So basically as most of you all know. My brother, _Zac, and I do all the work on my car, except for what the dealer does (Which I let Akram take care of that). I have been having an issue since the day I raced Pauliewalnuts. During the race I made 19-20psi and then shifted and it seemed like it slipped the clutch and then it was making 13-14psi.

Later on that day Boost started going nuts. Sometimes it will make 17-18psi like normal, but others it'll make 14-15psi. I thought it was the boost controller, so I added a Manual Boost Controller. This did not fix the problem. It seemed it did at first, then I go for a ride with Tommy Bahn to show him and it makes a max of 16psi in 3rd gear, which normally makes 18.4 or so. That morning though it made 18.7psi and I beat a GSXR 750 on the way to work. The weather difference was less than 10* On the way home I hit it in 3rd and it made 18psi or so and it felt better than ever. Then all the sudden it was like the car hit a wall. I did not look at the boost but the car felt like it was on motor only. I came to a stop a few miles down the road and the car started surging, there was on ABS/PSM/CEL on. Then I'm a little bit down the road and I try to pass someone in 4th and when I gave it gas it closes the TB and the car starts slowing. So I shift into 3rd and it starts moving again.

Another thing that has happened since I raced Paulie is there is a loud metal banging sound like somethings hits the bottom of the car when I go WOT, ONLY SOMETIMES! If I start really low in the gear and go into boost. It only does it once and while it does it there is no boost/air fuel change. Yesterday it actually did it while I was racing the bike, it only made the noise once. It has always been once, its like I almost ran over something and it hit my undercarriage.

I can't seem to find my durametric cable to scan for codes, so I'm kinda screwed right now. I don't know if anyone will actually show because there are no lights on.

I have checked all my boost hoses including making my own tester and tested with 25-30psi and there was ZERO leaks. I thought it was the MAF, but it would throw the CEL, etc. and it would not effect how much boost it makes because I have a Boost controller.

Hopefully anyone has any tips.. Other than take it to someone. I want to fix this myself unless its REALLY serious. Considering we built the car ourselves.. I want to make sure it's done right.

 

ABS + PSM + CEL (the unholy trinity) + irregular boost makes me think MAF, but the noise makes me worried that it might be mechanical. Have you checked the impeller for Flying Object Damage? I hope it's not the case, but your turbo may have inhaled something that is rattling around in there.

 

Sorry I did not write it right. There was no ABS/PSM/CEL That's what makes me think its not the MAF.

I need to check the impeller just to make sure, but I figure it would be smoking or something of that nature. Plus it is VERY random, as it does not always make it when I go into boost. It really sounds like something hits the bottom of my car.

 

try this?
https://www.6speedonline.com/forums/...ing-issue.html

 

Checked all my hoses last night. Had the boost tester on them.

I wonder if just the thud could be a broken or loose mount somewhere. Esp since it sounds like metal on metal and its random.

 

I think some wires are hooked up wrong.
Did you have the engine out of the car?

Good luck!

MK

 

Haven't had a problem till just recently. The closest thing is the intercoolers were removed and new ones were installed, but that was months before my problems after racing Tweety.

I blame Paulie for my car breaking!

 

how intense is this sound? these cars do make some very strange, mechanical-like sounds when it needs to pull timing fast.

this would make sense w/ your description above - start low in a gear where the engine has to work harder, peak torque when the boost fully hits.

i would stop (purposely) making these sounds til you figure everything out...

- chuck

 

More importantly,

How did you stack up against the Yellow GT2 (Tweety)?

 

That Damn Walnut is trouble!

But seriously, I am very sorry to hear about your problems, Chris.

 

Bad cats make a metallic noise sometimes.

 

Hey now don't go blaming little ole tweety.

 

I reset the battery, hopefully maybe the PCM will relearn everything because I did not do it when I installed intercoolers. But of course it started pouring right after I disconnected the battery.... Damn mother nature!

 

something is wrong and its not a flying object... LOL
check the turbos for damage... inspect the compressor wheels...

drain the oil and look for metal....
whos ecu?

 

The banging could be a f'ed up driveshaft or axle (you didn't convert to RWD did you?).
Man that sucks, hope you get it sorted Chris.

Does the car idle ok? Runs otherwise fine up and down the rpm range other than when you get on it?