Rb25, R33 Wastegate Problem

[goldgem]

I have recently finished buiding my r33 from a few bits and peices, engine wise its all standard with 3in exhaust and fmic, pod filter.

it runs fine but hight rpm around 4500 rpm the boost spikes to high around the 14psi mark then the timing retards and i get quiet some noise out the .

the tests i have done on the wastegate shows that at 8psi it starts to open a few mm but does not fully open untill 13psi. the turbo and waste gate are all standard so obviously the boost is way to much and i want it to run standard which i belive should be 8psi.

I was under the impression that the standard waste gate would fully open at 8psi not 13psi. is this correct??

regards adam

[Harey]

What sort of dump pipe do you have? I know some people have issue with split dump pipes causing the wastegate arm to fail on the dump pipe and cause higher boost.

[**RB2530**]

I have recently finished buiding my r33 from a few bits and peices, engine wise its all standard with 3in exhaust and fmic, pod filter.

it runs fine but hight rpm around 4500 rpm the boost spikes to high around the 14psi mark then the timing retards and i get quiet some noise out the .

the tests i have done on the wastegate shows that at 8psi it starts to open a few mm but does not fully open untill 13psi. the turbo and waste gate are all standard so obviously the boost is way to much and i want it to run standard which i belive should be 8psi.

I was under the impression that the standard waste gate would fully open at 8psi not 13psi. is this correct??

regards adam

How are you testing the WG?

If you are doing a static test (ie car not running and just putting air pressure into actuator) the results won't mean anything. The reason is that when the engine is running there is also some exhaust gas pressure on the WG flap that is helping it to push it open...So its opened by a combination of actuator pressure and exhaust gas pushing on it.

From what you are describing the problem may be that the WG flapper is not opening as much as it should. This could be because it is fouling on something in the dump or the linkage is binding or jamming which is stopping the WG from opening as much as it should.

[goldgem]

first thing i did was check the wastegate clearance and its all good and not binding at all, its a non split dump and im sure its noting to do with the waste gate. im starting to think the acuator may be a r32 type hence the high pressure to open. im trying to get my hands on a r33 waste gate to test and see what happening.

I have been doing a static test, and it "does not mean nothing" im sure the test is not 100% but i dearly doubt that no exhaust gases would make 8 or so psi difference.

any other thoughts

[**RB2530**]

first thing i did was check the wastegate clearance and its all good and not binding at all, its a non split dump and im sure its noting to do with the waste gate. im starting to think the acuator may be a r32 type hence the high pressure to open. im trying to get my hands on a r33 waste gate to test and see what happening.

I have been doing a static test, and it "does not mean nothing" im sure the test is not 100% but i dearly doubt that no exhaust gases would make 8 or so psi difference.

any other thoughts

Good to see you have checked for binding etc.

Ummm, sorry but I don't agree that the exhaust gases would not make a difference.

Good luck with it...Hope you get it sorted...