Need Rev Limit Help
 

Not getting much assistance over on the race thread so I will try here.

I run a Speed Challenge style 1988 RX-7. I am installing a Megasquirt to take control of the fueling side, but need help on the ignition side. I am assuming that the ignition controls the rev limit and not the fueling side.

I need to increase my soft rev limiter by about 300 rpm (400 would be better). If I can do this I will save the need to shift up and back down 3 times a lap at Mosport or sit on the 7800 rpm rev limiter for 3 times a lap. I have modeled this change and it will save me close to half a second.

I have also tried keeping my rev limit at 7800 but adding 20 hp and I only gain 3/10's. I will be trying to do both to gain more.

Anyone have any idea on a method that I can use to increase my rev limit. It costs a ton to have my ecu reflashed here (Toronto) and I would rather put in a complete programable system than reflash.

Just looking for something quick to try ( I have 8 ECU's so if I screw up one it is no great loss). Thanks in advance.

Not quite sure how you want to "quick try something". You mean some programming change in your current ECU? But you said you didn't want to re-flash it. I guess you could try an EEPROM programmer so you could do it yourself. It should be too hard since it is a simple change. Other than that I guess there might be a way to fool the ECU into thinking it is at a lower RPM. But that would mess with your fuel curves and stuff.

I can't really think of any easy way to raise the rev limiter.

Uh, isn't this illegal?


-Ted

Rev Limiter Help
 

Thanks for you help and concern. In the series I run in electronics are open, so changes to the ecu are legal. Secondly, in saying that I don't want to reflash the e-prom is really a question of economics. To get the e-prom re-flashed by an outside company will cost well over $350 and give me no flexibility afterwards. I don't have the know how to do this myself.

I am toying with going fully programable, versus just fuel and if no one can help than I just may have to but I hate to spend $$$ that I don't have to. I would rather spend it on tires. Anyways thanks to everyone for trying and if anyone has anything else please let me know. Regards.

Re: Need Rev Limit Help
 

You may want to contact this site to see if they can reprogram your ECU for less money.
http://www.pocketlogger.com/index.php?pid=rtek7feat

I would recommend a production standalone EMS. The Megasquirt simply does not have the resolution needed for speedway racing, and a production EMS has ignition control.

Thanks, I will contact them tomorrow.