Since I've turbo'd the car I've had the same problem. At high RPM at high boost the car will fall flat on its face.

I've been through 2 different turbos, 2 different wastegates, 2 intake manifolds and converted from draw through to blow through. I thought all of these things would cure it but it still happens.

When I scan it, I get no knock, my boost levels stay even and my AFR stays right on. So before I put idea in everyone's head as to what I think it is I want to see what you guys are thinking.

The problem happens at about 6k at 18psi and lower RPM's for higher boost, and not at all at lower boost.

I need some suggestions. Give me some info throw those ideas out guys.

I have logs but you can't see that there is even a problem on them.

 

Ported head?

 

No it's the stock head.

 

might be your problem..

 

How much timing when the problem happens, and is there any change (up or down) in the timing right before/after the problem?

Kevin

 

No it's linear through the issue.

Why would I be the only one with that problem? Is this something I should know about?

 

MAF and MAP voltages when the trouble starts?

Kevin

 

compressor surge?... more boost than can be used coming back to the turbine, just a thought. Buddy had the problem on his Evo

 

plugs? gap? possible spark blow out?

 

I'd guess that also, or your maxing out your injectors, but you should be able to see that via afr's

 

Plug gap would be my guess. What plugs are you running and how much gap? Try new plugs and close the gap .010" tighter and see how it runs.

 

drop the plug gap to .028

from what you described. you're blowing the spark out.

 

I always thought compressor surge was audible and this is my second turbo so I figured that would eliminate it. Anything is possible now though.

They are i normal operating range.

Injectors are at about 85%
This is what I think the problem is. I'm using a NGK BKR7E copper plug gapped to .28 right now. I recently changed them after the new setup was done, they probly have around 500 miles on them now.

I guess I can try gapping them to .24 and see if that helps the issue at all. I thought .28 was about as small as I should go with them.

Maybe I need a colder plug, what do you suggest???

 

the plugs are fine. you may have to up the dwell time on the coils a touch to get it to work right

 

What table should I adjust it with? I've never touched that before.

I multiplied dwell vs rpm vs volts by 1.1 where it happens, I'll give that a try. Is that what I should be playing with?

 

base dwell time
don't get crazy with it. it will fry the coils.

 

Is that extra 10% excessive?

 

thats fine in a voltage area and rpm area. leave the lower side below 5500 alone. from 5550-8k turn it up a smidge

 

How did you learn all this info? Thanks for the great help! I appreciate it.

 

trial and error mostly


and help from a group of 733t friends
lol

 

I went %110 and then %110 on top of that and it didn't make a hint of difference. It seems to happen right at 6k. IDK what to do now I thought I finally had a fix to the issue.

I'm going to try and drop the gap to .24 I think and see if that does anything.

 

watching. hope everything works out for you!

 

Someone has to know whats wrong. I can't be the only car with this problem. I will pay to get a fix.

 

like a complete studder issue? or a sudden drop in rpm then it picks back up?

 

this has happened to me before, spark blow out, not really feel it too bad but can feel it miss and you can hear it shooting ducks out back... only at boost levels of 18 or more which is odd caus thats what your describing.

wb confirms its not lean, hpt shows no kr. idc is at 68-74% w/meth. plugs are at .026 bkr7e.

honestly i just stay in it and it will stop. only does it when its cold and thick outside, and only misses once or twice then clears up...

i chalked it up to spark blow-out, and keep my foot in it

but i am looking for a fix as well!