T3/T4 a/r ratio??

[Overkill]

To all the guys running t3 hot side what a/r ratio and stage wheels are you using?
I have a t4 57 trim with a .48 a/r stage 3 hot side and thinking of going .63 or .82. I have full boost(23psi) @3400rpm and would not mind it coming in abit later for more power uptop.

[www.cp-e.com]

You definately need to get a .82 for this car

I wouldn't go smaller than a .63 but the .82 is optimal. Smaller than that gets a bit choked in the upper rpm's and ends the hp curve shy of what turbos should make.

[hackish]

A 0.48 is way too small but you can just do a bolt-on housing upgrade for cheap. On some 2.2l hondas I've made 30whp gains by just swapping to a larger compressor housing. I don't know that you can get the exact same bolt pattern on a 0.82 housing. Also, make sure you're using a stage 3 wheel.

-Michael

[Overkill]

Thanx Guys. Definetly stage3 wheel and i can get .63 .83 1.06 bolt on housings so will see over the next week or two.

[hackish]

Make sure the outlet bolt pattern is the same. You can get T3 housings in 4, 5 and 7 bolt patterns.

-Michael

[Darksun280]

57 trims are sense less you should just trade for a 50 with a 63 hotside. /The top end benefits of a 57 trim are moot compared to the increased spool time.

[Overkill]

To get a 50 trim in South Africa is a mission by the time it's here with shipping costs and shit you could buy a gt 35 or equivalent. The 57 trim costs 300 dollars and is off the shelf only reason it's on and not a 50 trim.

[Darksun280]

Originally Posted by Overkill To get a 50 trim in South Africa is a mission by the time it's here with shipping costs and shit you could buy a gt 35 or equivalent. The 57 trim costs 300 dollars and is off the shelf only reason it's on and not a 50 trim.

Damn. Oh well

[Justin Lee]

Im planing on going BT soon, I had thought about just throwing some bolt-ons on it and running the stocker setup for awhile but the more I read the more it seems like at higher boost the stocker turbo seems to be harsher on your internals than a BT setup.
So I think Im just going to gear up to do my BT build and it makes me feel even beter hearing the success these guys are getting on stock blocks

I believe a good bench mark for the stock internals would be 400whp which I plan to make with a 3582 twin scroll on a T3 but what A/R should I get with a twin scroll I had also thought of .82 or would 1.06 be too much?

Next is the manifold, I would like to do a top mount like StreetUnitMark has on his MS6 (except I want dual WG's) I just wonder if a 35r will fit on a top mount like this? I've tried to search and find an answer to this but to no avail. Also wheres a good place to buy the stainlees pipe kit for exhaust manifold fabrication?

Thanks for the help guys

[madvillain]

While on the subject here.. Im still a bit confused on something..

Say you have the same turbo, a 35r for example, and you can have a t4 0.58AR hotside.. OR you can have a t3 0.81 hotside...

Because this is a ratio of air:radius, aren't you going to see at some point there will be an equilibrium between the two? Will there not be some median number in between which will allow the turbo to spool at the exact same time (all other conditions equal) whether it be on a t3 or t4 flange?

[www.cp-e.com]

its a ratio that shows the correlation so not really because you have a much bigger radius...the numbers just get close for A/R because your doing the ratio.

Think of it like this. I have a 10 gallon jug with a 5" diameter on top. lets call that a 2:1 ratio. Now I also have a 20 gallon jug with a 10" hole on top. Also 2:1 but the latter will definately require a lot more flow IN to fill it. Make sense?

Tyler - PLEASE don't go t4. It will NOT be fun to drive.

Originally Posted by Justin Lee Im planing on going BT soon, I had thought about just throwing some bolt-ons on it and running the stocker setup for awhile but the more I read the more it seems like at higher boost the stocker turbo seems to be harsher on your internals than a BT setup. So I think Im just going to gear up to do my BT build and it makes me feel even beter hearing the success these guys are getting on stock blocks I believe a good bench mark for the stock internals would be 400whp which I plan to make with a 3582 twin scroll on a T3 but what A/R should I get with a twin scroll I had also thought of .82 or would 1.06 be too much? Next is the manifold, I would like to do a top mount like StreetUnitMark has on his MS6 (except I want dual WG's) I just wonder if a 35r will fit on a top mount like this? I've tried to search and find an answer to this but to no avail. Also wheres a good place to buy the stainlees pipe kit for exhaust manifold fabrication? Thanks for the help guys

I don't get this mentality. I am not being mean but why would you use a 35r for 400 whp. For 400-440whp go with a t3 3076. For up to 475-500ish go with a t3 3076 sized turbo.

Having a big turbo doesnt make you fast. Running the PROPER turbo for the power levels you want that keep the turbo in its efficiency zone is what makes you fast.

Also - just curoius - why do you "want" dual wastegates?

[Justin Lee]

Originally Posted by www.cp-e.com Having a big turbo doesnt make you fast.

understood, lol I like this ^

the twin scroll 35r is just an experiment Im wanting to try on this platform to see if I can obtain the same spool and powerband that a single scroll 3076 has, 400whp is a stock block goal just untill I forge the bottom end and then go well north of 400 and Geoff at full race swears by the dual gated setups for twin scrolls so I just take his word for it

so what do you guys think probably a .82 would be best?

[www.cp-e.com]

Honestly I would recommend the 35r twin scroll vband outlet with the .78 a/r

[Justin Lee]

do you not think it would get choked up high with a .78?

this is with the goal in mind of going 500+ after the bottom is built

[www.cp-e.com]

.78 flows a good deal. i've even made power with .63. The .78 will easily flow enough air for 500 on a 35r.

[Justin Lee]

The smallest T3 twin scroll I can seem to find is .82

[superskaterxes]

twin ewg's on a twinscroll mani will always be more efficient then a single one. but u need to be careful because if your not running alot of exhaust gas per certain conditions, it may be hard to module the ewg's open or closed by a very small percentage. ie if u need to release say 30% exhaust gas with a single ewg setup, now u only need to release 15% via each wg and its really hard to modulate a ewg with that small of an opening,

[djuosnteisn]

Originally Posted by superskaterxes twin ewg's on a twinscroll mani will always be more efficient then a single one. but u need to be careful because if your not running alot of exhaust gas per certain conditions, it may be hard to module the ewg's open or closed by a very small percentage. ie if u need to release say 30% exhaust gas with a single ewg setup, now u only need to release 15% via each wg and its really hard to modulate a ewg with that small of an opening,

This only becomes a problem as you approach the limits of the turbo, cause that's when your wastegating the least amount of exhaust.



I really like the twin scroll 35r idea....


And i also like full race alot. Very good company.

Here's some video i shot of our local subie guru experimenting with some of full race's borg warner setups:

2006 WRX Wagon, 600+WHP

2006 WRX Wagon, 600+WHP

[Justin Lee]

StreetUnitMark has a 35r on his twin scroll right?

I just wonder how much modifications if any will be needed to fit a 35r in my MS3 with a twin scroll replica like his, I really like his design it looks solid I would want to make it unequal length to have that rumble in the exhaust though

[djuosnteisn]

4088r.


Make life easy on yourself and go top mount, just like SSinstaller, suMark, or soon to be myself