bad night at the track

[11secondgs]

I really had a bad night. I was hoping for 11.00's at 120.

First run, I didnt heat my slicks up enough and ran a 14.11 at 112 with a 2.7 60 foot. HAHAAHAH comical! (car pulled very hard)

The second run was a 12.85 at 83 mph because the car once I get under full boost is like totally sputter and spitting, like bad spark or coil or the wrong spark plugs or something. I am running 26 lbs of boost.

It did this same thing for the next 4 runs. launch hard, then get up into the boost and PUKE!!!

It does this at about 20 yards before the 1/8th, and I have to like coast all the way through.

It never ever did this before, and has ran flawlessly with no changes over the past year and all this summer? What do you think I developed all of a sudden at my track. When it is burbleing, it sounds kinda like the rev limiter, but It isn't because I am only around 5,000 rpms.

Let me know what you guys think it might be before I tear everything apart.

Thanks,
Josh

 

[alb84]

Spark plug wires, or a weak coil. Probably wires though. Everything has to be perfect in the ignition department if you want to run 26psi. You might want to look at all the vac hoses, and intake hoses. One pop caused by a weak wire could loosen a intake hose, and then when the boost comes up it separates and leaks lots of air that has been measured and fueled causing a rich condition.
Danny

 

[TLIMITED]

I really had a bad night. I was hoping for 11.00's at 120.

First run, I didnt heat my slicks up enough and ran a 14.11 at 112 with a 2.7 60 foot. HAHAAHAH comical! (car pulled very hard)

The second run was a 12.85 at 83 mph because the car once I get under full boost is like totally sputter and spitting, like bad spark or coil or the wrong spark plugs or something. I am running 26 lbs of boost.

It did this same thing for the next 4 runs. launch hard, then get up into the boost and PUKE!!!

It does this at about 20 yards before the 1/8th, and I have to like coast all the way through.

It never ever did this before, and has ran flawlessly with no changes over the past year and all this summer? What do you think I developed all of a sudden at my track. When it is burbleing, it sounds kinda like the rev limiter, but It isn't because I am only around 5,000 rpms.

Let me know what you guys think it might be before I tear everything apart.

Thanks,
Josh

Check fuel pressure at WOT and also keep about a 1/2 tank of fuel in the car while racing,we had a 9.70 car doing the same thing and it was throwing the fuel to the back of the tank so a little before half track the fuel lines were empty.Hope this helps!!!!

 

[Quick6'n'-K.C.]

So..... you were having that kind of issues at 26psi and made 4 more passes AFTER THE FACT mmm.... were you expecting some magical wand to appear under the hood and fix the problems?

I could understand 1 or 2 studder problems, but 4 passes Are you actually trying to blow it up or what?

Drives me nuts when i read these kind of posts...... I have no idea why the pistons scattered and the rod came thru the block, buick engines must be horrible because i couldnt keep one together???


Try running thru the ignition system, plugs wires coilpcak ignition module and alternator.
BW

 

[87NAT]

I agree 100% with Bryan. If you have an issue back the boost down right away and start watcing FP and knock. These stutter/miss issues at high boost /rpms could be any of a number of issues but it takes some data logging and troubleshooting to get to the bottom of them.

"The definition of insanity is doing the same thing over and over again hoping for diffferent results."

 

[Clark6]

Check plug gaps too. depending on heads, and combo (didnt see it in your signature) may be too much air flow blowing out your spark. should be
from .028-.032. i think, depending on flow of air.

 

[11secondgs]

I thought it might have been a lean condition so I played with the alky just ever so slightly. 02's were at 757. The absolute instant it sputtered, I lifted.

I am crazy though, I won't argue with you there.

Today I will check the plugs, wires, and hoses. Is there a way to check the coil before buying a new one?

 

[johnnyttype]

Check plug gaps too. depending on heads, and combo (didnt see it in your signature) may be too much air flow blowing out your spark. should be
from .028-.032. i think, depending on flow of air.

X2 on plug gaps, especially with 26psi!

 

[Quick6'n'-K.C.]

I thought it might have been a lean condition so I played with the alky just ever so slightly. 02's were at 757. The absolute instant it sputtered, I lifted.

I am crazy though, I won't argue with you there.

Today I will check the plugs, wires, and hoses. Is there a way to check the coil before buying a new one?

Swap it with a buddies known good one.

Caspers sells a coil pack and ignition module tester, i have one and have used it over 100 times.

BW

 

[jetmech]

How old are your plugs. race fuel(lead) tends to foul them out.

 

[BetMinesFaster]

Where are you located?

 

[11secondgs]

I am in Green Bay. What are the best plugs for cars knocking on the 10's?

Also, what do you recommend to check the fuel psi at wot?

 

[melrob94]

Seems odd that you are knocking on the 10sec door and you don't have a fuel pressure gauge under your wiper to monitor pressure at WOT . Use a little duct tape to mount so you can see it during the run.