Thread: Help with my turbo options(pics! now)

Okay as per my build thread I have acquired a Avenir turbo swap of an ex-member from the old site (SkySheperd). It came with a whole bunch of swap related and just NX related parts, including 3 turbos!

Turbo 1: Avenir BB T-25
Turbo 2: GTI-r T-28
Turbo 3 S14bb T-28

Turbo 1 is supposedly is seized (however I can seem to rotate the wheels).

Which of these turbos would be best for my Avenir build my assumption was the s14 T-28 but... as per a old thread Andreas Miko says:

"The GTIR turbo has a bigger turbine housing .86 AR vs .64 AR. This will alow for better flow in th higher RPMs, wider power band and the power will not fall off as quick.

The compressor hosuing on the GT28 is a .60 TO4E which is alot bigger and will flow better than the GTIR T3 .60 compressor housing but this advanage will only be seen past 16-18 PSI. So in my opinion it is not needed and also causes fitment propblems.

So even though the GT28 compressor housing is better for high flow use the Turbine wheel and Turbine housing cant keep up.

The GTIR turbo is alot way cheaper than the GT28 turbo.

I have never heard anyone say my GTIR turbo is too laggy. So if th GT28 turbo spool up alittle faster than the GTIR turbo the diffrence on these small turbos are minimal.

The GTIR turbo comes with a wastegate and the GT28 does not.

If you were to put a T04B or T04E compressor housing on the GTIR turbo, the GTIR turbo would hands down kick the GT28 Turbos ass and still would be cheaper with this mod."

However I already have both so cost is not an issue. I could also conceivably make a hybrid.

Looking for 240-250WHP with potential for 300-350WHP if and when I get a P11/B15 tranny.

Thoughts on the best setup for my build? Thanks

Just keep the gti-r and use that.... You can swap the housing the the s14 for a slightly better turbo but it is a little bit of work. search to4b housing on gtir turbo or something along those lines, someone just did a write up on it.
Drew

I would run the Gti-r turbo.

Well that is two votes for the Gti-r seems like the easiest option of the two t-28s. Is there any benefit to a hybrid with parts from any of these set ups? I guess on major downside would be having to get it rebalanced if I went that route.

There is a slight benefit in the top end running higher boost levels swapping the t04b or whichever housing the s14 turbo has so if you have the time and know how you could go that route. A few people have done it but I have not seen any dyno sheets before and after. You wouldn't need to re-balance it as you would just be swapping housings. If it were me I wouldn't bother since sometimes it makes it more of a pain to fit and you may end up having to do some modifications to make it fit. I would maybe try it if I had a spare gti-r and still had the s14 turbo sitting around after you get the straight gti-r setup squared away. I think that if you are looking for 300+ whp, the gti-r with an external gate is the way to go. The internal gate works fine right up to around 300whp but you are going to be having a lot of heat at that point with an internal gate as the external will help keep the heat levels down and the boost levels more steady. With the goals you stated I would say keep the gti-r, sell the s14 and avenier turbos, use that money to send the gti-r manifold to Miko and have it ported & a flange for an external gate welded up. There is a correct way to do it and the ones that I have seen that Miko do worked flawless. You can hit 325+whp on the gti-r with an external gate. That is my favorite semi budget setup for the sr20.
Drew

Just noticed that you probably have an avenier manifold. The avenier manifold is a decent flowing manifold but I am not sure if that can be modded like the gti-r to run an external gate, you would have to ask Miko as I'm sure he knows. If not, sell that manifold and get a gti-r one, send it off and run an external gate. My 2 cents
Drew

Hey totaled200ser, Thanks for all the input! hopefully Miko or someone else who knows will chime in re the external waste gate mod on an avenir manifold.

However, as I am stuck with an B13 tranny for now (still deciding whether or not to case weld it [both for and against arguments seem valid]) maybe I would be okay with the internal wastegate for now?

You will be ok with the internal gate but you won't hit the goals you posted. Without cams it will take a decent amount of boost to even hit 280whp, which is still a fast ass street car.
Drew

I think you will be fine with the b13 tranny.GTI-R t28 with S4's=win.....

Yeah unfortunately I just clocked the gti-r and noticed the hole for the wastegate is cracked pretty bad in three places the worst being at lest a 1/2 inch long. So it might be out. Then again if I go the external wastegate route perhaps it won't matter.