Why exactly does this happen on our cars?

Im rebuilding - my 90 GTU N/A

And will this happen with my car

It happens on my friend Chris's t2
Just wondering

 

With a straight pipe yes.

 

he has apexi n1's

 

[B]flames rock!!

 

yes, with no converters it will do it, but i still cant make mine do it reliably when i want it to, it just kinda does when it wants.

 

I wanna go BRAP BRAP BRAP BRAP BRAP...

 

missed it the first time. it happens due to port overlap, which causes blowby...in other words, some of the intake charge just shoots right through the engine, so when it comes out the exhaust very hot and hits air (oxygen) it burns, hence flames.

 

Also, the fact that under most operating conditions the stock ECU runs the engine really rather rich, leading to unburned fuel, and the fact that the long moving combustion chamber isn't exactly great for keeping everything lit, and there's a lot of quench area to keep fuel from burning completely.

Basically, a good quantity of unburned gas gets kicked out under many conditions.

Patman, wouldn't intake charge going into the exhaust burn immediately upon hitting something hot? It has a good fuel/air mixture. The rich mixture is what's really responsible - there is no more oxygen to burn until it gets to the end of the tailpipe. Also, people with well tuned standalones seldom shoot flames, even with engines that have significantly greater overlap.

-=Russ=-

 

i blow flames all the time....
its the stupid stock ECU and our worn out TPS... and unworking acv and noe missions!

 

aw man my microtech wont let me shoot flames.

 

Whats a microtech?

 

microtech= brand of standalone ems

functions>options>MixTrim. +15% or so. your car will run like ***, but you'll make some flames. you gotta play with the mixture some to get it right.

 

I just hit the 2-step!

 

ditto.

 

dam son, whats your car drinkin? 151?

 

So then i will be able to do this in my n/a - fc if i remove emmisions and set up a straight pipe?

Oh and should i set it up as a single or duel exhaust?

 

Ok bud.... looky here.... Yes.. If you remove your emissions...

But.. look at those pics... its not something you do by revving the engine to 3 grand....

you gotta be hammering it......

As far as the mictro tech not letting you blow flames?? WTF?? why not??? Is the decel cut in that thing automatic???

 

you got a 2-step????? tell us more!!!!!

 

All Haltechs/microtechs/etc have 2-steps. ITs part of the ECU.

 

i have a full racing beat exhaust on my car (road race header, 2 pre-silencers, 2 mufflers) and my baby shoots flames when i downshift and get on it, or when i rev it up to 6k and feather the throttle rappidly. only works when the pipes are nice and warm though.

 

BLACK LABEL--why do you have 2 presilencers??
just wondering if its for emmissions or whatever

 

my revcut is set at 9250. no way am i gonna hit in on purpose just to make some flames.

 

I have one at 9k, and a toggle-able one at 4k. :P

 

OH.. your talkin about the ignition cut in the haltech itself......

I thought you had a seprate 2-step box on the ignition module to keep the RPMS at say, 4500, as the lights were comming down the tree....

 

The haltech has a 2-stage ignition cut.. I hold a button and my haltech cuts the ignition at 5000, and when I release the button my rev cut goes to 8200. Thats a 2-step.

Rat