rybern

iTrader: (5)

Went to strip last night with hopeful intentions to break into the 11's. 00 SS has done several 12.2 passes with SS3600, SSRA, LS6 intake, LT's, MSD wires, NGK's, duals, dynotune and DR's.

Only changes I have made to the car since my last passes are: drag pack(reduced 60lbs), new Denso o2's, removal of exhaust heat shields(7lbs) and removal of front sway bar.

Good 6-7 second burnout(555r's) and I staged. I stalled up about 1800 like I always have done and dead hooked. However, the car instantly falls on its face. I was stumped. I got on it a bit after coasting down the strip a bit and everythings seems fine. Still got a 2.032 60'. Spectators said that there was a spark that came from under the front end of the car behind the front wheel.

I looked under the hood and under the car and everything looked in order. I wrote it off as a fluke and tried another run, but got the exact same result. Dead hooked and fell on its face but still got a 2.070 60'. Once again folks said there was a spark from under the car.

I've made 13 previous passes with this car and I have worked my way down from 13.6(stock) down to running 12.2's with a 1.70 60'. I've never experienced anything like this with this car.

Any ideas?

99SSJarhead

iTrader: (2)

Start with what changed. A spark just behind the front driverside tire also happens to be around where one of those new o2 sensors sit. Could a wire be damaged and causing it to arc against something? A bad o2 sensor at the point of a hard launch could cause it to stumble and then self correct.

rybern

iTrader: (5)

That makes sense. Brand new O2's are Denso 234-4025. These were supposed to keep me from getting P1153 & P0155 codes. I'll put the car up on ramps and look for signs of a damaged wire and/or arching.

bbond105

While your under there check the positive battery cable around the starter area. The engine torqueing over under a hard launch could be shorting the battery cable.

rybern

iTrader: (5)

Gotcha. I'll do that. I really appreciate the suggestion.

irrational

check for knock retard if you are getting burst knock when launching. it could be a shorting issue but i would do a datalog first and check. My friend had this same issue, every time he launched hard it would fall on its face dead and then pick right back up. He asked me to watch him launch and i saw a shower of sparks come out from his left fender well on launch. His pos battery post had been hitting the fender liner when he would launch shorting out the entire system and blowing holes in the liner.

rybern

iTrader: (5)

Ah ha. You just reminded me that my battery isn't bolted down. I just went and looked at the battery and sure enough, there is a mark where the battery apparently tipped back and arched against the A/C can. MYSTERY IS SOLVED. The forward portion of my battery hold down is broke off. No I have to figure out a way to hold the front down.

This also means that my car is now doing better than a 1.70 60' because I never had this problem before these changes.

Chris Paveglio

iTrader: (2)

Wow whoever tech'd your car at the track needs a refresher. We DQ guys at autocross for battery hold down problems b/c of this kind of thing, or worse.
You can get or make a strap that goes from a bolt just behind the headlight, over the battery, and down to the bolt hold. You can make it with some 1 inch wide aluminum bar from the local hardware store. Year 1 makes the same thing but $25 for it is crazy.
https://www.yearone.com/Product/1982-02-camaro/bhfblk
https://ls1tech.com/forums/generatio...ml#post2283784

Jtm2085

iTrader: (1)

Glad to got it figured out op! And lol at the tech not catching it

rybern

iTrader: (5)

The only guy that looked into the problem at the track is me. I should have figured that out... especially since I knew the battery wasn't properly secured. But I totally forgot about the battery missing the front lip that secures it until Irrational mentioned "battery post hitting the fender", then the light bulb came on (in my head). Is there usually someone at the track that does this when there is a problem?

Thanks for the link to the strap. I'm going to make one from AL.

rybern

iTrader: (5)

Strap made and installed. Made three passes last night and all is good to go. Thanks guys.