Do these ECUs really do Spark Cut

[Highlander]

On the rev limiter, can they really do spark cut instead of fuel cut with b5205 and the likes?

Thanks

[GMPX]

The code path in the ECM certainly shows they can.

[Highlander]

Good! Hope it doesnt blow up

[swingtan]

I use Throttle cut only. I really hate the idea of removing all the fuel at max RPM, that just seems crazy to me! I also am not a fan of removing spark and dumping raw fuel into the exhaust at max RPM, but if you don't have ETC, it's better than fuel cut. Using the ETC for the RPM limiter works extremely well and I've been using it since I was testing the beta version of the COS with Valet mode. I know for certain that that works.

Simon.

[Highlander]

Will use that one instead... honestly.. fuel cut is the way to go.

[swingtan]

What's the thinking on fuel cut? I just don't like the idea of leaning out the mixtures at full song, but I may be missing something.

[Highlander]

They cut 100% of the fuel to the cylinder. If there is no fuel, there is 0 power. 0 power = 0 heat.

Dumping all that fuel on the exhaust just gives a nice backfire. I might go the way of ETC, but its just slower and it will start earlier. I think ETC is the way to go.

We have installed meth iny onto a zr1 and if we cut fuel, SOME fuel (from the meth) is going in the cylinder and IT CAN go lean there.

GMPX, is the ETC algo fast/safe?

Thanks

[Tre-Cool]

i use a mixture of spark and throttle cut. mainly because i dont run cats and like to have some flames pop out the exhaust on track days. looks awesome at night on camera. haha.

down side is, it tends to melt the rear bumper. oops

[swingtan]

The ETC cut works fine for me.

there are tables for what RPM the cut should occur, and then there are "predictor" tables that modify the actual RPM limit according to the RPM ramp rate. So if the RPM is climbing quite quickly, the RPM limiter comes in earlier to prevent an over rev. It all works very well, much like TC does when the ETC cuts power there.

Simon.