Rb25 Split Dump/front Pipe On Rb30

[joe blo]

hi mates. i just bought a rb25 dump/front pipe in one. since the rb30 is taller i believe il have to make the pipe longer on the down pipe. is it as simple as getting another bit welded in on the straight part that is equal to the difference of the rb30 and rb25 block or will the angles be out or any crap like that?

will have my rb25-30 done real soon finally. what power do you guys rekn itl do on standard rb25 turbo? not looking for a full beast. just wanna get it in the car and driving finally. and what psi would be the max i should run on the turbo? isnt it 12 psi on a rb25 so i should go less because of the extra capacity so the turbo will need to spin faster to make the same psi? so id go like 10psi max or something? will be running wolf3d ecu and standard injectors with bigger internal and external fuel pumps and surge tank. its a rebuilt na pistons bottomend 1mm oversize with standard cams and full 3 inch exhaust from turbo back.

thanks guys

[Adriano]

I would go 10 psi, should make around 200rwkw

[TiTAN]

yes you can use the old dump, mark the dump so you know how it lines up, chop it, fit both halves to the car, measure the gap and weld in required size piece to fill it.

[joe blo]

my rb25 turbo has a 10 psi actuator off a rb20 i think they are. that with a full 3 inch exhaust and greddy copy plenum and 80mm throttle body and stuff will make it go to like 12-13 psi wouldnt it? so should i go back to a rb25 actuator and just run it at whatever it goes to? hopefully not much over 10 psi

[bubba]

RB25 turbo on RB25/30 should make about 180rwkw but will choke the engine up, my power would fall over about 5800rpm.. by the time it got to 6800rpm it was only making 90hp...

I had to change to taller diff gears to make proper use of all the extra torque (went from stock 32gtst 4.3:1 to s13 auto 3.9:1)

It is a lethal combination though.. spooled from idle, 12psi by ~2200rpm so instant full boost in any gear and rolling on in 5th when others have to drop back a gear. Drop 2nd at 3000rpm without bogging down, fun times.