Hey everyone. I've recently got my Lancer Shelby back up and running with a very different top end and am suffering from serious boost creep issues, ie 24psi when I'd rather have it set to 10-14.
My setup...
2.5 Wisecos/ARPs throughout (old motor, nearly everything after this is brand new)
Todd Nelson ported G-head (new this year, had lightly ported head before)
+1mm valves, Comp conicals, PT cruiser lifters
TU R2 camshaft
T3/T4 50 trim hybrid, 63AR turbine (with ported wastegate) with a stage 2 exhaust, new large can WG
TU 3" SV, TU cast mani, 3" exhaust with open dump - (open during all testing)
Modifed 1 piece intake mani (cut open, runners shortened/ported, 3.8V6 elbow), 58mm TB
Large NPR intercooler
FWDP S5 3bar/+40s
I think that covers most of it. Now to the problem and what I've done.
It's been overboosting since I first got this thing running a couple weeks ago. It's much better than it has originally been. After setting my ignition timing the problem improved dramatically, and ign. timing has been double checked since, its right on. I originally had too much tension on the wastegate arm (adjustable). I have removed tension multiple times, each time the boost comes on slower at most RPMs but at high RPMs (45-5k+) the boost will still spike to 20-24 depending on what gear.
For nearly all testing I'm plugged manifold vacuum direct to wastegate.
This morning I removed A LOT of tension from the arm, to the point where I barely need to put any effort into putting it onto the swingvalve. I'm confident that its not a tension problem. I actually even had to shim my Z bracket closer to the swingvalve because my adjustable arm was on its last thread.
So with such little tension I have been out playing with the car more this evening and it is still creeping at high RPMs, through most the range it actually sits around 12, lower than it has been before.
Now I'm back to thinking it could be camshaft timing. I have degree'd my cam (not exactly by the book, no solid lifter and was having issues with my too short dial indicator, so I wasn't able to do the forward/backward then divide by two... but I think I got it in the ball park. Anyway - I have an adjustable gear of course. I am continuing to advance the camshaft - each time I advance it (2 deg on the cam gear) the boost will still creep but only at an even higher RPM. I'm at the point where it will only start to creep after approx 5200 RPM but this thing wants to pull higher.
So, any thoughts. Do I keep advancing the cam timing? Not that the marks are entirely accurate but I'm ~14^ ahead of centerline on my cam gear, which is ~5^ ahead of my measured centerline. I can't guarantee my measurements were exact but I'm confident it isn't that far out if any. With my camshaft adjustments, is it possibly the cam being too retarded causing overboost, so I should keep advancing?
Is there anything else stupid I'm missing? I've never dealt with such stupid boost creep before... but I've never had such a far from stock setup before either.
Thanks for any input, now to go drink away my sorrows, set off fireworks and enjoy the rest of Canada Day