GTV27 wrote:A mystery to me is why some racing cars have flames licking from the exhaust on the overrun.
I don't mean turbos, but NA racing engines. And I'm not talking about the short sharp spits of flame (my 105 used to do that), but long slow big licks of flame - think V8 SuperTaxis and you'll know what I mean
.
Now my questions are:
Firstly, how and why does this happen
Secondly (and I know this is childish and I SHOULD KNOW BETTER), but can I get my V6 to belch flame on the overrun?
So engine gurus - what is the go with this?
Easy peasey.
The engine tuner sets the engine managment system to add alot of fuel on over run/trailing throttle and either cut spark or massively retard it.
The excess fuel pumping thru the combustion chambers helps to cool them. The fuel passes thru the combustion chamber unburnt or mostly unburnt and then it ignites in the hot exhaust. The flame you see out the pipe is the end result.
If you realy wanted your v6 to do something that silly, you could try some sort of dodgy fake airflow meter signal that you send to the computer when on closed throttle above a certain RPM.
Using a closed throttle switch, a variable RPM switch, they close a relay that sends a voltage that coincides with a high engine load to the ECU.
Prolly won't give you the desired results tho.
Realy stoopid and will wreck your cat. converter (which converts cats into less harmful gasses
.
