Wankel engine in Racing?

There's a new ALMS car with a Renesis-based 20B (3 rotor).

 

One of the reasons, from what i understand a while back, was that an uncorked rotary is one of the loudest machines known to man. Most racks have those sound sensor deals, at least in sportscars anyway.

 

I do recall this car having a particular sound but it was not that much louder than the Porsches, Mercedes or Jaguars on the track. Accoriding to Mazda this is what happended:

"After Mazda’s resounding win in 1991, the Le Mans sanctioning body banned rotary engines due to difficulties in classifying and grouping the unique powerplants against standard piston engines".

Anyway it was bad to see a winning car go due to regulations.
Image Unavailable, Please Login

 

The noise comes from modifying the porting, or changing it alltogether. Street porting, bridge porting, and peripheral porting (moving the intake ports directly above the exhaust) is where the real noise comes from.

That and straight pipes.

 

New for this year is a Mazda engined Courage C65 LMP2 racer, which is campaigned in the ALMS. In recent years the Kudzu prototypes used the rotary engine, and IIRC a Welter was also equipped with the rotary.

They have been used in prototypes for longer than many think; in the early 1970s a Chevron B16 was already rotary powered. That car is still around, and a couple of years ago I have seen it race at Spa.

 

Yes that particular motor was designed to run in racing conditions. A regular rotary sounds horrible with a open exhaust. Loud isn't noramally bad but a rotary sounds unbearable. Conincidently I heard a honda crx many years ago in one of the support races for the Cart Series and it sounds so bad i covered my ears everytime it went by. Now you got these tards putting those mufflers on thier honda street cars. I hate those damned buzzbombs.

 

You know, for those of us that sleep at the track, one of those sheets of white letters could bring countless hours of entertainment.

 

Great shot Rob!

 

That's a cool pic !

 

As far as revving ability is concerned.....it just seems natural that it could *own* piston engines...

 

It’s interesting that the rotary makes so much noise. In ‘85 Mazda were racing a two rotor design for the last time - it was horribly loud, in fact it was so loud that an aluminum plate that shielded the carburetor was eaten away by the sound waves during the span of that year’s Le Mans. In ‘86 they changed to a three rotor design (and injection) and the engine was quieter. The nodes and anti-nodes of the first rotor’s sound waves were canceled out in part by the anti-nodes and nodes of the third’s rotor’s noise. If the engine had a racing weakness it was that there was very little flywheel effect on a rotor set up, a condition that made it difficult to select and hold a particular RPM. All well and good, but in the 757/787 cars the motor was married to a gearbox filled with Porsche syncros and they demand a slow gear change. A clumsy driver could break the clutch or input shaft after several hours of failing to match and hold the correct RPM when changing gear. In that respect they were harder to keep together than anything with a crash gearbox.

 

I saw the LeMans winner run a few yars ago at Laguna Seca, and it sounded great. Not to loud at all.

Too bad it was banned the year after it won. Sour grapes.

 

First of all, the win was somewhat of a fluke, comparable to the 250 LM victory in 1965. Secondly I highly doubt the rules were changed just to shed the world of racing of that bloody fast Mazda. They changed the rules just like they did in 1968 to interest Formula 1 manufacturers to enter or at least supply engines.

 

Current rules allow Rotaries at LeMans. No problems--But with LeMans (ACO), all engines are controlled by varying the size of the air inlet via restrictors, whether they are rotary, recips, turbo or NA. The issue is whether the rotary restrictors have place those engines at a disadvantage to non rotaries. Right now the rules are slightly bised towards turbo engines and/or large displacement 2 valve motors.

Remember that all engines are basically air pumps, the more air you pump, the more power you make. By restricting the airflow you restrict power. Very simple really. At LeMans the reistrictors hurt high rpm low displacement motors because the restrictors choke the maximum flow at levels below that at which these engines can produce peak power. (More complicated than that-but basiclly correct.)

Whether rotaries are hurt as much is something that I have actually been contracted to look at by a Japanese mfg. Can't give away names or results but based on analysis, you may be seeing a rotary turbo car at LeMans in a couple of years.

 

I had a friend who saw that car win LeMans. He said it was SO LOUD you could hear it circulate the entire track no matter where you were sitting. Doppler effect x 100. "How loud was it?" We asked. "It was so loud that when I was asleep and the car headed into the pits and the engine was shut off I woke up. The drone became such a constant background noise that when it went away... it seemed that something was amiss. It was awesome."

HUGE Pics on this page below, but well worth it:

(if you scroll 3/4 of the way down you can see the variable length trumpets on the engine)
http://www.scuderiaciriani.com/rx7/787B/

 

Has no one mentioned Formula Mazda?