What do you guys think??

[rxmartin]

I had just finished up putting together my 87 gn. Here is what I did....ATR cold air intake, 36# delphi injecotrs, 160 thermostat, ATR wires and delco plugs, Poston Adj. Fuel Reg set 43psi Static, 3" Atr SS Downpipe with ss High flow cat and Borla Catback, upgraded intercooler hoses, Poston Plenum Spacer, Atr PCV Check Valve, Delco Coil Type II coilpacks and module, Racetronix Hotwire and Fuel pump (Walbro 340)upgrade, Poston Adjustable wastegate Actuater with ported stock wastegate, and running 15-16 pounds of boost with Turbotweak closed loop chip. Now My problem is sometimes when I take off the line the turbo goes all the way up to 19-20 psi then drops to 15-16 and stays there. When this happens the car knocks a little about 1-4 counts on the scanner. At WOT (60 mph increasing, 15-16 psi)the car reads as followed-
TPS:4.14v
O2:850-920mv
Knock-0 sometimes 1-4 when I punch it
MAF: 255
Blm:128

Now at Idle in park fully warmed up in closed loop the car reads this-
TPS .42-44
O2-150-900'smv
IAC 5-10
Idle 800-900rpm
BLM-155-160???????A little lean and don't know why
no vac. leaks or exhaust leaks either
What do you guys think????

 

[DCVING 6]

sounds like you've got a little boost creep. What you'll need to do is port out the wastegate hole on the exhaust housing of the turbo. You should drive around for a week or two and let the carbon build up on the exhaust housing. It will give you a template of where you need to port to. Do a search on "porting exhaust housing", you will find some more info on it.

 

[TurboSlacker]

TPS is way too low for WOT.
4.5V and higher is better. Be sure the carpet mat is out of the way and you really smash your foot into the floor.

BLM's are very high at idle. What are the BLM's during highway steady cruise? If they're above 140, I would still suspect exhaust leak. No cracked d/s header?

 

[rxmartin]

Hey guys,
I did port the the wastegate out just a little with a dremel. I just open it up a little bit around the carbon template. Do you think I just open it up more. I am using ATR dp and it has a larger puck on it. As for the BLM on the freeway and cruising they are sitting around 129-133. I also double check for leaks I couldn't see any leaks at all.
Thanks for the replys.

 

[TurboSlacker]

Cruise BLM's look really good. Maybe talk with Eric to see if he's willing to add more fuel at idle to bring down the idle BLM's. Of course, make sure there's absolutely no leaks first.

I had similar boost spike problem for a while with a Thrasher chip and Kirban downpipe. I don't have the problem now, but since I changed a lot in my combo I'm not sure what solved it. I am using an adjustable bleeder valve in line with the stock wastegate rod (stock wastegate solenoid disabled). I know what you're explaining is more like an initial spike in 1st gear, then lower but steady boost in the higher gears. A little different that traditionally creep which steadily increases.

 

[turbo2nr]

I would keep an eye on the waste gate swing arm on your ATR dp. Mine got stuck after a few months of driving! I have heard plenty of bad stories about this from other people. Mine got stuck in the open position. I was lucky! I could not move it at all with my hands, or vise grip pliers. ATR fixed it for free (I paid for shipping). Other people have wasted motors when it gets stuck in the closed position and over boosts. your problem is with the bushing in the downpipe. POS!


Scott

 

[rxmartin]

Ok I did some more exploring with the help off eric and I found that the one check valve(pcv valve replacment) I bought from poston was passing to much air so it leaned my idle out to much. So I am going to get a reg. delco pcv today and see what happens. As for the first gear boost spike I am going to do so more test and adjust the wastegate rod to see what happens.
Thanks agian guys
Kevin