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Hiya all :cheers:

If you've seen the "Pushing a mostly stock R33" you'd know where this question comes from.

Anyway, I have an R33 Spec2 and would like to run ~2psi more boost and hold it properly. At the moment I have a GFB bleed valve controlling the boost level, but it bleeds off quite quickly after peak boost is reached - though I know that the Rb20DET turbos seem to run a couple psi higher boost than the RB25DET ones, so theoretically if I used the same boost control they do I should get similar boost behaviour - so wouldn't really need to rely on a bleed valve.

I can get an R32 RB20DET turbo for free, does anyone know if I can use the actuator/actuator spring with the RB25DET turbo? Any thing I should know?

Cheers in advance!

Dan.

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Can you get me an actuator free too??  Im willing too experiment.

Yes they are a straight bolt on.

Haha - I'd love to :) One of my friends blew his R32 RB20DET turbo recently, running ~18psi through it :headspin: This is how I am getting one so FREE, I just happened to think of it when I was pondering how to alter my boost actuation.

How long have you been running 13psi through your stock turbo??? Thats pretty up there...

12-13psi for a good 8 months or more and it gets its fair share of caining.

Im ringing around now to find a R32 actuator, apparently you can bend the rod to put more pressure on the spring.

Yeah, I know about that way around it - but I would rather not :)

  • 4 weeks later...
12-13psi for a good 8 months or more and it gets its fair share of caining.

Im ringing around now to find a R32 actuator, apparently you can bend the rod to put more pressure on the spring.

Update - I have an R32 GTSt actuator on my car now :cheers:

On "stock boost" I am running 10-11psi, seems to come on stronger - feels particularly meaty around 4000-4500rpm. I find it hard to tell if its any better up top, there is definately a LITTLE drop off in the high revs. It will be going on the dyno on the 21st August for a boost and power read out, to see what the difference (if any) really is :)

I bought a HKS actuator and yes still notice some drop off, not as severe though.

Ahh ok - so the R32 actuator is a good (price wise) alternative :cheers: The ultimate would be getting an electronic boost controller then, but the better actuator is going to make its life easier... when I eventually get that sorted.

So you are still getting drop off below 10.9psi?

10.9psi for myself is the stock boost level for the rb20det actuator.

To hold more boost I elongated the actuator bracket holes and pulled the wastegate towards the front of the engine bay.

This preloads the actuator spring and reduces the total travel of the actuator, effectively stopping the wastegate from opening as much.

The result.... boost comes on harder and will hold anywhere up to 1.1bar without a bleeder, if adjusted too much it will get boost creep and make 1.1+bar.

This setup works best with a bleeder to help bring boost up hard in the mid.

The RB20DET's are pretty tough and will hit a fuel cut before you blow the turbo (well mine does at just over 1.1bar). So You drive along with the spanner adjusting. Or you can do it on the Dyno which is much much safer.

I've had it running 1.1bar like this with a bleeder for the last 6 months.

Prior to this setup I was running a Blitz SBC-iD and 1.1bar.

Which one works better and holds boost more consistently?

The bodge job with the bleeder, the EBC held boost well but driving up a hill on load at around 3000rpm and putting the foot down would see a boost spike.

Its cheap.. A Free MOD!.

For the R33 people, I think the best thing to do is get one of these R32 actuators on your car, and then mod the factory bleed solinoid so it's on all the time (there's a DIY thread about doing this).

So you should get the (new) stock boost of 10psi with the R32 actuator, and have the factory solinoid bleeding off to bring it up by 2psi = 12psi :cheers:

Total cost would be just the R32 actuator, and you'd have the benefits of everything looking totally stock standard :)

J

  • 6 months later...

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