Nisif

My old t3/t4 turbo has an 1/2" of side to side shaft play and I'd like to replace it with something that fits my new found needs.

Want I'd like to achieve:
-400 whp on 93 octane
-Good midrange power. It's a street car. I'd like to see close to 150 whp by 4000 rpms, similar to my old setup.

Specs:
-81.5 mm LS Vtec. No Sleeves. LS transmission
-Arias pistons w/ eagle rods. should yield roughly 9.4-1 compression ratio.
-Stock GSR head and Intake Manifold
-Revhard Log Manifold w
-Tial Wastegate (38mm I believe) with open dumptube
-2.5" turbo piping
-2.5" downpipe with 3" exhaust
-Precision 1000cc injectors

I've looked at countless dyno graphs. Mostly on Evans Tuning and a few on here.

Based on Evans Tuning site the GT30 turbo is used quite often with the results I'm looking for.

I also had someone recommend the Precision 5858 but i think it may deliver the power on later then I'd like.

I would like to spend around a $1000 or less but if it's well worth it I'm willing to increase my budget.

Any personal insight? I'll attach a graph of my last setup, this was done with a ls engine (same bottom end) but with a stock ls head and intake manifold. Again I would like to have similar if not better numbers down low and through the midrange but achieving 400 whp peak (or more).

Here's my old LS setup on 15 psi:

bigmikeinteg

Look into STC turbos great reviews. User name The Shodan he will be able to guide you more specifically

DC_Legacy

3076 but at $1000 or less I know that would have to be a pre-owned unit

Also I'd personally see 3" DP and exhaust + a short ram working out better than a log with 2.5 but I know with the right amount of boost and tuning its possible, just probably a better means to get 400 with better exhaust flow for that turbo.

wantboost

iTrader: (2)

A gt2871 would net you 400hp with about 20-30hp of wiggle room left.
Gtx2867 is another option.

A gt3071 or 3076 will do it and leave a bit more power on the table.

Personally I'd use an EFR7163. Spools about 300-400rpm faster than a 3076 at the same pressure levels, makes more midrange torque and power but is only 20hp down on the top end .
Plus the compressor flows 60lb/min at its limit.

The turbine wheel won't let you get 60lb out of the turbo but there's no reason 50-55 isn't doable

Nisif

Bigmikeinteg: Good to know, I sent him a pm.

DC Legacy: I haven't seen many pre-owned units at that price level. I may consider buying new. Which size turbine A/R would you recommend for the GT3076? My downpipe has a 5 bolt flange which I may need to switch depending on the turbo. It's a tight fit at the moment (close to the radiator) but I'll make an effort to upgrade to a 3" dp. I'll look into some short ram manifolds as well.

Wantboost: I looked into the Borg Warner 7163. Price is a little more than I'd like to spend assuming I can score a used one. I did find the following however...


How about this:

Rebuilt GT3071R. I'm not sure which size turbine trim A/R this is but I'm waiting for his response. According to Garrett's website they offer a 0.64 and 0.86 A/R. Any suggestions?

http://www.ebay.com/itm/Turbocharger-genuine-Garrett-ball-bearing-turbo-GT3071R-with-billet-compressor-/181600450355?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a483af733&vxp=mtr

wantboost

iTrader: (2)

.86

You can't think about t3 housing sizes here since the volute is an entirely different design. Howeverin terms of overall size the .86 t25 housing is closest to a .63 t3 housing in terms of overall size and flow.

Andif you're going with a 3071 and you plan on running decent pressure levels you need a ported shroud compressorcover. The bigger t04x cover in the photo doesn't help anything. You won't make more power with it. The ported shroud t04e is more than sufficient

hpmx18

the 35r will give you that easily no issues

Schister66

GT3255b

Look into this ^^. I ran a gt3255b on my stock block gsr and it was a blast. Full boost by 3800rpm on an SLS miniram. Made 315whp/218wtq at 10.5psi on pump gas.

Schister's STC GT3255b stock block dyno

Boost4Breakfast

hy35 or even an he351cw for a little more flow.

Nisif

THanks, good to know. The turbo I listed ended up being 0.64 A/R. I'll continue looking. I'll take your advice and get a ported compressor cover if i go with that turbo. I only listed the one above due to the price and that it was rebuilt. I contacted STC (Speed Trapp Consulting) as well to further assist with my options. They have a great selection of turbos to choose from.

Nisif

The price is ideal although the power is a little lower than I would shoot for around 4000 rpms in comparison to my old setup. Do you have any graphs of that turbo at higher boost levels hitting 400 whp?

Schister66

I never pushed it that hard but my tuner bought the turbo from me and used it on a built LS. He made over 400whp and low 300s tq at 20-22psi IIRC (its been 5 years so its hard to recall exactly) so I know its possible

wantboost

iTrader: (2)

what specifically are you looking at from STC? I can help you out with his stuff.

Schister66

Of the turbos listed on STC's site, I would choose between the GT3255b and GT3251b. You'd have to double-check with TheShodan to see if those units are still available - i know they're soon to be discontinued in lieu of their new line.

Another option is the STC Hunter

phaphon

I have the gt3251b I bought from the shodan. Will be selling it soon for sure might be willing to part with it now maybe . I only put about 1k miles on it. Pm me if interested . But yeah shodan has a lot of good info to give out

I just took a look at my graph I made about 170 I think by 4.5k rpm if you want I can text you my graph . Turbo max out is about 425 whp

wantboost

iTrader: (2)

As far as I remember TheShodan will still offer the gt32 lines and others along side his new line. If it's on the new site it's available.

Might have another avenue of marketing for STC, I can't say much more than that but if it works outit should be a promising outlet ��

Nisif

Okay, wish he had a dyno graph. That sounds ideal and turbo is in my price range.



Heard back from TheSHodan. He recommended the Hunter turbo along with the GTX3071R and GT3071R. The GT3255b is discontinued.

Good to know, at this point it looks like I'll be going with the Hunter turbo with a 0.63 A/R turbine housing. I'll keep you guys posted

Schister66

The Hunter is a good turbo and gets from me. In for results

wantboost

iTrader: (2)

Perhaps I need to tell Mac to make a note on his site lol

Schister66

Yeah, you should let him know to update that.

He PM'd me a while back saying that the GT32xx series would eventually be discontinued, but I wasn't sure the exact timeline. I guess that time has passed...