Wastegate Issues

[sleepydsm]

1992 Tsi AWD 5 spd blah blah blah

I have an external HKS standard (40mm) wastgate on my exhaust manifold. It has a "1 bar" spring (its yellow).
Mods:
BR 20G
FMIC
660 Injectors
SAFC(five knob)
GM Maf/Maft
Greddy Type RS BOV
255 Fuel Pump
Adjustable FPR
CAI


My Setup:
I put a manual boost controller on my car today, preping for the RF rice day tomorrow. I put the MBC on a line going directly to my wastgate. That vaccum line starts at the intake manifold, goes to a t, and then to the wastegate. My bov is hooked off the T fitting.

The Problem:
At WOT, maybe 85%+ throttle at least, when the boost goes past 20 the car studders and shakes. Its as if the wastgate is fluttering, kinda like howa a BOV does. This only happens when there is a boost controller on the car, and its above 20 PSI. Anyone have any ideas whats wrong? I assume my wastegate is fine because it works as it should when the MBC is NOT hooked up. Thanks!

Kevin

[Swifty1638]

you sure it's not misfiring? pulling timing? Cause it's bad to run higher then 18 psi on pump..you running around on bonnie and steve's 111?

-A. Swift

[dsm10sec]

Cause it's bad to run higher then 18 psi on pump..


MAYBE if you dont have control of timing...

[Swifty1638]

true, but the fuel characteristics of 93 octane these days..I'd never run higher then 18 psi on pump..would you? timing only gets you so far..

-A. Swift

[TheBlizzard]

Saying you can't run that much boost on pump is a very general statement. All cars are different and just because your doesn't like it doesn't mean the next car will not. It has a lot to do with what turbo he has as well as his supporting mods, if he has a 14b I would be more worried about all the hot air coming out of that turbo at 20lbs than I would be about timing or anything else.

Sleepy, you are going to have to list more about your car in this case because if you don't have sufficient supporting mods then yes you could be just running to much boost which could be causing a lot of problems. Edit your first post with more information or I will delete this thread all together because the only answers your going to get from your question are assumptions.

[CDeutsch]

If it feels like the BOV then maybe it is. ;) You could try giving it it's own Vac/Boost source. What BOV is it and is it vented to atmosphere? Need more info, like TheBlizzard said.

[blageo23]

I could maybe list the mods hes got. So when he checks it he might have the answer.
His Mods:
BR 20G
FMIC
660 Injectors
SAFC(five knob)
GM Maf/Maft
Greddy Type RS BOV
255 Fuel Pump
Adjustable FPR
CAI
That should be All the info you should need.

[JET]

20 psi might be it on pump gas with that setup. With some tuning you might be able to run a tad more. Try retarding the base timing 3* or so and see how much that helps.

[sleepydsm]

Thanks Mike for listing that info. Sorry for not listing enough info! And yes I'm pretty sure it's just my retarded Greddy Type RS. I think it just isnt set hard enough to hold that kind of boost. And I'm not ghey enough to use 93 octane, I use BP 92 ;) And maybe one day I'll get me a 5 gallon pail of VP import for the hell of it.

[TheBlizzard]

BP 92 is better than Holiday 93 or most other pump gases so you are using the right fuel. And if you blow off valve wasn't holding the boost it would just leak out, I doubt it would studder and shake like that unless it was somehow surging.

Like I said earlier it all depends on your car, some cars like more boost with less timing and some cars like less boost with more timing. In most casing more boost equals more power even with less timing. So in my opinion you would be better off lowering your base timing and then try to run more boost and see if it doesn't knock.

And as far as your BOV goes, if you adjust it and it doesn't go away then try a different one to rule that out. There is a chance that the WG might be messed up to but the symptoms from that are going to vary depending on whats wrong with it. I think Shanes WG messed up recently, maybe he can shed some light on what happens when they take a shit on you.