i dont expect to just bolt on a bigger turbo ("close to" a straight bolt up isnt a straight bolt up) i'll prolly end up spendin a bit of cash on the change cos i got a few other things to do while i got the chance. im just tryin to find out the best way to spend my money

Hey Sooty, Just in case it helps,
I bought a T28 off a S14 Sr20Det, it's the bush bearing one not the ball bearing one (*cringe* more lag for me), but it was in really good condition, practically no shaft play, all seals and bearings in good nick, seemed too good to be true. Paid 400 all up. There are lots on the silvia forum and even a couple on Ozdat.

Oh, and the engine guy said that keeping the engine stock (with stock boost) and swapping the T25 to a T28 should happily make at least 150 kw at the wheels (not sure if he said a high flowed T28 or not). Again, people say lots of things before you give them your money so not sure how accurate that is. I'll let you know as soon as I find out though.

i think i'll end up goin ball bearing, the lag on the T25 pissed me off. have seriously contemplated a disco potatoe, are they worth the money?? id like to have over 300hp atw, would $4000 get me there??? rebuild and turbo, probably extra for a decent computer i spose

if the lag on the t25 pisses you off then dont bother going to a disco potato. they take alittle longer to spool up than a t25 (not THAT much longer) but gives a nice kick in the ass... 4000 MIGHT be enough to get you there if you can do everything yourself. and the motor doesnt need a rebuild. you wouldnt be able to keep it at a daily 300rwhp. the motor would die pretty quick with stock internals... and a rebuild with forgies will cost around the 4000..

Hi Sooty
If you are finding that lag is an issue with the standard T25 there might be an problem with your set up as they achieve maximum boost very early. What rpm are getting to full boost in second and third gears?

If you find there isn't an issue I wouldn't go any bigger than a T25G as even a .60/.64 T28 will have noticeably more lag than the standard T25.
Regards Matty

it was boosting to about 6-7 pound at about 3500-4000rpm then would hit full boost at about 4500. from 2000-3000 it went from like 2 - 4 pound i think. it was ok but it seemed like an eternity before it'd pick up boost
if thats not how it should be what could the problem be???

im runnin a ca box and 3.9 R31 skyline diff, pretty big front mount cooler, k&n filter,
2 1/4 exhaust and about 9psi. pretty basic set up.

a standard ca18det shouldnt have much lag
i big fmic will make more lag but not much i have a sr20det standard wit big fmic and 14pis and there s a split sec of lag and i mean split sec

these turbos crack on inside usualy in the wastgate hole area Very comn
when get hotter crack get bigger..

also the ball bearing types have a divider inside this strengthn this fault in the turbo

just a possibility if all else on outside is fine.

I may have missed it somewhere but are we talking about a T25 on a CA18 or on an a-series?

If we are talking about CA18's then lag should be non-existent with the stock T25. I am still running the stock turbo on mine and it annoys me how it's on boost so easily. I haven't tested it but it would easily make 8psi by 2500rpm but probably earlier.

If we are talking about an a-series then those response figures that were quoted earlier sound realistic.

from sooty-grunter s other threads i would think he has a ca18det .