FWD-TT Is it possible to...

[Jason61991]

I want to know if it is possible for a car to have a small turbo and a larger one, instead of two being the same size.

If anybody has done this.... does it work?

[Ominous]

I can tell you that people here have done it, however I'll let others (look: more knowledgeable) elaborate.

[Hannibalzero]

Yes, it is possible to run mismatched turbos. If you are using the traditional manifold setup (ie. front bank feeds front turbo, rear feeds rear), then you won't want to get too big of a difference. But a smaller difference (ie. 13G & 9B, or 15G & 13G) shouldn't be a problem.

[Kibwe Walker]

no problem as long as you are using the same turbines on each turbo (compressor doesn't really matter).

If you mismatch the turbines you will have different amounts of backpressure on each bank (front/rear), and let your mind play with that scenario at 6k rpms with give or take a few from 15 psi. You are basically playing musical chairs with your bearings and rods and sooner or later the music will stop and something is going to be left out .

Why do this anyways?

Just save up a bit longer and get a twin setup if the same turbo as there is no real benefit to mismatching on our cars since our setup is NOT sequential.

[cbehnken]

meh, manifold is so different front to rear that running mismatched turbos really doesn't change that much.

When possible run the turbo with the bigger turbine on the front bank because it is the worse header and your backpressure will get closer to even.

That said I am running a DR650 on the rear and a 13G with stock turbine on the front.

No problems thus far and the engine is as smooth as ever.

I have nearly the spool of 13Gs with a lot of the top end of the DR650s. Eventually I may swap out the front for something closer like a 13T with the L turbine, but I am in no hurry and I like this setup.

BTW, the track numbers were pre DR650, hopefully in the next few weeks I will get to run again and see if it made any difference.

[Jason61991]

Thanks all.
So there is no benefit from mismatching turbos?

[cbehnken]

Originally Posted by Jason61991

Thanks all.
So there is no benefit from mismatching turbos?

of course there is some benefit. Basically you have averaged the max power you can make between the two sizes and done the same thing for the lag.

Usually with relatively small turbos it doesn't make a big difference. Really the only reason I have this setup is I want more power than the 13Gs can supply and I got this DR650 cheap.

Also, I have a good upgrade path. 13T/15G/DR650 are all close enough that I can upgrade the front one when I move to bigger fuel and start using meth injection.

[Kibwe Walker]

If you are worried about spool time and power get the 13t's as their bang for your buck is unrivaled. With them you get 13g spool numbers with 15g power for about a 1k for the set.

If you want more power than that (450ish to the wheels on race gas), then move up to dr650's or 19t's or just save and go tdo5 or larger.

[Hannibalzero]

Originally Posted by Kibwe Walker

If you are worried about spool time and power get the 13t's as their bang for your buck is unrivaled. With them you get 13g spool numbers with 15g power for about a 1k for the set.

If you want more power than that (450ish to the wheels on race gas), then move up to dr650's or 19t's or just save and go tdo5 or larger.

That pretty much sums it up. I don't see any point of buying mismatched turbos unless you get an unbeatable deal on each turbo. As cheap and well-performing as 13Ts are, you might as well just get a set of those.

[cbehnken]

Originally Posted by Hannibalzero

That pretty much sums it up. I don't see any point of buying mismatched turbos unless you get an unbeatable deal on each turbo. As cheap and well-performing as 13Ts are, you might as well just get a set of those.

how's $300 on a good DR650