Jump to content
SAU Community

Recommended Posts

What he will be doing is changing gears a lot more, he has a big power band and a mountain of torque which means he can easily drive the "wrong " gear, been able to hold gears is easier and faster, with that much power you want taller gears to help settle the car and make less rail happy out of corners

And when driving the car on the freeway it will be reving higher then it needs to and this is a street car first and formost

He has already complained that he has still been caught in the wrong gear at times

And it a lot cheaper to throw the box in and say nope they are to short, then it is the change the lot and say f**k shoulda left the diff alone

Farken 4 PPG boxes, my rajab. The helical dog 1-4? How much grunt, Dave?

The problem with aftermarket gear sets is the size of the gearbox casing is the limiting factor for gear strength. If you can't make the gears physically bigger and space them further apart there are limitations on stength. Gear design, material and heat treatment can be optimised but only to a point.

The most cost effective option is the new Quaife sequential for the GTR, totally new design and much improved in comparison to their original GTR sequential which is a modified Dodge Viper Quaife sequential. I think they are around the $9k English pound... group buy? :)

The problem with aftermarket gear sets is the size of the gearbox casing is the limiting factor for gear strength. If you can't make the gears physically bigger and space them further apart there are limitations on stength. Gear design, material and heat treatment can be optimised but only to a point.

The most cost effective option is the new Quaife sequential for the GTR, totally new design and much improved in comparison to their original GTR sequential which is a modified Dodge Viper Quaife sequential. I think they are around the $9k English pound... group buy? :)

Only rated to 750 HP though which is a bit of a bitch. Looking at the ratios, they do look pretty neat.

I just got a quote back from Marcus and he said $12,700 for the OS88. Thing is, there is $2k give or take with GST and Duty. They do say 5,000 kms of "race/track kms" before it needs to be inspected. I'd say that would be no let off and yank on the stick. There is nothing stopping you from clutching in and pulling the lever.

Bob posted a quick video of his OS88 last night on Facebook. Seemed pretty stout.

It doesn't matter which way, it's not going to be cheap for a solution that's gonna be tough enough.

Paul.....I think the best thing to do before you commit to anything is do a spreadsheet comparing all of the relevant transmissions available by type, cost of acquisition, Max HP, gear ratios options (inc extra costs for this where applicable) and ongoing maintenance / servicing costs at the recommended servicing intervals and then make you're assessment.

My two cents worth

  • Like 1

Paul.....I think the best thing to do before you commit to anything is do a spreadsheet comparing all of the relevant transmissions available by type, cost of acquisition, Max HP, gear ratios options (inc extra costs for this where applicable) and ongoing maintenance / servicing costs at the recommended servicing intervals and then make you're assessment.

My two cents worth

That's not a bad idea.

I'll type something up and post it in here.

Might be useful for other guys also.

  • Like 1

The wait time really isn't an issue. I've just bought a house so it won't be ordered next week!

Taken from another thread on here;

Quote

The original Quaife H-gate 6 speed was developed back in 1991 for Trust (aka GReddy) Japan. In those days the primary objective was to get an extra gear, with two overdrives (5th and 6th) so the top speed trialers could make 300kmh. It was never really designed for lots of extra strength. When you fit a new cluster of gears into any stock gear casing, you cant alter the diameter of the gears because the shaft positions cant change. So all you can do is improve the tooth design and possibly the width of the gears. All that was done as that product evolved during the '90s. Thing is though, by then most serious cars were making 750hp or more so the gears would eventually fail - due to their stock diameter. It was obvious something more serious was needed. The sequential is a completely different thing altogether and is completely different internally to the older H gate kit. Its a direct derivative of Quaifes universal 6-speed sequential, an entirely different product altogether. It was re-designed in fact to fit a new car specific 32/33 GTR casing, I know cos I lent them my car to model it on. The sequential has enormous gears by comparison to the H. I think there are about 65 sequential boxes around the world now and remarkably few spares have been supplied during the 11 years they have been out there. Spares are generally available at the moment, whereas for the older H-pattern, none have been made since 2001, so spares if not on the shelf have to be made to order, meaning much longer lead times. I think the most important thing to remember about the sequential, is its a racing transmission. It uses straight cut gears and is as noisy as you like. Not the preferred option for a daily driver really, but lets face it, there arent too many options available for the GTR. What I really wanted to do here was just answer the heresay and explain the product. The same basic principle goes for anything on the market - if the gear diameter is the same as standard, the strength is ultimately limited by that factor alone, so watch yourself spending fortunes on anything that fits into the standard casing.

The Getrag really intrigues me, so little info out there,but if you want to fit one of those in a 32/33, will need a 34 transfer and 34 gear ratios in the front and back axles, because all the ratios are completely different. As the 34 had a dual mass flywheel (as do Supras,M5's and 911 turbos), when you switch to a twin or triple with a solid flywheel, it seems to put alot of pressure on the constant meshing gears, or input driven pair as they are known. Whether these ultimately fail or just get noisier and noisier I really dont know. Getrags seem to manage 700hp quite successfully in the 34, Supra and others, so I assume it has bigger gears than the 32/33- Anyone care to comment on that ? The Quaife sequential is noisy in all gears however, as all of them are straight cut. As far as using it goes, you will either love it or hate it. It needs you to shift definitely and aggressively, mainly due to a mixture of the large gear diameter and the sequential mechanism being mounted on the side of the box. Treat it like a motorcycle gearbox, pushing it hard into gear, and you will get on with it just fine. Press it delicately and it probably wont engage the next gear up or down. What did Richard Bell say out of interest ? He hated his initially whereas Brian loved it. I sat next to Rich at that drift place in Wales and made him have a go with it properly, by about the 3rd lap he loved it. So much so that after two more sessions, he broke his lovely new engine !

Anyway, hope it was ok to post, just thought a bit of background might help

cheers, Tim

That's is another point, the quaife is straight cut noisy and the OS88 is helical cut so not as noisy

Paul.....I think the best thing to do before you commit to anything is do a spreadsheet comparing all of the relevant transmissions available by type, cost of acquisition, Max HP, gear ratios options (inc extra costs for this where applicable) and ongoing maintenance / servicing costs at the recommended servicing intervals and then make you're assessment.My two cents worth

Well said :)

My mechanic had a couple of runs off the limiter (8K) and it bogged (2.1 & 2.2 60').

I went off 6-6.5K and managed a 1.85 and 1.75 60'. This is with 275/35/19 Kumho Ecsta's and twin plate DCS clutch. I'm thinking the rubber is too big.

Tried two-step on the street and it bogged also. Stock engine so I took the two-step off.

Have you ordered the OS88 yet? :D

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



×
×
  • Create New...