loss of power when ext. wastegate opens

[conceptvip]

The problem im having right now is when i reach max psi (set at 19psi) and the ext tial wastegate opens up the car just loses it power in the high end and doenst pull strong at all. Im still running the stock 1g manifold could this be why? Im running a agp L2 turbo and my buddy with his almost stock 1g awd is able to keep up with me at higher speeds thats how bad this is. My knock is pretty high also when this happens around 12-15 counts of knock around 5500rpm with 93 octane. If any one can help me figure this out it would be a big help. thanks

 

[97gstnick]

dude! i have the same problem. but mine might be because i dont have a dump tube. so the exhaust goes right under the hood. but now my car misfires at 4500. i can give a little gas past 4500, but if i boost it will start sputtering.

 

[conceptvip]

sounds like u might have bad plugs. I have new wires, plugs, and swaped coils over.

 

[97gstnick]

well i swapped plugs with my friend and it still did it. i bought wires and it still did it. im guessing coils...?

 

[99gst_racer]

hmmm.... Have you checked for boost leaks yet?? When the WG is open, you are at full boost, and if you had a boost leak, it would feel the most noticable at full boost.

 

[Goobdog]

If you're dumping the wastegate into the atmosphere the knock sensor could be picking up the noise, maybe check your knock sensor or re-route the external back into the o2 housing if it isn't already.