S15 Turbos in R32 GTR

[Sacony]

Does anyone know if two S15 turbos can be used in replacement of the standard R32 GTR turbos?

[Roy]

I have thought about this myself.... as a sort of poor mans N1s. Unique Autosports in Sydney ran them on a VG30 in his 300ZX. The engine made well over 300rwkws on an engine with plnety of blueprinting.

So would be interesting to see hwo they go on an RB26, only prob i can think of is if the exhaust/dump flange may be different despite both being GT25s...and also whether the std wastegate actuator clears everything

[tang0]

they would also lag like whores as they are designed for 2.0 litre engines, and you are only flowing exhaust from a 1.3 into them ..

other than that they should be pretty sweet

[Roy]

Yeh but have you driven an S15, the turbos are very responsive. The exhaust A/R would most likley be the same as the HKS 2530 / Nissan N1s at about 0.64.

The way i see it is they are more/equally responsive to 2530s on the SR20, can make 200rwkws on an S15, use steel turbines, but i suspect they are 270 degree plain bearings just as the std R32 GTR turbos are. And they are dirt cheap, you just have to fight CA owners for them.

I dont think they would be laggy at all. My only concern is the orientation of the wastegate actuator

[Sacony]

thanks for the repy guys, was hoping someone had tried it. was suggested to me by an S15 owner.

[jaik]

Dont forget GTR manifolds dont have studs in them like the S15 ones, therefore youre going to have to either put studs into the turbos or use some massive wild bolt

JK

[daler32]

seein as its for a 2l wat bout for a rb20 oh and before i get owned i know nothing at all bout turbo compatability with anythin just attempting to find out more

[32vspecII]

they will require a new custom manifold and dump pipe to fit on a rb20 . but they will be quite well matched to the rb20 . support about 200rwkw , possibly more with cams. they are not ball bearing however unlike similar aftermarket garret GT turbos so dont pay to much

[predator]

they would also lag like whores as they are designed for 2.0 litre engines, and you are only flowing exhaust from a 1.3 into them ..

other than that they should be pretty sweet

I doubt it.. a single turbo off a GTR is fairly small on it's own and wouldn't really give much power to a 2L either. But in twin form they do quite well

2x S15 turbos would be interesting.. although in the end probably too expensive for the gain. Seeing as every other SR owner wants them, it's probably almost as cheap buying two separate aftermarket ones.. or even better an proven RB26dett twin turbo setup in the first place

[discopotato03]

S15 turbos are a modified Garrett GTBB , 2 x 360 deg annular contact BB's . The CHRA is very similar to the Garrett GT28 "320 hp" turbo with minor differences in the compressor wheel to improve response and efficiency .

With the right housings they could work similar to 2510's . The turbine is not the same one used on GT2530's , 28RS's etc so don't know what the engine rev potential would be in the higher boost ranges .

I believe RB26's need compressor covers with the two mount holes for that water/oil plumbing gadget .

Unless they are a give away something designed for the RB26 would be easier to bolt up . You can buy from Garrett a BB GT28 thats in theory identical to the HKS GT2530's so new for less than the HKS tag . I think those open bladed NS111 turbines are worth the effort on an integral gate setup . I'd reckon a fiddle with the cam timing could offset the trivial amountof lag these turbos give over the std bush bearing T28's .

[Cubes]

The S15 I drove really didn't make all its boost until around 3000-3500rpm (1bar).

They do actually feel very similiar to an RB20DET running 1 bar as to where and how power is first made.

The Difference with the s15 sr20 is the gear ratio's are shorter & it appears to have more torque off boost which makes the car feel less laggy but really if you watch the rev's and boost guage they get up and going at roughly the same rpm's. Boost is made earlier with the sr20 but peak boost still takes until around 3000-3500rpm.

If that makes sense?!?!

So lets say the 600cc drops spool time peak boost for the sr20 turbo's down to around 2600rpm.

2600rpm x 2 if you were to use two of the suckers would = peak boost by around 5000rpm.

I'm not sure if it works like that in practice though.

[TTT]

there are 2 different turbo's on the S14's S15's..

not all are ball bearing..

here is how you tell them apart.

All that matters is the garret number, everything else just confuses matters

466541 = ball bearing

466543 = bush bearing

for the second bit of the number

-001 = S14 turbo (no splitter between wastegate and turbine exit)

-002 = S15 turbo (splitter between wastegate and turbine exit)

serial numbers are your friend

and it doesn't matter if it's a JAP spec or AUS spec.

there were some BB aus spec's and some NON BB Jap specs and vice versa.

to give you an idea of what the true BB ones are like on an S15, on of the guys in the nissan Sports car club in sydney gets 1.2Bar boost by 2200rpm and holds till close to red line.

[32vspecII]

most aus spec ones are not ball bearing there are very few infact . if you go through nissan and ask for a replacement s15 turbo you will not get a bb turbo . which sucks because they are only about $1200 thru them .

In short it may be hard to find a true BB s15 turbo and be carefull when buying 2nd hand if its claimed to be BB . CHECK THEM NUMBERS!

my 01 aus spec is not BB

[OkiC33]

What us really poor people do over here is buy GTR Nismo Turbines, w/ the exhaust port and put them on the CA Silvia's. It's a great drift setup, and i'm guessing since you can put a 15 turbine on a CA, and you can put a R turbine on a CA, they both probably fit on the R. I know to put R turbines on CA's you have to rotate the compressor side 90 degrees to get it to fit on the manifold. So you might have to do the opposite when putting a 15 turbine on an R.

[discopotato03]

I know you can buy the S15 BB CHRA , maybe not through Nissan but Garrett dealers can get them . One I know has tons of second hand stuff so he could cobble one together .

[pnblight]

ha guys i mate of mine REP003 is installing a rb26 in his 4door gts and has the std turbos fitted with s15 ex housings and wheels with gtr centre i think ,which had to have studs fit also i believe sounded pretty wild to me but should be interesting to see how well they work i will have get more detail off him, as only going off memory. And he believes he can use the s15 dump pipes (stainless separated unit)

the reason he did this i believe is to do away with the ceramic wheels

[rep003]

Thats true

I've just had GTR turbs rebuilt using SR20 shafts/zorst wheels/housings , but keeping the GTR core so the oil & water lines still fit! Just drilled & tapped 10mm studs in zorst flang to mount em......

SR20 zorst housing on GTR turbs

looks just like that