My friend who owns a 93dx coupe with stock 1.5 sohc motor has been spraying Nitrous succesfully for over 7 bottles now. Well today on his "drilled" shot, he hit it hard on second gear and he heard a really loud backfire and lots of smoke. The big pop blew off the whole cold air intake off along with the cone which got stuck under the car. The cone also lost most of its paper element which looks like it burned. We took out the cars plugs and one had a broken end on it, but we replaced them and the car still runs. Were gonna do some tests on it, but my question is why did it do this "pop" and blow off the intake.

 

Early Detonation? Timing was off? I'm voting for the first one.

 

Nitrous backfire. It occurs when fuel puddles in the intake manifold, and ignites. Most of the time due to spraying to early of an RPM. This can be from many reasons, one being your Fogger is to close to the TB, and the Fuel/n2o can't mix properly before it reaches the intake manifold, so fuel actually puddles up inside, somehow. That's what it sounds like to me, but correct me if I'm wrong.

I had this happen many times on my old Focus ZX3 on a 75, never caused any harm, but definately isn't good for the motor.

 

Damn. That happened to my friends 91 dx back in the day squeezing 50. It tried to push the filter through the hood, big *** dent

 

jdmvic... awesome avatar

 

yea the nozzle is real close to the throttle body and i think his timing was off, ill let him know today and well get to work on it.

 

any full shots of the avatar?? email me..haha

 

sorry thats as big as she goes i think, anyhow do any of you know how far from the tb the nitrous nozzle should be?

 

I wouldn't go any closer than 6 inches. I think NX recommends 6 inches too. Hope this helps. I would even go as far away to say 7-8 inches, but then again, 6 should work fine, altho I had backfires being that far away from the TB, I also sprayed to early most of the time anyways.

 

that sucks

 

i dont know if he can spray too early, hes got the switch so it goes on at full throttle. maybe if he guns it full starting at like 2 or 3k then i can understand.

 

timing problem and it might be turned on to early , or he hit rev control and the lack of fuel and them returned of fuel from rev contol can cause a problem
tony

 

Oh.. the youth the youth..

remember the first time she blew me.. those were the days....

 

here are some pics of the cone after the nitrous backfire

 

^ that is what i call heatsoak

 

Damn, those after pics are crazy looking. Guess it's time for a new filter!!!

 

Very interesting; first time I've heard of this situation. Your friend is lucky he didn't lose more than a filter and some plugs. I wish that had happened to me instead of melting my piston and rings.

 

if he wants to continue spraying, i would suggest getting an RPM window switch from MSD off summitracing.com

so the nitrous solonoid doesnt turn on till a certain rpm, say like 3000 or 4000 what rpm is should be can be adjusted, this might help the problem. but yet i dont spray so i dont know...

this could stop your spraying to early problem.....just a suggestion

 

well you guys know how it blew the first time, well we got a new motor in it and it ran fine with no nos, but i think due to my friends errors in putting the motor back together and not setting the timing the headgasket went this time. i was driving the car and a silver hatch with turbo pulled up so he decided to go, so i did as the owner instructed me too and she gave up in like 3rd or 4th gear. but after a new gasket and little tuning well have it up again.

 

Here is what happens......sorry for crap vid(not mine) this guy thought it would be sweet to dyno 100Shot

http://www.coneheadsracing.com...P.mpg

 

that video hurts. it wasnt even in the high RPMs yet

 

Yeah, you guys seen the video of the V8 Firebird that has a backfire while dynoing with the hood open. That **** is scary, flames everywhere.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GsR HtCh &raquo;</TD></TR><TR><TD CLASS="quote">that video hurts. it wasnt even in the high RPMs yet</TD></TR></TABLE>

I wonder if it is covered under warranty

 

not if they find out about the 100 shot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GsR HtCh &raquo;</TD></TR><TR><TD CLASS="quote">not if they find out about the 100 shot.</TD></TR></TABLE>

haha, dude it was a joke, there's no way they'll cover that under warranty. On the other hand....my buddy has a EP3 and he popped his motor. They gave him a new one. It's not modified or anything, I still don't understand how he blew it.