Staggered turbo setup? lag reduction?

[AutostradaVR4]

I got to thinking last night about turbo upgrades, but with 2 different size turbos instead of the same size. Ill keep a 9b, maybe have it clipped or something, and replace the other with a big td05. The 9b will spool quickly to reduce lag and the td05 will hold more boost to redline.

Is this even possible with the way our cars are setup? with the turbos in parallel? I know there are other vehicles that use such setups, but it seems like having more backpressure in one bank might lead to problems, so i assumed the turbos were in series rather than how they are on our cars.

if it is possible on a 3/s, has it been done? What turbos do you think would yield the best results? and is there more room in the front or rear stock turbo location for the larger turbo?

EDIT: one more thing. is there a better small turbo to use than a 9b?

[Ralliart 3000gt]

I always though both our turbo's spoiled at the same time in apposed to that of the supra which which is suquential and has one small turbo spoil then the larger one spoil at higher RPM's

[AutostradaVR4]

Originally Posted by Ralliart 3000gt

I always though both our turbo's spoiled at the same time

they do. i was just wondering about seting up ones that dont, if its been done on a 3/s, and if can be done on a 3/s w/o causing problems.

[Igovert500]

This has been covered multiple times on 3si, so if you do a search you can find alot of good info. While there are people who are running two different sized turbos, AFAIK, they are pretty similar in size. ie, a 9b and a 13/15G or something like that. Nothing as drastic as a 9b and a td05. As you mentioned, our turbos are in a parallel setup, not sequential. So you can't really have the one spooling the other (without some crazy piping). Basically, I think you would have some serious issues with the 2 banks running so completely different. I mean one would be always spooling and have td04 housing, and then one would be running off a td05 and headers or adapter plates...I just think it would cause issues.

If you are really worried about spooling downlow with big td05s, do the supporting mods, and then toss in a small wetshot down low to get them spooling. I think it would be a hell of alot easier and less problematic. my .02

[Linebckr49]

i agree with everything Igovert said.

only thing i have to add is that for a general rule of thumb (and i'm pulling this one out of my ass opcorn, if you want a different sized twin turbo setup, stick with the same sized housings. i.e. 9b & 13g/15g/dr650r (both td04) or 14b & 16g (both td05) OR for those crazy enough...a local 3s guy in Ft. Worth...18g & 20g (td05...but both very huge...come to think of it, 20g comes in td05 and td06 sizes, but i'm pretty sure he's only got the td05 size since his headers are the same.)

[AutostradaVR4]

some good info guys. thanks, I will do a search over on 3si like you said.

I was thinking of a drastic size difference mainly because i would imagine there isnt any real spool time difference between say a 9b and a 13g. but if you think it would likely cause problems with one bank having more backpressure or w/e, ill probably end up sticking with 15gs, just only get one turbo, throw that on the front bank, and if i dont really notice anything spectacular, get the 2nd 15g.

now all i need as a few thou'... $$$$$$

[Igovert500]

Seriously, if you are short on cash, get 15Gs or 13Ts. If you shop around, you could get a set of either for under a grand. The cheapest route of supporting mods could also be found for another grand if you are really hurting on money.