i'm pretty sure that S5 ECU's cut at 8500 and that S4's are 7800, Why would they make fuel cut 1500 RPM after redline!? now if the tach is so bad that it's off by 700 RPM's?

 

The only problems I have with high revving is those damn coolant hoses. I've had to replace 3 different hoses in all different spots. The only time they go is when I rev over 6500 rpm. At least now I won't have a problem in the future with all my new hoses

 

he must work for an oil company.

 

s5 n/a is deffintly 9k or higher. ever seen that video of the kids blowing up a white fc?

they litteraly put a brick on the throtle and peg tha tach past 9k.

it only stops (after about 10 minutes) when it over heats and sets the wiring harness on fire, not cus the engine blew up mechanically! that should tell you reving your engine isnt too bad for it.

 

No difference. I'm only relating from my own experience. There both the same. What I should have said is my vert has no problem with this.....Sorry for the confusion.

 

Yea... i was just making a statement. I know arent different and that was the point of my post.

 

Well, the JURY has deliberated and the Verdict is in ! There were so many great answers to this question, that I think this thread should be ARCHIVED. My question was no great one, but the answers are very pertinent to the High Revving reliability of the Rotary Engine and the answers alone make this one to keep.

 

I guess mine is gone or your wrong, I "accidentally" hit 8500 in second in my S4 passing a 626, hehe, twas fun... again. BRB, gotta go for a drive...

 

Those who have installed rotary engines in homebuilt airplanes employ a 2:1 reduction to the prop and often are spinning their rotaries above 6,000 rpm continuous.

 

according to the S-AFC on my car, peak revs I've ever seen has been about 8100, leading me to believe that fuel cut is right around there... I've hit it a few times now (no tach).

this is on an '88 TII.

Terrh, posting under compubob's account.

 

i accidentally hit 8.5K in my 91 vert while i was listening to some loud music. nothing happened and i still take it to 8K or so once a week to keep carbon out. my engine loves it.

 

Vert MPG :thumbdown: 15-17best, but my last car was an 91 accord. so you can see the difference, should have kept it for the commute, still not as fun though.

 

I suppose I'll go take my car out with the peak hold feature on the SAFC enabled & see where fuel cut actually is.

I know that the stock tach is very inaccurate up at high RPMs.

Basically, there are several things that can happen at HIGH (usually 10k+) RPM operation that are Bad.

The eccentric shaft flexes slightly at high RPM (hard to believe if you've ever held one, but it does). If it flexes enough, the corners of the rotors can contact the end irons. That's Bad. "Race Clearancing" the rotors trims down the corners slightly to make room for this flex.

The other Bad Thing that can happen is the clutch/flywheel/pressure plate assembly blowing up. The forces on the flywheel at 10000+ RPM can be enough to literally rip the flywheel apart. It blows up with somewhere around the force of a normal hand grenade. Not a good thing for your legs. This is why scatter shields are required on high revving engines.

Now, Mazda wasn't dumb. The fuel cut on the engines is there to *prevent* either of these things from happening. You just can't rev a stock engine high enough (with the stock ECU) to cause either of these. The only real problem on a stock setup is overheating - the cooling system can't take sustained high RPM operation without the temperature rising. And, it's not so much the high RPM operation as the high air/fuel flow. Light throttle high RPM operation is fine - you can run down the highway at 75mph in 3rd all day long and the engine won't overheat. Doing low speed autocross stuff, you'll probably notice your temperatures start to climb. As long as they don't get excessively high, there's no problem.

Oh, and revving a cold engine up high will usually blow a coolant seal. Let it warm up before beating on it.

Basically, rev it high. And premix. It'll love you for it.

-=Russ=-

 

HHAHAHA you need to check your spelling more!!!