After Swapping To Rb25 Turbo On My 20, I Have Lost Power

[c0ntrol]

hey guys, its my first time swapping a turbo on anything other than sr20det.

few months back decided to get this rb25 turbo, i swapped it in, having to make a nipple/bung on the intercooler piping close to the turbo(because the 20 turbo has one on the compressor housing for the wastegate.)

Soo i start this thing up and take it for a spin, also whats noteworthy is i kept the rb20 actuator, it worked fine before and they hold more psi soo installed it on the rb25 turbo, when i tried to do a pull, i notice there is noo power at all when i get into boost, like feels even slower than if there was no turbo at all. i can still here BOV after closing throttle, but its almost always now accompanied by a backfire. I also stall just about any time i go into neutral from cruising.

I tried checking for vac and boost leaks, i cant find any, boost gauge doesnt spike or drop pressure when im on the throttle heavy.

theres no misfire or bogging under pressure, only the absence of power, and i can tell its running richer now too, despite no wideband at the moment. I can smell it. and not to mention all the backfiring.

I have even got another great condition low mileage 25 turbo since then and the same thing occurs.

My car ran strong before swapping the turbo chirping 2nd gear pretty hard. now i dont even think i can pull a toyota corolla. it is seriously soo slow.

the gaskets looked good when i swapped the turbo as well.

I am soo lost on this.

[Ben C34]

How did you try looking for leaks? Did you pressure test it?

[scotty nm35]

Sounds like a leak, otherwise your turbo may not have liked the extra boost... In which case call Hypergear.

Trusting in S/H turbo's will bite you in the ass most of the time.

[jiffo]

Sure you haven't left a rag in the pipework?

Most 20 owners have done the cheap 25 turbo upgrade and they go pretty well, my S13/Rb20 certainly did.

Noticed a big difference when I swapped back to the 20 turbo.

Keep checking.