warp0007

After removing all emissions, including OIl system and running premix. Is there a higher rev limit thats safe?

88t2romad

not necessarily, thats all based on balancing, reduced weight, hardened gears all thatgood stuff

warp0007

Specify will ya.. Cause id love to do those mods as well to give myself an extra 1000 or 2

sar

iTrader: (1)

Well, like its been posted you don't actually have to change toooo much to be able to rev high safely, i think there is a story of some guy running 17,000 rpm in a race with a 12a w/ stock rotors.

I'm assuming that you're in an s5 for the 8k limit.

Basically, as you pass 10k rpm you will need a scatter shield, amazing clutch - flywheel, better spark, really deep porting and no desire to drive like actually on a street. You could pay $2000 to get your rotors lightened and get everything ceramic coated. I would also suggest a lightweight flywheel and lightweight wheels. Like the 88t2romad said, hardened stationary gears will be like you more (this generally comes with the race rotors). A nicer exhaust and intake wouldnt hurt also.

What is the big deal with people thinking that revving higher than 8000 is that amazing anyway? Without the massive porting there is no power up there. If you really don't want to shift you should be able to get to 8500ish on stock ports. Our rotary cars already do rev a lot higher than most other cars, unless you're trying to compare yourself to an indy car or gas turbine engine.... we're even close to the v8s in nascar.

Project84

You need to dyno your car and find out where it peaks out as far as power and torque. There is no need to spend the money to increase how high you can rev if the engine isn't making power up there. The only gain is going to be that you can tell your friends "look, I can rev this high in nuetral". Its a lot of expensive mods that have to be done to get the engine to rev higher under load and still work reliably.

Syonyk

I wouldn't push much past 8500 RPM for extended periods without a scatter shield/blanket around the flywheel/clutch.

Also, at high RPMs, the eccentric shaft starts to flex. You'll need to clearance the rotors (basically, shave a bit off the sides near the apexes) to make room for this, or the rotors will hit the end irons, with predictable consequences (trashed rotors, trashed housings, stuck seals).

Premixing and emissions removal has nothing at all to do with the physical structure of the motor.

-=Russ=-

warp0007

What is it about people jumping to conclusions about high reving LOL Im only refering to about 9 or 10. What car is it the Acura Type R or whatever redlines at 9. I drive a cbr 600 rr love redline at 16!!! And the point really, was to make a higher rev point SAFE. Not so i cant drive or shift at 10 grand all day dont get it twisted. yeah rotaries have no problem in fact love reving in those 7.5 to 8s. But wouldnt it feel great if you knew your car was safe for up to 10 and you still shifted at 8.5 You sure wouldnt worry as much about OVER revving. It happens all the time.

ddub

You need to do a LOT more than just premix

To be safe you'll want hardened stationary gears, balancing is a good idea, etc. You WILL need standalone or carb, something besides the stock ECU because it not only has a rev limiter, but it is terribly inefficient past the stock redline and craps out on you. You should NOT do this on stock port, it's completely worthless since stock N/A rx7's, for example, start losing power 500 rpms BEFORE stock redline because they aren't flowing enough.

Is that what you wanted to know? In short, with what you did you aren't going to be able to go higher any safer. If you want to go higher expect to open up the engine, rebuild/port it, change some other things, and get standalone or carb and tune it for those revs.

Icemark

why go any higher than 8K on a S5 non turbo, or 7k on any other FC??? I mean the intake can't keep up with any higher RPM and you are just looosing HP and torque at that point anyway.

Syonyk

Ehm... The S4 ECU has a fuel cut at 8000 RPM, the S5 ECU has a fuel cut at 9000. I'm perfectly fine with that. I'm inclined to trust Mazda's engineers when they decide that 8000 RPM for a brief period of time won't hurt my engine. Also, as mentioned before, the stock ECU can't fire the ignition reliably up past ~7500 RPM on the S4s, and it's having issues well below that.

Also, I've only hit the fuel cut RPM a few times. Once was just testing it to make sure it worked (when I got the car), and then a few times on an autocross course when I was staying in 1st on a straight before a series of corners.

As repeatedly said above, unless you have some seriously modded internals, there's no power at extremely high RPM, you can cause engine damage by running at extremely high RPM without clearancing the rotors/hardened stationary gears, and you'll need a standalone to fire it anyway.

-=Russ=-

R-apid-X-haust-7

ok kinda on the same sobject since its in the same conv area minus the rev situ. how many people have taken the oiler metering system off and are running premix. i was thinkn bout doing it but im thinking that it would be a pain in the *** especially if you have to sell your whole house these days just to get a couple gal. of gas, then you gada get out your measuring cup and funnel, while the fu*ks behind you are honking waiting for gas.

warp0007

I plan on having it done when revoultuions rebuilds my motor. You have to do it religiously if yoru not up for it dont do it. But it makes for a cleaner running engine I feel.

Syonyk

I've been running nothing but premix for the last 10k miles or so (since my engine rebuild). Really, once you get used to it, adding the oil isn't that big of a problem. It's worse in the winter, but in the warm (40F+) weather, it's nothing special. It weirds me out filling up other cars now... I feel like I'm forgetting something.

-=Russ=-

sar

iTrader: (1)

I know my car won't blow up when I hit 10,000 rpm, I misshifted from high 3rd to 2nd once and while spinning 4 times my tach was maxed out and beeping. The RX-8 has a 9000rpm redline because it has different port timing.

The reason for the buzzer at redline is a friendly reminder that your engine whispers "i know i sound soft, but i'm doing you no good here, shift"

warp0007

i dont know if you were addressing me but i wasnt talking about the 8 that could rev 9. Somone before me was like no car redlines at 9 and i was talking about that Acura Type R

tie pilot

easy way: buy a couple 16 oz bottles of your favorite premix, and then get a big jug of the same. keep the 16 oz bottles in your car for when you fillup with gas and keep the big jug at home for re-stock. all you need is the little bottle and a funnel when you do a fillup at the pump, just put all 16oz in (16oz of mix : 16 gal of fuel). it adds maybe 30 seconds time to a fillup.

-marshall