I agree with Jim even if your car can rev to 8000 rpm's it doesnt mean you have power up there, I normally shift at about 7300 to 7500...

 

As I said, I have CarTest 2000 also. That's not what the chart you posted is showing.

The top speed calculations break down after a certain point. It seems to work fairly well for stock and mildly modified cars, however.

You are right, I didn't pay attention to the loss curve where top speed was concerned. I was looking at the terminal speed shown for each gear, which is obviously not real world. You cannot hit the calculated gear-limited speed. Ever wondered why on paper 4th gear should be good for about 149 mph, yet you shift from 4th to 5th at about 140?

I did too. However, from real world results with engines producing less power in heavier cars, I know for a fact that my engine is capable of better performance in the quarter mile than what CarTest was estimating. That was another reason I stopped using it.

 

I run my car up to redline often but cruising around town I keep it around 2000-3000 rpm. No need to be cruising along in 2nd gear at 35mph. Revving it constantly increases engine wear and engine temp.

 

I agree with most of you... revving it up constantly increases engine wear and engine temp... shortening the life of your engine. But then again, what fun is it shifting at 3k rpm anyways??? In short, rev it up every so often to give it some excercise...

 

Apex seals do not get more brittle. However, the springs underneath can set if the car isn't driven or started at all for extended periods of time. This is different than babying it.

IMO, running it hard when the engine is cold (I too watch for 180F water temp) is destructive. Driving hard regularly on a warmed engine will shorten the life of many components, but how much I don't know. Since heat from the turbos is the significant difference between the 13B-REW and it's shortened lifespan vs. the NA 13Bs that last for triple the mileage, I'd say running it hard (under boost) will shorten the engine life for certain.

Babying it completely isn't really bad as long as the car doesn't sit for long periods. It's not like our cars have valves to gunk up.

Dave

 

If I remember correctly:

According to the Mazda training video on the rotary engine, our power plant is designed so that high revs actually remove carbon deposits from the housing walls. I guess the real question is how high is high revs?

 

true... how high is HIGH? At what point does it go from removing carbs safely to adding serious wear? Of course, this is all when the car is warmed up...

 

during normal driving, highest ill rev is 3500, i kinda have to cause the car has no low end torque since im non seq, i have to rev it that high to get moving even a little or to keep up with the pace..

but i try to hit 7500 at least twice once a week..most of the time i hit it twice all in the same trip..then i think im putting to much on her and i let her rest for more than 24 hours hahahahahahaha

hot damn, i treat this car like a bitch!! LOL

 

I like the drive it like you stole it mentality. 4-5K shifts daily are my only method of transportation, I'm glad this car can handle it.

I love learning more and more about my rx-7!

 

Jim has pointed out that shifting at a little over 7500 is going to give you the best performance. I agree. It appears that Mazda agrees too. That may be why they installed a buzzer to tell you to shift. If you are at WOT, by the time you shift after hearing the buzzer, you will have shifted at the optimal rpm.

It could also be that Mazda didn't want people to over rev the engine

 

you'll def be slower if you rev higher than the engine can flow. Running mine at the track, I can lose 3 mph going through the traps by shifting too late.

 

[QUOTE=jimlab]some people are just fascinated with high rpm and they're not aware that their engine isn't making any more power in that range.

Not if you've got a big race port...

 

Which is probably why I ended the post with...

 

Probably...

 

I usually shift at about 4-5k rpm daily driving, but I do spirited driving every time I drive the car so it's common for me to reach 8k rpm at some point during a commute...plus I heard rotaries love to be revved!

 

****, I was able to lose 11 mph from shifting too late last tuesday. No point in shifting past your max hp/torque.

 

Now, I have had the impression in my head to take it easy untill I can afford to replace my engine but after all this I hear about not worring how often you give it some gas thats all I can think about is how much gas Im going to be shooting out my apexi exhaust! How do you guys that say you take it to higher rpms often afford the gas?? I mean Im so cheap I dont think I used my a/c once this summer and I live in St. Petersburg, FLORIDA!

 

Ok I got a related question that I've been wanting to ask for a while... is there anything bad/wrong w/ revving your engine high but slowly/without boosting? Ex., I find it's much easier to get a very smooth shift at 5000rpm and up, yet when the speed limit's 35, and 5-0 is around, I'm not exactly gonna come off the line boosting lol. That, and if I haven't had a chance to give her a good run, at least I'm revving her high enough to clean out some carbon deposits. So i have - on occassion - slowly raised the revvs to 5, 6, or even 7K rpm w/o really getting on the gas. The boost guage remains at 0mmHg, but I dunno if this is bad, since a) she remains at higher revvs for a longer period of time, and b) I know the 2nd turbo is fully spooled but not boosting, since it comes online by 4500 - 5000 rpm...I'm wondering if going past that w/o producing boost has any ill effects?

 

I know this isnt the original point of the post, but when I drag I always end up taking 3rd out to around 105 (I think about 8100 rpm) because the top of 3rd comes so close to the end of the 1/4 that the time to shift to 4th will slow me down more than riding out that last few feet in 3rd. I guess I should just try taking 4th at the end and see if it changes anything.