Silvia Club of NSW

hey guys

im just checking out the horsepower ina box site for turbo prices, and see there are 3 t28 turbos.

which one is the t28bb that everyone is always talkin about?

besides the horsepower difference and the price, is there any advantage about getting the 450 one as opposed to the 350 one im thinking of gettin?

Garrett GT28 450hp ball bearing turbo $2149
Garrett GT28 400hp ball bearing turbo $1950
Garrett GT28RS 350hp "Disco Potato" ball bearing turbo $1815

about what rev's do these turbos kick in. my stock one on my 180 kicks in at round 3000 revs.

Garrett GT28 450hp ball bearing turbo = T04 inlet, 44lb/min flow, .70a/r comp cover, .86 exhaust housing. (will have lag due to large exh housing but will spool up hard at around 4000rpm)

Garrett GT28 400hp ball bearing turbo = T04 inlet, 44lb/min flow, .70a/r comp cover, .64 exhaust housing. (much less lag due to smaller exh housing but will reach a maximum of 400hp) IMO a better set up for mid range spooling at around 3200rpm. same core assembly as the 450hp.

Garrett GT28RS 350hp "Disco Potato" ball bearing turbo = choice of either a 2-bolt t25 flange or a T3 inlet, 39lb/min flow, .60a/r comp cover, .86 exhaust housing. claims of 350hp is not giving enough credit. ive had this one on my SR20DET and produced 220rwkw with supporting mods. ive measured 5psi of boost at a very low 2200rpm but the noticeable spooling up is at around 3000rpm.

to give you a run down in my opinion, the 450hp GT28 is perfect for a set up including FMIC, zorst, computer, larger injectors, cold air induction.. etc, stage 1 cams.

the 400hp GT28 to be used with much the same set up but can get away with standard internals and cams and should still produce around the 230rwkw mark

the disco potato once again is a good all rounder much like the 400hp GT28. similar power gains with early spooling.

all 3 have the typical GT series dual ball bearing set up. pretty much unbreakable.

just to confuse you even more, depending on your budget, you may consider the HKS designed GT25/35 or the GTRS. both of these are very much compatible with the SR20DET and retail at around the $2700 mark.
morrie from horsepowerinabox is very very helpful with technical support and turbo selection.
good luck with your choice.

The "T28BB" everyone raves about is the factory S15 turbo. There are a few versions, and it appears that most Australian delivered S15s came with the non ball bearing version, which isn't quite as responsive as the ball bearing one, usually found in Jap spec S15s, and some S14s.

From memory the S15 turbo is pretty much identical to the Garrett GT28 320hp turbo.

_________________
The Engine Whisperer - fixer of things

thanks heaps for the info guys

id prefer a turbo which spools up earlier, dont really want to boost at 4000 rpm. i think ill get the disco potato one. 200 rwkw is plenty for me

mark

If 200rwkw is you goal then just get a 2nd hand S15 turbz, there have been many a S15 making this power with standard turbo.
With the money saved you could spend on heaps more mods.

On the subject of garrett turbos i've just been told there is no supply of 0031 cores for the GT2535 turbo i want.

What i have been offered is the same GT2535 housings but using the 0018 core which has a larger comp wheel. Are then any dangers in mix and matching parts like these ?

really? who told you this joe?
going the 0018 CHRA might require the .70 comp cover. not sure, ill make some more enquiries. im guessing the comp wheel may be too big for the .60 cover. if someone can correct me or back up what im sayin, id like to know for sure but IMO, technically, i think im right.
GCG seem to come up with good combos. they may be able to source the right core for you. if not, try John at Garrett in chipping norton.

Morrie mangaed to find one for me, and at a dam good price too compared to GCG and Ray Hall.

It was either the Disco Potato or the 2535 - 0031 Chra and i went for the 2535 due to the fact it looks exactly like the stock turbo.

Once its on ill let you know how it performs !

very good.
how much did morrie do it for?

$1700

Ray hall wanted $2300 and GCG $2500

excellent. he's very fair with prices.
ill stay tuned to see how it performs.

Charles,

What are you putting in the new S15?

I'm curious to see what baby you're going to fit as I'll be doing a turbo myself soon.

Not sure what I'll choose, the Disco or the 400HP version..

hey eugene,
well as you know i got rid of the s14a but before i did, i took out the turbo and put it in my brothers car. it is infact the 446179-0032 CHRA with a T3 inlet and .64 exhaust housing. much to my surprise, with the absolute correct tune, we are now getting 250rwkw at a perfect 12.4 a/f running on 15psi of boost and not a pound more.

what ill do is more than likely get the same one again for mine once i complete the other supporting mods. should be in about 3 weeks to complete everything. im sooo jealous. i hate driving a stocky.

250rwkw without cams right ? Excellent. The 0032 is rated at 400hp isn't it ?

Haha,

Top stuff. That's a fantastic power figure your bro is achieving. I was hoping to get about 230rwkw with the 400HP version. Also, some guy is selling the same turbo for $1750. Do you think that's reasonable?

And finally, what support mods does your brother have? Where did he get her tuned?

cheers matey,