Benefits of twin turbo over single

**grandkodiak** · 05-10-2006, 02:36 PM

New to the turbo game... wondering about dual turbo setups... do people do it just to double thier psi? or does it not work that way? like could you run twin rear mounts off the ypipe both at 5psi and see any difference over a single at 5psi?

**ProwlerZ** · 05-10-2006, 03:14 PM

I'm not the best person to try to explain forced induction, but I do know that twin rear mounts (STS) don't work. There simply isn't enough pressure running through a split system, be it duals or an inversed Y-pipe, to generate the proper spooling. I'm sure someone will jump in with a more technical description, but simply put, if you want to run a turbo system, have a twin system fabricated to run under the hood. It'll be costly, near 7k, but you'll never regret it.

**grandkodiak** · 05-11-2006, 11:27 AM

Well on using twins as a whole to bein with... how is it better then 1? i can only see it as each turbo only get half the total pressure, so i dont see how its better then running a single turbo... just dont see the mechanics behind it... thought someone could point out what i'm missing

**HSVFREAK** · 05-11-2006, 07:00 PM

Im no forced induction expert but have currently have twin turbo's on my ls1. Im making 531rwhp of a stock motor,With the addition of valve springs. I have a iron block 402cid going in the next few months. Im expecting 800+horsepower at the wheels. Here in oz we are yet to see that of a single turbo setup

**oneBADDz** · 05-11-2006, 07:05 PM

The ideal twin turbo setup is a large turbo and a small turbo. The benefit over a single turbo is that you can have a small turbo that spools quickly to help you down low, then the larger turbo to push more boost and help make major power up top. Simply put you get a quick spooling turbo so that you don't have lag, and a large turbo for big power rather than having to compromise with one or the other

**grandkodiak** · 05-11-2006, 07:19 PM

How does that set up though? i'm guessing both are on the single part of the ypipe in parallel with a switch? or do they work in series and push each other?

id really appreciate if people could post up pictutures of thier turbo setups, far easier for me to disect a picture then keep askin silly questions

**oneBADDz** · 05-11-2006, 07:26 PM

one off of each side

**Hi-Po** · 05-11-2006, 07:30 PM

OMG thats beautiful.

**oneBADDz** · 05-11-2006, 07:37 PM

Originally Posted by Hi-Po

OMG thats beautiful.

lol, I bet you know what that it

**myk02k** · 05-11-2006, 07:54 PM

Im also no turbo expert, but from my experiences in the F-body meetings, the reason why you can only find a bolt-on turbo at the rear is because of clearance issues. Having a remote turbo set-up is supposively suppose to prevent the turbine from heating/overheating. If you do decide to go with a twin-turbo set-up I'm almost sure you will need them mounted almost over the motor and get a cowl hood for it to fit. That should also aid in cooling. The only name I've heard that creates a twin-turbo system for the LS1's is Incon, although I can't seem to find the exact product with pictures online.

**oneBADDz** · 05-11-2006, 08:03 PM

LS1 GTO

**myk02k** · 05-11-2006, 08:06 PM

C5 Z06 LS6 with the Incon Twin-Turbo
http://www.turbochargedpower.com/Movies/ttvette.wmv

The Incon Twin-Turbo kit on an LS1 is advertised to produce 700 HP. Good luck on preventative maitenence with that one.

**Reggie West** · 05-12-2006, 06:05 PM

Twin turbos can be used for a street car or a race car.

Some companies use twins on cars with very little space in the engine compartment.

On race set ups twins work better because you are in the power band much faster and there is less lag with two smaller twins flowing the same amount of air as opposed to one big one.

Turbos will work just fine under the hood. You cant melt one or anything like that.

As far as turbos go, you want airflow instead of boost. Pressure is resistance to flow nothing more.

You can put down major power with either twins or a single it just depends on what you are trying to build and how much horsepower you want to make.

For the street a single kit works just fine.

For a race car on the strip you can go to twins just as well.

Hope that helps. Looke at NASTY TA's thread on here for his car. That is one of the nicest single set ups I have seen.

**grandkodiak** · 05-12-2006, 08:16 PM

I'm more interested in the technical aspects, but thank you for the post

**ericwilloughby** · 05-13-2006, 02:53 AM

Originally Posted by grandkodiak

New to the turbo game... wondering about dual turbo setups... do people do it just to double thier psi? or does it not work that way? like could you run twin rear mounts off the ypipe both at 5psi and see any difference over a single at 5psi?

Double PSI? No. Pressure is not an issue. The more boost-psi the more airflow, yes. But you can get 20psi out of most any turbo. Unless it's really small and the engine big.
The only REAL, Major I mean, differance is the logistics of the install and efficiency. I.E. Do you have two pipes, banks of cyl. Or 1 big pipe at the rear. Close to the engine is more efficient. because of the extreme heat close to the engine, the exhaust flows, pushes the turbine faster-harder. On a rear mount, STS, you loose so much heat by the time it gets back there you need both pipes to push 1 turbo to do the job.

I'd guess there is a significant lose of efficience on the STS. But it's cheap and easy to install. Anybody care to guess how much HP differance there would be on a STS vs. a twin under hood system. Everything else being the same?

**ericwilloughby** · 05-13-2006, 03:11 AM

Originally Posted by grandkodiak

How does that set up though? i'm guessing both are on the single part of the ypipe in parallel with a switch? or do they work in series and push each other?

id really appreciate if people could post up pictutures of thier turbo setups, far easier for me to disect a picture then keep askin silly questions

Parallel, always. No switch or electricity is needed. Just spring and diaphram for pressure control.

http://auto.howstuffworks.com/turbo.htm

**grandkodiak** · 05-13-2006, 07:05 AM

Sure I see all that, but I'm wondering how a sequencial setup is mounted... especially on a v8 being...

so two small turbos on an lt1 would be better at the same psi then 1 larger turbo because they would spool quicke, even though each is only getting half the amount of exhuast pressure then if you were running 1 off of all 8 cylinders? what is the optimum size for a dual and single on an lt1?

**oneBADDz** · 05-13-2006, 08:49 AM

Originally Posted by grandkodiak

Sure I see all that, but I'm wondering how a sequencial setup is mounted... especially on a v8 being...

so two small turbos on an lt1 would be better at the same psi then 1 larger turbo because they would spool quicke, even though each is only getting half the amount of exhuast pressure then if you were running 1 off of all 8 cylinders? what is the optimum size for a dual and single on an lt1?

the sts is the only time you run 1 turbo off of both pipes. It spools as fast as many smaller front mounts because it has both banks pushing it. Any trade-off for mounting it at the rear is more than made up by the fact that both banks are pushing it. Skeptics think that mounting in the rear causes lag because of the distance traveled, but it spools faster thanks to both banks which makes up for the distance

**ericwilloughby** · 05-13-2006, 07:03 PM

Originally Posted by grandkodiak

Sure I see all that, but I'm wondering how a sequencial setup is mounted... especially on a v8 being...

so two small turbos on an lt1 would be better at the same psi then 1 larger turbo because they would spool quicke, even though each is only getting half the amount of exhuast pressure then if you were running 1 off of all 8 cylinders? what is the optimum size for a dual and single on an lt1?

Sequencial. There is no such thing. I heard of it on one production car about 20 years ago.

2 vs 1 turbo is impossible to determine which is better. The only dif would be how much energy it takes to drive one large turbine compared to two smaller ones. Who cares. It's mostly free power anyway. Lag is a non issue now days. Especially with variable nozzle tech.

The exhaust scroll is matched to how much you will be running through it. CID. 1 bank or 2. Engine mount or rear. The STS is a larger turbine because is has much slower exhaust gasses going through it.

As I said the BIG OVER WHELMING factor is the ease of installation.

**99TAWS6** · 05-15-2006, 09:04 AM

In the old days when turbos were pretty laggy the twins would have even more advantages.You can and could run smaller turbos which would spool up faster than big singles.
The main think here still applies.The power is not so much boost as airflow.More airflow usually means more potential power. So 60 pound single turbo might give a 650 hp potential where two 50 pound singles could give doube the hp potential and it is because of flow not boost. Boost is mostly relevent when you are talking the same turbo at different boost levels as airflow will increase as boost goes up to the point where you get more too much hot air and the efficiency of the turbo drops off.

Practical example..I can run my stock 14b talon turbo at 20 psi.It will make more power at 20psi than 10 if can keep the charge to the tb cool enough not to get problems excessive intake temps. I could try to run it past 20psi but not a lot happens past 22 or so ,For more power past 22 then time to get a bigger turbo with more airflo potential. Like my new one..It flows 65 pounds compared to factory think 30pounds or so. Huge difference in power potential.The new turbo at 15 will likley be more powerful than the stock one at 22psi.And the new turbo is efficient to over 30psi also.

The twins I have ordered are supposed to be able to do over 1000rwhp potential.
That would take one big single turbo to get to the same power level and it would still likely have a lot more lag.

The other advantages to twins are the sound.twice as loud as single usually..and I like turbo sounds!! They look interesting and I love the words "twin turbo" just sounds like powerful to me. You can hear a twin car on the dyno on www.gmrspeed.com site.
It does increase cost of the system ,you need two wastegates,two turbos.