Hey guys, I tried searching the forums for this, but it's hard to find my exact question. I've read elsewhere that it is good to run the engine up to redline every once in a while (when up to temp, of course) to reduce carbon buildup. I wanted to ask the experts (you guys) if this was the case. I have been avoiding taking my FD to redline just to avoid unneeded stress and wear on the twenty year old engine. I was wondering if this is a good practice to get into. I mean if I HAVE to redline my car, I will I've also ward that it can be dangerous if there's already some buildup, it can break off and damage the engine. So what are some signs of carbon buildup?

 

...................Just Do it!......
You don't need to beat the **** out of it..like 9K redlines..every gear change...
but don't drive it like shifting at 2000 rpm..
a Nice 4500 and up is perfectly ok..It's not gonna break!

 

Rotaries love to spin. That said, 20 years is a long time on the oil seals and water seals, etc.
My race car saw 8K not infrequently. A street engine in good health should be fine at 7K, but if you have doubts, build up to that. Keep it cool, and well oiled and make sure the metering pump/system is operating, and you should be fine.

 

Yeah I just replaced oil and oil filter so that shouldn't be a problem. I'll be a lot more comfortable running it hard after I get the temp gauge linearized.

 

i bought into that adage after joining this board, but quite a few years ago i remember a discussion on the subject that included an explanation that overall load was the point. the explanation was that (and i'm paraphrasing) if you do a lot of local stop-and-go driving, then the redline-a-day thing was a way to stave off carbon buildup, but if you do a lot of highway driving (i think there was a time mentioned; e.g. 20 minutes), then you're already doing the same thing.

 

you can drive these cars on a highway?...
I've been using mine to hold up my garden rake!..(LOL!!!!!)

 

High boost/high rpm creates alot of heat. So if you take the car high in the rev range JUST to reduce carbon, seems like your you're trading the stress of heat for less carbon. Neither is good for the engine.
I assume the car is new to you and this may be a little much for a new owner, but you might consider a simple/inexpensive boost-activated water-injection system. You'll get a gradual (safer) reduction in carbon, along with cooling and knock control. Been running a system myself for a couple years with no issues....and I pre-mix with a working OMP. When you have time, go to the Auxillary Injection section of this forum and start reading some of the stickys from Howard Coleman.
A thread on my installation. Pictures are gone but if you're really interested I think I still have them ----> https://www.rx7club.com/auxiliary-in...ion-fd-959565/

 

Diabolical1, yes I do more local driving so this does seem like a decent solution. What a shame, I have to run it hard :P

And Sgtblue, you are correct in assuming I'm new to his whole rotary-ownership deal. That's why I wanted to post this here as opposed to the 'big-boy' forums. If you want to see pictures of the new FD, check out my introductory post in that section of the forum. But yes the heat is what I was worried about. Is it just putting unnecessary stress on an old engine, or is it a worthy trade-off to get rid of the carbon buildup is what this there's was really about. That's also why I mentioned above why I'm anxious to get the temp gauge linearized so that I can tell what the engine is doing. With this injection system, am I correct in assuming it's injecting water into the combustion chamber (almost called it a cylinder, whoops)? How does that work, what are the pro's vs con's, and how much does it cost? I might plan to do that later as first I'm going to focus on the reliability mods and other little issues, but I could put it in my future plans.

 

Take the car on a nice cruise on the freeway no need to drive harder than you want to.
That said most rotor owners enjoy their redline regularly with no major problems.

 

The engine does not need to go all the way to redline. It just needs to periodically operate in the rpm range in which the secondary fuel injectors are active.

Like most other automotive engines, it also helps to avoid long periods of idle, and to avoid very short trips. Also, Top Tier gas will help reduce deposits.
Top Tier Gasoline

 

Thanks, I'll keep in mind to avoid long idles and short trips. What exactly is wrong with doing those? Just curious. I do always try to make it to Shell though. I just know they have better gas. Sure enough that is a Top Tier brand. Also, what range do those secondary fuel injectors activate? For driving I'll just rev it higher than I normally do, but again, I'm curious.

 

I agree...do the reliability mods and then look into it. Probably shouldn't have...I only mentioned it because you're concerned about carbon. But basically..yes, it injects/sprays/mists a small amount of distilled water into the intake track. In my case, just before the throttle-body. The water serves three purposes...reduced knock/slowing combustion event (similar to raising octane), carrying out the heat from the combustion event with the exhaust (better cooling) and de-carboning the combustion chamber. The cons are that you have to install it, in my case you have to fill up the windshield washer tank periodically with distilled water (~$1 @ gallon).
I have less than $350 in my system.

 

That's cool. I'm not overly worried about carbon buildup, just wondering if redlining was a good thing to do. This car is as much a tinkering/engineering project as it is a driving car so I'm fascinated to learn about all these things as I haven't done much with cars prior to this.

 

I look at it this way:
Piston engine will suffer at constant HIGH rev..
Wankel engine Loves to be "up there".
The Funny thing is I still can't get over the sound of the engine in High Revs.I hear it whining and think it is Gonna break!..
But I drive the car in 4-5K Rpm 2nd gear in town..just to get that "snap" when you Punch it.My Buddy asked me Why I do that and I Punch the gas and say "this is why!!"...lol!..question answered!

 

Honestly, it is a rotary. as long as you don't take it over 3k rpm while cold youll be fine. just let it get to normal operating temperature then floor the gas pedal to redline through 1st, 2nd, and maybe 3rd gear then slow down to the speed limit. do that once a week and you should be cool. the other thing i have found that helps is to cruise on the freeway for about 3-5 minutes at around 5000 rpm. as long as you are on stock boost and have a good radiator, heat shouldn't be much of a worry. If you are still worried about it look into fd reliability mods.

And i would be worried about carbon build up because it can the engine and requires a carbon cleaning. its easier to just go ahead and rev it to high rpm once a week.

 

9k a day keep Mr.carbon away

 

I just do an oil change regularly early

 

Steady rise of RPMs is good ;P

 

I like This

 

9K will tear up your engine.

 

^ +1. A catchy phrase thrown out to add to a post count.
Someone following that advice won't have a problem with carbon build-up....it'll be dust. The car will be setting on jack-stands.

 

And this is the sole reason I love rotary engines.

 

Premix + a redline a day, keeps the carbon away!