Can I Borrow A Spare Actuator - Please :)

[benl1981]

Hi guys,

Having issues with my car (R33GTST), The boost is dropping from 18psi below 6000rpm to 3 psi (i.e. dropping 15psi) above that. Something wierd is happening. Just trying to check the actuator. I've tried 2 seperate boost controllers and once the boost is set above 12psi the boost drops off badly. Set at 10psi it will hold to redline

Anyone got an rb25 or rb20 one I can borrow or buy. I'm trustworthy

I think it could also be the exhaust, going to try dropping that and taking it for a run.

Cheers

PS. Im on the northern beaches. Would travel to hornsby etc...

Edited February 14, 2008 by benl1981

[Abo Bob]

I've got an R34 one in Sutherland!

Check your cat.

[SECURITY]

ive got one at my place (somewhere) for an r33 gtst. im in bankstown.

[stolen_s15]

You have the GCG hiflow correct?

Some of them tend to do this, search for ghetto actuator mod should sort you out. Try and source an rb20 actuator too, and do the mod to that.

[benl1981]

Thanks a lot guys. Might see if I can get closer though..

The preload is ok. I have an Rb20 actuator on it now that Im thinking may be suspect.

I have dropped the cat and it appeared ok.

The centre muffler is also under scrutiny

I hope its not valve float or anything more major.

Sometimes it will rev to redline perfect but most of the time boost will drop to about 3psi

The thing is it worked perfect on the dyno for 2 hours and for the first week. Something has happened!

Edited February 14, 2008 by benl1981

[Abo Bob]

When I first boosted my GCG with stock actuator hard it ran fine at the higher boost - 1.2 bar - for about 3 weeks then just wouldn't hold it anymore. I replaced it with an adjustable HKS one and that fixed it.

[benl1981]

Nice to know abob. When you say didnt hold how much was it dropping? Mine is dropping from 1.2 bar to about 0.2bar!

Thanks

Hopefully this will fix it!

[evil_weevil]

gee's Ben thats no good!

What does Yavuz think it is?

Unfort I havent got anything to lend you mate

[benl1981]

Hey Chris! I ended up getting my car tuned by MRC in Castle Hill. Closer to work. Mark is pretty reasonable and seems to know his stuff.

He thinks it is either the actuator/boost controller or collapsed cat/muffler.

I have kind of ruled out the cat and the boost controller.

Going to try the actuator and then drop the rear exhaust..

Hows your beast going?

[FATAZZ]

Ben,if you haven't already got 1 i do have a rb25 actuator here at Doonside. all yours if you like.

[Abo Bob]

Nice to know abob. When you say didnt hold how much was it dropping? Mine is dropping from 1.2 bar to about 0.2bar!

Thanks

Hopefully this will fix it!

Never dropped that much, more like 1.2 down to 0.9 which is why I suspect exhaust but maybe your actuator is broken rather than just oo weak to hold it.

[benl1981]

Thanks for all the help lads.

Turns out my actuator is fine and everything else.

I modified the air snorkel to clear the FMIC intercooler pipe. (Im still using stock air box).

I just took the air snorkel off (sucking hot air I know) and holds 15psi to redline. Peaks at about 18. Just as I had at the tune. I had created too much of a restriction by reducing the air snorkel in places to clear the pipe!

I pulled off the inlet plenum (not fun), dropped the cat, Pressure tested inlet, bought HKS actuator and the answer was right there!! Could have saved all that mucking around

I guess on the dyno the bonnet is open so the problem didn't show up.

I might reuse the snorkel but bring in a cold air feed into the bottom of the snorkel..

Edited February 23, 2008 by benl1981

[Abo Bob]

Well at least you know now. It didn't sound like actuator to me but I didn't think of intake.