adrynalinjunkie

iTrader: (4)

That about sums it up I am trying to decide on twin 62mm Turbonetics or a single GT-91 for my forged 370 with a custom eps turbo cam and a 3400 stall ptc converter.

I am looking for 750 rwhp on 92 pump with meth on the street and 8.5xs at the track.

The main goal is avoiding lag and maximum fun on the street. This will be in a 2900# chevelle with 3.55 gears`and a MVB TH 400 and steam roller et streets.

03supercobra

iTrader: (38)

A 91 is way overkill for 750rwhp. Id stick with the twin 62s for that kinda hp and no lag.

Grr

iTrader: (2)

GT-76 would be enough turbo for that HP

Fbodyjunkie06

iTrader: (10)

750rwhp also won't get him 8.5's at the track either. I think what he is saying is he wants to be able to drive it on the street on pump and then turn the wick up to run 8.5's at the track.

71 chevy

iTrader: (18)

at 2900 lbs 750 whp will get him to 8.5

Nitroused383

iTrader: (10)

I think guys like LS1Curt, Los and Automagic need to chime in here. They both run a decent sized turbo quite a bit on the street. So with the correct converter is there really much lag? I really think a genuine Garrett GT 4788 will be the fastest spooling unit around. The GT47 wheel will out spool the TV series turbine wheel used in the PT88 and GT 88 / 91.

00ultraz28

iTrader: (2)

you can make more power than that on less turbo with less lag .... less weight is less load on the motor also .... You could make more power than that with a s 400 80

TheLS1Lover

Might Mouse runs a T4 91mm and has made quite a bit of HP, I'm pretty sure they have the PT88 exhaust wheel so it should spool pretty good while maintaining a good hp level.

Fbodyjunkie06

iTrader: (10)

True wasn't really thinking about that just the hp number. Gonna need a good short time still. It is doable at that weight though.

mike13

iTrader: (27)

If like you say main goal is avoiding lag I would go with a smaller turbo then a 91. Someone like Jose @ forced inductions can help you pick a turbo that will give you what your looking for. He has some borg warner turbo combinations that will fit you like a glove.

adrynalinjunkie

iTrader: (4)

Yep that's what I am saying. Like I say max fun with least lag on the street. I really don;t want more than 800 rwhp on the street because I doubt I could hook it even with steam rollers.

Don't get me wrong though I am looking at building the fuel system E98 compatible with a cable driven pump. So I can get that 1000 rwhp dyno slip and run 8.50s with ease.

But the main focus is fun on the street and LOTS of street driving.
I will call Jose at Forced Inductions on Monday.

***It would be great to hear from guys that run autos with good stalls on the street about lag and if lag will even be a issue with the right stall and cam?

mike13

iTrader: (27)

Here's the issue, a turbo that works good at 750rwhp and has little to no lag on the street isn't going to get you 1000rwhp. Same with the torque converter. I would focus on a turbo and converter combination that gets you 750rwhp-850rwhp.

From experience no lag will not be a problem especially with the right converter, the converter makes or breaks the combination.

Fbodyjunkie06

iTrader: (10)

Cconverter, rear gear, cam, timing and air fuel ratio will all help or hurt spool time.

manueltarin

iTrader: (6)

I run a 91mm with 3.23 gears and have almost no lag. It's on a 408 though and 3600 yank.

adrynalinjunkie

iTrader: (4)

Thanks bro that is exactly the type of info I am looking for.

Anybody else run a Auto with a good stall and a big turbo notice lag on the street?

Fbodyjunkie06

iTrader: (10)

Ask mightymouse....or 98z28cobrakiller or his buddy LS2formula. They have extensive experience with big turbo(s) on the street.