Is anyone running a full T4 turbo with a vband clamp. I am curious if the stock downpipe can be chopped and weld a v band onto it. Will a full T4 fit under the stock intake manifold? Is it worth going for the dual ball bearing? Also, what is the difference between the GT spec turbos and the standard garrett ones?

Thanks,

Andrew Wojteczko

 

Hi Andrew,
Tong G is running one but I think
it'll be too laggy for street use.

 

You could weld a v-band to the stock downpipe.The problem is the back of the t-4 housing is 3" and the stock downpipe is only 2.5" so basically it wont work.

The t-4 is not too laggy if it is set up right. The t-4 can also make way more power per psi of boost then the KKK hybrids.

 

Hmmmm….sounds familiar Tim….!
Tim is setting up some GT35s for installation in my 16v 3.1 liter and 16v 2.6 liter projects.
Now if I can just get the pistons out of JE….

Chris White

 

yeah, yeah rub it in. I think that next year I am dumping the T04 and going to a Garrett. How is the GT25, Tim? I am assuming that one would need a custom manifold and DP? Can you still make the "old" manifold instead of the bullett looking thing?
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

 

Today i went to my friends shop, he sells turbos and rebuilds them.

he showed me the GT30R what a turbo. i want it ,anybody have $1400 to lend me.

 

Why not use a T3 housing
instead. It may not flow like
a T4 but from what I heard,
it will outflow the KKK anytime
with less lag too.

 

I plan on also going to the GT30R. That is a badass turbo.

 

Excuse my turbo ignorance, but if you keep your turbo in its efficiency zones, such as the small one for the 60-1 HIFI say 15-20psi at around 74%, then the better model turbos give you a bigger efficiency range, but if you are not boosting outside of this range, why go there? CFM?

 

No you have the right idea. Assuming the turbos you are comparing have the ability to flow enough air for your engine, (most will) then CFM is pretty irrelevant. The CFM is determined by the engine configuration, not the turbo. At a given boost, a GT30 is not going to flow more any more CFM than a 60-1 on an mildly modded 951. Efficiency is the main variable for the compressor, although the same is not true for the turbine. Increasing the turbine size will add Peak HP at the cost of higher RPM Boost threshold. The trick with turbine sizing is to just get into full boost at the beginning of your powerband.

 

im going with a hks gt3037s

 

Need some more help,
I have some concerns with one of the formulas i am using to calculate my mass flow rates for using compressor maps,
it reads MF = density * Displacement * RPM / (2*Volumetric Efficiency)
My concern is that in this formula as Ve decreases, Mass flow increases, this doesn't seem correct does it? This formula is from Sport Compact Car 2003.
Also, another concern I have is what value to use for VE, changing between 65 and 80 seems to change what is the ideal turbo.

I have found a company offering a GT35 for $775 with either a T3 or T4 turbine, they are calling this the Blowzilla for some reason. The GT35 compressor seems to match most of my data, but how do you chose T3 or T4, there seems to be little info on interpreting turbine maps. Please help.

thanks again,

Andrew Wojteczko

 

Andrew-

What I have been doing is calculating Volume flow instead of mass flow, then converting to mass flow:

If you get the CFM, you can then adapt the numbers to Mass flow of lb/min. Be sure to factor the turbo efficiency into your calculations. The Volume flow to mass flow only works at standard temperature and pressure. You must correct using the ideal gas law. If you dont want to be that accurate, you can convert volume flow to mass flow like this:

lb/min = CFM x .0756

This assumes you are at STP.

BTW, are you talking about www.cheapturbos.com ? This is where I have been browsing around.

 

Also, here are the VE's I have been playing around with:

3" exhaust all the way, MAP style intake, this is also assuming a larger turbine housing than the #6 (this being a major VE factor) Ported and Polished head, and a decent valve job.

These are estimates, so Keep the flaming to a minimum

3000=.70
3500=.75
4000=.80
4500=.80
5000=.75
5500=.75
6000=.70
6500=.65


Here are the VE numbers I have been playing around with for the above mods plus a 4:1 longtube exhaust manifold and crossover, T4 turbine housing, sheet metal short runner intake manifold, and John Milledge cam:

3000=.65
3500=.70
4000=.75
4500=.80
5000=.85
5500=.90
6000=.85
6500=.80
7000=.75

 

Interesting estimates! I've been looking for something like that when looking at turbo maps.