How bad is that for engine? (MT)

Note that I DO go over 5k, but a lot of my drives are about 0.5 miles (to a vanpool to work), and so about 5 days a week when the engine isn't warmed up I try to keep it under about 3500.

 

take the long way and warm her up alittle more.

 

let's put it this way. The rotary engine is MEANT to be driven in the high range. Staying under 5k just bogs down the engine.

If you drive short distances, just keep the gears in 1st, 2nd or 3rd and you should be fine.

 

i thrash it when it's not warmed up. i know i should't but sometimes i can't resist. :D

 

If you only have to drive 1/2 a mile to your vanpool location, you might as well walk over there. Half a mile is only a couple of blocks. That's maybe 5 mins!!!

 

I always wonder about that...I can't help but drive mine pretty hard and in the high rpm range...but I also can't get the thought out of the back of my mind that I'm reducing the life of my engine by keeping those rpms up there...after all with regular engines I was always told to keep the rpms low....oh well hopefully I keep changing the oil and the engine won't blow up on me

 

the higher the rpm's the more force on the apex seals and the better the seal against the housing. higher rpm's also = more oil pumped into metering chamber and more lubrication, also more oil to apex seals for an even better seal.

high rpm's in a piston engine = piston slap and valve train/spring wear. you don;t have those problems in a rotary.

 

so wait...the engine bogs below 5k rpm now? wow. that number just keeps creeping up and up. when i first started reading here, it was below 2000. within a few days it was up to 2500. shortly after that it was 3500. now its 5k. its getting a bit absurd.

 

oh come on now, you know what I mean. I only said 'bogs down BELOW 5k', not AT 5k. It's not secret that the car does not move at low RPMs.

 

Short trips, without proper fluid warmup, is absolutely horrific on the engine.

You are probably putting more wear on your engine in 10k, then someone would with 100k on a highway.

Buy a bike. Save the car for longer commutes. Remember it can take as long as 10 minutes for the oil to reach operating temp. Just because the coolant dummy gauge hits the middle, doesn't mean the car's warmed up.

 

for spirited drive, i agree that the car performs better in the upper rpm range, but to say that car doesn't move in the lower rpms is just plain wrong.

this car is my daily driver, and atlanta traffic sucks ***, so i spend a good deal of my time on the roads in traffic, and for driving in a civilized manner, it does fine at 2k rpm and above. starting in traffic only takes 1k-1.5k rpm, and if i'm a few cars back in line, i've even started at 750rpm with no bogging.

yeah, the car is low torque, but it still makes more torque at 1.5k rpm than a civic makes peak, and if those cars can drive around with such minimal amounts of horsepower and torque, then surely our cars can too.

really, the only time you need to go into the upper rpms is on the track, or for overtaking. the rest of the time, the 8 is perfectly happy in the 2.5k-3.5k range. and contrary to what everyone on the forum insists, you actually can accelerate in those rpm ranges.

 

Two words (Carbon Lock)

 

Are we driving the same car?

I can get out and walk faster than my RX8 'accelerating' at 2500 RPMs.

 

You're crazy...if I'm at the 2.5-3.5k range I can have the gas pedal floored and people on bicycles start sounding off those little ringing bells they have to get out of their way. :o

and 750rpm not boggy? If I don't take 2 mins to release the clutch at those levels I'm gonna end up twisting the key to restart a stalled car...always a good way to get attention to a sports car in traffic.

 

fine. whatever. below the 5k rpm the engine bogs, dies, kills your pet and steals your money, and is so slow in doing so, it actually goes back in time. the only way to even get it started in traffic is to rev it 10k and side step off the cluctch. and even then it bogs.

 

Mugatu and Niro,

If you have "dangerous" lack of power before 3500 - 4000 rpm's you could have bad ignition coils.

 

I don't know about you but my car is quick all the way down to 3k rpm's I can accelerate pretty good in 4th at that rpm, something must be wrong with some of your cars, granted it isn't as quick as of top but I have no problem trolling around town at that rpm.

 

I may be exagerating just a bit...but I don't have "dangerously" low power below 3,500...but it's definetly not "quick" at that rpm....I would be really surprised if I changed gears at 3k every gear and still be able to beat a civic (who's the guy that said we have more hp at 1.5k then civics??).

 

Okay, I have two responses for your suggestions. First, I have to leave at 6:30am and I don't get back till almost 6pm. I am not a morning person, and always tend to go to bed too late. Practically it's just not going to happen that I'm going to get up another 10 minutes earlier each day to drive my car around the neighborhood a few times before spending another hour in a van to work. Yeah, maybe in an ideal world, but it's just not gonna happen. Nor am I going to drive it everyday to work, because I'll be putting a HECK of a lot of miles on it, and spending about $9 in gas each day from that alone. I need this car to last more than 4 years, and that's about all I'd get if I drove every day to work. That and the daily cost of gas would be a bit much for me.

I do however keep the engine on while I'm waiting for the van, and by the time it comes the temp. gauge is usually just a little under halfway. This is the first I've heard about it being a dummy gauge. The oil pressure gauge, yes, but why has noone mentioned the coolant gauge? Not sure I buy that. Anyway, I then make sure to do the 3k rpm before shutoff trick every time.

Second, I would love to just walk or esp. ride my bike to the pickup spot. However, to do this I would have to cross a bridge over a major freeway. Said bridge has no pedestrian lane. So I'm pretty much stranded and forced to drive. This definitely annoys me. It seems like that'd be a great excuse to get some exercise every day as well as saving wear and tear on my car.

Oh well. I didn't ask for a lecture on what I should or shouldn't do, I asked what would happen to the engine if you never go above 5k. Man I'm feeling argumentative today :D No hard feelings I hope.

 

I agree with this. I own the AT and have never experienced any problems with power below 3000 RPMs. It gets up and running just as fast, if not faster, than a piston engine car that has similar HP/TQ figures. I'm just about always pulling ahead of everybody else around me without even trying when I'm stopped at a stoplight, and I rarely take it over 3500 RPMs to prevent those 2nd fuel injectors from coming on.

I also drove a manual when I initially test drove the RX-8, and the entire trip, I never revved it over 3000, despite the salesman wanting me to, since I didn't want to flog a brand new car. The car felt absolutely fine and didn't feel like it was bogging down at all. I could feel the same amount of "pending resistance" at 3000 RPMs that tells you to upshift just the same as a typical piston engine car.

I dunno, but those that say their cars aren't making any usable power down low should consider having their cars checked over...

 

then you're dangerously low on fun extraction factor. Not good.

 

that was me, and 1.5 might be an exageration, since dynos typically start displaying data at 2k-3k rpm. but its probably not far off, considering that the civic is rated at 110-111 peak torque (depending on the model) at the crank. factor in a 20% tranny loss, and your looking at around 89 ft/lb peak. dynos that i've seen for the 8 have it around 105ft/lb at 2k rpm at the wheel.

and for the OP, actual consequences of not going over 5k rpm is possible carbon build up and improved fuel economy. short trips have their own issues that may or may not overlap those of not going over 5k rpm.

so, rev it up as often as you can to clear out the carbon (try for at least 1x a week minimum) and enjoy the car.

 

I have the exact same concern as Niro as far as constantly redlining it...wear and tear. Sure, the engine can take it (and I have my doubts about that even), but can the transmission?

 

First of all to whoever said it, NEVER EVER run a rotary hard until it is fully warmed up!!! You are just asking for an engine rebuild. Remember that each side housing and the intermediate housing are cast iron. The rotor housings in between them are aluminum. These metal have different thermal expansion properties. If your car isn't warmed up yet and you get on it hard, the engine is building up heat very quickly. The rotor housings will try to expand faster than the cast iron housings. What can happen is that the rotor housings will just warp and you will get water leaks. They might leak into the engine of it might leak out of the engine and be seen a small coolant puddles on your floor. Let the engine fully warm up first. This is just asking for trouble.

I recommend taking a rotary up to redline at least once every time it is started. Preferably under load such as 1st or 2nd gear. This is usually within legal speeds. This helps keep carbon buildup off of the rotors and rotating auxillary port valves. With the 2nd gen RX-7's, it was not uncommon to find a car that was never revved up high or driven under a heavy load very often. Some people just bought them to drive like every other car. Alot of carbon would buildup inside the engine and often carbon would lock the auxillary port sleeves shut. These were impossible to free up without taking the intake manifold off and even then I have broken several of them permanently in the attempt to fix them. My current 1st gen RX-7 is a prime example of this. I bought it from the original owner who was a woman in her 50's. She just drove it. The car was taken care of and ran fine but the interior of the engine was full of carbon. I spent alot of time cleaning up that engine when I rebuilt it.

2 big rules for rotary engine longevity:

1: Let them warm up fully before getting hard on the throttle or taking them to high rpm's
2: Hit redline at least once a day but every time you take it out would be better. If you can't do it under load then fine but hit redline. You won't hurt anything. This is why redline is here.

 

tranny can take the most beating in 5th or 6th gear it's turning thousands of times faster than the engine ever will and in redlining it in first or second is nothing compared to running it as a daily driver in 4th or 5th at highway speeds. Manual tranny last forever, the syncros go before the gears do unless there's a manufacturing problem. Keep the fluid changed and it may well last foever if you are good to it.