rotary crazy

I heard they are making that much power but at about 12,000 to 13,000 rpm, but that engines durability cant be very good

rotarygod

They definitely aren't doing it on a stock motor! They machine their own eccentric shafts so they can use a center bearing. This takes a lot of stress off of the main bearings as well as reducing eccentric shaft flex at high rpm's. That's the cause of rotor to housing contact and why high rpm rotor clearancing was always necessary.

They don't seem to always put up all of their information on their website. There is also some stuff that used to be there that isn't anymore. They were on one of the forums a year or 2 back with a dyno cahrt and pictures of their setup. I wish I knew where. It was highly impressive and more than I have ever seen anyone else do with a 2 rotor before.

Their dogbox transmission gear ratios are set so you have an extremely high rpm range and those are used for road racing events so they must have a way to keep the engine alive at higher rpm's than most people can. I think it's the result of the center bearing personally.

rotary crazy

yes, it was on ausrotary some time ago, I saw it, the reason they have briged ports is because in the class they race Pports are not permited

rotarygod

There are 2 main problems with extended high rpm use, aside from cooling and oil flow of course. The first is eccentric shaft flex causing rotor to housing contact. The flex also throws off the balance of the engine so it holds power down a little bit even when there is no actual contact. The obvious way to fix this is to add a center bearing which will support the area that flexes the most. The other issue is with bearing life. That's a lot of stress to be putting on a film of oil and the eccentric shaft only has 2 bearings, one at each end. By adding the center bearing, they have added 50% more bearing which drastically reduces the stresses on the bearings.

The center bearing takes care of 2 big issues on it's own. I wish Mazda would add a 3rd bearing to all rotary engines but that would be higher manufacturing costs and they don't have any engine failures as a result of not having one. I don't know why their race engines don't have them though.

bern

A little better

Pos Car Cls CP Driver Now Laps Gap Intv Last Lap Best Lap Best Speed BL # Stops Last Total Car Make/Model Team Tires Notes
1 88 P1 1 Nicolas Minassian Fin 10 0.000 0.000 1:11.317 1:10.829 129.10 5 2 2:18.334 1:00:44.919 Creation CA06 Judd Creation Autosportif Michelin --
2 2 P1 2 Allan McNish Pit 12 0.081 0.081 1:18.049 1:10.910 128.95 6 3 1:36.582 53:38.932 Audi R10 Audi Sport North America Michelin --
3 15 P1 3 Stefan Johansson Pit 13 0.261 0.180 1:28.078 1:11.090 128.63 12 2 2:51.291 52:25.679 Zytek ZG348 Zytek Michelin --
4 1 P1 4 Frank Biela Pit 8 0.543 0.282 1:17.901 1:11.372 128.12 3 2 2:13.268 52:00.267 Audi R10 Audi Sport North America Michelin --
5 7 P2 1 Lucas Luhr Pit 6 0.580 0.037 1:33.467 1:11.409 128.05 4 2 2:58.044 57:03.138 Porsche RS Spyder Penske Motorsports Michelin --
6 6 P2 2 Timo Bernhard Pit 7 0.802 0.222 1:18.527 1:11.631 127.65 6 2 7:07.073 57:55.023 Porsche RS Spyder Penske Motorsports Michelin --
7 16 P1 5 Butch Leitzinger Pit 3 0.909 0.107 4:43.075 1:11.738 127.46 2 1 49:45.616 49:45.616 Lola B06/10 AER Dyson Racing Team Michelin --
8 20 P1 6 Chris Dyson Run 12 1.178 0.269 1:12.419 1:12.007 126.99 8 3 3:14.504 57:09.467 Lola B06/10 AER Dyson Racing Team Michelin --
9 9 P1 7 Duncan Dayton Pit 8 1.487 0.309 1:20.843 1:12.316 126.45 6 2 4:18.767 54:59.756 Lola EX257 AER Highcroft Racing Dunlop --
10 37 P2 3 Jon Field Pit 7 2.567 1.080 2:34.402 1:13.396 124.58 4 4 2:57.166 57:44.231 Lola B05/40 AER Intersport Racing Goodyear --
11 19 P2 4 Ben Devlin Fin 14 2.704 0.137 1:13.566 1:13.533 124.35 13 3 2:16.164 54:21.051 Radical SR 9 AER van der Steur Racing Inc Kumho --
12 12 P1 8 Michael Lewis Pit 10 2.943 0.239 1:32.459 1:13.772 123.95 9 2 3:02.547 54:10.000 Lola EX257 AER Autocon Motorsports Dunlop --
13 27 P2 5 Didier Theys Pit 7 4.938 1.995 1:29.801 1:15.767 120.69 5 2 2:32.019 53:01.120 Lola R05/40 Judd Horag - Racing Michelin --
14 3 GT1 1 Johnny O`Connell Pit 4 7.381 2.443 1:46.212 1:18.210 116.92 2 1 20:07.337 20:07.337 Chevrolet Corvette C6-R Corvette Racing Michelin --
15 4 GT1 2 Oliver Gavin Pit 5 7.631 0.250 1:27.290 1:18.460 116.54 4 1 17:18.533 17:18.533 Chevrolet Corvette C6-R Corvette Racing Michelin --
16 009 GT1 3 Pedro Lamy Pit 3 7.718 0.087 1:27.835 1:18.547 116.41 2 1 25:24.604 25:24.604 Aston Martin DBR9 Aston Martin Racing Pirelli --
17 8 P2 6 Guy Cosmo Pit 8 7.881 0.163 1:28.146 1:18.710 116.17 5 2 1:52.773 52:01.740 Courage C65 Mazda B-K Motorsports Kumho --
18 007 GT1 4 Darren Turner Pit 2 8.030 0.149 1:32.510 1:18.859 115.95 1 1 25:39.690 25:39.690 Aston Martin DBR9 Aston Martin Racing Pirelli --
19 62 GT2 1 Ralf Kelleners Pit 8 11.593 3.563 1:34.142 1:22.422 110.94 7 1 15:34.315 15:34.315 Ferrari 430 GT Berlinetta Risi Competizione Michelin --
20 31 GT2 2 Joerg Bergmeister Pit 5 11.716 0.123 1:30.319 1:22.545 110.78 3 1 16:27.573 16:27.573 Porsche 911 GT3 RSR Petersen/White Lightning Michelin --
21 61 GT2 3 Maurizio Mediani Pit 9 11.920 0.204 1:22.749 1:22.749 110.50 9 1 15:08.818 15:08.818 Ferrari 430 GT Berlinetta Risi Competizione Michelin --
22 50 GT2 4 David Brabham Pit 8 12.241 0.321 1:33.549 1:23.070 110.08 4 2 2:35.751 17:14.279 Panoz Esperante GTLM Multimatic Motorsports Team Pa Pirelli --
23 21 GT2 5 Bill Auberlen Pit 6 12.263 0.022 1:30.457 1:23.092 110.05 2 1 15:15.908 15:15.908 BMW E46 M3 BMW Team PTG Yokohama --
24 51 GT2 6 Gunnar Jeannette Pit 9 12.320 0.057 1:23.556 1:23.149 109.97 3 2 3:02.209 17:24.048 Panoz Esperante GTLM Multimatic Motorsports Team Pa Pirelli --
25 45 GT2 7 Marc Lieb Pit 13 12.322 0.002 1:33.747 1:23.151 109.97 3 3 2:20.160 18:15.513 Porsche 911 GT3 RSR Flying Lizard Motorsports Michelin --
26 44 GT2 8 Lonnie Pechnik Pit 6 12.465 0.143 1:34.185 1:23.294 109.78 4 1 14:24.567 14:24.567 Porsche 911 GT3 RSR Flying Lizard Motorsports Michelin --
27 22 GT2 9 Bryan Sellers Pit 3 12.478 0.013 1:31.075 1:23.307 109.76 2 1 15:22.609 15:22.609 BMW E46 M3 BMW Team PTG Yokohama --
28 23 GT2 10 Robin Liddell Pit 9 12.685 0.207 1:27.082 1:23.514 109.49 6 2 1:38.007 16:26.873 Porsche 911 GT3 RSR Alex Job Racing Michelin --


-Bern

bern

I know that motor and set up well... this is for the Australian Improved Touring Class. They also run slider intakes in this class. I just don't remember 380hp being quoted. I've actually held and studied both the 2-rotor and 3-rotor multi-piece e-shafts from Guru. They are very light weigth quality pieces. My only real concern with the addtional center bearing pieces, is that they are needle bearings, not tins. After some calculations, we determined that the speed experienced on the individual needle bearings at high-rpm is sonic, and are not sure what happens to the oil film at these speeds. Interesting stuff.

-Bern

rotary crazy

I think i heard that intersport car was in trouble againg?

It all depents on the others reliability now, lets hope the mazda finish the race in good shape

Its a shame EFR dint get to drive today, that guy is fast

bern

How do you know they don't?

-Bern

rotarygod

They may now with this engine for all I know. All of the pictures you see of Mazda race engines taken apart lack them. Even the 26B lacked it and that motor had an awful lot of effort put into it.

rotarygod

Update from Mulsanne's Corner:

Mazda's John Doonan, though very tight lipped, did tell me that Laguna Seca will be the venue for Mazda's "monumental" announcement regarding the LMP2 program for '07. Expect a new chassis and the announcement of an engine program (yes, I know we’ve been saying that all year…THIS time, trust me!). BK Motorsports will continue to be the factory endorsed effort.

rotarygod

If they can put a roller bearing in there I don't see why they can't get a conventional one to work. Who knows why they did it that way?

Tirminyl

Lets talk about that word in red. With their use of that word, my mind goes racing with all sorts of things that they can do that will be monumental. Man, I don't want to give my hopes up.

rotary crazy

4 rotor for sure

rotarygod

Bernie, do you know if the Courage going to be at Sevenstock again this year?

rotarygod

I hope it isn't the confirmation of the hydrogen rumor we heard earlier this year.

rotary crazy

me too, mazda needs to be competitive not to star developing a new tecnology that may lead to a dead end

Renesis_8

At 8:01 pm (8h 15m running), Elliott Forbes-Robinson (#8-P2 Courage C65 Mazda) into the pits. Fuel only, no driver change. No coolant pressure, going behind the wall.
________
Glass Pipes

rotarygod

Does this get anyone else's attention in regards to the Porsche?

"The RS Spyder's 3.4L V8 churns out 504 horsepower at 10,300 rpm."

They've still got a small restrictor plate. One that's even smaller than the Courage's. How the hell do you make that much power through roughly a 2" inlet on a naturally aspirated car??? Does anyone know what the rpm limit is on the Courage? On the old 787B they shifted at a fairly low (for a peripheral port) 9000 rpm.

Renesis_8

Hey RG, I am interested to find out how the Porsche make that much power at THAT RPM as well...

The 787B shifted low for longevity, it probably shifted at that low-rpm (9000) because it could just unleash the rumoured 930hp @10,500 rpm whenever they needed to go fast. If this rumour is true that is.

Edit: At Le Mans, an 8500-rpm limit was used during the race and up to 9000 rpm was allowed for qualifyin

from http://www.fd3s.net/787B/index.html#SPE
________
Solid valve

David Haskell

17 to 1 compression!

No RPM limit on the Courage.

CERAMICSEAL

And unfortunately the rotaries can't take advantage of this same concept. They are practically maxed out in the compression department.

rotarygod

A high compression ratio is about all I figured would help.

rotary crazy

then the only way we can be competitive its force induction?
A 4 rotor engine using a restrictor would give limitted avantages over the 3 rotor plus more weight and cooling problems?

have there beeng any endurance FI 13b car, appart from the allmost stock fd that ran the bathurts 24 race?

rotarygod

I can see 2 options right now. A naturally aspirated 4 rotor or a turbocharged 2 rotor. Each has their own issues. A 4 rotor adds length and weight over a 3 rotor. The restrictor plate on a 3 rotor is also LARGER than on a 4 rotor so that would really hold power back with a smaller restrictor plate on a larger engine. Average power should increase but will that really offset the extra weight?

A turbo 2 rotor would be a smaller engine but you'd add stress on the engine itself as it is now workign harder for it's size. You are also introducing issues with space in regards to intercooler plumbing fighting for airflow with the radiators. The restrictor plate size would again be different but I wonder if it would actually get any smaller? Normally if you add forced induction then the restrictor plate does get smaller. Smaller engines can use larger plates though so would a smaller engine with a turbo still have roughly the same size restrictor as the current 3 rotor? I don't know.

Cooling requirements are closely tied to power output so I'd only see an issue with cooling if power was raised over the current car. A turbo does add a little more heat to an oil system though, a 4th rotor does add more area for heat, and a 2 rotor has less area for heat to build so there would still be some subtle differences between engines even at the same power level.

Each system has it's own unique issues to overcome and that's part of racing. The one thing we can be fairly sure of is that they shouldn't be trying to stick with the current engine setup as it just isn't working out. I guess we'll see what they are going to do soon enough.

bern

A correction on my part...

On the 3-rotor power levels.... I've researched this further and have discovered that the factory 767 LeMans cars were claiming to develop around +480hp from their 13G (3-rotor race motors).

On the '07 announcement update... both are true. New chassis, but from my information, it will not arrive until at least 2 or 3 races into the '07 season, maybe. On the motor, Mazda will run full speed ahead on 3-rotor development, now that they also have the GT program using the same motor. A 4-rotor "might" be an option. We'll have to wait...

From conversations with Mazda folks this weekend, the Courage is scheduled to be at SevenStock-9 at the end of the month.


-Bern