parish8

iTrader: (6)

Plan is a pair of 6766 turbos on a 408 at 1000+hp.

I like the compact vband in exhaust housings but could fit t4's. will the smaller appearing vband housing be a restriction?

sr71bbjr

iTrader: (52)

Not at 1000 wheel. They v band housings are a .82 AR which is smaller than whats available on the t4 housing. Which i believe is .96 and goes up to a 1.32.
I made 1105 rwhp in my vette with a pair of 6265's and v band housings. If i were to build a kit toady i would without a doubt go with the t4 housing if you have the room. I just had to redo my entire kit cause i built a big motor and the .82 AR wasn't going to work well with a 430 ci.

LS1NOVA

iTrader: (12)

I think so.

black98ws6ta

iTrader: (77)

A smaller exhaust a/r will almost always cost you power(but make it spool better). A larger exhaust housing means more flow and less back pressure. Which also usually allows more timing, and more power. A/R is just a ratio of area, the v band inlet housing is considered T3 sized. A T3 and T4 housing could have the same A/R but the T4 flow much more.


I have a customer with a 402/small cam/small head and a pair of vband 6766's and they spool very fast and it makes 900 wheel through an auto at 20 psi on e85

stevieturbo

Ive been researching various TT related stuff lately.

And as far as I am aware, their V-Band housings are all based on T3 units, so is unlikely they will be anywhere near ideal, especially for a bigger motor.

The Tial ones go to much larger A/R's although may not fit those turbos.

LS1NOVA

iTrader: (12)

They do make for one hell of a street car though, insta spool on a 427.

LS1 240sx

iTrader: (1)

I thought Turbine housing have just a air ratio for spool/tuning purposes, from what I learned the turbine wheel is what allows more flow ONLY.

stevieturbo

No.

If you use a very small A/R housing, it only has a tiny hole in it. A housing with a large A/R has a larger hole, hence slower gas velocities into the turbine so less spool. But more flow at the top end.

So it's a balancing act finding what works best overall for each user.

LS1 240sx

iTrader: (1)

so the turbine wheel wouldn't hurt you if it was small? just run a large a/r with the small turbine?

stevieturbo

Yes it would.

But if you used a huge turbine with a minute A/R, then the turbine housing would be the restriction.

As I said, it's a balance between them all.

If you choose a turbine wheel that is too large, you'll never get it to spool

LS1 240sx

iTrader: (1)

Gotcha

toretto

iTrader: (12)

I hate to bring this back from the dead, but I have been curious as to why people say the Vband Flange is like a T3?

The inlet area is 6.447 compared to 5.98 on a T4 Non Divided flange.

So IIRC, the .81 T4 flange should be tighter on flow that the .82 THV housing.

Does that make sense? Also there are 2 different ARs now, the .63 and .82 housing.

stevieturbo

Because the area doesnt relate to the flange. It's further down the scroll.

The V-Band housings in this case are based on T3 scrolls.

black98ws6ta

iTrader: (77)

The t4 flange is much larger then the "t3 sized" v-band inlet housings. Precision also calls them "t3 sized".

Fathouse

Pte is coming out with a t4 based vband housing soon. For the 75mm sized turbin wheels.

rotary1307cc

iTrader: (5)

Just go look at the gt35 turbine maps if you want an idea of how much the A/R of a housing changes the mass flow of a certain turbine

GR8GAME

iTrader: (10)

My turbo from BEP has a V-banded exhaust inlet with a 1.30 a/r... S475

Are you guys specifically talking about much smaller turbos?