T25->T28, worth it?

[tazjig]

Ok, now i have read so much about swapping the t25 with the t28 non BB, I was just wondering if it is actually worth it. I am going to be upgrading my turbo soon and it seems to me that the t28 is not really worth the money, no? you may be able to get a few more ponies in the long run but for an extra few dollars wouldn't it be worth it to go to something better? I just wanted to get some opinions from people that have done the swap. Thanks.

[Canadiancochl]

SEARCH!

non BB isn't worth it in my mind. . . all depends on what you want doodI'm doing s15 bb t28, good for ~330rwhp . . and thats perfect for me, and a quick spool.Want more. .you'll need to go t3/t4/. . .

All depends on what you want dood.

Dr.

[tazjig]

i have been searching, i figure i would like to make about 300hp and i dont think a t28 non BB is going to make that much, a BB turbo will but then i will be spending as much as an aftermarket turbo, no?

[Projex240]

SEARCH!...

Dr.

oh man, i guess all 24 of your posts have made sense and never asked a newb question....

I hate it when people say that.

The search function sucks, and doesnt always help.

But to touch on it. The t25 can make 260-ish and thats been seen many times. I havent seen a t28 have *too* much improvement over that power level. Get the s15 BB, or save up for a little longer and get a aftermarket turbo. The s15 turbos are selling for aroun600 bucks. Good power, but theres other options out there with a greater potential for not too much more.

-Josh

[cheez80]

I'm doing s15 bb t28, good for ~330rwhp . . and thats perfect for me, and a quick spool.

usually, s15 t28 maxes out at around 300whp. the pulsar gti-r turbo, which is not ball bearing, has a larger compressor housing and can hit about 320-ish whp.

an s15 t28 is probably not going to have enough juice to take you very far past the 300whp mark.

[tazjig]

Thanks guys, by the way im not a newb, im just tired of reading old posts and wanted to get some real opinions from people that have recently done the swap.

[itssr20]

Where can the S15 turbo (gt28r) be had for $600?

Tazjig: if you want 300whp or a lil more go w/ gt2871r

[RMiller]

usually, s15 t28 maxes out at around 300whp. the pulsar gti-r turbo, which is not ball bearing, has a larger compressor housing and can hit about 320-ish whp.

an s15 t28 is probably not going to have enough juice to take you very far past the 300whp mark.

GTiR turbo has a smaller compressor housing. T3 vs. s14 and s15 turbo's t04b. I've never seen them side by side though, so maybe I read wrong. gtir has bigger turbine, .86 a/r vs the .6 of the other two, and the compressor wheel is of different trim. Still, it makes more power than the others.

Ball bearings aren't a big power adder, they improve transcient response.

[tazjig]

where is the cheapest spot to get a gt287r?

[DawgMode]

http://store.yahoo.com/cheapturbo/gartur.html7 columns down

[tazjig]

there is a store near me that deals alot with turbos, they are a diesel motor and turbo store, would they be able to get me turbos like this? or are they just for specific applications?

[itssr20]

if they deal w/ Garret I'm sure they could.

[Projex240]

i have been searching, i figure i would like to make about 300hp and i dont think a t28 non BB is going to make that much, a BB turbo will but then i will be spending as much as an aftermarket turbo, no?

If you would like around 300, then go with the s15. Its proven, and cheaper than your other alternatives. If you want response, thats your turbo. If you are willing to sacrifice a little response and low end power, then maybe a bigger turbo. The gt2871r is not exactly a laggy turd, but its not a very fast spooling turbo either. Stick with the s15 turbo for that all around performance that you said you wanted. Youll be happy.

plus, if you change your mind, s15 turbos arent hard to get rid of.

-Josh

pss--heres a nice one to look at. There are alwasys s15 turbo new and used on ebay from japandy, and japspecialist or something like that.

http://cgi.ebay.com/ebaymotors...33742

-J

[tazjig]

With an S15 BB turbo, i should be able to run 15lbs no problem right?

[Projex240]

ive seen people run more.15 psi on a stock s13 t25 is normally what people run, 16 psi actually is more the norm with an output of around 250-260.That s15 turbo should have you around 300 at around 17-18 psi im guessing, but of course, you have to have proper supporting mods . Downpipe, exhuast, maybe cams, etc.Youll need injectors and a maf. The stock maf doesnt handle anything over 260-ish. The injecotrs are about at the end of their rope too. The s15 injectors can be found for sale. Ive seen them go for pretty cheap sometimes. The euro ones are 444 and the jap spec ones are 480--check ebay out.

-Josh

[tazjig]

ya i've already got the injectors and maf, im just gonna wait to get my turbo and an safc to put it all in at oncethanks

[boost_creep]

not to threadjack,but are there any mods that have to be done to the hot pipe or intake pipe when swapping in the s15bb?

[tazjig]

im not 100% sure but i think that the hotpipe at the turbo has to be angled a bit differently

[Nismo_Freak]

ive seen people run more.15 psi on a stock s13 t25 is normally what people run, 16 psi actually is more the norm with an output of around 250-260.That s15 turbo should have you around 300 at around 17-18 psi im guessing, but of course, you have to have proper supporting mods . Downpipe, exhuast, maybe cams, etc.Youll need injectors and a maf. The stock maf doesnt handle anything over 260-ish. The injecotrs are about at the end of their rope too. The s15 injectors can be found for sale. Ive seen them go for pretty cheap sometimes. The euro ones are 444 and the jap spec ones are 480--check ebay out.

-Josh

444's are top feed injectors used in the GTR

480's are the side feed injectors used in all S15s

S15 injectors are pretty worthless at 300whp ... duty cycles are very high from experience. You should opt for 740's or 550's.

[Nismo_Freak]

Not all S15 turbos are ball bearing... keep that in mind when purchasing the item. There are at least 4 part numbers for the S14 - S15 turbos out there.

[RobDET]

not to threadjack,but are there any mods that have to be done to the hot pipe or intake pipe when swapping in the s15bb?

Yes. The turbo outlet elbow needs a little grinding because one of the studs is in a slightly different location. If you have an aftermarket one it should already be set up for this.

The inlet will not work quite right. It has the holes on the compressor inlet clocked differently

The outlet on the compressor side has the holes clocked differently too. I got a generic flange that made it so i could just put any hose on the compressor outlet. You can use the stock S13 outlet if you modify your hotpipe.

The oil return is in a slightly different place also. It's no big deal to handle this. Either get the S15 outlet or a longer rubber hose.

All of the things can be taken care of by getting S14 or S15 peices. That's what i did for the turbo inlet because that's a particularly nasty bend.

[RobDET]

Phas 2 motortrend should be able to help you with the parts you need like the oil return tube and the dump pipe. They also had an S14 inlet when i called them that they had just taken off a customers car.

[Projex240]

444's are top feed injectors used in the GTR

480's are the side feed injectors used in all S15s

S15 injectors are pretty worthless at 300whp ... duty cycles are very high from experience. You should opt for 740's or 550's.

alrighty. Thanks for clearing that up. Now I feel dumb b/c I cant count how many times ive told people that. I forget where I read it.

ALso--i didnt know all the s15 turbo werent duall BB. I thought they were all dual ceramic BB. Which models came with which?

-Josh

[boost_creep]

thanks so much for all the info robdet..i gonna have take this into serious consideration...looks like more work than expected

[elvis240sx]

what about fuel management or ecu problems? this sound stupid, but can you run an s15 bb turbo from a stock sr20 ecu? i assume not since you would need bigger injectors, correct?

[RMiller]

If you change the injector size or maf, you need a fuel controller of some kind.

[Nismo_Freak]

If you change the injector size or maf, you need a fuel controller of some kind.

And ANY upgrade to the turbo will require both.

I'd suggest piggy backing it with an Emanage or getting the ECU ROM tuned.

[tazjig]

An SAFC will do the job too right? thants what i plan on using when i upgrade my turbo, and injectors and maf.