Trans difference

[project86]

hey guys, Are there any notable differences in the 1st gen 8s vs the 2nd gens? I.E. should i prefer one to the other?

[chibikougan]

Brian has farked with them enough. He should have some answers all I know is starter issue.

[WE3RX7]

What is the intended use for the transmission? Street or full race? Drag or Road Course? If you're looking for a transmission swap, there are better transmission options from the MX-5 world IMHO.

[TitaniumTT]

Elaborate please....

[WE3RX7]

Well you've been in the S1 trans more than I have but I've been looking at doing an NC2 MX-5 (late 2010+ production) 6spd. Its built by Mazda, not Aisin. Stronger steel/metal used, better synchros, shift rods, forks, etc. In theory it won't wear like the S1 RX8 trans will, causing the grinding and shift keys/detent pins to vacate their premises. I haven't really played with an R3 trans yet (S2) but it's probably fairly similar in improvements like the newer NC MX-5 ones are. Better 4th gear ratio too...

To answer the OP question, if starting from scratch with a custom build... and I had a choice of S1 or S2 RX-8 trans, I'd select the S2. But if I could go with ANY Mazda production trans in the recent years, it'd be the NC MX-5 6spd (mounts on the drivers side PPF as well as the RX-8 so may be fairly easy to mount). Also, more support in the racing world for MX-5.. the weaknesses the MX-5 trans has have aftermarket fixes for already.

I for one don't have many issues with my current S1 trans. It has been raced for the last 6 years pretty consistently and has over 90K miles on it. However, I've never been a gear slammer and take the right time between gear selections... also, I really believe the precision of the Exedy unsprung clutch system has helped tremendously with the RX8 trans. Is my trans perfect? No, but it's lasted WAY better then I thought it would...


More trans research for next year as I'll probably pull the engine/trans for updates at that time...

[TitaniumTT]

Originally Posted by WE3RX7

Well you've been in the S1 trans more than I have

More than I care to admit as well

Originally Posted by WE3RX7

but I've been looking at doing an NC2 MX-5 (late 2010+ production) 6spd. Its built by Mazda, not Aisin.

Right there it has my vote...

Originally Posted by WE3RX7

Stronger steel/metal used, better synchros, shift rods, forks, etc. In theory it won't wear like the S1 RX8 trans will, causing the grinding and shift keys/detent pins to vacate their premises. I haven't really played with an R3 trans yet (S2) but it's probably fairly similar in improvements like the newer NC MX-5 ones are. Better 4th gear ratio too...

I'm sure it is which makes it more desireable... however... when stuffing it into an RX7, it causes problems. I'm fairly confident I've solved all my trans issues that arose from moving the shifter back 3.5". The problem with the S2 and later trans is that they're top-loaders... which creates an entirely new set of problems when moving the shifter back in theory. Having seen a few pics of the S2 trans, my latest attempt could work for the S2 trannies but I would have to physically have one to dick around with... a quick search on Fleabay turned up 1 S2 trans for $1050....

Originally Posted by WE3RX7

To answer the OP question, if starting from scratch with a custom build... and I had a choice of S1 or S2 RX-8 trans, I'd select the S2. But if I could go with ANY Mazda production trans in the recent years, it'd be the NC MX-5 6spd (mounts on the drivers side PPF as well as the RX-8 so may be fairly easy to mount). Also, more support in the racing world for MX-5.. the weaknesses the MX-5 trans has have aftermarket fixes for already.

Problem is adapting it to the renni or any 13B for that matter... I bought a different mazda trans and there was no realy wasy way to make that happen without thousands worth of custom machining etc etc.... For that reason alone I would start with a renni tranny just because you don't have those issues at all. It's a matter of making the slave fit and the shifter. S1 shifter I'm fairly confident I have already solved.

Originally Posted by WE3RX7

I for one don't have many issues with my current S1 trans.

Nor do I... in the RX8 anyway Had the imput bearing replaced that's it... and it's still noisy...

Originally Posted by WE3RX7

It has been raced for the last 6 years pretty consistently and has over 90K miles on it. However, I've never been a gear slammer and take the right time between gear selections...

That is the key right there as I explanied to Kyle in a pretty lengthy pair of PM's....

Originally Posted by WE3RX7

also, I really believe the precision of the Exedy unsprung clutch system has helped tremendously with the RX8 trans. Is my trans perfect? No, but it's lasted WAY better then I thought it would...

Agreed.... just hit 206,000 on my RX8 tranny... Fluid is huge as well... I am NOT a fan of the royakl purple anymore.... I'm switching out to redline in teh RX8 and the Amsiol high shock in the FC... see which one holds up better and then just keep using that....

Originally Posted by WE3RX7

More trans research for next year as I'll probably pull the engine/trans for updates at that time...

Lemme know... I thought you had a solution that would bolt up to the 13B. That's my biggest thing... and shifting...everyone says go T56 but I fucking hate that tranny.... :shudders: I plan to put a 383 in my other RX8, and that's the only thing that i don't want to deal with at all... Just because I may look into a ZF tranny, even though those things are bucks.. they hold a ton of torque and shift soo smooth.

If you see an S2 trans for a decent price... lemme know and I'll grab it up and start fucking around with it,.... you know.. because I have so much time

[WE3RX7]

Originally Posted by TitaniumTT

when stuffing it into an RX7, it causes problems.

Yea, wasn't sure what the OP was planning to do (RX8 or RX7). Any of these trans in an RX7 vs RX8 is going to pose a few challenges. I think fitting it to the RX8 would be far simpler since both are PPF cars and mount on the same side. As far as mating to the engine and shifter location, dunno yet...

Originally Posted by TitaniumTT

a quick search on Fleabay turned up 1 S2 trans for $1050....

NC2 6spd isn't much better unfortunately, which is why if I'm going to spend that money, I want it spent on the right setup.

Originally Posted by TitaniumTT

That is the key right there as I explanied to Kyle in a pretty lengthy pair of PM's....

It is probably the 2nd most common convo I have with RX8 owners who are still shocked that I'm on my original engine and original trans. The RX8 trans is actually wonderful in many ways... you just need to treat it right.

Originally Posted by TitaniumTT

Fluid is huge as well... I am NOT a fan of the royakl purple anymore.... I'm switching out to redline in teh RX8 and the Amsiol high shock in the FC...

Redline is all we use in any of the cars (Rx7, Rx3, Miata, Rx8, etc. etc.) but the trucks get Mobil 1 because Ford.


I'm sure we'll discuss transmissions more when the time comes. I'm so deep into so many projects right now. I share in your disease, just not as good at it, lol.

[TitaniumTT]

Originally Posted by WE3RX7

Yea, wasn't sure what the OP was planning to do (RX8 or RX7). Any of these trans in an RX7 vs RX8 is going to pose a few challenges. I think fitting it to the RX8 would be far simpler since both are PPF cars and mount on the same side. As far as mating to the engine and shifter location, dunno yet...

Going in an FC

I believe it's a drop in for the S1's, just need to carry over the switchs

Originally Posted by WE3RX7

NC2 6spd isn't much better unfortunately, which is why if I'm going to spend that money, I want it spent on the right setup.

The end will be way more expensive though as all the custom adapters and such to get it to bolt up to the renni. Personally, I would just drop an S2 tranny in... 1st is really only the difference in terms of ratios....

Originally Posted by WE3RX7

It is probably the 2nd most common convo I have with RX8 owners who are still shocked that I'm on my original engine and original trans. The RX8 trans is actually wonderful in many ways... you just need to treat it right.

Exactely.... what does a stock renni put down for torque? 125ft/lbs? My Cosmo is making 330ft/lbs... it's not a weak tranny as most of them think and when I explain to them that they broke it when zero torque was being applied to it, IE Clutch disengaged, foot off the throttle, and that it was infact thier fault... well.. that never goes over well

Originally Posted by WE3RX7

Redline is all we use in any of the cars (Rx7, Rx3, Miata, Rx8, etc. etc.) but the trucks get Mobil 1 because Ford.

Yerp... I threw the Royal Purple in because that was all I had access too... gonna change out all the fluids before hibernation... which is being postponed because they didn't salt yesterday or today

Originally Posted by WE3RX7

I'm sure we'll discuss transmissions more when the time comes. I'm so deep into so many projects right now. I share in your disease, just not as good at it, lol.

Definitely... if you hear of an S2 trans for cheap... lemme know... I'll swipe it just to play with it... if it's all FUBAR'ed fitting into an FC chassis, I'll toss it in my 8 and have a 4th S1 trans in the basement

[WE3RX7]

I need to stop acquiring project cars long enough to work on the ones I already have...

[project86]

Ya i was asking for the purpose of using one in my FC. Brian fed me a slew of info via PM over the last couple days... but whats this about a Miata trans you say???

[TitaniumTT]

Originally Posted by WE3RX7

I need to stop acquiring project cars long enough to work on the ones I already have...

Maggie has imposed a no more cars rule We'll see how long that lasts after a get one or two more on the rd... We'll also see what happens when I go to sell her Jeep to buy an FC sheel for a track car

Nah... I wouldn't do that




OR WOULD I!!!

Originally Posted by project86

Ya i was asking for the purpose of using one in my FC. Brian fed me a slew of info via PM over the last couple days... but whats this about a Miata trans you say???

I have experience with the MSM trans.. and I can tell you that they will not fit in the RX8 case and the dentent balls are in different locations.... sooooo if all is the same internally... basically between the Miata and the S2 renni... ge the S2 renni and make it fit....

Like I said... if someone comes across one for a decent price... lemme know... I'll snatch that bitch up and dick around with it.

But I KNOW I can make the S1's fit and work and looking at the pics... taking the same approach as my last at the S2 trans... it should work and work well....

I may call Darin and see if he has an S2 trans kicking around he wants to sell cheapish...