OS Giken Gear Ratios
 

Hey Guys, I have been in contact with the representative for OS Giken here in the United States. He stated that OS is currently in the process of testing, producing, and distributing kits for the RX8 6 Speed Manual. The only downside is that according to OS Giken the gears are so narrow that they are unable to produce a kit capable of withstanding the stresses of forced induction. I'll update this post as I get more information regarding the release and actual ratios for the kit.

Subscribing

you should subscribe multiple thousands of dollars to your savings account :hahano:

For NA only gears... no thanks. The 512 finial gear is bad enough at $1500

Well the rep said it would be 1000+ if I wanted to get them developed for myself. However since os giken already has them in the works they shouldn't be several thousand dollars. Definitely not saying they are going to be cheap. just saying they wont be a couple grand thats all.

I'd be surprised if it's that cheap, their LSD for the RX-8 is $1500 (which I love BTW). The big problem is the yen being so low compared to USD, the current exchange rate is a killer for us to import anything from Japan.

there are some alternate parts from Japan if anyone is interested, but they are several grand too. There is a new countershaft assembly with different 1st & 2nd gears ($2600 + freight) to make 1-4 a close ratio setup

from ３．７６０　２．２６９　１．５３９　１．１８７

to ３．０１４　２．０６２　１．５３９　１．１８７

and then there are also two alternate 6th gear ratios to go from the OE 0.843 to a steeper 0.795 ($345 + freight) or a shorter 0.862 ($650 + freight)

That is interesting I will have to check them out. Whats the manufacture? I checked out prices for OS Giken's other kits to get a feel for what the prices will be and Team RX8 is right itll be about $1000-$1500. I think the cheapest set I found was $650 for a honda and the most expensive I found was $4000 for a nissan silvia.

Enlighten me please, why change to close ratio gears in the trans when you could just change to 4.77 or 5.12 rear diff gears? If the gears solved the weak s1 trans problem that would make it more tempting but if OS gilken says it cant handle FI I don't see it solving anything.

Additional, I don't think anyone with FI really needs close ratio gears, 4.77 gears with FI should be more then enough.

Me personally. I'm not sure I want to go FI. I am having enough problems rebuilding my RX7 and her turbo's. I don't want to worry about having to install and tune one on my 8. So that is why I would like to go with the close ratio gears. That and I am looking to improve acceleration for my RX8.

The close ratio gears with the shorter 6th gear will make a great combination with the lower rear gear for an NA track car. Otherwise the OE 1st & 2nd gear are almost useless with it and the OE 6th gear is too steep for track use.

It's a tempting possibility… I definitely am curious which side of the range that the price comes down on… I don't track my car; but this does have some possibilities.

if it really is that cheap then it must not be much of an upgrade. Any other serious upgrade I have seen for other transmissions like the Miata or FD3 are all $4000+

http://www.par-engineering.com/secti...da&sectionId=7

Barrington Performance will sell you an RX8 transmission that has been rebuilt with Hewland dog ring gears. 5 speed, with about any ratio you can think of. 6k for a complete box, but a pretty good option since you don't have to engineer a way to mount/adapt a non-rx8 transmission.

I believe the answer is about the rpm drop from one gear to the next. Changing the final drive does not decrease the rpm drop. Sure they spin up faster with a 5.12, but you still drop way out of the power peak on each shift. Stay above a certain rpm for best performance. Of course for FI this is not really an issue, or something with more displacement than a rotary.

I can always count on you to show me something I wasn't aware of :)

http://www.barringtonperformance.com/rx8.html

I have been considering the g-force GSR or GT4 for my next class jump, but it does have the conversion headache factor. I would seriously consider dumping the PPF if going that route.


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Any news on the OS giken set?

Team - Can you tell me who the manufacturer of those gearsets you mentioned are?

nope, the only new gear sets I know of are for the Nissan Z cars and possibly the FRS/BRZ

OP hasn't posted since this thread and also hasn't longed on since Aug.

if you're a member of Facepalmbook you might try asking OS Giken there. The contact I had there is gone ...

Otherwise Revolution is the only one I know of offering any gear set for the RX8 6spd

PPG has some gear sets for the s13\s14 cars and the s2000: S2000 Product Range - Pfitzner Performance Gearbox

Don't they both run on az6 gearboxes?

Yeah, those revolution ones aint cheap. I'll see what OS Giken has to say.

I'd imagine OS will be somewhere around the same .. I dont expect a dramatic drop in price


subbed either way

Yeah, i can imagine the OS will be about the same price, but i would suspect it would be for a complete 5 gear set or perhaps a 4 gear set. The revolution one is really only a 2 gear set as the 3rd and 4th are factory ratios.

I wouldn't expect to pay less than 5000$ for a complete gearset.

Why? There 5 gear set for the FD is 3500 and that's retail off there website. I've seen them for 3100. No reason why it has to be much more than that.

I was referring to PPG's prices.
Keep in mind that the production numbers play a role... how many rx8 gear sets would they sell?

You should contact some manufacturers to see if their s2000 kit can be fitted on our transmission as well. The model is the same (Aisin AZ-6) but there may be some internal differences we're not aware of. Same goes for the Nissan S15

Kings Performance – NEW Kings Performance S2000 Dog Box gear set is available now!

S2000 RACING GEARS, STRAIGHT CUT

Contact them and see what they come up with.

I'm not aware that they are the same, but am not 100% sure.

The Barrington link from Ebb above is your best shot for a bolt-in race trans. They can convert both the S1 and S2 trans to either Hewland or Webster dog ring gears & ratios