2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

rpm rev limiter

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Old 07-22-07 | 11:52 AM
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rpm rev limiter

I recently found someone that can raise the rev limiter so that I could get the maximum rpm and power out of my RX7. Only a $100 and my car flies now!!!!!!!! If anyone is interested let me know...I am told that you really cannot over rev your rotary engine....it just runs out of power at a certain rpm....mine tapers out around 8600 rpm!!!!! Anyone want more on this...let me know.
Old 07-22-07 | 12:46 PM
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Yeah, whatever. Why would you want to raise your redline when you need to shift near the original redline anyway.

Scam.
Old 07-22-07 | 01:12 PM
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how email is sandordeli@gmail.com
Old 07-22-07 | 01:41 PM
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sorry pal, there is no rev limiter. if you want more rpm's safely, rebuild with porting.
Old 07-22-07 | 02:14 PM
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No rev limiter = no legs.
Old 07-22-07 | 03:06 PM
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Originally Posted by mazdaverx713b
sorry pal, there is no rev limiter. if you want more rpm's safely, rebuild with porting.
I may not have taken an incredibly good look at this, but I fail to see how porting will protect your engine against high revs. It'll provide more top end power so those high revs actually mean something, sure. But safety? I highly doubt it. I read the Renesis used better rotor balancing, bearings and lubrication to raise the rev limit.
Old 07-22-07 | 03:47 PM
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oh man...better put on a ballistic blanket on. Sounds like one day your gona be driving, hear a noise and you look down and your feet are mangled.
Old 07-22-07 | 04:34 PM
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Originally Posted by mazdaverx713b
sorry pal, there is no rev limiter. if you want more rpm's safely, rebuild with porting.
i am calling you out.

these car came with rev limiter and rebuild with porting doesnt make the high rpm safer, in a sense, they make it less safe because it actually makes power that could hurt something
Old 07-22-07 | 05:54 PM
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these car came with rev limiter and rebuild with porting doesnt make the high rpm safer
If you rebuild with the right parts it does.

I do call BS on the original post though. If its so great, why don't you post this incredible info? Sounds like you want people to pay you $100 to do this so called great modification.

If your engine is stock, I doubt you have power past 7500 (S5) or 6500 (S4)
Old 07-22-07 | 09:02 PM
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motec08 is just out to scam someone who doesn't know better! And on the 1st post eeeeveen!
I've got an S5 and have taken it to 9 grand, ONCE... no rev limiter to stop me.
Old 07-22-07 | 10:13 PM
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Hell, my s4 will go well past where the tach is pegged, probably 8.5k+
Old 07-23-07 | 12:29 AM
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what are the differences between the s4 and s5 motor to make it create rev higher?

b.s. on post.
Old 07-23-07 | 12:33 AM
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Originally Posted by slpin
i am calling you out.

these car came with rev limiter and rebuild with porting doesnt make the high rpm safer, in a sense, they make it less safe because it actually makes power that could hurt something
i've never seen or heard of an SA, FB or FC with a rev limiter and i own at least one of each and i can bury the tach in any one of those cars if i choose. find me a 7 with a rev limiter and then post back. as far as porting is concerned, with the correct engine build and porting, one can operate the engine safer at higher rpm than one could with a stock engine. a lot of heavily ported engines will make peak power near 10K and run it reliably for track use. i wouldnt run a stock port/build engine anywhere near 10K
Old 07-23-07 | 01:45 AM
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Originally Posted by mazdaverx713b
find me a 7 with a rev limiter and then post back.
Every FC made came with a rev limiter. If you haven't found it, you haven't revved high enough with the stock ECU. Note, it's not at redline...

as far as porting is concerned, with the correct engine build and porting, one can operate the engine safer at higher rpm than one could with a stock engine.
Porting has absolutely nothing to do with redline, or how high the engine can safely rev. Just clarifying that.
Old 07-23-07 | 01:50 AM
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I heard the 86 didn't have a rev limiter.
Old 07-23-07 | 02:36 AM
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Originally Posted by mazdaverx713b
i've never seen or heard of an SA, FB or FC with a rev limiter and i own at least one of each and i can bury the tach in any one of those cars if i choose. find me a 7 with a rev limiter and then post back.
S4 fuel cut is around 8000 RPM. I've hit it. Would you like video proving this?
S5 fuel cut is around 9000 RPM.

Apparently the S4 ECU is clocked low enough that ignition timing starts wandering around if you're above around 7500 RPM, but the S5 ECU runs faster and can handle the higher RPM (source: ECU teardown site I found ages ago).

The stock engines won't flow well that high, but a bit of intake/exhaust/porting work and the engines will continue making power up to (and in many cases past) fuel cut.

There are several things that will fail, mechanically, on a stock engine at high RPM.

The most dangerous is the already mentioned flywheel explosion - if the clutch/flywheel grenade at speed, without a scatter shield, they fly right through where your feet are. Look up flywheel explosion pictures - it looks like a hand grenade went off in the transmission tunnel. Not a pretty sight.

The second issue is that the eshaft starts flexing at high RPM. The S5 rotors are lighter, which is part of it's raised redline. If the eshaft flexes too much, the corners of the rotors will contact the irons, causing rotor and iron damage, causing the corner seals to stick, the side seals to stick, and basically requiring a fairly expensive rebuild to fix (as the rotors, seals, and possibly irons will need to be replaced). A "race clearanced" rotor has the corners ground back slightly to delay the contact.

There's no good reason to raise the redline on a stock engine, and with the clutch/flywheel explosion risk considered, it's not at all worth it.
Old 07-23-07 | 03:29 AM
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Originally Posted by RotaMan99
If you rebuild with the right parts it does.

I do call BS on the original post though. If its so great, why don't you post this incredible info? Sounds like you want people to pay you $100 to do this so called great modification.

If your engine is stock, I doubt you have power past 7500 (S5) or 6500 (S4)
name right parts. what? the same **** Mazda use? rotor balancing Or lightened whatever doesn't magically install itself on aport job.Nor they come in any regular rebuild. you idiots...
Old 07-23-07 | 03:33 AM
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Originally Posted by mazdaverx713b
i've never seen or heard of an SA, FB or FC with a rev limiter and i own at least one of each and i can bury the tach in any one of those cars if i choose. find me a 7 with a rev limiter and then post back. as far as porting is concerned, with the correct engine build and porting, one can operate the engine safer at higher rpm than one could with a stock engine. a lot of heavily ported engines will make peak power near 10K and run it reliably for track use. i wouldnt run a stock port/build engine anywhere near 10K
take a pick at one of the 8 FC I have. Any one of them.
Do you know what a rev limiter is?
Old 07-23-07 | 03:41 AM
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If heard that our cars can run all day at 10k (na im guessing) but you NEED to have a way to protect yourself against the clutch fragging. BTW this is in a racecar not a street car.

If you wanna know about rev limits talk to henrick, he knows more about the ECU then anyone here.

For the S5 NA Rtec 2.0 the rev limit is apparently can be moved to 9200
Old 07-23-07 | 05:05 AM
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Originally Posted by AUGieDogie
If heard that our cars can run all day at 10k...
Pretty much any engine can by built to do that but only a complete fool would believe any stock rotary can.
Old 07-23-07 | 09:59 AM
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Don't forget oil pressure. Running at really high engine speeds for extended periods of time with only stock oil pressure would most likely give you spun bearings.
Old 07-23-07 | 10:35 AM
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Originally Posted by slpin
take a pick at one of the 8 FC I have. Any one of them.
Do you know what a rev limiter is?
trust me, i'm well aware of what a rev limiter is. however, i've never run my FC's that hard to find it. i'm not going to risk an engine to find a rev limiter. i'd sure as be wise about it and not abuse my cars. thats just plain ridiculous. as far as first gens are concerned, they dont have them and i'm fairly new to the FC and have not taken my 10AE over 7500rpm.
Old 07-23-07 | 10:41 AM
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Originally Posted by NZConvertible
Pretty much any engine can by built to do that but only a complete fool would believe any stock rotary can.
two of the voices in my head DO call me a complete fool. That specific info was from a racing website i found many years ago. My guess it would run all day for a veiw days only and then be rebuilt. But I always liked to daydream about it.

Personally I just shift at redline, knowing that if i screw up, i SHOULD be ok. should being the optomum(sp) word.

That being said, if I decided to get Rtec 2.0 for my N/A vert i would NOT bump up the limiter.
Old 07-23-07 | 10:42 AM
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Originally Posted by NZConvertible
Every FC made came with a rev limiter. If you haven't found it, you haven't revved high enough with the stock ECU. Note, it's not at redline...

Porting has absolutely nothing to do with redline, or how high the engine can safely rev. Just clarifying that.
i know that porting has nothing to do with how far an engine can rev. i understand that the internals are more important(lighter rotors for example) and was suggesting that if you're going to open up an engine for a rebuild and want max power out of it, most peope are going to choose to port the engine and replace the rotors, bearings, and seals with ones that will allow sustained higher rpm use.
Old 07-23-07 | 04:23 PM
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FLAME WAR!!!!!!!!!!!!!!!!!!!!
ide trust slpin any day!

peace


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