SR t25 best choice for me? unique setup possibly

[SPIRONIUM]

In short I just need a turbo recomendation and some input on my setup. I'll soon be undergoing my first turbo project, my ultimate goal is for the engine to behave like it is NA but also have 220-240whp. I would like to run a low amount of boost ~6psi also i would like to do this all on a close to stock de. Check out my setup below for my reasoning. This could be reliable on a good tune right? I have a low budget therfore i'm looking for an OEM turbo i can find at the Junkyard or on ebay ex: TD04HL-13G mitsu, volvo, saab, 1jz turbo. Bottom line is there a turbo that is more efficient than an sr t25 at ~6psi?

Final setup so far:-Sr 370 injectors-1300gsxr ITBS with custom plenun and velocity stacks on de truck manifold-Equal length ex mani (stock sr manifold with welded KA flange for a while..)-Free flowing elbow + exhaust system-Very short intercooler piping, small intercooler-Cams ground for NA pdm, jwt?-300zx MAFS-Enthalpy tune?-SafcII + wide band-t25????-external wastegate?? (more efficient than internal??)

[lilskyline240]

Definitely dont get teh ITBS no point as the stock plenum flows pretty well...and its gunna be harder than hell to make a charge pipe if u have ITBS

short intercooler piping really wont do anything....smaller piping will...reduces teh lag....

heres the setup im running and its a PERFECT driving car

sr t25555cc injectorstuned ecuSS autocrap bottom mount maniHKS o2 elbowsr20 downpipe3in megan catbackJGS SS oil lines kitsr20 SMIC

[SPIRONIUM]

Well i'm halfway finished with the itb setup, i know that i can make it work so i'll see what happens. I got the ITBS for cheap and i have a mig welder with some skill to use it. Short intercooler piping is supposed to give better throttle responce. So small intercooler piping can reduce lag? Does anyone have any input on NA cams in a low boost app? Does anyone have experience with a different turbo at low boost on a de?

[lilskyline240]

if u wnat a bit bigger turbo go with a t28 from an s15 they are BB and should give u the same spool time as a t25 but about 30whp more at the same boost level

go with crower V2's, they work great

[Rekless KA]

my internals are completely stock , i have a t25 from a CA. do u think the t28 from the s15 is the way to go, is it easy to find? and how much do u think a ok 1 should run? money wise? ---everyday driver

[lilskyline240]

prolly can find one on ebay for like 400 or so...in pretty good condition

[hannibal]

I think you can find an S14 T28 for less than the S15 turbo. IIRC, they are similar except the S15 has a Incon (composite) turbine wheel. An even better T28 is the GTiR turbo, but those are pretty rare.

SR 370cc injectors and the stock MAF max out around the same point (240-250whp). No need to use the Z32 MAF with the 370's.

Reducing the volume of the IC piping reduces lag. Shortening the length or decreasing diameter both reduce the volume. As you mentioned, a properly sized IC can help reduce lag too. IMO most people run too big of an IC, whether out of ignorance or simply for the bling factor of a huge IC.

[SPIRONIUM]

Cool, i knew that the s15 turbo made more power than the redtop turbo, i didnt know that it was pretty much the same except BB. Although.. i've been reading that this turbo is capable of 300 HP, and since i do not plan on making that much power, is there a better turbo option for me? Or is there no point to get a smaller turbo? (assume that i will Not want any more power than what i said originally) Also, i already have a Z32 mafs, should i throw it on or use the stock? I've read that the z32mafs is a little harder to tune with the safc.. Thanks guys

[hannibal]

I think the S14 (blacktop) T28 is BB like the S15 turbo. Search the web or check with some SR guys.

Not sure about tuning the SAFC, but if you get a ECU tune (Enthalpy!), definitely use the Z32 AMF. Also consider getting larger injectors so you 'never' have to go back for a retune. Z32 MAF and 550 injectors are good for ~350whp in case you decide to get a bigger turbo and rmake that much power.

Are you sure the SR T25/T28 are capable of 300whp?? That seems a little high to me. They run out of efficiency around 15psi (I think) and I doubt they're making 300whp at that point. A T28 is the smallest turbo I'd use in your situation.

[SPIRONIUM]

The s15 t28 turbo is good for 300whp for sure. Cool i'll get some type of sr20 turbo then and keep it bolt-on-style easy. One last question so i can wrap things up with this.... In terms of spool up and boost control stability: s15 internal wastegate + large elbow/downpipe + electronic boost controler =to large external wastegate (s15 internal welded shut) + seperate exhaust for waste flow + electronic boost controller?? Even marginaly, what is better? As you can tell i want to get the most efficient power possible.

Oh **** also, for intercooler piping, i'm assuming that the stock sr20 pipe diameter is optimal for this?

[2FourTee]

I don't know if anyone mentioned it, but a Nissan Pulsar GTiR turbo is a good choice as well. It's got a larger turbine housing A/R (.86 compared to .64)

ALthough it isn't ball bearing, it should still spool plenty fast and give more power up top then that S14 and S15 turbos.

[Rekless KA]

would all of those t28 turbo's just bolt right on my existing bottom mount manifold?

[SPIRONIUM]

The t28 bolts on just make sure to get the inlet/outlet pipes or make your own. Phase2motortrend sells an adaptor kit if going from the t25-t28.

I'm probably only interested in BB turbos, but thats good info about the GTiR