Rev. Limiter
 

I've been thinking about this for the better part of 10 mins. Would a rev limiter work on an older FB like ours?How would it be wired? Which would work best (if you've tried it)?

use your brain and your right foot as your rev limiter. 8,000k+ rpm = boom :bigthumb:

Forgot to say I had apex seals and a crazy street port. So I (along with a friend's 11k autometer guage) say 8k isn't even touching the "real" redline. Just wonderin though there are times when you're foot gets heavy and desperate times call for desperate measures.

It's not the engine you have to worry about... Its the accessories attached to it. Stuff like the water pump, P/S pump (if you have one), etc will be the first things to go blamo.

well then you could get some underdrive pully's or something

MSD6AL's on both leading and trailing. The write up is on the Mazspeed site.

my cousin had a stock 83 12a which he told me that when he reved it up past redline he could hear the rpms still rising which of course is not good at all... just thought id share that

my 4a corolla did the same thing.. the problem is that the engine still makes power to accelerate past redline, but redline is a value scientifically determined by teams of japanese engineers. This value is the maximum rotational speed the engine should be spun at to avoid rapid degeneration of it or its perhipherals.

later, my corolla engine started clacking.. everywhere... then i drowned it.. the saddest day of my life. may hatchi rest in peace, amen.

edit: relevant information

would it be acecptible to limit the leading ignition only? the trailing system is so weak anyways it may not make power beyond leading limit, or would be so incredibly weak the operator would be more inclined to shift..

i personally agree with the brain+right foot method, though misfire systems make for great cigarette lighters.

rev limiters make little sense when you arent making much power. but on turbo cars of higher power cars of any kind, damn yes! my supra i'd blow the engine in no time, if i punch it off the line i cant just watch rev's, they go too damn quickly if the wheels spin i'll be hitting the redline at the top of first, and it just makes more sense to be watching the road than the tach.

id still will never install one of those monster tachs in any car i ever own. atleast in the RX the tach is highly visible and you can feel when the car stops drops out of its powerband. start getting into aftermarket turbos, fuel, etc things get messy....

the car comes with the shift buzzer just use that.

We have apex seals too, I dont think different apex seals make a difference in where you will redline, just how long your car can handle being redlined. Same with a streetport. Sure, The egine can handle 11k rpm, but for how long? How well can everything attached to the engine hold up when its all spinning 2000rpm faster than what it is rated for. But if you feel it is neccisary, go for it.

edit: I could really only see it coming in use if you are pushing 300+ RWHP and have an ultralight flywheel so it revs in about 1/2 a second to redline.

Yes, there are different apex seals for high rev rotaries. They are a low life carbon type that don't chatter as easily as the iron ones. I think its generally accepted that 8000 rpm on a stock 12A won't hurt it at all. Anything above that is just stupid and the 12A or even 13B probably don't make much power above this number. But if you have streetporting or something of that sort, then a higher redline may be desired. That on top of how fast the car will reach the high rpm's will warrent a rev limiter. A cheaper way to protect your car would be to use a large shift light mounted close to your line of vision to tell you when you've reached your desired redline.

As a little tidbit of info, my original 12A with 275000 KM on it went way past redline 3 times. I'm guessing 9000+ as the tach was pegged for at least 2 or 3 seconds. Only reason it went this high is because the throttle stuck open either because of my floor mat holding it under a WOT run or the choke linkage coming off and proping the throttle open.

^ yea I agree, most of you people have no idea what your talking about though.

edit: ok that was a little harsh. Mostly the people who spout off about revving to anything in the region of 8k without damage. Have you never heard of apex seal chatter? or what happens when you try to shit mad fast yo and miss the gear and spin it up. a rev limiter is a good idea.

there is no point in going above redline since the power drops off around 7k, look at dyno graphs. you want to stay in the powerband, thus shifting is a good thing... unless ofcourse its the end of a autox track and shifting will drop you a precious 1/2 second.

Apex seals don't start to chatter untill 8400 rpm. I've heard of 12A's reved to 8000 regularily without any problems. Sure, there is no power up there, but sometimes you just accidentally rev up too much. I guess thats the whole point of this thread though. But the fact is, if you miss a gear shifting "mad quik", no rev limiter is going to save your engine.

It's not just the peripherals you have to worry about... think of e-shaft flexing! Or degredation of stationary gears, side seals, etc....

To build an engine to go past redline, you need to replace/upgrade practically EVERYTHING. Just slapping in "apex seals and a crazy street port" won't up your engine's ability to survive higher-than-redline conditions.

And I didn't even mention cooling. If you've got the "beehive" water-to-oil cooler, it's barely sufficient for regular driving, let alone high-rpm operation. A proper air-oil cooler, a more powerful oil pump, a higher pressure oil bypass will all help with keeping oil temps low. A larger water pump (such as an S4's water pump) along with a better Rad (you can get custom large aluminum ones made) will help keep coolant temps down, and keep your engine safe.

As for installing a limiter, you'll either have to take Directfreak's advice and install an ignition controller, or switch to an engine with fuel injection and install a standalone fuel management system.

Your car comes with a buzzer installed and your car's driver SHOULD come with common sense installed... between these two the car should be fine. If not, perhaps either the car or driver should be replaced ;)

Jon

sounds like you dont know how to drive yo.

riiiight. I don't have 2 track records and a class championship for not knowing how to drive.

By missing a gear I meant letting out the clutch without engaging a gear when trying to shift fast. Sure if you throw it in a lower gear the inertia will force the engine higher. As for revving to 8k, do it in your car everyday and then let me know how long it lasts.race engines don't last long for a reason.

wat track records do you have. around your block?

http://autocross.mcscc.org/resources/mil-record.htm
edit
done with this e-pissing contest