Well, after a couple of days on the T25G I'm very happy with the results of changing the turbo over from the Mitsubishi TC05-12A to the Garrett (Nissan) T25G off my old Silvia on the 4G63B you see here. There were a couple of problems with correct vacuum lines and having the standard SR20DET BOV venting to atmosphere, but once the BOV was 'plumbbacked' and Roy from C-Red sorted out the vacuum lines, all was running much better. Unfortunately I can't screw too much boost in due to a detonation problem, and the boost cut that the standard ECU has (50% injector duty cycle).
Next I'll be getting the vacuum advance sorted out and then look into how I can change the fuel and stop the boost cut. We were going to be intercooling it but couldn't find an easy route to the front, but we'll be looking at moving the washer bottle and overflow bottle soon which may give us access through to the front area. Unfortunately, unlike the Starion, there's no room to go around the sides of the radiator.
Pics of the completed conversion:
- Overview (from top)
- Garrett T25G
- Garrett T25G
- T25/T28 Adaptor Plate
- Standard Internal Wastegate Actuator
- Standard S13 SR20DET Blow-off Valve
- BOV Return Pipe (uses part of an R33 Skyline return pipe)
- BOV Feed adapted into Intake Hose (I cringed when he cut this - they're hard to get hold of these days in good condition)
Of course it will never be 100% complete, but she goes a little better and sounds better now with the soft woosh of the BOV between gears. I have a small feeling that once the vacuum advance has been sorted out, I might be able to get a bit more out of her before hitting boost cut.
I also suspect some of you are asking yourselves why? Well, at first I thought the old TC05 was on its way out because I thought he compressor was banging against the housing - I now know the sound was the engine pinging its tits off! But the T25G turbo from my old Silvia I once owned and cost me all of $200. It's bigger than the TC05 too and in relatively better condition to boot. The cost of the conversion was more my time as I had a contra deal already setup with Wayne & Irene at Embleton Engineering in Myaree. As you can see, a top rate job was done. It will also allow me to use cheap T28 flanged turbos in the future - which reminds me I have that HKS GT-RS I should give a go for Drag Combat this weekend ; )