T28 question - need some honest opinions

[Rittmeister]

I have for a few months (years) been considering upgrading from the stock T25 on my redtop SR to a T28 of some flavor, with supporting mods. My reasoning is that the T28 is a better match for the engine - power all the way to redline, rather than falling off at the top the way the T25 does - but still retaining good spool characteristics and not breaking the bank.

Let's be honest - this is not a new idea. It's a proven path to a well-balanced car, which is what I've always tried to maintain. It's mostly a street car but I do a HPDE every so often and would like to get to the dragstrip here and there. I'm not trying to break any records or cover any new ground, but I like to work on the car and I've done damn near everything else I can think of.

My anticipated setup is:

S14 or S15 ball bearing T28
550 or 740cc injectors
Z32 MAF
Tuned ECU

This isn't accounting for the little stuff like stainless lines for the turbo, adapter kit for the piping, etc, but then those don't have any bearing on my question, which is this:

How much will an upgrade like this affect the reliability of the car?

I did some searching and no one's really addressed this issue. I like the car the way it is and I assume I'd like the same car with another 40 or 50 horsepower. I plan to run the T28 at 7-8 psi most of the time, with possible jumps no higher than 12 now and then for fun. Yes, the car will be faster, but right now I can't break it with a hammer. It doesn't overheat, it doesn't make strange noises or exhibit gremlins at all. I drove it 1700 miles in four days in the spring of '06 for a convention and it didn't blink.

Any input gratefully received.

[status:one]

Go for the S15 ball bearing turbo

[WoolyS14DET]

Dood as loong as you do the Injectors, MAF,ECU upgrade and do the S15 T-28 you will not have any issues at all !!! Im running a GT3835,Z32 MAF,Nismo 555, with a wolf ecu and boost is at 15 psi all the time and I daily drive the car and it runs great and has no problems!! My car has no issues at all it rens great. I drove it 2 hrs last weekend to the ZMOG BBQ in LA from SAn DIego and it didn't overheat or nothing !!!

[SR2Zero]

Pretty much, if you drive like you say you do, it will be a very reliable set up. Considering it'd been seen that the sr stock block can hold 400whp, a s15 turbo will be no problem. And yes, as said above go with the s15 turbo.

[flip3d]

what RPM does the bb t28 spool at? all i know is its "early"

[mr_240sx]

t28, 550, z32maf and enthalpy tuned ecu at 15psi is totally worth it! and still reliable like a stock engine.

[WoolyS14DET]

I think it starts spooling at like 2800 RPM

[Rittmeister]

I guess I should clarify - I'm not looking for recommendations one way or the other between the S14 and S15 turbos - I've done extensive research and while it's clear the S15 turbo is a bit better, it's also more expensive, and it's likely that if I go ahead with this project the decision between the turbos will be a financial one.

Here's another question - how much should I expect gas mileage to be affected?

[mr_240sx]

hwy cruising it wont be affected much.... but i did notice a change with my 550.

[renegade_ewok]

S14 or S15 ball bearing T28
550 or 740cc injectors
Z32 MAF
Tuned ECU

This isn't accounting for the little stuff like stainless lines for the turbo, adapter kit for the piping, etc, but then those don't have any bearing on my question, which is this:

How much will an upgrade like this affect the reliability of the car?

I did some searching and no one's really addressed this issue. I like the car the way it is and I assume I'd like the same car with another 40 or 50 horsepower. I plan to run the T28 at 7-8 psi most of the time, with possible jumps no higher than 12 now and then for fun. Yes, the car will be faster, but right now I can't break it with a hammer. It doesn't overheat, it doesn't make strange noises or exhibit gremlins at all. I drove it 1700 miles in four days in the spring of '06 for a convention and it didn't blink.

Any input gratefully received.
This is the exact setup I am running right now on my blacktop. T28, Nismo 555ccs, Z32 MAF with a rom tune, only difference is I am cammed too - The turbo is really nice, starts spooling hard around 2800ish with full boost not much later but there is a kind of turbo falloff near redline. Not bad at all like other cars I've driven, but its still there kinda.

Gas mileage will go down a bit if the tune is crap just because the injector impedance is a lot less for the fuel so it will just dump if it isn't tuned. However, if it is tuned properly your gas mileage just is determined by your right foot. Highway cruising is just fine and its power on demand. I don't know my gas mileage exactly, but its pretty good.

I drove like 110 miles on a quarter tank (little bit more, but not much) just cruising on the turnpike

[fliprayzin240sx]

Gas mileage will all depend on the rom tune with that 740cc and how much you can stay OUT of boost. Personally, since your already doing all that, I would personally say, why not upgrade to a GT2871R? Your pretty much there, only thing you need more is a damn Headgasket. Even if you decide to stay with any good ol T28, you would more likely need a better HG.

[lflkajfj12123]

why in the world would you need 740cc injectors with an t28?

t28 is probably good until 350ish hp TOPS which you don't need such large injectors to make those numbers

and i agree with ray gt2871r can make 400 hp on a good setup

[Pho Man]

my s14 stock T28 front mount, downpipe, exhaust and a filter with greddy emanage laid down 276whp at 15lbs. Drove it daily until I started to take everything apart. Wont have a problem with just the T28, very quick spool-up. Loved it.

[Rittmeister]

I appreciate the input from everyone.

On the 740cc - it's something I'm pondering. More headroom, so to speak. I'd rather run 740s with room to move, than 550s that are nearly maxed most of the time. I don't know what I'm talking about with these though, haven't researched the injectors fully yet.

On the T25, at stock boost, the car laid down 225 at the wheels (big exhaust/dp/outlet, front mount). If I could get 275, or even 250-260 or so whp I'd be happy, especially at a relatively conservative boost level. Remember guys, this is all about driveability, not big numbers. GT2871, while tempting, is NOT going to happen.

[lflkajfj12123]

just get the s15 t28 ball bearing then if the s14 one you're talking is the nonbearing one then scrap that idea

they can be found cheap

you don't need the 740's for the t28 PERIOD its a waste

300 is acceptable with the t28 at 1.5 bar and matched mods

[renegade_ewok]

just get the s15 t28 ball bearing then if the s14 one you're talking is the nonbearing one then scrap that idea

they can be found cheap

you don't need the 740's for the t28 PERIOD its a waste

300 is acceptable with the t28 at 1.5 bar and matched mods
Since when can the T28 do 21psi?!

[lflkajfj12123]

yeah i didn't mean that oops its late i mean 15psi

which is like 1 bar

[Sileighty_85]

You can hit 300+ with the T-28
On mine @.8 I put down 255
Stock ECU
Stock Injectors
Stock MAF

But definalty need 550cc's
Starts leaning out pretty bad after .8

[Def]

what RPM does the bb t28 spool at? all i know is its "early"

Mine spooled to 14 psi a couple of hundred RPM *BEFORE* my T25 did. It responds much better down low than the T25 due to the ball bearing CHRA.



I say do it. I had a T28 for a few years on my car and did some track events at 1 bar and it was fine. Whenever I was on the street it was at 18 psi.

Now I have a GT2876R .64 and it's even more fun.

[fliprayzin240sx]

I appreciate the input from everyone.

On the 740cc - it's something I'm pondering. More headroom, so to speak. I'd rather run 740s with room to move, than 550s that are nearly maxed most of the time. I don't know what I'm talking about with these though, haven't researched the injectors fully yet.

On the T25, at stock boost, the car laid down 225 at the wheels (big exhaust/dp/outlet, front mount). If I could get 275, or even 250-260 or so whp I'd be happy, especially at a relatively conservative boost level. Remember guys, this is all about driveability, not big numbers. GT2871, while tempting, is NOT going to happen.

On a non-ball bearing T28, I highly doubt you'd hit anything more than 280whp and thats on 14 psi. Hate to break it to you bub, your 225 whp on 7 psi stock T25 is a fucking fluke. Dyno is way the fuck off, 180whp is average, 200 whp with mods. 550cc injectors starts pushing it at around 320-330 whp. 740cc hit their max at around 420-440 ish. You want 275, get a Spec R T28, push it to 10-12 psi and that might get you to 275 depending on the tune your doing. ROM TUNE on its own isnt gonna cut it (unless its a DYNO rom tune).

[Rittmeister]

I have been meaning to dyno the car again since that number, which did seem high. Mods are Greddy front mount, Megan outlet/Topspeed downpipe/3"cat/Veilside 3" exhaust. This was on a Mustang dyno; on the stock dyno software it did 204 hp; they have software that will give you a readout as if it were a Dynojet, which is where the 225 came from. I even pulled the VC and measured the cam lobes to see if they weren't stock; there's no explanation for the higher-than-expected number, which is why I'd like to have the car re-dynoed before doing this swap (if I do it at all).

[adictd2b00st]

i've run that exact setup on 2 seperate cars..........super reliable and drives very much like a stock car will, with some power on tap when you need it :) the only difference is i've always run 555's , but same idea. 300whp is perfect for an s-chassis car, and this will put you right around that mark

[Howard92884]

On a non-ball bearing T28, I highly doubt you'd hit anything more than 280whp and thats on 14 psi. Hate to break it to you bub, your 225 whp on 7 psi stock T25 is a fucking fluke. Dyno is way the fuck off, 180whp is average, 200 whp with mods. 550cc injectors starts pushing it at around 320-330 whp. 740cc hit their max at around 420-440 ish. You want 275, get a Spec R T28, push it to 10-12 psi and that might get you to 275 depending on the tune your doing. ROM TUNE on its own isnt gonna cut it (unless its a DYNO rom tune).

Yeah 225 is pretty high for a stock SR with a T25. My stock redtop with Front mount and 3" exhaust made 180whp on a dynojet. Flip pretty much hit it on the nose.

[mr_240sx]

yeah my stock redtop with 10psi (t25) and greddy fmic, and apexi n1 exhaust made 213rwhp but its been dyno tuned. i wouldnt expect anything higher than 215rwhp on redtop.

[renegade_ewok]

With some 550cc injectors, T28, standalone w/dyno tune (like PFC), turboback, FMIC, and MAF people around here have been pushing 300whp with a good tune. 300whp is possible on a T28, but you need a good tune.

It's all in the tune - gas mileage, power, reliability.

[mr_240sx]

yes 300hp is possible with t28 and supporting mods but its all in the tune! Its always in the tune!

[lflkajfj12123]

On a non-ball bearing T28, I highly doubt you'd hit anything more than 280whp and thats on 14 psi. Hate to break it to you bub, your 225 whp on 7 psi stock T25 is a fucking fluke. Dyno is way the fuck off, 180whp is average, 200 whp with mods. 550cc injectors starts pushing it at around 320-330 whp. 740cc hit their max at around 420-440 ish. You want 275, get a Spec R T28, push it to 10-12 psi and that might get you to 275 depending on the tune your doing. ROM TUNE on its own isnt gonna cut it (unless its a DYNO rom tune).

from pbm

See Eisuke San from parts Shop MAX Japan tune a redtop SR20 with S14 turbo in an S13 chassis to 324ps to the wheels! Thanks to Martin for the footage, translation, and techno music. We also get to meet the youngest team MAX driver. We get a look around one of the garages at PSM Japan and Martin explores tig welding.


http://www.youtube.com/watch?v=MXcFuVa2EZ0

[mistamacadamian]

This is the exact setup I am running right now on my blacktop. T28, Nismo 555ccs, Z32 MAF with a rom tune, only difference is I am cammed too

what numbers are you making? im about to get my head back and have the same set up as you. im running bc 264's.

[downshift_sideways]

I'm dyno'ing mine again soon.

s13 sr
550 injectors
z32 mafs
tuned ecu
t28 turbo.

If you have the chance. Try to get the s15 bb turbo.
or save up a lil more and as Ray said. Get a gt2871r. or HKS

[renegade_ewok]

what numbers are you making? im about to get my head back and have the same set up as you. im running bc 264's.
I dont know, I have HKS 264/272s and have never hit a dyno yet - as soon as I get a boost gauge (was stolen out of the car) I'll hit the dyno soon since right now I'm at like 9-10 psi and dont want to crank it up without knowing... I plan on doing like 16psi when all said and done.

[mistamacadamian]

tight tight. have you noticed a big difference while on 10psi with cams? that was my low boost setting and my friend slightly modded e36 kept up with me in 2nd gear and half of 3rd then i started to pull so it was kinda slow to say. I was at around 280 before my built head on 16.

[renegade_ewok]

tight tight. have you noticed a big difference while on 10psi with cams? that was my low boost setting and my friend slightly modded e36 kept up with me in 2nd gear and half of 3rd then i started to pull so it was kinda slow to say. I was at around 280 before my built head on 16.
On the rom tune, I wouldn't expect over 300whp because the tune runs rich and i can feel it bogging in between shifts etc... Its really not all that great. I would expect in the range of a tad under 300whp but if I were to pick up a PFC with a tune I am pretty sure the cams would put the T28 over the 300 marker as it breathes really hard in the midrange. With the cams you really get a hard punch in the face at like 3500 when you start coming into their powerband.

I've gotten a ride in a stock SR and then mine so I really can't exactly tell you the difference haha - only problem is sometimes it takes 2 tries to start and the idle shakes the car :naughty:

On my current boost setting I've walked a few cars but I haven't had a run in yet with a proper car (TBE Evos/STis or better) so I really can't say yet what it would keep up with

[mistamacadamian]

wonderful, ive got a dyno tune rom tune so we will see how it runs until i get a JWT ecu since i cant get a re-tune at XAT...sucks. ill be posting videos up this week when i get it back

[Def]

At 1 bar with my T28 I would walk lightly modded EVO 8s pretty good, at 18 psi I could do the same to the ones with the 10.5 cm^2 turbine housing. At the same 18 psi I could also pull pretty handily on STis/E39 M5s/'03+ SC'd Cobras etc. I put out about 300rwhp/280 rwtq with boost spiking to 18 psi and falling to 16 psi with stock cams(I tuned it myself).

The GT2876R I have on there now is faster, especially on E85.

[Pho Man]

I appreciate the input from everyone.

On the 740cc - it's something I'm pondering. More headroom, so to speak. I'd rather run 740s with room to move, than 550s that are nearly maxed most of the time. I don't know what I'm talking about with these though, haven't researched the injectors fully yet.

On the T25, at stock boost, the car laid down 225 at the wheels (big exhaust/dp/outlet, front mount). If I could get 275, or even 250-260 or so whp I'd be happy, especially at a relatively conservative boost level. Remember guys, this is all about driveability, not big numbers. GT2871, while tempting, is NOT going to happen.



I just had the Emanage with stock injectors. Never had a problem with cutting out.

[tougekid]

im getting an s15 bb real soon, got 264 BC cams to go in . 525 injecterson, and an e-mange ultamite allready on the car.
my shop usees an mustang dyno. any idea what the numbers would be??
i know theres the tune var. but i think around 260 for daily and 280 for track are good est. what do you you guys think?

[adictd2b00st]

ok bumping this rather than making a new thread........ i just got my car tuned this week ( s14 t28 with power fc djetro and the usual bolton's, stock cams, redtop sr) for 18psi, but its dropping pretty quickly to ~14.5 psi at around 5k rpms. sound like i may have a problem with the wastegate? i coulda swore the t28 was supposed to be able to hold the 18 to redline, or am i wrong?

[Def]

Once you hit about 300 rwhp the boost will fall off. My boost dropped 1 psi up top when I put in HKS 264/264 Step1 cams compared to stock cams, but the turbo was flowing slightly more air based on MAF voltage.

On the average SR it'll hold about 17 psi up top without too much trouble.

[adictd2b00st]

see thats what i thought...... seems like some of it is bleeding off. i will try swapping wastegates and see what happens

[Def]

You can try tightening the actuator arm up a bit, but it seems like it's a combination of the compressor running out of steam and the turbine pressure really rising towards redline with that much power so it pushes a lot on the flapper.