Revving over 7K a bad thing?

[guyaverage]

My friend bought a 90 RX7 GXL and it's motor died b/c the previous owner never revved it past 3500. Those motors NEED to be revved if you want them to last. This is the same for most engines, even the K8 or KL motors.

I babied my T2 and it died an early death because of this, but I'm not sure this is a good comparison (Rx7 versus piston engine). Each face of the rotor only sees 2/3's the combustion events a piston sees at the same rpm. Rotaries need high rpms to burn off carbon buildup on the rotor faces, otherwise chunks can break off and jam between the housings and apex seals, breaking the seals and destroying everything in its path. This isnt so much a problem with piston engines breaking rings because carbon.

Reving a piston engine up that high? I would say if you keep your oil changes timely, and especially if you use synthetic oils, it shouldnt be too much of a problem, unless you do it every freaking time you shift. Dont expect your alternator, water pump, and power steering pump and timing belt to set any world records for long life either. Ditto for the clutch. Shifting gears at rpm's too much higher than where the peak HP is doesnt do a whole lot other than make more noise in my opinion.

[quicksliver]

Originally posted by Gro Harlem:
You will actually destroy some engines if you always keep the rev's low. My friend bought a 90 RX7 GXL and it's motor died b/c the previous owner never revved it past 3500. Those motors NEED to be revved if you want them to last.

This is the same for most engines, even the K8 or KL motors. You want to rev them high every now and then to prevent carbon build up from building up too much internally.

Yah, and this is coming from the guy that lowered his car...didn't get a 4-wheel alighment and went through a set of tires within a couple months lol.

[992mmx3]

You don't want to always rev your motor up. This will not prolong the life of it. Now, bogging your motor down will do damage.

[tical]

i have a 93' GS with some bolt-ons. i use Valvoline sytec synthetic oil. i have the tendoncy to drive my car like im racin all the time but never go over 5800 rpms (for the most part). should i back off or is that not ganna do much damage cause i run synthetic oil??

thanx

[Nd4SpdSe]

what funny is that some of the racers around here suggested that when i race, i shift at 7300

[Tyler17rose]

Why the hell are you guys reving so high anyway? I RARLEY pass 4,500rpm...

Liar

[Gro Harlem]

Originally posted by Quick Sliver:
Yah, and this is coming from the guy that lowered his car...didn't get a 4-wheel alighment and went through a set of tires within a couple months lol.

Funny, I don't see many posts of any value coming from you on this board

<small>[ December 12, 2003, 09:30 PM: Message edited by: Gro Harlem ]</small>

[MX3KL08]

I wonder how hard it is to run the engine at 3200-4000 rpm down the highway in 5th gear cruising for an hour or so? I never shift over 3000 rpm since I don't race or abuse my car.

[stang67fb]

little off topic here but...how many of you actually like the very close ratio 5 speed tranny we got in the mx3? Cause now that i got my ZE i ******* hate it.

[IanL]

Originally posted by stang67fb:
little off topic here but...how many of you actually like the very close ratio 5 speed tranny we got in the mx3? Cause now that i got my ZE i ******* hate it.

I know what you mean; I often accelerate to 30 in traffic in 2nd, then shift to 5th. You could fit an MX-6 MTX, the final drive is higher.

[HFStuart]

KLDE with 21 mph/000rpm in top vs K8 18.5 mph/000rpm

I'm betting that even with the bigger capacity and more power the 2.5 with MX-6 box will be more economical. Someone posted some perfoemance stats recently that showed the performace drop (with a ZE) to be minimal too.

Also Quaife do a Torsen LSD for the MX-6 box - I don't know hat the ratio is but there is a good chance that fitting it to an MX-3 would give the same gearing as the MX-6.

Stuart

[lakersfan1]

Originally posted by MX3KL08:
I never shift over 3000 rpm since I don't race or abuse my car.

How in the hell do you do that? I shift at 5,500-6,000 on this engine for liesurely driving. If I shifted at 3,000, I might fall asleep at the wheel out of boredom. Even on my 626 with the crappy 2.0 I4, I shift at 4,000.

[IanL]

Originally posted by lakersfan1:

Originally posted by MX3KL08:
I never shift over 3000 rpm since I don't race or abuse my car.

How in the hell do you do that? I shift at 5,500-6,000 on this engine for liesurely driving. If I shifted at 3,000, I might fall asleep at the wheel out of boredom. Even on my 626 with the crappy 2.0 I4, I shift at 4,000.

We all have our own driving styles - I'd say the boredom factor arises from lack of speed, not the revs. If you're overtaking, 6,500rpm is sensible to get past quickly and safely; if you're coming up to cruising speed with no urgency, changing up at 3000 rpm saves gas and lengthens the journey by a few seconds each instance - I'm not that pressed for time.

<small>[ December 13, 2003, 01:08 PM: Message edited by: IanL ]</small>

[MX3KL08]

Yeah I just don't need to get up to speed that quick but if I keep the rpms up in 5th gear it accelertates up to 80 pretty quick. Just gotta keep the radio loud enough to keep me awake.

[mx3man83]

If you are serious about the best possible shifting points(from a performance stand point) you need to get your car dyno'd and see what RPM's and in what gears you achieve the most HP and TQ. I rev my klze up to about 6700-6900 when racing. The only times I rev past that point is when I'm trying to be loud and obnixous :p (which is not too often). During daily driving I usually shift at about 4500-5000 RPM.