Exhaust flames

Was watching footage of Steve Millen driving his new GT at Targa NewZealand (I think) and on every shift he got a nice belch of fire.

Does this happen with a 40?
 

Mike Pass

Supporter
I guess it depends on the setup. If you put in fuel on the overun then you get flames. On FI setups you usually cut the fuel on the overrun but if you want the flames program in fueling when the throttle is closed. With a carb run it rich at tickover and set a high tickover - you can get some nice loud pops and bangs in the exhaust pipes as well! Not very green I know but a big V8 and huge carbs and a lead foot isn't either! The best flamer I drove was a Mk1 Sierra Cosworth with a touring car engine that spat 3 foot flames out of a side rectangular exhaust (no muffler) which was 8" by 4". It got some strange looks from the locals as we drove through rural Ireland lanes at a rapid rate (on slicks as well!).
Cheers
Mike
 
It is not uncommon to see oval track cars belching a 4 foot flame on deceleration. I have had backs fire that blew out the cheap fiber header gaskets on my 377 small block chevy with 180 headers.

Orange rotors look cool too.
 
You want flames?

With a carbureted engine, while driving the car at speed, in gear, shut off the engine and floor the throttle. The engine will continue to turn (driven by the gearbox), and the intake will suck fuel and air through the carburetor, but there will be no spark because the ignition is switched off. A few cycles will see your exhaust system filled with unburned fuel and air in the perfect mixture. Then turn the key back on and

BANG!!!!!!!!!!!!

The results can be quite impressive, up to and including a completely exploded exhaust system. I've only done it once, in a Shelby GT350 clone (before I was smart enough to know the result of such experimentation), and the explosion sent a fireball out from the bottom of the car and burned two black circles on the pavement. It's a testament to the strength of Flowmaster mufflers that they didn't explode.

Needless to say, I would recommend trying this with utmost caution, if at all!
 
Hmm, there is a setting on some ecm's i'v seen that had an option for 'off throttle fuel compensation'. I did hear that it was used to help cool the engine. I guess the cold fuel coming in cools the engine, but does heat the exhaust a bit.
 
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