rotarygod

I learned a little more about the Renesis ignition timing. The split is anywhere from 5-15 degrees depending on load or rpm. This is a first for a production rotary but is a very common tuning style for aftermarket ecu equipped rotaries to get better power. This still leaves the fact that the idle firing order is crazy.

boarder

Anyone learned any more information about the plug setup/timing ?

*cough* bump *cough*

MazdaManiac

iTrader: (3)

Well, I have found two things:

1) you can advance the timing out to Timbuktu and the damn thing won't ping. I think I got all the way out to 17° of additional advance (on 93 octane) before I logged and knock sensor activity.

2) There doesn't seem to be any power gain beyond 3° - 5° of additional advance. OEM timing is seemingly already in the best range.

Omicron

RotaryGod and Maniac, you guys continue to amaze me. Keep up the great work!

But, um, is it Maniac or MazdaManiac? Inquiring minds want to know... why the new User name, Jeff?

MazdaManiac

iTrader: (3)

Thanks.

I wanted to be MazdaManiac all along, but some other nimrod grabbed the name back at the end of 2002, made two posts and bailed.
BOOSTED 7 cleared it out for me so I could grab it up.

My WEB domain is www.mazdamaniac.com so it only makes sense!

I'm also MazdaManiac on all the other WEB forums I'm on (like www.mx-3.com, www.mx6.com and www.mazdamp3.com).

boarder

Interesting.

Has anyone tried wasted spark mode (with different plugs/coil most likely) yet ? I'd be interested in any results (power, emissions, flooding, etc).

Trying to figure out why Mazda would have such a strange setup. Wish they would just ante up the info (yeah right ).


MazdaManiac: Do you know if Greddy is gonna upgrade their Emanage for the timing setup for the RX-8 ? Longshot question, but I figure you would know if anyone here (since you have one working on an RX-8).

MazdaManiac

iTrader: (3)

Wasted spark seems to be just that - wasted. The trailing plug does enough for emissions and wasted spark probably won't give you any power in this application.

The "strange" setup is for fairly obvious reasons - emissions.
By firing the plugs in reverse order at idle, you get a longer burn in the ignition chamber. Not good for power, though since it is essentially preignition.
At start, you get easier starting, like you would with a straight ignition retard on a regular high-compression motor.

Greddy might address the ignition issue since it affects a wide array of vehicles.
They might also release a new version of the E-Manage altogether.
Doesn't really matter much since the problem is easily solved with $1 worth of parts on the user's end.

wakeech

i, quite a long time ago, read an ASE article on the good ol' R26B's ignition system, which used that super-leading plug (which was situated well above the trailing plug, sticking out at a funny angle to keep it square in the engine) to use the geometry of the motor at something like 90* BTDC (could be/probably is less) while the rotor is still coming round to maximum compression to ignite earlier the A/F charge, and utilise the "leading deep depression" combustion chamber shape formed into its surface (as opposed to the "centre deep depression" bath-tub shape found on our 13B's). sorry for all the footnotes shoveled into the middle of my sentance there. oh, ought to note that this was used in the uppest of the upper rpm band range, i'm sure only because the rotor had to make it 'round fast enough.
edit: gonna email that too-good-for-us new father to see if he can re-dig that up for "us".

this useage (early ignition of the trail plug... i'm curious, do you have a number for when??) could again be an attempt at utilizing the extremely unique wankel compression geometry to squish the A/F mixture and ignite it in a false-stoic environment (as it's obviously never homogenous in the combustion chamber at any time), and accelerate the combustion with further compression, then POW, lotsa super efficient push to keep the motor running.

buger heard tale of some crazy theoretical number like up in the 20:1 side of lean (!) that this motor can supposedly run safely on... haha, i surely don't suppose you're brave enough to try, eh MM??

MazdaManiac

iTrader: (3)

Well, I don't know about 20:1, but I have had it cruising at 17:1 for some stretches.

wakeech

schweet.

Omicron

Ok, thanks for clearing that up Jeff. Perhaps we can somehow consolidate all your "Maniac" posts onto your "new" forum name. I'll check. But in the mean time, I could seriously do without your new flashing avatar. Makes me feel queasy.

Sorry for the thread hijack. We now return to your normally scheduled programming.

neit_jnf

I have a MS Word document about the R26B, explains the ignition and continuosuly variable intake and more on the design of the engine. Too big to post though, any ideas on how to share it with you guys?

MazdaManiac

iTrader: (3)

You can send it to me and I'll PDF-it and host it on my WEB site with a link here.

You can e-mail it to me HERE

syntrix

pm'd ya, after pm'ing you and after you responded to my pm.

MazdaManiac

iTrader: (3)

I don't see any PM's.
Maybe you PM'ed me while I was responding to your non PM and it got PO'ed?

syntrix

I pm'd him.

http://rx8.swankmonkey.com/r26b/


Word to html conversion... It works, but my pdf tools are on my lappy, and it's at work this weekend.

wakeech

awesome.

so of course i have remembered it wrong, and the 3 plug system was there to clean up combustion at high rpm while the motor was firing under really really high amount of advance. the 3rd plug fires in a far-trailing capacity to ensure propogation of the flame front in the trailing section of the combustion chamber.

so, in short, i was wrong about the idea before, and because at idle/low engine speed (where this trail plug fires before the lead plug), there shouldn't be too much problem for the flame front to "propogate" its way to the trail side of the rotor and fairly evenly burn back there too.
basically, my idea is rubbish, and i'm again stumped until i can fabricate some more bogus theories.

wakeech

diagram A

wakeech

diagram B

MazdaManiac

iTrader: (3)

Here is the document as a paginated PDF:
http://www.mazdamaniac.com/pdf/r26b.pdf

wakeech

ah, very pretty and easy to read. thanks.

MazdaManiac

iTrader: (3)

I aims to please. Probably easier on your eyes than "Wordified" HTML when you are staring at a Mac, anyway.

neit_jnf

Thanks for the help with the document guys. It looks way better here for the eyes of everyone than sitting inside my computer neglected...

pp13bnos

Rotarygod, heres your chance to ask Mazda directly.

http://www.rx7club.com/forum/showthr...hreadid=276389

CJ

wakeech

man, i never check that place often enough.

thanks for posting most of the questions i'd ask. especially about the seal clearance thing...