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http://www.rhdjapan.com/os-giken-6-speed-sequential-transmission-rb26dett.html

Brand: OS Giken
Product: 6-Speed Sequential Transmission RB26DETT
Torque Capacity: 120kgs
Engagement Type (Synchro/Dog): Dog

Yeah, I've thought about that. Realistically, I'd need both cars at the same time, not to mention the space to do it. I will own a white R34 GTR one day Marko. The whale needs a play mate ;).

  • 2 months later...

Update?

No update. Car is still at my best mates workshop getting the boot seam welded and a few little bits repainted. OS88 should be ordered towards the end of the year. 3-4 month lead time with that though :(.

We have a Modena in our r33 gtst track car(rb34 680rwhp/1600kg w/driver & fuel). My god it is one of hell of an amazing box. The shifts are quick and positive, up and down with no clutch. 1 year in worth of racing and its still working like brand new. It seems to be handling the power and weight of the car well. Cant say the same for the 3.69 r200 diff though. We have broken one already, stripped teeth off crown wheel.

FYI Modena top gear (6th) ratio is 1:1. The box is also a fair amount lighter then a standard rb25 box. From memory the difference was about 9-10kg.

They can supply input shaft to suit whatever spline you want also, we were already running the chevy spline from the bigger PPG input shaft so they made it the same so we can reuse the clutch.

Also we switched to the Modena from a PPG which we killed several times over. Just couldn't handle the load.

I know not a lot of that is totally relevant to your build thread mate but thought it might be useful for others who are searching for info on potential gearboxes.

Also this is based on racing experience, nothing on the street so I cant comment on how streetable the box may or may not be. The only downside is there is custom mounts to be made, and you need to knock up a shifter mount in the car as its a remote mounted shifter that is independent to the box. It is attached to the box via a short linkage. Then there is the pull cable/lever for the reverse/neutral lock out.

Think I have covered everything that is worth knowing, hopefully it may help someone.

I might have missed in the last few pages but what is an OS88 box worth?

The Modena box is awesome but I don't think it can be mated to the 4WD transfer case :(

I also think it is straight cut, so it will have the whine to it :(

And a fair bit dearer then the OS88, from memory the Modena was $20k + get stuffed tax :(

Yeh it does have straight cut gears which do whine abit, but not much worse then a loud exhaust system. But for street driving it wouldn't be the most aurally friendly for sure.

The other issue is the top 1:1 for a street car as you said. We had to find a r200 diff that had a ratio so we could get a reasonable top speed, a s15 diff was used with a 3.69 ratio.

Man..... So nerve racking. I just bought a PPG 1-5 dog box last year and are about to install it this year but when I read stuff like "PPG don't hold up" I get bent out of shape. I dunno what power I'll put down but a guy in the USA with the same head and turbos/intake/exhaust but a 2.6 unlike my 2.8 put down 840whp on e85 (which doesnt sell in this country). Soooo im potentially pooched.

Man..... So nerve racking. I just bought a PPG 1-5 dog box last year and are about to install it this year but when I read stuff like "PPG don't hold up" I get bent out of shape. I dunno what power I'll put down but a guy in the USA with the same head and turbos/intake/exhaust but a 2.6 unlike my 2.8 put down 840whp on e85 (which doesnt sell in this country). Soooo im potentially pooched.

  • 2 months later...

Little bit of an update here.

The os88 will be ordered within the next few days. Just waiting on account details of where to sent the coin and it will be full steam ahead. I ended up going through import monster.

Then the wait begins.

  • Like 1

I believe Exedy do the plate in the centre hub with the larger spline hub. I haven't contacted them yet, but if that's the case I'll buy a new coppermix and go that way. I really don't want to give the coppermix up.

Exedy is dreadful, based on running a twin plate in past - yuk

pretty much more brutal than my os giken triple plate & that is saying something

ive never driven a coppermix but that will change when you're back on the road :)

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