Jacob b

Is there any way to hook up a bee r rev limiter to a 12a without extensive modifications to the ignition system? I have a hood exit exhaust and I really want to see flames. I know it's silly but it would be really cool. And having a rev limiter will help prevent over revving during drifting.

mustanghammer

iTrader: (3)

Rev limiters are really hard on Rotary engines. I stole this link from earlier thread when someone asked about installing a rev limiter on a rotary engine: FC3S Pro v2.0:&nbsp K2RD HOF

Over revving a rotary engine is not that hard on them (no valves, valve springs to mess up) if you don't make a habit out of it. Use a shift light and just back off when it comes on. As far as getting flames, because of a two step....that won't happen but a broken engine will.

Benjamin4456

I've wondered the same thing myself, although more as an over-rev precaution rather than flames and noise.

I'd like to try making a little setup with some solid state relays and something like an atmega328. Should be pretty easy to do in theory. Just sense the rpm off the coil negative like the tach does and cut power to the ignition coils if it crosses a pre-set threshold. I'm sure there's a little more to proper rev limiters than that, but the concept seems easy enough. Unfortunately I'm not sure when I'll ever get to that as I'm a bit preoccupied with other projects. Might be worth giving it a shot yourself if you have the knowhow or are up for some learning. I thought there was a commercial version of this available, but when I looked a month or so ago I couldn't find it.

yeti

iTrader: (1)

I have a bit of that work complete. I was building an rpm switch so I could trigger relays at certain rpms to do this or that. AC, fan, whatever.. I had thought about ignition cut too. I ultimately scrapped the project but I have the arduino code and stuff if you want a look.

mustanghammer

iTrader: (3)

I have a Summit Racing RPM Switch that I use to turn on a shift light. It is programmable for RPM, cylinders, etc. Was cheap and works great.

If you feel the need for a rev limiter just get an MSD 6AL or equivalent. In fact most of the spark boxes out there have a rev limiter built in. I run a 6A on my car.

Personally, I have rev'd the **** out my racing engines for various reasons like missed shifts that pegged a 10K tell tale tachometer. Upon disassembly I am not seeing any chatter marks or broken parts. Enjoy the fact that a rotary doesn't have pistons, valves, valve springs and spend your money on something useful and needed.

peejay

Don't put a rev limiter on a rotary, it kills them. They don't like the shock loads.

I do have a 2 step that I use as a way to flat shift. It engages at 6000 and I shift at 8-10, so it never shock loads stuttering on a limiter, it just cuts out. No exhaust fire.

(If you have 3mm apex seals, never go over 8000 for any reason with stock seals)

tommyeflight89

iTrader: (4)

Wow a hood exit exhaust on a 12A, sounds like the most obnoxious way to make 100HP, as you get passed by a fully loaded minivan...

Also maybe a hood exit would have less chance of flames to develop from over rich? Not sure.

KansasCityREPU

iTrader: (9)

Just do the old time flames by wiring a sparkplug into the exhaust exit.