I have a situation with my car that I have not figured out yet. It happened this weekend at the track. I am running a single fogger NX wet kit on my car. I have made about 7 passes on a 150 shot last month with absolutely no problems and I decided to jet it up to 200 hp jets to try and get into the nines. Well on the first pass down the track with the 200 jets this weekend I spun out of the hole and had to pedal the car felt good then I got into 3rd gear at about 5000rpm and the engine shuts off and then pops a little. I coasted around to the turnaround and got towed back to the pits. I checked to see what was wrong and I was getting spark at the coil but none out of the opti. I had an extra old opti that has 33k miles on it so I decided to change it out in the pits. I changed it out in 2 hours and the car fired right up. My opti that came off the car sounded like a baby rattle inside---come to find out I shattered the rotor and ruined the cap and just about everything else in the opti. I made 6 passes with the swapped opti all NA running in the super street bracket racing class. The car was running good and there was no misses nor slower E.T.'s. So the last pass of the night I decided to try the N2O again. This time I come out the hole good but the car was laying over once I got into second and third but it was still pulling pretty good. At about the same point as the first pass the car shuts off and backfires through the intake. I coast through the lights to a 10.5@117. Now, I checked under the hood and my fogger nozzle moved on me and pointed downward into the intake. My airfilter was mushroomed out and completely blown off the CAI. All of my plugs look good and I am still getting spark but the spark is intermittent so I am thinking the opti is shot again. Now do Lt1's have camwalk that could cause the opti to fail? Why would my opti only fail on the bottle? Could the vacuum lines that go to the opti be causing the fuel to ignite which is causing the opti to shatter? I am shifting at 6300 Rpm's so it is not like I am spinning it high. I ordered a new opti and I am going to be putting it on this week but I wouild like to get to the bottom of this and figure out why the opti would fail only while on the bottle and only in third gear. Any suggestions or info will be appreciated.

Thanks
Matt

BTW---If this is not advanced enough then please feel free to move it. I figured that the opti experts(i.e-Fred, etc) would be able to shed some light on this.

 

Did you check to see how far the dowel pin extended out of the front of the cam - I went through the same thing and after the second one checked mine out - fresh from comp cams the dowel was 0.790" from the front of the cam - spec is 0.600". I would check this asap.

Chris

 

Thanks Chris,
I will be checking that once I get this opti off. I was reading that some were having problems because of this. The thing that gets me is that it only happened when I was spraying the 200 shot on 2 different distributors. It did not happen at all on the motor (6 passes in between the 2 failures) and on on the 7 passes I made last month on the 150 shot. Would the nitrous cause cam walk? The car seemed fine NA. Could the N2O get inside the distributor and cause a failure?

Thanks again for the help

Matt

 

Its possible for the rotor to come loose and shatter. Were the screws still in that hold the rotor on?

Is it possible you are spraying the wet (????) nitrous into the air line to the Opti? That would probably ignite if you had fuel, air and nitrous in the Opti, along with the spark.

To check, move the air line for the Opti away from the elbow completely.

I'd move this, but I don't know whether to put it in LT1 Tech of N2O Tech.......

 

Hi Fred,

The rotor was still partially attached to the distributor. The bolts were still in place although one of the bolts was a little bent but that could have been from all of the pieces floating around in the opti. I moved the vacuum line that is normally on top of the elbow down into the CAI but the other line is still in the stock location---> I did this after the first run.

Thanks for any help

Matt

 

Sounds to me like the car is just revving so fast that it's killing the opti. You gotta remember that these things are meant to live in a stock 5800 rpm max street car that goes 0-6 in 5 seconds.
I had it happen on my car once. I pulled the opti off and it just fell apart. I don't know wtf kept the thing running

-Shannon