Race engine tuning in "over-run"

[JoeMag]

For those who have tuned race motors, what sort of fuel "tuning" do you do in over-run? Cut off fuel or have a target AFR you're look'n for?

[TimT]

Cut Off.

Unless you like backfires, pops, and wasting race fuel.

[JoeMag]

Thanks!

[dannobee]

Nearly always a fuel cut.

[TimT]

Nearly always a fuel cut.

However there is always someone who wants the fireworks, to be loud, and possibly blow apart their exhaust..

[jpnovak]

Yep. Fuel cut and crank up the timing. Grab that off-throttle decel.

[dannobee]

Originally Posted by TimT

However there is always someone who wants the fireworks, to be loud, and possibly blow apart their exhaust..

Prolly the same guy who pulls a money shift, then says, "but it has a rev limiter on it, why did it bend the valves?? We'd see that once in awhile, too.

[JoeMag]

Thanks... how does cranking up timing help w decel if no fuel is going in?

Though I must say I loved the massive flames my 930 racer used to make. One time I glanced in mirror on a shift and they were above rear deck!