9000 Aerd Stg3 boost levels

[sevenman]

I seem to have solved some problems I had with fluctating boost levels, and am about to order a new APC valve to cure this (am currently using one provided by Mark E).

While the boost seems steady, it only goes as far as the start of the red section on the in-dash gauge. This is about what it was before the upgrade, and lower than before I encountered the recent problems.

I disconnected the battery overnight as I was worried the car may have adapted badly after the problems, but this morning the boost still wasn't as high as expected.

I plan to order a good length of vacuum hose to allow me to connect my graduated gauge in the car and get some values - does anybody know what I should expect for a Speedparts Stg3 on a 9000 Aero?

Thanks

[philcrombie]

I had this and it gave just over 1.3bar peak at about 3krpm or so.
On a cool day it would go past the end of the red and into the black.
End of the hatched area is about 1.1bar max so same as standard

I guess this is the list I would go down:
1) Have you ever run your stage 3 properly - it's not out of the realms of possibility that the ECU still has it's standard tune/there's a fault.
2) Dump valve is leaking
3) Wastegate is leaking or base boost is off. (Check with your gauge)
4) Leak in small bore hoses - I think you said these were all new? Can't recall, but if not get them done as they will fail evelntually and it's pennies.
5) Other leak somewhere - less likely but worth going round and tightening all the jubilee clips.
6) Are you using optimax/97+ Ron? Won't get full boost without it.

hmm -that's all I can think of for now. Shouldn't have sent me that DV back so soon !!

[sevenman]

1) Have you ever run your stage 3 properly - it's not out of the realms of possibility that the ECU still has it's standard tune/there's a fault.

I think that in the period between the install and the APC problem it was running fine and producing boost just past the end of the red area.

2) Dump valve is leaking
3) Wastegate is leaking or base boost is off. (Check with your gauge)

I think these were tested when I unplugged the hose from APC valve to wastegate and it produced super-boost.

4) Leak in small bore hoses - I think you said these were all new? Can't recall, but if not get them done as they will fail evelntually and it's pennies.

All new other than one to in-dash gauge.

5) Other leak somewhere - less likely but worth going round and tightening all the jubilee clips.
6) Are you using optimax/97+ Ron? Won't get full boost without it.

Always runs on Optimax, despite Shell closing all local stations


Shall give it a while and a few more drives before I worry too much.

[mac_xpert]

I would agree with the above, but i would check the large diameter hoses form the turbo into the intercooler and upto the throttle body fully. The jubilee clips can loosen, but the hoses can also perish and split.

[sevenman]

Sadly I don't think it is to do with any of the large hoses. During my diagnosis tests I unplugged the hose from the APC valve to the wastegate. This allowed the car to produce very high boost levels. After a couple of short tests I stopped doing this for engine health reasons.

I think that rules out any problem with the actual process of creating high boost.

More tests will be done this weekend as my new APC valve has arrived and more hose to be able to easily connect my graduated boost gauge.

[sevenman]

My new APC valve seemed to have cured the problem.

The car now merrily boosts past the end of the red and holds fairly steady.

It's hard to spend very long with that much boost as I just end up going too quickly