiens Civic on PTE 6765 Ran a 9.7 at 156MPH. check post #48http://www.honda-tech.com/show...age=2

this is mike from awd performance in south fl ran 8.98 @ 156mph 784 hp

http://www.youtube.com/watch?v=xuT3P5Sb2us

[hugogos22]

In terms of doing roll races. You need to know your car. I only do 60MPH rolls or 25MPH rolls. This places my RPM on around 6500RPM give or take a couple hundread rpm. Compund boost works on many applications but i dont see it being worhwhile on a 2.0 or 2.2. To have 700rwhp and spool at 4500rpm will be quite a accomplishment.

[jbracy7]

i had problems keeping my 340whp from stepping out on me even in second to third it still got sideways on me 700hp sounds a bit crazy to me