boost problems

[quickbrick]

ok, with my stock turbo using the thrasher chip my car would boost up to 19 psi then fall to 17psi, which i really liked. from what i heard its supposed to spike like that with that chip. even though thrasher says nothing about a quick spool on it. but my problem is since i put the new turbo on, it boosts up to 19psi for a couple seconds then falls to 14psi(seems real slow) for a few seconds then it raises to 16 psi and runs good the rest of the way. what could be causing this drop in boost? everytime ive raced my car lately i take off the line hard but i get passed in the mid range then i cant catch up. any good ways to check for leaks on the turbo. for some reason i keep thinking its leaking. any ideas? i have the wastegate rod at about 4 3/4" length, i think stock is 5 1/16" if that helps at all.thanks

 

[quickbrick]

ttt

 

[Chris McDade]

1.Whats your fuel presure? How do the plugs look? Any tunning tools? Sounds like the car is running rich. Try to leann on it a LITTLE and see if it gets any better.

2.You could also have some vacum leaks.

Check #1 first.

Let me know

 

[quickbrick]

my fuel pressure is at 45 psi line off which is recommended by thrasher. my o2 millivolts read 850 at wot on my scanmaster. that seems a little high. i get about 4 degrees of knock when it goes to 19psi then goes to 0 degrees. i would try to lean it out but thrasher is recommended 45 psi only. with my stock turbo i was gettin oil on my plugs. with the new one they look fine.
how can i check for vac leaks on my turbo. when i put the ta49 on i did notice the whistle is a lot louder than the stock turbo. which made me think the 3 bolt flange was leaking. i filed it down some, and it was the same. so i tried a gasket and its still the same also. i dont know what else to check. i wish i could fix this cause i paid a lot of money to make my car slower.

 

[quickbrick]

???????????

 

[dconnor]

make sure the wastegate puck is swinging freely, could be binding open in "spots"

850 is pretty dang rich on the 02 counts, I'd suggest dropping the fp down to ~43 & boost to 16. then go make a few dial in passes, tuning the boost & fuel by ~1lb at a time until you have it optimized to what YOUR car likes best.

Doug C.

 

[quickbrick]

thanks, ill check that