RX-Hachi

Interesting read in the Jan. 05 Sports Car International on the Grand Am racing RX-8s. Did you know they use the stock transmission in the race car? SpeedSource claims the stock trans is very robust, lasting 3 races without a rebuild. So who says our transmission suck? THEY ROCK!

The race cars also use the stock brakes as well, albeit with different pads. First year, right out of the box our RX-8's have taken the Grand Am ST championship (thanks to SpeedSource). What's more impressive is that these cars aren't that different from our stock RX-8s.

truemagellen

sweet thanks Hachi...

rotarygod

While road racing does involve alot of shifting through the gears, a hard launch on a dragstrip is what will kill it faster than anything. This is where it's weakness shines through.

RXE16T

.....and that's meant to be good?

Foureagles

I wouldn't say it sucks (what would that really mean, after all?), but I don't much care for it.

My Dear Wife & I each have '90 Miatas, and with either of those you can do a no-lift redline fan-&-yank in any gear, all decade long with nary a crunch or complaint. Well, I do renew synchros & forks about every 100,000 miles, but that's a pretty long time under such hairy treatment!

MDWs 8 demands shifts that are much more deliberate, both up & down, and that just buggers my timing. The Miatas WANT to do it, while in the 8 it feels like abuse. Granted, 9,500 RPM vs 7,200 would certainly make a difference, as would more clutch & gear mass, but hell, back in the day, I ran 9 grand small block Chebbys with M-22s that were more agreeable. I had planned to swap a 6-speed into my Miata until I met the 8. I decided to test-drive a 6-speed Miata, and it had the same issues.

It IS good to hear that they seem to hold up well in road race conditions. I wonder what sort of torque those Grand Ams make?

{{{{

Red Devil

The Grand Am cars are natural aspiration; the torque can't be too much more than the street cars.

Speed Racer

The transmission is definitely one of the weak links on this car. Casual Racing has already seen the synchros fail on both of their race cars. This happened in the span of just a couple of races (SCCA Touring-2). The cars are still driveable but it is now much more difficult to shift quickly. Now that the racing season is over they can take their time in rebuilding the trannies and get ready for next season.

G8rboy

I agree with Ted- the Miata's 5speed transmission is in my mind smoother, stronger and more confidence-inspiring than our Aisin 6sp.

StewC625

I definitely find it interesting and disappointing that I can't "no clutch" shift my 8's transmission. I could do that with ALL of my hondas - especially when they got some miles on them - just match revs and click click.

rx8wannahave

Please tell me that you were not (NOT) pressing the clutch to change gears? I don't understand your statement...is that what you are saying?

Anyway, is there (probably not) tranny's out there that would fit a RX8 and is better? Is the tranny the problem or is it more the weak clutch?

Explain...

Luftwaffle

Yes, I think that's what he's saying. Basically, rev match the engine revs between two gears so that you can go from one to the other without touching the clutch pedal. I've never done it before and have been advised against it. The potential for damage is too high for me to mess with that stuff. My friend accidentally did it in his Trans Am once while reaching for his soda. Never did it after that though.

G8rboy

Stew-
Let it wear in a bit... I don't make a habit of it, but I can go from 2-3-4 clutchless, if I take my time... it's usually the slow drop from 3-N-4 that I do when cruising in a residential neighborhood. I find it smoother now that I'm running Red Line in my tranny, so I'm sure that helps. It was very easy in my Miata at 100k miles, as well my old Celica at 200k miles.

Feras

iTrader: (1)

6spd miata and 6spd rx8 share the same transmission so that problem is not surprising

Icemastr

Truck drivers shift without pressing in the clutch all the time. All they use the clutch for is when they are stopped. I have heard of them not having to replace the clutch for over 200,000 miles because of this and pretty rare to rebuild the transmission.

Your comparison of race cars at about the same power levels of the stock car having rebuilds after every three races hardly applies to our main concern with transmission strength; which is how will the transmission handle major increases in power and hard launches.

StewC625

Yup ... shifting gears without depressing the clutch. On all of my Honda cars (Hondas have such sweet transmissions - Acura or Honda ... all the same), you could easily slip the car out of gear without depressing the clutch, and then if you carefully matched the revs to the engine speed (requires good knowledge of how your car runs), you could easily slip it into the next gear.

Honestly, I never actually used this technique in real driving - as in regular upshifts/downshits ... instead I just played with it.

But, I can't even pull the -8 out of gear ...

rx8wannahave

I never heard of that type of shift...but I think I might have done it once or twice by mistake. I'm glad to hear people are not doing this normally cause it seems it's not worth the risk.

I do wish they made a clutchless standard tranny...I know they have but it's still not a common practice.

G8rboy

Try bringing it out of 3rd at around 4500rpm, and into 4th around 3krpm, with a brief moment in neutral.

StewC625

Actually, I managed to do this last night - did a 2-3-4-5-6 run of upshifts followed by 5-4-3 down ... just a matter of REALLY carefully matching revs ...

Not that I'd ever do this in real driving. Just fiddling ...

Douglas_Baker

There is no such thing as a true clutchless standard - the clutch is required to get you going. There are cars that will allow you to shift the gears without depressing a pedal, but they still have a clutch - it is just engaged/disengaged by the computer. It is also worth noting that many of the vehicles that claim to have a "clutchless manual" are nothing more than an automatic transmission that allows you to control the gear selection.

There is little wrong with clutchless shifting when done appropriately. Rev matching does not hurt your clutch/transmission - forcing a shift without matching the revs is what causes problems.

d-

racesput

In fact, if you can match revs that well, it's even better when you ARE using the clutch! I'm sure your clutches last a long time StewC625. Cheers and good job.

G8rboy

I bet Stew even double clutches on occasion, just for ***** 'n grins... I know I do.

mtnpass

You still need to remind yourself that these are Miata trannies...They are inferior compared to previous RX trannies. I believe this will become even more evident when we start seeing FI kits as commonplace. My clutch never blued after 15,000 miles. THe FD and FC both had better suited drivetrains than our 8. I guess I will have to stockpile RX8 trannies when the FI time comes. Wife is going to love this idea.

Icemastr

You do know that you could swap in a different transmission? Like a T56, Getrag 6 Speed, or Turbo II / 3rd gen RX-7 5 speed?

Red Devil

Yeah, and you can get a rebuilt FD tranny for about $1200 now as I recall?

Cam

iTrader: (1)

If you could swap any tranny, which would it be?

Im not very car savy, but how would you be able to know which tranny's could be swapped into an Rx8, or does it matter? Example: could you swap a S2000 tranny into the Rx8?