At what rpm will the engine not be damaged?
 

Hello,

I've read the stickies and a lot of posts about redlining at least once a day and driving it rough to keep the engine healthy. Heard a lot of stories where the rotary engine dies because of low rpm gear changes.

I have wondered what do you guys mean by "rough" driving. For example, at what rpm should you change to a higher gear? and what is the estimated lowest rpm change possible that will still be good for the engine? I know that piston engines you change at about 3.5k rpm.

Right now i'm changing gears at around 5k rpm for the rx-8 (it's 2007 btw), but it seems like it's always struggling with such high rpm, but when i change gears at lower rpm it seems perfectly fine, if not sounding like it's not hurting it.
NOTE: the car was warmed up on both occasions.

Thanks for any input,

Chris

you don't have an rx8 at all do you .........

sounds like you mean the transmission isn't as smooth to shift?

Hi Chris

I'm not sure whether you have an AT, but assuming that you have a manual transmission, you can safely upshift all the way to redline.

In the 6MT, the full potential of the engine doesn't come into play until higher revs: The VFAD in the air intake open at about 6,000 (?) rpm and the APV in the intake runners opens at about 7,250 rpm.

The power does start to drop off beyond 8,000 rpm, so ~8,500 rpm shifts are probably the 'best' to keep in the powerband.

Carbon build up on shorter, low revving trips is what seems to be most problematic for the engine. In the city, cruising from light to light, I generally shift before 3,500. Under those conditions, a full-throttle trip (or two, or more) to at least 8,000 once a day will (hopefully) keep intake tract valves from gumming up and should heat the engine enough to burn off light carbon deposits on the rotors (the Mazda 'zoom' cleaner described in other threads will periodically remove heavier deposits).

On the highway, at 110 km/h I think I'm about 4,000 in 6th gear. I feel comfortable with an hour or so at about those revs without worrying about carbon - then I drop two or three gears and give it a clean for a minute.

uh yes i have an rx-8 and yes the transmission isn't as smooth, but what i meant is it seems to be harming the engine when i shift at 5k-6k rpm, should i be shifting at like 4k?

the engine barely makes power under 5k. if you shift below that point you're not using most of the engine's capability.

Shifting at those numbers wouldn't hurt the engine. More like your transmission is feeling more of the brunt. Still, I wouldn't say it's bad.

Ahh thanks for the informative post, and yep it's an MT.

Its not harming the engine...if anything go to the dealer and check if syncro's are bad or something. Maybe you just need to learn to drive stick better?

God no! You should running that motor up to 9000 RPM. Either there's an issue with your engine, or you need to find a local who's familiar with rotaries to show you what your car likes. I'm down in Seattle. I'll happily flog your car a bit to show you what it wants.

Thanks for help, and it's got nothing to do with me not being good at driving MT (not saying i'm good or anything) it's just the engine doesn't sound like it's smooth, but maybe it's just me.

The main point is, if i change gears at 3.5k rpm just say, and redline once a day and rev up to 5k before shutting it off, will this cause in an engine replacement in the long run? or will this be okay?

Yes, you're lugging the engine and causing unecessary stress to the transmission.

DRIVE THE DAMN THING CORRECTLY, AND QUIT BEING A LITTLE GIRL.

Sorry to thread jack here, but is that what that wonderful sound is at around 7k? Almost sounds like a little BOV.

You are releasing the clutch too fast and/or not properly rev matching, or there is something wrong with your transmission/clutch. The 8 should shift smoothly at any RPM from 3-9K. You can even shift at lower engine speeds, but you'll probably end up lugging the engine.

MM kk thanks everyone for their help

probably the VFAD - it's a diverter in the air intake (before the filter). It opens at higher revs to give the engine a much more direct airflow. At lower revs, it make the air take a longer, quieter path.

At what rpm will the engine not be damaged?

What kind of bass-ackward question is this?

Every RPM damages this car except 9k. :banghead:

the engine cannot be overrevved, the limiting factor in the redline is the transmission's max revs, so don't worry about it, altho if you accidentaly downshift into 2nd from 5th while doing 70 you can overrev the car and send it onto limp mode

That and the fact that the fuel won't burn fast enough.

WOW ! I mean WOW!
I'm surprised no one got this.
The answer is ZERO. Zero RPMS will not damage the car.

The minute you start it the engine begins to wear, hence you are damaging it.

^ yeah, because we all know how healthy rotaries are when you leave them to just sit there.

Beat the piss out of it yo will b fine. If any of you or Original poster has ever ridden 2 stroke dirt bikes? Well if you have treat it exactly like a 2 stroke beat the living shi* out of it and it will always come back begging for more!!!(most times until you melt a pison in the 2 stroke but thats another story and another beer) ha

At 0 RPM, the engine will not be damaged.

^ Leave it long enough at 0 rpms, the rotors will rust! Lol.

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