****UPDATE-VIDEO****

http://www.youtube.com/watch?v=Nn5Cr6tSv0I

Here is a video of the actual problem. Sorry that it's not very clear, but that's the best that I can do at the moment. The video shows a 3rd gear pull and when it hits 6,000 it does a fuel cut and immediately goes back to normal and goes all the way to the limit.

Hello all,

Yesterday I visited the dyno to get a tune for my new setup:

FP Red
PTE 1000cc
Megan o2
ETS 3.5 FMIC with pipes
GSC S2 cams

Well, as soon as my tuner adjusted the timming and AFR's, and started to get on it... We encountered a problem and we can't figure it out... As the car started to go up in RPMs and hit 6,000 it suddenly stalled like if the rev limiter was set at 6,000 . You could see the graph go beautifully all the way up to the 6,000 range and then BAM it didn't wan't to go any further.

I told my tuner that before I installed the new parts I was having the same problem which I thought it was tune related. If I was going 65, go down to 3rd(high RPM) and WOT the car would go with out any problem. However, If I was going 65 in 4th(lower RPM) and WOT the car would obiously lag more, but as it was going up in RPM probably by the time it would hit 6,000 I would encounter the same stall(hick-up) problem but It would go back and keep going till the rev limiter. I'm pretty sure that if we would have keep the WOT at the dyno when we encountered the problem the car would go back at it and hit the rev limiter, just as it does on the street.

My tuner said it could be a bad cam sensor or some other type of sensor in the car. Please if anyone else has encountered the same or a similar problem, please help me out! I will greatly appreciate it. Thanks in advance

 

Could be your clutch.

 

Could you elaborate on this a bit more? The clutch is a ACT street with about 20k miles, 0 launches on a T.R.E. Stage 3 tranny. Seems to work just fine

 

Sounds like an issue I had on my car when I finally got off the stock turbo. PM Jason@Spec-Ops and I'm fairly certain he can help you out.

Josh

 

Put the car in 5th at about 40mph and floor it. If your revs climb but your car doesn't accelerate like it should, it's your clutch. You mentioned it doesn't happen in lower gears which would lead me to believe it's your clutch. Higher gears=more load.

 

if it was still revving and just not accelerating I would think the same thing, I may be misunderstanding the OP's comment.

Josh

 

Ok so I did exactly this and the car seem to go fine. As a matter of fact, as I did a couple of runs the car didn't show the problem at all . Now I'm really confused .

 

personally from what your sayin sounds like you might be hitting boost cut considering your hitting higher load cells in 4th gear...whats your boost cut set at in your rom??

 

I have no idea . However, it was tunes at 27psi before the mods. Yesterday at the dyno it was running at 25psi and in 3rd gear and doing the stall/stutter at about 6,000 RPM. The car also has a greddy electric boost controller.

 

almost sounds like it is ignition... you may need new plugs, some sort of coil on plug setup or whatever. If the RPMs continue to climb after the hiccup, its not clutch. It would be clutch if the RPMs climbed first, then came back down and the car continued to drive. If i have read this right that is.

 

Well we installed new plugs right before the dyno session. Is there any other modification to the ingnition I should consider? Thanks

 

Didnt see where you added a fuel pump? Your cutting out at High rpm's ? = no fule or no spark.

 

I forgot to mention it, but it has a walbro 255.

 

Check this for sure ^

During initial tuning of my car on E85 there was so much fuel being dumped until it all got smoothed out that it fouled out the plugs, plugs were brand spankin new when we started tuning. Car was built and tuned at AWD so it didnt even leave the shop to get there for the tune so it was a very short period that they were receiving massive amounts of fuel.

Popped new plugs in and it cleaned it all right up.

 

This is my point exactly, if you were on a brand new set up your fuel trims were possibly very rich which will lead to fouling out the plugs quickly and possibly where you are developing the stutter from...

The only other thing i can think of is the issues that people had with the FP Reds and comp surge or something like that... i dont remember the thread exactly...

You getting tuned on pump or another fuel?