I have been developing a 2-step rev limiter with retard for a while now and its almost done. I let a few people know and they are all asking for details.
So here are a few.
A 2-step is an ignition cutting rev-limiter and on turbo cars like ours has several uses.
1: when running alky injection, if you hit the factory rev limiter in the ECM, the ECM cuts off the injectors, but your alky is still spraying. Now you are at high RPM, high boost, and deadly lean. This breaks engines in a big way. So by setting an ignition cutting limiter below the ECM rev limit you will save your engine if you over-rev.
2: for foot-brake launching, you can reduce the torque the engine makes, and raise the EGT by using an ignition retard when brake torquing. Using a partial rev limit helps spooling on the brakes and also works for rolling brake torquing.
3: for trans-brake launching, generally guys don't use retard, just a full-cut style rev limiter and adjust the limiter setting and their boost controller to set their staging boost level.
There are lots of ways to configure and adjust a system like this, I have just listed a few.
So, on with the show.
[YOUTUBE]http://www.youtube.com/watch?v=eGaWYxsKq0E[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=CQESvfZqSNI[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=DqbUfcRpqcU[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=4SGQ5sMtskM[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=Z4tJLulBQMk[/YOUTUBE]
a picture of the config switches
The unit shown is my prototype, they should be ready for 'you guys' in the early spring. Stay tuned.
Bob
So here are a few.
A 2-step is an ignition cutting rev-limiter and on turbo cars like ours has several uses.
1: when running alky injection, if you hit the factory rev limiter in the ECM, the ECM cuts off the injectors, but your alky is still spraying. Now you are at high RPM, high boost, and deadly lean. This breaks engines in a big way. So by setting an ignition cutting limiter below the ECM rev limit you will save your engine if you over-rev.
2: for foot-brake launching, you can reduce the torque the engine makes, and raise the EGT by using an ignition retard when brake torquing. Using a partial rev limit helps spooling on the brakes and also works for rolling brake torquing.
3: for trans-brake launching, generally guys don't use retard, just a full-cut style rev limiter and adjust the limiter setting and their boost controller to set their staging boost level.
There are lots of ways to configure and adjust a system like this, I have just listed a few.
So, on with the show.
[YOUTUBE]http://www.youtube.com/watch?v=eGaWYxsKq0E[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=CQESvfZqSNI[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=DqbUfcRpqcU[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=4SGQ5sMtskM[/YOUTUBE]
[YOUTUBE]http://www.youtube.com/watch?v=Z4tJLulBQMk[/YOUTUBE]
a picture of the config switches
The unit shown is my prototype, they should be ready for 'you guys' in the early spring. Stay tuned.
Bob