R33 - 7psi limited boost no matter what

[locutus_of_bris]

Ok, finally have an aftermarket ecu in the car and went to the track for some testing instead of just fun.

It came about in a race when the bleed valve hose came off and the boost pressure never changed. Then in the pits we set the rev limit to 5k and wound the advance up from there to spool the turbo to flat out, again we never passed 7psi.

The car is stock essentially, as far as I know turbo is standard and only has cat back from a previous owner. I am presuming it should go significantly higher than 7psi and now I am pretty much ready to do some winding up as the new ecu can control all of this as a preset or from a dash dial.

Should I be looking for a wastegate problem/adjustment/fault or is there something else?

Any suggestions welcome

Thanks in advance

D

[locutus_of_bris]

kick

[Guilt-Toy]

Need more information

[paulr33]

well if you were running and the bleed valve line came off then you would have lost manifold pressure and the actuator would have never opened which would have resulted in some catastrophic event??? anyway the ecu won't control boost nor does it have the ability to. the stock boost is about 7psi, controlled by the turbo's actuator. if you change the actuator spring to a higher pressure one, it will open later. or you can change the rod length also. or you can get an electronic boost controller and trick the actuator into seeing less pressure than is actually at the manifold so it opens the actuator much later, thus running more boost.

so in summary you need a boost controller.

- actuator change

- actuator rod change

- electronic boost controller

- bleed valve

[grim32]

first check all intercooler hoses,never no one could be split. wire the wastegate shut,drive with caution it should boost up. if not drop the dump pipe and check that the wastegate is seating and isnt broken. if all fails might be time to pull the turbo off for inspection

[blur]

my old laurel (with r33 gtst rb25det installed) would not boost above 7 psi at first too, but i found the factory bov was leaking, blocked it off and hey presto, more boost!! may be worth trying, blocking it off??

[locutus_of_bris]

Thanks for the suggestions people, definately gives me something to go one with.

Paulr33 - I have a bleedvalue on the wategate actuactor but this is the hose that came off - making me thing it must be jammed in its current position or it should have boosted off the scale. The ecu I am running is capable of controlling the boost with the factory components fitted but even trying this we peaked at 7psi. So it must be a prob that under any (including fault condition) its limited to 7psi. Might be just as well given the bleed valuve hose came off and going off scale is not a place I want to be.

Grim32 - I will look into this and see if there are any probs in that area. Kinda was what I was thinking but never had to deal with it before. Also hoping to get rid of the factory turbo soon anyway - the new ecu wants more

Blur - I will try that as well - easily enough done to see if it's a quick fix.

Will let you know what I find. Can't wait to finally have a bit more than 7psi.