Grant M

Good stuff. Have you any noticeable difference in the AFRs? Or egts?

peejay

In theory, maybe, but the problem is that when we measure power, we're measuring the per-rotor power minus the per-engine losses.

How much power does the oil pump and the water pump take to turn, and does it scale linerarly with the number of rotors? i have a feeling that it's closer to a set per-engine loss and not a per-rotor loss, so for everything else being equal, the more rotors you have, the more power "per rotor" you are going to make.

Food for thought.

GtoRx7.

iTrader: (12)

Well the fuel map from the previous setup was only tuned for power runs since the prototype slide throttle could not be driven on the street. So no data on AFR difference. EGT's I'm not sure about either as I install them while doing dyno runs. I will get all this info soon though I hope!


You are totally correct Peejay. Its something worth noting, but wont change the math a whole lot. Example- A rx7 waterpump takes around 4-5hp at 9000 rpm, and a drysump pump I'm guessing is around 15hp. Round it off to 20hp plus maybe 1 more for the alternator. So 21hp divided by 3 is 7hp on each rotor and a 4 rotor is 5.25hp, a mere 1.75hp per rotor advantage. Small enough to basically leave out for engine to engine comparisons.

Grant M

How is the clutch coping at this power level? Or is it it rated to take more?

peejay

There are some near-200hp-per-rotor 13Bs out there, depending on what criteria you want to consider.

Logan, thanks for the info! I knew the water pump couldn't take much power to turn (they get driven by the backside of a simple V-belt easily enough, after all) but the oil pump has got to be the engine's main power sink. 15-odd HP to drive the drysump, eh? I wonder what the OEM pump requires. I found a source of fairly inexpensive dry sump pumps and am weighing the balance between power and efficiency vs. not relying on a belt-driven accessory.

Or maybe I should save that line of thought for Audi engines. The biggest hurdle in making Audi power seems to be that you can't rev them over 8000 without the oil pump coming apart. If my RX-7 is good to 10k then I want my other car good to 10k too

Grant M

200bhp must be using methanol and more than 10,000 rpm?

peejay

The highest I've reliably heard of was on the order of 13k in qualifying, on gasoline.

I don't know much about methanol, that's a drag racer thing.

Grant M

That's a lot of air to shift at that rpm. Must be some big PPs or a combination of big semi PPs and side ports

scrapp

iTrader: (1)

would like to subscribe.

Powaova

wow what a unique build. thats awesome!

Grant M

My engine builder is making 156 HP per rotor. 312FWHP here on uk dyno not sure on fuel type. He uses a full PP, butterfly TBs 62mm I think. I know they're bigger than 55mm. They made that power at 10,000rpm, tuned the inlet manifold to bring the peak power in at 8,000rpm to make the engine last a bit longer.

Not sure on the exhaust manifold but it passed the 96dB limit on uk tracks.

Not sure how it could get the HP up anymore but I would say that to get a noticeable difference in car it would have to be an increase of 10% minimum. That would be 343FWHP. Which is a lot.

Grant M

Going to slide TBs would increase airflow 10-15%?? But it probably wouldn't give that 10-15% more power surely?

GtoRx7.

iTrader: (12)

The clutch is a mean piece, rated at 650ft-lbs. If that slips with a 3-rotor n/a then I should get put in the hall of fame lol


In the world of racing, yeah 150 per rotor was the standard high output. Like the MFR 13b PP race motors were rated at 300hp. There are guys getting 350-375 now of course with more rpm etc. But these are all flywheel measurements


Slide throttles do flow more, but I would guess in the 2-3% range making about 1-2% more power.

All the talk of hp per rotor .... is this all flywheel measurements? I would say 155 per rotor (flywheel) is definitely the upper edge in street form. Ours at the flywheel is around 190hp per rotor, so 200 isnt out of the question

Grant M

Slide only 2-3% more I suppose at 10,000rpm 3% more adds up to a lot of air, I don't know the
Math to calculate the actual amount of air moving into the engine at that rpm but I'm sure you do.

With NA tuning 2% increases In HP are great, anyone can strap a turbo on and add 2more psi and make more power.

Do you know if you are making the highest HP per rotor now? Or are there Mazda backed teams still making more??

I was talking flywheel HP BTW

Kenku

Last Mazda backed teams doing rotary stuff that I've heard of were the Grand Am RX-8s, and those had rev limits to something like 8500rpm. So sorta by definition they're not going to be making more. The R26B is at something like 170hp per rotor though, and that was 21 years ago... and also it was designed to last for 24 hours at a time.

There just isn't much R&D being done on high power NA rotaries, or at the very least not by the sort of people one would think. Certainly not in SCCA.

GtoRx7.

iTrader: (12)

I can say rather confidently that we produce the most DOCUMENTED horsepower, which is a public dyno chart for anyone to view. Highest ever, who knows. There are a ton of smart people out there. :-) N/a is all about the hard work and small gains, which is why its heavy hitter game!

A

just startn

iTrader: (33)

CLR balanced 4rotor? Or touchy subject?

Rxmfn7

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GtoRx7.

iTrader: (12)

Yep. Carlos is a good friend and a very busy man. I might have some good news very soon however


Lol, Lenny knows exactly how this goes!

just startn

iTrader: (33)

Your scaring me....

GtoRx7.

iTrader: (12)

Why is that?

Grant M

CLR 4 rotor, what power are they at? Xtreme rotaries are also developing their own 4 rotor, aluminium plates, making 650HP so far. It's on their website.

What's the good news Gto?

GtoRx7.

iTrader: (12)

I dont think Carlos (CLR) has had the need to develop a 4 rotor at the moment. Racing classes are really limited, and that is what his bread and butter is. I saw the xtreme 4-rotor, getting any info let alone a dyno chart out of them is next to impossible.

I have to wait on the good news, its the small amount of supersition in me that prevents saying it too early

Grant M

Yeh xtreme keep things very close and behind closed doors, althiught they do have a dyno video of a bridge port motor with quad throttle bodies making 350FWHP which seems prety good.

I'm guessing you have got titanium rotors on the way??

McCarthy

Have loved watching this monster develop. Been a source of much inspiration and certainly made me re-think a few things on my builds as I've gone along.

With such promising results from the semi PP triple I can't wait to see how you develop the Quad.

Keep it up dude.