RX8 E-shaft vs 13B-RE/REW shaft

[vex]

Originally Posted by joff

Where'd this figure come from and would you mind explaining?

I assume these are the forces on the stationary gear that would otherwise cause it to twist? How is this relevant to E-shaft loading? I'm just a genuinely curious lurker -- have no credentials for an opinion, and no data points to offer so feel free to ignore...

It's from an ASE article regarding the 13B engine from an FD. Loads exerted on the stationary gear play a very large role in an asymmetric loading of the eccentric shaft. Since the loading appears to be greater than what the eccentric shaft sees on the bearing load. This means that a majority of the deforming load applied to the stationary gear should see abnormal wear when you have a case similar to Glenns. This is assuming that an abnormal ignition event caused the initial deformation of the shaft.

The actual title of paper is "Recent Technology Development of High-Powered Rotary Engine at Mazda" by Takumi Muroki.

It also has an interesting portion about timing and the propogation of the flame front depending on the location of ignition (10* EW TDC, 20* EW TDC, 30* EW TDC).

[joff]

Originally Posted by vex

It's from an ASE article regarding the 13B engine from an FD.

I figured it must have been from SAE -- I wish those papers were cheaper than $15 an article. Thanks for sharing and attempting to accomodate a newbie, but I think I'll still need to read the full text to really understand whats being said here. :-)

[vex]

Originally Posted by joff

I figured it must have been from SAE -- I wish those papers were cheaper than $15 an article. Thanks for sharing and attempting to accomodate a newbie, but I think I'll still need to read the full text to really understand whats being said here. :-)

I swear I have portions of dyslexia or something, I screw up so many acronyms.

[Chadwick]

Not to discount Glen’s findings as I respect his knowledge and personal experience, but seeing how my name was brought up I figured I should respond.

The RX8 shaft has been in my car since March of 08 and has consistently been spun to 9k RPM and seen above 300 lbs rwtrq. We pulled the motor apart a few months ago to try out the ALS apex seals and the front and rear stationary gears show no signs of wear and the shaft is still like new. As a mater of fact, most of the bearing babit was still there. I would estimate at that time the motor had close to 30 races on it and around 400 street miles. Now the motor has around 40 races on it and another 600 street miles and is still going strong. At the most resent ProSolo we gave last years National Champion in a 500+ rwhp, single turbo, 3 rotor a good run for the money.

I have plans at the end of this race season to drop this motor in my street car and build a new one for the race car. The new build will be using the RX8 eccentric shaft along with a few other tricks to reduce the rotating mass. Time will tell, but at this point I see no reason to go back to an REW e-shaft.

Dan

[MOBEONER]

when you guys use the rx8 eccentrics do you also get your rotors lightened as well or do you just swap eccentrics?
I am rebuilding my engine in November just to freshen it up. Its reading 15psi vac right now and i would like to rebuild it and i am interested in the rx8 eccentric.

[FreeLance]

Back up top! I'm going to be using the rx8 e-shaft in my newest build and I'm just wondering if anyone has any updates. I respect ALL opinions in this thread but am always open for more data or experience.

[730RWHP12A]

Originally Posted by howard coleman

just cruising around and bumped into this thread. i am scratching my head as my friend Jose Le Duc runs RX8 cranks and he is making over 1000 rwhp. a couple of weeks ago he ran a 7.50 at around 180 mph. he leaves the line around 10,000 rpm.

hmmm.

hc

enough said, from an accurate source... rx8 e shaft for the win.. it is tapered too anybody know how good that is?

[730RWHP12A]

Originally Posted by Chadwick

Not to discount Glen’s findings as I respect his knowledge and personal experience, but seeing how my name was brought up I figured I should respond.

The RX8 shaft has been in my car since March of 08 and has consistently been spun to 9k RPM and seen above 300 lbs rwtrq. We pulled the motor apart a few months ago to try out the ALS apex seals and the front and rear stationary gears show no signs of wear and the shaft is still like new. As a mater of fact, most of the bearing babit was still there. I would estimate at that time the motor had close to 30 races on it and around 400 street miles. Now the motor has around 40 races on it and another 600 street miles and is still going strong. At the most resent ProSolo we gave last years National Champion in a 500+ rwhp, single turbo, 3 rotor a good run for the money.

I have plans at the end of this race season to drop this motor in my street car and build a new one for the race car. The new build will be using the RX8 eccentric shaft along with a few other tricks to reduce the rotating mass. Time will tell, but at this point I see no reason to go back to an REW e-shaft.

Dan

what class did you run ?

[Chadwick]

Originally Posted by 730RWHP12A

what class did you run ?

We run the car in SSM.

[Buggy]

I have the Rx-8 shaft in my Rx-4's engine along with the Rx-8 stat gears and bearings. This is an NA setup mind you so I'm not really pushing these parts to their limits. I've got probably around 6000 miles on this engine with no problems of any kind. Runs great, still builds good power and wicked oil pressure. I don't know if there is any real significant gain to going with the 8 shaft, but lighter is lighter and cheaper is cheaper...... Those were good enough reasons for me.