Hey guys i know its probably been asked before but i cant find anything specific in the search. i'm currently putting a rb20 into my 92 bmw. so far the mods for the motor are r33 turbo, custom intake plenum, front mount short plumbing, 255lph fuel pump, remap chip for the ecu. what i'm aiming for is about 300horsepower at the wheels. What other mods am i gonna need to get close or over my power aim, like bigger injectors or after market exhaust manifold, cams etc. i'm gonna run about 15-16 psi everyday and eventually forge the motor. any help appreciated cheers

15-16psi on stock RB turbos = Epic fail 12-13psi is a safer (slightly) option

and from what ive seen rb25 turbos on rb20s will make around 200rwkw. 300hp is 225kws.

post up some pics of how it fits as ive been wondering about a conversion of this sort for a while.

why go through all that effort with the conversion for a rb20?

go rb25 i cbf going through why, just do a search....

unless u really dont have room, go rb25

the reason for rb20 is for one cost to start with and if/when this motor fails it will be getting a fully forged rb30det(rb25 head). and for now the 2 litre keeps my insurance down as i'm already payng heaps for a euro car. As for the turbo i will post pics of my mates bmw with an rb20 which is running the standard rb20 turbo and has been running 15psi for the last 18-19 months with no problems/smoke. The turbo willbe staying as is for a month or 2 till i can upgrade but my exhaust will be very custom so i'm chasing a turbo that will fit both my t3 flange manifold and the dump pipe

You will need a bigger turbo than the standard RB25 turbo to make 300rwhp

Something like a HKS2530 or RB25 high flow turbo will get you there

the rb25 turbo isnt ball bearing is it? what other turbo's of standard cars will fit and be adequate? dont want to pour thousands into the turbo setup

rb25 turbo is ceramic, and isnt ball bearing unfortunately.

they cant/shouldnt take more then 13psi (11 to be uber safe)

as suggested, try the hi-flow option, or the hks 2530.

cheers

eddie

Yep you might get away with around 14psi since its on a 20, few people have and most you will see is 18xrwkw on an internally standard 20 thats in pretty good nick with supporting mods

I would suggest a second hand high flow if your not looking at spending a great deal

high boost is a problem on the rb25 turbo itself, not really on the engine.

engine wise, should be good on 16. but the turbo cant take more then 12 to be safe

kool thanks guys might run 14 to start with till i get my hands on a second hand hiflow. any tips on where to find one/suppliers? the reason i was thining around that psi is mainly because my mate has been running 15psi for 18 months racing/ draging the car and has not had the turbo fail and it is only a standard rb20 one

i run 15psi on my rb20 with rb25 turbo all day long n been good for months.

14-15 is real high man i wouldn't recommend that at all!

pffft 15psi is safe lol, yeh run 15 through it, then dont complain when the rear wheel falls off, and the front wheel then chews into the housing shattering the wheel putting metal peices into your intercooler or into your engine...

just do what is suggested... 12psi and save up for a highflow that you can push 18psi through.

maybe its just me, but id rather do things right the first time, even if your on a budget (even more so if your on a budget)

rb25 turbo is ceramic, and isnt ball bearing unfortunately.

they cant/shouldnt take more then 13psi (11 to be uber safe)

as suggested, try the hi-flow option, or the hks 2530.

cheers

eddie

Rb25 turbos are BB...and ceramic...

the rb25 turbo isnt ball bearing is it? what other turbo's of standard cars will fit and be adequate? dont want to pour thousands into the turbo setup

rb25 turbo is ceramic, and isnt ball bearing unfortunately.

they cant/shouldnt take more then 13psi (11 to be uber safe)

as suggested, try the hi-flow option, or the hks 2530.

cheers

eddie

R33 turbo's are BB, i know this because i was told they were not and went out and bought a bush bearing rebuild kit for my S1 turbo only to discover once we got the turbo apart that they are actually a GT28 as opposed to the T28 which is a bush bearing.

Actually there a hitachi turbo not a garret....so they aint t28 nor gt28

Thats just basicly a rough size estimate that is given to them (the stock turbos)

You will be able to run slightly higher boost with the rb25 turbo on an rb20 rather than an rb25 because of the engine capacity.. I did say SLIGHTLY higher tho..

edit: i do agree you will probably struggle to get near 300hp with this setup..

Edited May 22, 200818 yr by nitestalkr

Actually there a hitachi turbo not a garret....so they aint t28 nor gt28

Thats just basicly a rough size estimate that is given to them (the stock turbos)

obviously the turbo is the same as a garret then since MTQ use a T28 rebuild kit for them.

would the stock rb20 clutch handle that power?

Edited May 22, 200818 yr by mark_sudakov

If the clutch is a new standard clutch...then yes...but why would you put a new standard clutch in...