Jump to content
SAU Community

Recommended Posts

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 :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Lamb roast on Saturday will be different 🥲
    • They are under bucket shims. Tomei provides a test shim kit and then any measurement of shim required. 
    • I always wondered how you were supposed to buy a set of 24 buckets and somehow magically have every single one of them yield exactly the desired clearance. I would have thought you'd need to assemble a cam with either 12 "sample" or "example" buckets of known top thickness (or a single such sample/example 12 times over!!) measure clearances at every valve, and then do the usual math to work out what the actual "shimness" of each bucket needed to be, before buying the required buckets to make up he thicknesses that you didn't have on hand.
    • I now seem to be limited in power due to my rev limit/hydraulic lifters in my built RB25. I'm looking into converting over to Tomei solid lifters. Question for anyone that has done the conversion. I was always under the impression that when using the Tomei solid lifter conversion, you would also require new valves (Longer or shorter stems, I can't remember which).  I don't know where I got this idea, as so far I see no mention of this in any of the Tomei documentation. It just states I need the Tomei solid buckets, solid lifter cams and upgraded springs. As my head is already built, all I would need is another set of 1000$ Kelford cams, 500$ buckets and about 4H hours of my time installing and I'm off to the races!?!? There's no way it's that simple, I must be missing something? 
    • I couldn't agree more. I should have started from the get-go with a NEO or solid bucket conversion. I started looking into converting over to solid lifters yesterday. Now for some reason I was always under the impression that when using the Tomei solid lifter conversion, you would also require new valves (Longer or shorter stems, I can't remember which).  But I see no mention of this on any of the Tomei documentation. It just states that I need the Tomei solid buckets, solid lifter cams and upgraded springs. As my head is already built, all I would need is another set of 1000$ Kelford cams, 500$ buckets and about 4H hours of my time installing and I'm off to the races!?!? There's no way it's that simple, I must be missing something? 
×
×
  • Create New...