OK,

So we raced last weekend. We did not win anything but the car was performing quite well. We had less reliability issues and only suffered gear box issues despite a partial replacement of the internals (gears, cogs,...) since last race weekend. On Saturday, the driver bent the 5th gear fork, which is an original Renault part made of brass! The mechanics repaired it for the races on Sunday.
First race was not bad with a good mid field finish. Second race was much better until the fork bent again! As the 5th gear was only used at the very end of the straight line (it's a very slow track) , the team decided to remove it (loosing the ability to engage 5th) and increase the REV limiter to compensate (the driver could stay in 4th longer). It costed us 3 sec per lap in the 3rd race and we did another confortable mid-field finish.

More important, some Mazda France managers were invited and they were pretty interested by our project. We might do a full race season next year...

On the technical side, with the new gearing, the engine speed often drops to no lower than 6400 RPM and rarely to 6000 rpm. Sounds like the APV might not be essential especially if we carry on increasing the REV limiter. I'll do some tests on the importance of the VDI at the next opprotunity.

The engine still pulls strongly, idle at a steady 1400 RPM, and starts very easily from cold. Amazing what that little buzzer can handle! I love the Renesis. So much so I bought a used one that is down on compression on one side of rotor #1 in order to rebuild it.

To be continued...

Fabrice

 

Video of the Renesis powered prototype : http://www.youtube.com/watch?v=Dedre-CTRp8

Pure rotary pleasure.

I'm the guy with the laptop...

 

Hello from Sweden Fabrice! Nice video good sounding car but can be better. I have been into Mazda rotaries for 25 years and i am a hardcore rotary engine builder for living (18 hours a day)! I must say that the Renesis engine do respond good to both bolt on and engine block preparing but you must think twice when it comes to a N/A engine. I have a 2004 RX-8 and have done some mods to it. The exhaust system made 10 hp with stock exhaust header. Of course i have developed prototype 1 header for the engine which we shall test next week on my RotoTest hub bench (very accurate). Then i have prototype 2 and 3...I am also in progress of developing both the cold air inlet air filter box and a new simple but high efficient intake manifold. To sum i8t up i have some pretty good experience when preparing rotary engines which is (almost) always dyno tested. Of course i have a rotary flow bench since 1997. What i try to say here is that i can develop parts on flow bench dyno test it and manufacture it here in Sweden. If this sounds interstesting you can Mail or PM me!

Best REgards: Lasse wankel Sweden.

 

Hey I am curious if it still makes power up top when you increased the rev limiter, I assume you're spinning it close to 10,000rpm?

btw, nice video, although it does not have the "burpy" idle of a PP 3 or 4-rotor, it sounds nice!, also were there any other rotaries running on the track when you recorded it? I thought I heard another rotary =D
________
AnitaLove live

 

Hi There! Interesting. I'll e-mail you.

Not quite 10000. 9500 RPM in fact was our new limit for the weekend.
There were no other rotary race cars. All psitons, but some sound good too. There were a few Civic Type-R engines too.

Fabrice

 

I have all the parts on Tuesday then we begin fabricate this week. Shall be really interesting to see the flow comparisions between stock inlet manifold and ML Wankeltrim custom one! I will post some flow numbers in the following weeks.

/Lasse

 

Here are some flow numbers at 10" of water: Stock fronthousing total flow of 4-port and 6-port: 142 cfm at maximum opening of both ports. Ported 4-port and 6-port (stage 0.5) 2 mm and radiused: 155 cfm, that,s an increasement of 9%.
Exhaust port stock: 73 cfm. Radiused only and cleaned up no porting: 82 cfm +12%! This weekend Mikael will flow the intermidiate housing stock and stage 0.5.

/Lasse

 

oooh i believe i have posted in the past that i believed there was at least 10% more left in the exhaust

good work all!!

 

Ok. So now the Renesis stage 0.5 is ported. Intermidiate housing stock inlet port 51 cfm ported stage 0.5 63 cfm increase 23%! I have not the numbers for the intermidiate exhaust today but will post it tomorrow. Otherwise Mikael is busy building the fabbed sheet metal inlet manifold which we hope shall boost the cfm numbers.

/Lasse

 

We're planning to build a second sport proto next month, still powered by the excellent Renesis HP.
I'm rebuilding an engine right now and I'd like to know what can be done to it in term of modification of internals in order to achieve better durability (1 year between rebuilds) and higher max. RPM (10000 RPM min.).
This car would be used in sprint (20 min) and endurance (4 and 8 hrs) races.

Cheers,

Fabrice

 

wow, great news! now you gotta shoot us more videos=d...

ceramic seals, RB light weight rotors w/ snap ring (are they allowed?), but then durability and high rpm kinda go against one another... haha...
________
Violet_Voss live

 

Ceramic seals : do they require a change in the housing material ? Also, I'd need to check whether ceramic is allowed in the regulation.

RB light weight rotors : I just had a look at these on their website. I'm NOT paying $2000 for a 2,2% gain in weight .

Snap ring : don't know about those. Will do a search.

Lightened flywheels are limited to 10500 rpm.

 

I think you need to refer to time between rebuilds in hours not years. There are many items that can improve the life of these engines, however in a racing environment all bets are off. Better seals are a must,better lubrication,better bearings etc. etc.

The harder you stress the engine (RPM) the shorter the life span and it is NOT on a linear scale. While an engine with a max RPM of say 9800-10000 may last 30 hours between rebuilds one that sees 10500-11000 may last 3-6 hours.

Good luck with the cars they look like great fun!!

 

you need to start off with new housings for the ceramic seals, that's all

 

Thanks for the very helpful replies.

I intend to set a different rev limiter for Sprint and Endurance races. And I can do the same for Qualifying / Race.

For lubrification, I was thinking of using full synth for the internals and 2-stroke for the premix.
Or an adpater from Sohn that converts to a mechanical pump, but there is some space interference I need to work on. The car will be rented out to other teams sometimes, and you can defnitely trust them to forget to premix...

TeamRX8, I don't want to change housings that are perfectly fine. So ceramic will be for later.

What do you guys think of using 3 mm apex seals (require machining of the rotor grooves).

And what are the solutions in term of stronger bearings? Can they be found for the Renesis? Same as previous 13Bs?

 

Does someone know who is the engine builder for the Mazda Pro series?

 

i dont know the answer for that, but if you asked that ? i would talk to mazmart... knowledge is power...


beers

 

So, nobody here knows?

 

it was discuse here in the forum , I just dont remember the name, ask paul from mazmart

 

OK, Swoope and Rotary Crazy, I'll ask Mazmart.

 

I think it is Drummond. Try 541-659-8634.

 

Thanks, but the mods mentionned above are not at the agenda any more. Due to new developments, we'll have to stay very close to production.

I will however have a look at what Drummond does, by curiosity.

 

I know jack ****... but I remember hearing that at higher rpms the e-shaft can flex and f stuff up. I was told to add a center bearing to decrease distortion.... not that i know if they make one for the 13b-rew though..

 

Drummond does the FM rebuilds, I'm not so sure about the FPM Renesis rebuilds ...

 

Shaft flex is not a problem until revs exceed 11k especially on these motors. The problem occurs on nose of crank due to the mass of the counterweight. This has been reduced since the 3rd gen motors which carry a larger front spacer allowing more torque to be applied tightening the front bolt. This in turn adds rigidity to the nose. The 3 rotor (13G) was one of the first to apply this. Also the motors are better balanced these days and have lighter rotating assemblies. All this is to say you could get in trouble with a downshift by accident while attempting to upshift at high revs, otherwise there's not much problem or need to resort to the center bearing.

Paul.