1G RB25 Turbo Conversion

**cultus** · 05-09-2007, 02:14 AM

Aug 31 was Malaysia's National Day, my friend was away for VW convoy, so I have his workshop to myself. I only have a day to do this but I got most of the flanges done and parts .. all shops are closed.

My front turbo was jamming up, register boost according to my meter, but the car has no power at all after 3krpm, so basically I was driving NA without boost.

The manifold, I have enlarged the restriction you see there of course

Flange ready to match up to an elbow for the down pipe. 2" diameter a bit smaller than ori downpipe

Started at 10am and at 7 pm wah la

So much more room now, the exhaust shop was having a nightmare last time trying to bend the pipe with the mounting, steering rack/column in the way. Will try to recycle the ori heat shield for the clutch pump one of these nights

I adjusted/turned the inlet housing, so now the actuator not really pulling well. Was running at .4bar only

So clamped the copper pipe and stuffed a few cable ties inside, now at .8

**IN 05 NT** · 05-09-2007, 07:48 AM

haha love the boost controller!

**chris davey** · 05-09-2007, 08:18 AM

Did you have stock turbos before? Or was the manifold you modded used with some other single turbo?

How does it compare to stockers.

A lot of work for one day. I would always get stuck waiting for parts.

**cultus** · 05-09-2007, 03:40 PM

The cable tie is a first for me as well

getting late and desperate, the copper pipe clamping was ineffective, can't find correct size vacuum pipe ...

Yes I was having the stock twin turbos, could heard water boiling sound somewhere near the distributor each time I stop after hard driving. It was running fine after the 1G conversion 2 yrs back, 6 months ago, they started whistling on and off but car running even better, then end of story for the front turbo.

I got the blitz manifold only, the matching KKK was sold, as I wanted factory turbo ( price & availability ) so I did the flange to fit the RB. Both the RB 20/25 can be used.

RB 20 : "nissan motor", most common here with "16V"
RB 25 : "nissan" only, with 45V1/2/3
At a glance, they are almost the same and I got away with RB20 price.

It is better than the twins I had, lower rpm bit more responsive than before, with better pull after full boost as well. The engine compartment is hotter without thermal shields, so I raise the hood with 4 nuts as spacers.

**Mr Multivalve** · 06-09-2007, 03:08 PM

That is an impressive amount of work, looks a bit like my engine bay good job.

**mrshin** · 06-09-2007, 07:40 PM

The welding on the pipes, and especially the wastegate rod, is pretty, er, special!

**Hydra** · 07-09-2007, 12:07 AM

Uhh, is that evidence of welding on the steering column??

**cultus** · 07-09-2007, 04:09 AM

The steering rack was from the GA70 halfcut, I think it was too long even after fully retracted, so cut and weld.

I can't weld ... you should have seen the huge bulge of weld on the oil return pipe that was coated with gray silicon ha! ( now it's nicely grind down and coated with copper ) An aquarium valve has replaced the cable ties as well.

**EldarO** · 07-09-2007, 04:26 AM

the next mofo that calls me dodgy after seeing this, i swear, ill punch in the throat.

love the work though, WRX turbo wouldve been a better choice! cant argue for the price and time involved, ghetto boost controller FTL!

Elmo.