Hmm, if these are the definite gear ratios,

I can tell you that 1st gear is a PITA(for daily drive) with the FEED gear. And with the multiplication its going to get, its going to be even more of a pita.

Yes, it gives it a lot more get up and go, but 1st gear goes by so quickly in daily driving, I usually shift in the first 10 or 30 feet (due in no small part to how loud my midpipe gets at 5K+)

Performance is great though, glad Mazda took the suggestions of the people that did the final drive install

 

Awesome - thanks for the knowledge Jason.

POS comment rescinded. I like the feel of the tranny and have no issues w/mine. Just a little concerned/irritated by some aspects of it, like the constant smell and frequently noted "fragility" and grinding. All of which feeds my fears of post warranty days w/the 8.

 

Jason, thank you for all your input.

What exactly do you mean by "overthrowing" a gear?

 

Great info , Thanks Jason

Now I wonder can I just drop my "old" 6 sp Aisin gear box for the newer Aisin 6 sp box.

 

Fantastic post. Well, terrible in that now I will be fretting about my gearbox every time I drive her hard....but great info.

I too would like to know what "overthrowing" a gear means....in reagrd to the comment about third gear above. Thanks!

 

Again Jason,

thanks for the great info and confirmation of the trans type in the 09 car. You are an asset to this forum for sure. Share some more when you have time.

Seal.

 

wonder who will be the first to 'upgrade' to this transmission. Wonder if the turbo guys will be eyeing these... (as a substitute for the 3rd gen Trannys they're so fond of now)

 

i dont know but ill bet ABBID will be the first to break one

 

When I say 'overthrowing' the gear, I mean pushing the shift hub past where it needs to be to engage the gear. I'm not sure why, but both 3rd and 4th gear on the RX-8 Aisin box are without a 'fence' to keep the hub from going too far. The shift hub slider teeth are what drives the car, and there are matching teeth on the gear itself. When you shift into a gear, you engage the hub (splined to the shaft) to the gear (free spinning on the shaft.) Most gears have a raised flange on the hub-teeth to 'catch' the hub slider and keep it from going too far. Curiously, neither 3rd or 4th in the Aisin box have this flange.

I just built two MX-5 boxes today - and it was a great reminder of how much better it is. Very stout gearbox. And the great thing is that it's not an outsourced Aisin box, it's all Mazda. It's a very nicely designed box. As I said, it has a few flaws, but Mazda is aware of them, and fixing them.

I'll keep this up to date with everything we find out... I know that '09 tranny is still sitting in the tech center at Irvine. Hopefully they will send it to us to test! We'll have the tech notes on the '09 soon too, and that should have the ratios so we can confirm that. Interestingly, the project leader for the car doesn't even know if the ratios are the same yet! I'll report back as I get more info!

 

It will be great if we can drop the current 6sp and use this new one instead.

 

wee!

I may not be the first one to get the tranny but I'll keep my eye on it.

All depends upon my DD and the new sports cars comming out.

At some point I need to stop modding the 8 and concentrate on saving for a new sports car.

Of course I will keep the 8 as a track only car.

 

so you can break it ?

 

The side the PPF on does change how the torque of the engine is transferred into the transmission case. The twisting of the case in one direction might not cause a problem, but you twist it in the other direction and it will.

Rotaries are definitely harder on gearboxes due to temperature... but the failures that are occurring in RX-8 gearboxes have nothing to do with temp. Also, many have mentioned that 'RPM' could be a factor... again, higher RPM simply means higher heat, and heat isn't killing these things.

 

because it suck

Lets just hope that the new box in the 09 version can be use in our 8. I really want some *bullet proof* boxes like the old 5 sp that the rx7 has.

 

Thanks for the great info. Jason. I too will be interested to find out if the new box will swap with our '04-'08 MTs. Of course that would mean a new combination of gear ratios since we'd have the 4.47 final drive with the '09 gear ratios. Probably not in our favor performance wise since we'd have overall taller gear ratios.

 

If the ratios are about what we predict them to be, in other words about that of the NC's gearbox, this new gearbox with a 4.444 won't have a huge difference in performance from that of the current box. That makes a swap an attractive proposition if it turns out to be more robust and you're willing to spend the money.

 

If I pirate this from the OPs post and add in the swap option:



Car (1st 2nd 3rd 4th 5th 6th FD)
04-'08' RX-8 (3.760 - 2.269 - 1.645 - 1.187 - 1.000 - 0.843 - 4.440)
09' RX-8 R3 (3.815 - 2.260 - 1.640 - 1.177 - 1.000 - 0.832 - 4.770)
09 RX8 gearbox in 04-08 chassis/final drive -(3.815 - 2.260 - 1.640 - 1.177 - 1.000 -0.832 - 4.440)

Revs @60, '04-'08 RX-8 - 2nd - 8391.9 / 3rd - 6084.1 / 4th - 4390.1 / 5th - 3698.5 / 6th - 3117.9
Revs @60, '09 RX-8 R3 - 2nd - 8807.4 / 3rd - 6391.2 / 4th -4586.9 / 5th - 3897.1 / 6th - 3242.4

09 in 04-08 RX-8 Rrevs @60- 2nd - 8358 / 3rd - 6065 / 4th - 4353 / 5th - 3698.5 / 6th - 3077

All in all not a big change RPM difference wise. I don't have a feel for what that would translate to in acceleration numbers.

 

3100 rpms at 60mph makes for shitty highway fuel economy on a rotary when driven at average highways speeds (75mph). The 09's economy is really gonna go to **** now with these more rev happy ratios. Mazda needs to re-think the 5th and 6th gear ratios as there is no need for anyone to be doing heavy acceleration on these two gears. These engines have a bad enough reputation for fuel economy as it is. My Fc and Fd run at 3,000 rpm at 75mph and get 27mpg on the highway.

 

Funny you say this.

Was at Le-Mans in 2002 with the Auto-exe team covering them for an Aussie motoring mag.

Anyway, the team entered two cars. Same chassis, same gearbox.

2lt turbo engine in one, 26B-PP engine in the other.

Similar power from both (26B was choked via a 48mm intake restrictor)

26B version snapped the main shaft on the box on lap-5

2lt turbo version did the complete 24-hr race. No box trouble at all.

Rick Engman suggested at the time, "Rotaries have high Snap-Torque" & can break boxes much easier. We should have upgraded the box in hindsight"

You know boxes behind rotaries Jason. Is this true..........???

 

Jason,

Great info, thanks for your insights. I'm surprised that the new '09 6th gearing would continue to be so tall, I hope gas mileage doesn't suffer over long trips. I guess Mazda figured they would rather just have the extra zip and said gas mileage be damned. Who knows maybe the found a way to keep mileage the same.

 

Funny you should say that, because I made my original controversial statement based on a conversation between Rick Engman and Dr Francesco Iannetti regarding the pulses generated by a rotary compared to a piston powered car in terms of power being sent to the box as observed with an oscilloscope.

The other reason I think you may see more failures on rotary run gearboxes IS rpm related and was explained to me by David Haskell of Speedsource: No matter how good a synchro box is you need to take your time to shift. At elevated rpms the situation is worsened for impatient drivers. There are more driver caused AISIN RX8 failures than manufacture faults despite the excellent, thorough and professional asessment provided by Jason.

Seal.

 

I hear what David is saying about RPMs, but it has more to do with RPM drop... a high revving engine that drops to a slow RPM in the next gear will have a harder time than a very small rev drop. The AISIN box had some pretty big rev drops. But many of the problems we see on T3 and Koni Challenge boxes are from the design weaknesses.

Anyway, update... I have the '09 ratios confirmed:

1st
3.815

2nd
2.260

3rd
1.536

4th
1.177

5th
1.000

6th
0.787

Reverse
3.603

Final Drive
4.777

I will update the gear charts and repost sometime over the weekend... unless someone beats me to it!

 

Thanks for your contributions Jason!

 

Thanks for the info!

 

I'm in no way quoting David. I'm very fortunate to have him as a friend. I quizzed him on what they do and what can be done over two years ago. I won't go into the details of his prep but the most important and basic thing to me (That would apply across the board, rotary or piston) is speed shifting is a recipe for disaster in a synchro box. Since they've had various drivers in their cars over the years it was obvious that some drivers were much worse than others on the equipment. I'm in full agreement with your assessment by the way.

We can't thank you enough for your contribution Jason. Very good to see those ratios, especially the overdrive.

Seal.