mike, how did that happen?

 

i'm betting you hit the rev limiter on the spray

 

LOL Talk about LUCK!!!

 

wow nice pic

 

I obviously got a littly hasty about "selling my nitrous and doing a turbo". I think nitrous is a great way to add horsepower. In response to some comments made in this thread about my situation:

I DO have a wideband gauge in my car, and my friend said while riding in my car when the backfire happened that it said 17:1, which is way lean. But he said he cant be sure if that is what the true A/F ratio was during the backfire, or if I just got out of the throttle. Anyhow, it seems that my stock fuel pump is terribly inadequate to handle fueling a H/C car with a TNT 100 shot. But I still cant understand why a lean condition would cause a backfire, as I thought they were most likely caused by puddling of fuel in the intake.

It seems more than possible in hindsight that the car could have hit the rev limiter prior to backfire. For the record, I do have a window switch and the settings were as follows: set to come on at 3000 and shut off at 6400. My rev limiter in my car is set at 6600. Could these close parameters possibly be a cause?

I DO have HPTuners, but I was not logging at the time. Should have been................

And I also had TR6 plugs in.

I am not giving up on nitrous quite yet....I just hope that during the backfire I didnt hurt the motor at all, I have my stock LS1 intake that I will put on and see if my motor is ok after such turmoil. I hope so, because I dont want to rebuild it yet, it only has 25K on it!

By the way, does anyone have the stock air filter holder plastic/radiatior condenser holding piece they would like to sell? It pretty much destroyed it during the backfire.

 

you had an a/f of 17-1, that is 90% of the problem.. the other is that you are shutting the nitrous off probably too close to the limiter, either up the rev limiter, or back the nitrous off sooner, at least a 500 rpm gap.

 

Want to make sure it doesn't happen again?
Get a huge pump, 42 pound injectors, scale the MAF, and put it on as a dry shot. If there is no fuel in the intake, it is less likely to blow.

 

a lean condition makes cylinder temps rise. which in turns makes detonation more likely to occur. especially with nitrous use. just my understanding of that situation

 

that pic should be on a t-shirt

 

I was also going to mention your injectors. Mine were maxed out (HP Tuners reading 105%+ duty cycle) with just the mild mods I have. With a H/C car I'm sure you were running over 100% easily. You were probably maxing our your pump as well...

 

Looks like you've got all of the points. Your whole fuel system is inadequate--upgrade the pump and the weenie 26# injectors that came on the 00 cars. Make sure you have the right plugs and gap. Give yourself some room with the rev limiter and try it again. Get a shiftlight too.

When it goes lean and you start getting detonation, all it takes is for that to happen with an intake valve open and there goes the whole intake charge.

 

I agree. The pump took a crap, the engine started leaning out, [that was the noises you heard first], then the elapsed time allowed the lean condition to increase in severity, and the explosion occurred.

 

Think of running way lean like a blow torch, a hot spot (plugs or numerous other things) will get a lot hotter, like glowing hot. then it will remain hot after that cly is done firing, but then you have an ignition source for the next batch of fuel coming through (before next cly fires), and bam, a back fire.
Robert