13k RPM rotory?
 

hey, i was thinking,
i want to get about 13k out of the rotory.
light weight rotors are nice, and i dont think are necessary yet.
what if i get new seals, high performance.
this is why i think that:
1. over revving a piston engine makes the valves float, to fix- get new valve springs.
2. i think over revving a rotory makes the seals float! put high performance seals and maybe make them,.... whats the word... not float?

please correct me if im wrong. Thanks.

I think the rotary goes harmonic at right around 13,000, so I don't think your exercise is such a good idea. Also, at such elevated rpms, it wouldn't be just the engine that would be a problem; everything attached to it would need to be designed to withstand that rpm including the alternator, water pump, transmission, etc.

You should try it and let us know how it goes ;)

ill ask

why do you want to go to 13k?

whats the benefit?

ya you would have to retune your whole 8
k think about the t curve. its all jacked up after that 13K fun.
NOT DISSING THE 8
we dont have much midrange to begin with. id say that if you wanted to do that. 1 ask someone who can give you a better answer ROTORYGOD?
2 FI MAN. if its going to be anything but a waste of time id say a an 8 that has a late spool up and high potential to go a long ways after would be nice. full boost at 4K and peak at 10 or 11 would be amazing.
DO IT GO GO

Take a video so we can all enjoy, I mean the whole operation to get it to turn that fast.
I want to know how you are going to set the timing correctly and fuel management might be an issue, I think you will run out of fuel before you can reach 13,000 rpm with out bigger injectors. Lean is not good for a rotary at high RPM's.
Anyway have fun and keep us posted.

Its impossible to get 13k outta the renesis NA, you wont have any power up top. And light weight rotors are nescessary... the stress increases exponentially with rpm i think. I think if you want high rpm, whatever the reason is, you should shoot for 12k ish, 13k i think its reaching the harmonic frequency, I dont know how you can get over that, and also eccentric shaft flexing is a concern, maybe at 10k.

Just still try to give u a constructive reply, I dont think a high rpm rotary is good, and its most probably not street drivable...

I dont know how to get 13k rpm outta a rotary, maybe RG and some others could help you out.
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Web shows

Ive seen rotaries hit upwards of 11 and 12.

Ive downshifted and accidentally hit 13... but thats different then running it to 13 regulairly.

well, first of all, i dont have a rotory yet, so you know.
im asking this because i love the rotory engine concept, and i got to test drive one last week. i want one, but probably not going to get one for a few more months.
im realy cerious about the potential of the rotory engine, and i know the 20b can easily hit 13k. is a 20b transplant daily drivable? or should i just stick with the stock rx8 and a few mods here and there. (how about a hachiroko? :))

Why do you want more crankshaft speed over, well, speed?

You need to learn a lot more about rotaries first. The seals will acutally be held out stronger the faster you run the engine.

There is nothing in a rotary that starts to float at higher RPM. It's really all about air flow into the engine and efficency. You could make the engine do it (and probably without too much harm) but the torque would drop way off and you'd be out of power.

first off, i believe that there is no light weight rotors available for the renesis. correct me if im wrong, but i have yet to see any

racing beat makes them.
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ECIG FORUM

Its not really possible for the engine to rev and stay at that RPM for long, one of the reason is that the eccentric shaft will not be able to stand it. Second is that in order to get to that kind of RPM, alot of things has to be changed, say, fuel, intake, etc

your biggest issue going that high is going to be the bearings on the eshaft. I'm not sure how high an rpm our bearing can take, and to what extent they can be upgraded. In addition, unless your going to go pport for both intake and exhaust, I'm not sure you can flow enough air with the side ports to make any power at 11K+

You should note that the Mazda Lemans race cars didn't go over 9K. It wasn't like F1 where the cars all rev to 18K+.

9K RPM should be good enough for most people. higher doesnt mean its better.

Whats the point of revving it further when you make no more power ? Just wasting fuel and your time. Mazda dont need over 9K to win Le Mans.

20k.....
 

It is easy to design a Wankel that will break the 20,000 rpm level, some of the primitive models that Felix himself made ran above 20k, but the Renesis is a long way from one of them.

The E shaft carries two rotors, but has no centre bearing and will bend enough to let the a rotor contact the housing.

The side port layout also restricts the breathing beyond 9k.

The whole ignition system - coils, plugs and controls, would be maxed out well before 20k.

Otherwise, quite do-able.

S

i understand now
it is not worth to spend that much money to make a rotory go to 13k, its better to keep at 9.5 red and just hype up the turbo or somthing (please dont tell me what to do,, ill brouse around on other forums first)
ill just buy a rx8 and later, ill start building a hachiroko.
thanks!:)

Everything comes with a price. and we're getting what we paid for now.

Im not saying its impossible, its just that theres no point(and not that possible) with our current engine.

like you said, alot of stuff will give up the ghost way before you can even hit 13K rpm mark.

Money is everything baby !

*and Im reading that book right now*

understand now
it is not worth to spend that much money to make a rotory go to 13k, its better to keep at 9.5 red and just hype up the turbo or somthing (please dont tell me what to do,, ill brouse around on other forums first)
ill just buy a rx8 and later, ill start building a hachiroko.
thanks!

The rotaries that Felix Wankel had spin over 20K were VERY different from the current one. They had a spinning rotor inside a housing that spun inside another housing. Combined they could go really high but each surface never saw that fast of a speed. It's all relative to your frame of reference. His motor also had 6 spark plugs. Each was on a rotor face inside the engine! Have fun changing that.

In order to take a Renesis up to 13K rpm, you need to do a few things. You'll need new engine management. The stock ecu won't do it. You'll need a new intake manifold. The current one doesn't make any power that high and is worthless up there. A completely custom built one will be necessary. This of course will retune the engine higher but everywhere else you will lose power. Basically your power levels will be lower than stock about 99% of the time you are driving just so you can say your engine hits 13K. That's a tradeoff that you can't get around so don't expect to. In order to remove the intake manifold, you need to take the engine out btw.

While it's out, it's time to upgrade some stuff to give you the ability to rev that high. Your eccentric shaft will warp and your bearings will die at sustained rpm's that high so you can't just leave the engine alone. You will need to buy a Guru Racing eccentric shaft. It is lighter than stock and has a center bearing. They will also need to install the center bearing for you in your center housing. Allocate about $3K just for this. You will also want to use lighter balanced rotors that have the ring gears locked in place. Fortunately Racing Beat makes these. Plan on spending over $2K for these. Lighter better seals would also be wise. Ceramics are the only way to go for this purpose. Ianetti sells the nicest ones for $1600 a set.

Now you can't forget about the importance of cooling. You'll need to upgrade your oil coolers and radiator. The water pump is not designed to spin nearly this fast so it will cavitate and you'll have no cooling ability. You have 2 choices here. One is to severely underdrive everything. You may or may not have adequate cooling ability at lower rpms though and your alternator will spin very slowly. The other option is to have a custom built water pump impeller made for your purposes. There are a couple of companies that can do this. We can't forget the transmission. You will need a new one with custom gear ratios. The stock one can't handle the rpms and its gear ratios are al wrong anyways. You will also need a special race clutch, prefereably a 5" double disk and a lightweight flywheel.

I'm sure I'm leaving some things out but you get the idea. Plan on spending about $20K to be able to say you have a 13K rpm engine. You'll get worse gas mileage and power will be less than stock for daily driving but you've got 13K! The other option is to spend about 1/4 of that and get a turbo. You'll be faster and have less sacrifices.

Make new meter sticker that says 13k instead of 9k, stick it in tachometer area.

:cwm27:

HOW COME I NEVER THOUGHT OF THAT !

Holy shit ! Im going to *Upgrade* right now ... let me turn my printer on first ...

:ylsuper:

get T shirt that says "went to 13k & lived"

lol.... thats wonderful...
but as i said, in a ew years, ill buy a AE86 and supe that thing up untile there is no tommarow.
who needs turbo when you have 1600lb to haul around