Troubles at the track!!

[3.8L V-8 eater]

Hi, to all

I raced at the Buick event yesterday in Norwalk, Ohio...Lots of fast cars and had a good time!!

Here's the deal. My combo is the same with the only change being going from a 6262 CEA to a 6265 CEA...My first pass was 11.1 and 60ft was 1.7, but only at 120MPH car when right is usually at 123 to 125..Did not record the pass on power logger...Second pass was 11.0 and 60ft 1.4 but only 118MPH so I knew something wasn't right, but I did record that pass

Looking at the data I noticed my boost quickly ramped up to 25 then back down then back up bouncing around till about 90mph then just a slow steady decline with me going through the traps at only 18lbs??? Car did not miss or sputter running fine no codes scanmaster numbers look fine no knock etc....After I got home I took the car back out recorded a few more logs and the only thing I see that doesn't jive is the maf numbers seem low to me...I have it on right setting in PL for the Extreme chip, but maf numbers at 25lbs of boost was 490G/S......Should that not be higher??? Also TPS was only 4.1 did not remove floor mat, but that should not cause low boost issues either...

 

[turbows6]

Check for exhaust leaks is probably a good place to start.

 

[3.8L V-8 eater]

Check for exhaust leaks is probably a good place to start.

My scanmaster is showing 130 BL while cruising so I would think an exhaust leak would be detected there and the numbers would be higher

 

[turbows6]

My scanmaster is showing 130 BL while cruising so I would think an exhaust leak would be detected there and the numbers would be higher

An exhaust leak won't significantly effect your fueling (or o2 reading) while you are cruising around under vacuum unless it's a severe leak. Under vacuum cruising around it doesn't really matter to the motor whether some of the exhaust is blowing out a crack somewhere, or past a gasket, or at the ball flange on the crossover pipe etc. etc. etc.

It could be something else simple too. Maybe a cracked silicon coupler on your intercooler piping or a crack in your intercooler's end tank etc. Sometimes couplers get cracks you can't see unless you poke around on them. Maybe it's a hose clamp that isn't tight enough ........... you get my drift.

It's most likely you have an exhaust or a boost leak.

It could be something else though too. Maybe your alcohol kit is turned up high enough that the turbo isn't spooling properly. Alky will cool the exhaust and that effects spool-up. If you have the large A/R hot side and the larger 65mm exhaust wheel, it's conceivable your alky kit settings could be the culprit. Especially since it spools, but then you start losing boost (after the alky kit is running)

I'd check high-and-low for a boost or exhaust leak first though.

 

[buickGN3:16]

Love the thread title.. Sooo true, these cars rule for running around the streets at mid range boost but the cant handle the dragstrip in my opinion. i've seen it too many times

 

[3.8L V-8 eater]

An exhaust leak won't significantly effect your fueling (or o2 reading) while you are cruising around under vacuum unless it's a severe leak. Under vacuum cruising around it doesn't really matter to the motor whether some of the exhaust is blowing out a crack somewhere, or past a gasket, or at the ball flange on the crossover pipe etc. etc. etc.

It could be something else simple too. Maybe a cracked silicon coupler on your intercooler piping or a crack in your intercooler's end tank etc. Sometimes couplers get cracks you can't see unless you poke around on them. Maybe it's a hose clamp that isn't tight enough ........... you get my drift.

It's most likely you have an exhaust or a boost leak.

It could be something else though too. Maybe your alcohol kit is turned up high enough that the turbo isn't spooling properly. Alky will cool the exhaust and that effects spool-up. If you have the large A/R hot side and the larger 65mm exhaust wheel, it's conceivable your alky kit settings could be the culprit. Especially since it spools, but then you start losing boost (after the alky kit is running)

I'd check high-and-low for a boost or exhaust leak first though.

My next step is to rule out the boost controller by eliminating it and going straight from the compressor to the actuator....You may be onto something with the alky I didn't think about...I just took the car out of storage and it had a bad alky pump so the one that's on there is new and maybe stronger...Never mess with it much I just set it on 6 and leave it which is the case with this new pump....Will also take a real close look at the I.C. hoses and vac hoses....

 

[3.8L V-8 eater]

Love the thread title.. Sooo true, these cars rule for running around the streets at mid range boost but the cant handle the dragstrip in my opinion. i've seen it too many times

I hear ya on that one .....