Faster Spool Up

[Restless 33]

This mite be a stupid question but as far as i know the V8 supercars use a spark plug near the end of their exhausts to create the fire you see out the back...i think this is there so it creates some sort of back pressure or something like that...

i guess wat i'm asking is if we were to place a spark plug near the end of our exhausts wouldn't that cause a pull of air through the turbo on gear changes keeping it spinning.

i'm not looking to do this for the rice factor just interested if it would work and how i wud go about doing it.

also would there be a way to turn it on and off.

thanks for any feedback...also be nice with replys i'm learning still.

cheers, Mark

[Sydneykid]

What the?

In a V8 Supercar we run excess fuel on overrun to help cool the cylinder heads down. This unburnt fuel hits the hot exhaust and ignites, hence the flame out the pipe.

cheers

[fEkuaR]

hehe spark plug in exhaust... on a street car you cat converter is in your exhaust to burn unburnt fuel ect

[paulr33]

you can use aftermarket 3rd party tools to help assist with turbo lag and "spooling up" if this is what you are referring to? I suggest you do a search on anti-lag. the idea is to retard the timing and dump fuel on gearchange to keep the exhaust housing spinning and so when you come back on throttle the turbo is still spinning at a higher speed that it would have been when you back off throttle the normal method. the result well in theory is not as much lag as the turbine is still running at a high speed, enough to bring the compressor back into its efficiency zone quickly

[R31Nismoid]

as far as you know...

i'd like to know where you found the information telling you that.

spark plug in the exhaust indeed

[scathing]

Back pressure is not something you want in a turbo setup. That will increase lag, not decrease it.

So, logically speaking, if the V8 Supercars were igniting fuel in the exhausts to generate back pressure...it would be counter productive on a turbocharged car. It wouldn't "pull air" through the exhaust - it would just block it.

Of course, as people have said above its not the case. You can blow flames just as easily in your car by pulling out your cat and running non-baffled mufflers. Just rev the car hard and pop off the gas.

[scathing]

A fair few pro off-street race cars will run anti-lag. Most involve dumping excess fuel on throttle-off (normally by running it rich and taking timing out), and will either use a spark plug in the turbo's exhaust housing or rely on the hot turbine itself to ignite the fuel.

Normally they'll use an aftermarket ECU, so you can program and choose what conditions you want the anti-lag to kick in.

Aside from being very street illegal, you have to be a pro racer to run such a setup since your turbocharger then becomes a consumable. There's few faster ways of f**king your turbo's wheel than causing explosions on them.

[Restless 33]

like i said it was just someone telling me they had been wondering about it who maybe doesn't know much at all. ohwell was worth asking...i didn't think it sounded right hence the "be nice with ur replies" part