I need some thoughts and opinions one or two (or three !) things when I'm done with this build . The build will feature my new 2 piece e shaft with center needle bearing , over sized stud kit , pineapple / excessive oil pan (if I can get my hands on one ) , clearanced rotors , loop line mod and the racing oil pressure regulator (from previous build) for higher oil pressure . The point of all this is to be able to extend my rev range while using average boost , like 25 psi . I am now wondering the following ............

1 . How high should I rev the motor ? Whats the highest reving turbo motor on here ?
2 . Do I need three window race bearings too ?
3 . What a/r turbine ratios should I be running , .82 or 1.06 ? the turbos will be a pair of GT3040R's (3082) , Gt3540 compressors and GT30 turbines.

 

This probably isn't directly relevant, but I'm just havin a 13B EP built and I have asked the builder about the wear in procedure and max revs- basically he said that for the first 1000km to take it not over 5k rpm, then after that we drop oil and replace then new oil and then set the rev limiter to 9k. At 9k the standard apex seals and springs basically reach the limit and will start to not react fast enough for a perfect seal.

Hopefully someone else has experience with your exact setup and can provide some more specific info.

 

1. i would probably say 9000 to 9500, unless you can find a way to get greater spring pressures for the apex seals. it's more wear, i know, but you pay to play, right? i have no clue of who has the highest revving turbo motor.

2. i would. the only other choice i'd consider would be the FD mains.

3. with twins, i'd say use the 0.82 A/R. i doubt that one rotor would get a 1.06 lit quit enough for you to not have to play catch.

 

I don't have actual experience but I think some use dual springs to support the apex seals to reduce seal float in these higher rpm situations. Sure wear goes up as diabolical1 stated, but you could reduce some of the wear with lower friction ceramic seals and maybe only doubling up the small springs. The reason I say small springs is because I would think that's where you would need the most support without too much pressure. Even on the stock engine, the larger spring tends to slightly over load the apex seal on the edges anyways. Ever notice the housing edge wear? Sure it's mostly from the corner piece digging in but even the opposite side of the housing will also show wear. The nice thing about these engines is you can take them apart so easily for inspection.

 

Only 9500 RPM's ???, I did 10000 K with my last half bridged motor! I'm sure I read somewhere about guys who sucessfully did 11K and 12K on stock seals without a problem , am I wrong ??

 

well, if you say you read it somewhere, you probably did. however, i try not to tell people to do things that i wouldn't feel comfortable doing myself. hence, my response. i thought that that was far enough over stock. by the way, i take it you already have a ballistic blanket. spending all the time, effort/sweat and money only to watch it pop sucks no matter how seasoned you are - at least, that's how i feel.

anyway, i'd be curious to find out what kind of seal/spring configurations those guys were using.

 

The stock apex seals have a tendency to severely chatter above 9000 rpm. You need lighter seals, essentially, to rev any higher without causing chatter.
Carbon apex seals (no boost or nitrous), or ceramic apex seals are your only options.

 

Anyone else care to contribute ?

 

If you want to continue down the path of financial and pshycological disaster keep reving your engien to stupid levels !

I have a customer/friend here with a semi bridge road car that makes well over 600rwhp (on dyno have recorded 578rwhp) on road at around 8000rpm, it has a rev limit of 8500rpm and it does not need to rev any higher. If you want more power you simply add more boost to it (we dynoed at 18psi and on road run 21psi hence power "claim").

Rotaries turn into self distructing pieces of **** (bigger than what they are already) when you combine hugh power with escalating rpm's their reliability goes down the tolilet very very quickly, you will have lots of random failures of stationary gears and probably the odd end plate that will break into multiple pieces as well.

There is no reason from a power producing perspective to adopt a strategy of increased rpm v's the far more reliable method of increasing boost to normal levels. You can make over 700rwhp and have a block that wont be a hand grenade, how much power are you aiming to make 800rwhp for the street?

I think you should rethink your strategy mate.

 

agreed

 

rice,is there any way to stregthen the plates themselves to protect them from cracking at that kind of power level and rpm?

 

There is really no need to rev that high with a turbo Engine.Crank up the boost if your not happy with the HP.

Go and read "The Rotary Engine " by K Yamamoto.

Ref Fiqure 3.17 attached.

Revving to 7000 Rpm the Stationary gear load will be Aprox 180kg
Revving it to 8000rpm will take the load up to aprox 380kg.
Revving to 8500rpm will take the load up to aprox 500kg!!!!

To up the Rpm with 1500 ,the load goes up by 320kg.So in other words there is a load of 500kg,on something that is roughly 30mm wide...

Unless your building a motor that you want to last a few miles,and demand the ultimate HP,and is prepared to pay the price for it.Pro Dragracer..?

Karis

 

You could probably have them cryotreated.

 

Look its just all so not necessary in this day and age of turbochargers + people waking up to technologies that have been around for almost 100 years (water and alcohol injection).

Most engines I keep revs to around 8200rpm some 8400rpm, 8500rpm tops. mainly for the resons given above. Its common regurgitated data from various technical papers that predate nohas ark and it has not changed very much over the years, the frequency points have been moved by using more pins in rotor gear but at end of day its not healthy for a wankel of those dimensions (when running at high power) to do much higher revs.

Sure we have all done it (reved to 10k+) but why, because we had no other way of making power back in NA days. I'd have no hesitation in running 4 bar boost with the correct turbocharger before I would waste my time running 10.5k or more, the gains you get from rpm are minor compared to how much you can gain from boost pressure. Lots of people dont understand the rotary suffers very badly from frictional losses too above 9500rpm. It realy is a case of barking up the wrong tree !

Stick to 8.5k absolute tops and anjoy a very very long life from your street/race engine, lots of parts will last much longer....... secondary items like apex seals and bearings last so much longer too.

 

So I guess I wasted my money buying a 2 piece e shaft with center bearing , huh ?