[SlowSix]

No this isn't a thread about my pipe dreams for my car (not yet atleast )
but this actually started from my friend and I discussing how to build his WRX (doing a hybrid 2.5 build if anyone knows anything about subarus).

Anyways, what is a good turbo to run on a stock block 3.8? How about a built 4.2?
But the real question is, how bad is the turbo lag? And how does it compare to something like a procharged car?

I have a friend with a big turbo evo that is hitting over 30 pounds. And the lag is pretty bad, the car goes nowhere then just hits you in the face with boost, and is hard to keep in boost when driving.
Are turbo v6s like this? Especially since I see guys running relatively large stuff, like 61mm turbos and such.

Just curious pretty much, and thinking about where I would like to go with my car.

[JTs03v6]

Originally Posted by 01SilverSixer No this isn't a thread about my pipe dreams for my car (not yet atleast ) but this actually started from my friend and I discussing how to build his WRX (doing a hybrid 2.5 build if anyone knows anything about subarus). Anyways, what is a good turbo to run on a stock block 3.8? How about a built 4.2? But the real question is, how bad is the turbo lag? And how does it compare to something like a procharged car? I have a friend with a big turbo evo that is hitting over 30 pounds. And the lag is pretty bad, the car goes nowhere then just hits you in the face with boost, and is hard to keep in boost when driving. Are turbo v6s like this? Especially since I see guys running relatively large stuff, like 61mm turbos and such. Just curious pretty much, and thinking about where I would like to go with my car.

A good turbo for a stock 3.8 would be something like a 5557,5857,gt30r, or a 6262. For a 4.2l I'd go with 6262, 6265, 6765, or a gt35r.

i'm running a 6262 .63 a/r on a 3.9l engine and it starts to spool around 2800rpm, full by 3500rpm.

As far as lag, if you go with a 57mm ex wheel or gt30r, it will spool instantlly on a 3.8l.

Dont have aby real data comparing my prochargr setup to the new turbo setup now. Both setups pull hard. I will say this though, pound for pound the turbo will out shine the blower. It took me 15psi and a cam to hit 400rwhp, where as the turbo would have hit 400rwhp on 15psi alone. So there is a parasitic drag with the blower.

[Green_6er]

also that evo had 4 exhaust ports and your car has 6. the more the exhaust, the faster it will spool (comparing the 2 with similar sized turbos)

[SlowSix]

I realize that green ^

I was just curious cuz I was looking at some of the dynographs on v6power and a lot of them didn't look like they were making full boost until almost 4000 rpm or higher.

[JTs03v6]

One thing to keep in mind though, you will spool faster on the street vs spooling on a dyno because of load. Your car is under more load on the street vs the rollers. Also keep in mind that when your on a dyno you dont just punch it from a dead stop. Ususlly you get it up to around 2-3000rpm before you go wot on the dyno because you have to dyno in a higher gear(3rd for auto or 4th for manuel)

Also exhaust housing plays a big part in spool up. For a street car t3.63 a/r. For mostlly track t3 .82 a/r for a stock 3.8l. I would not go with a t4 housing unless I were shooting for more than 500rwhp. This is my prefrence and i know some will disagree with that statement, but to each their own.

[SlowSix]

Yeah thats true about the dyno thing.

If I wanted something that spools up quickly like a GT30R would you be choking the turbo in higher rpms?

[ESG-642T]

Originally Posted by Green_6er also that evo had 4 exhaust ports and your car has 6. the more the exhaust, the faster it will spool (comparing the 2 with similar sized turbos)

Do you want me to tell you why this is wrong, or do you want to try and figure it out yourself?


Anyway, turbo lag beats not having a turbo... And a procharged car won't come anywhere close without more boost.


Also OP, I don't know where you live but a 61mm turbo isn't large... People around here daily drive 70s and a few crazies DD 80s (supra guys and the crazy crowd in the 85mph buicks)

[SlowSix]

Originally Posted by ESG-642T Do you want me to tell you why this is wrong, or do you want to try and figure it out yourself? Anyway, turbo lag beats not having a turbo... And a procharged car won't come anywhere close without more boost. Also OP, I don't know where you live but a 61mm turbo isn't large... People around here daily drive 70s and a few crazies DD 80s (supra guys and the crazy crowd in the 85mph buicks)

I live in the Pittsburgh PA, Area...we don't see supras around here haha.
There is an 03 cobra with a 76mm. Anything else you will only see at the strip.

[JTs03v6]

Your not going to choke on the top end with a gt30r and stock 3.8l. I'd go with a .82 t3 and you should be good for more than the stock engine can handle.

As far as spool, if you throw a gt30r on your car, you are gonna spool that sucker hard. I'd guess full around 28-3000rpm if not sooner.

[Green_6er]

Originally Posted by ESG-642T Do you want me to tell you why this is wrong, or do you want to try and figure it out yourself?

enlighten me lol. I just thought that it made sense.

[JTs03v6]

displacement, headflow, c/r, etc...

4.2l v6 vs 4.6l v8...They could both spool a 60mm turbo around 2800rpm. On my 3.9l I can spool my 62mm wheel at 2800rpm.

[SlowSix]

Originally Posted by JTs03v6 Your not going to choke on the top end with a gt30r and stock 3.8l. I'd go with a .82 t3 and you should be good for more than the stock engine can handle. As far as spool, if you throw a gt30r on your car, you are gonna spool that sucker hard. I'd guess full around 28-3000rpm if not sooner.

Thats what I like to hear!!!