B5254T4, I'm hoping with the shorter sessions in the time attack format and not needing to launch the car the reduced shock loads will extend the life of the box. We will just have to test it and see what it can handle. What application are you running your sequential setup in?

Gernby, the shift times help but I expect it's the straight cut gears and optimized gearing that will make the biggest improvement in lap times.

 

Do straight cut gears make for less drivetrain loss? Is it easy tol change the gearing for different tracks, or does this gearbox just automatically have geaing that's better for road courses?

 

WOW

 

How about no more having to push the clutch, and shifting speed faster than just about anyone could manage, lap after lap, all day long?

 

Your concerns are valid arguments, however from his other build threads, it's clear he's building a "no expenses spared" car. Sure $10K could possibly be spent in other ways to shave time, but I'd be willing to wager that if you can name it, he's already got that base covered. The car has been stripped and caged, has bodywork, suspension and wheels, and the engine will be turboed (as well as having other work, I'm sure). That covers everything except perhaps framework and transmission. I'm just generalizing of course, but what else would you suggest at that point?

 

A V6.

 

Awesome.

 

if we could have had this as an option for even say $1000 more from the factory, I still would have passed. this only belongs in a race car. takes the fun out of daily driving.

I had a DSG in my last car (2008 GTI) and trust me, the allure of a transmission shifting really fast for you dies quickly. the DSG is considered one of the best sequential gearboxes you can get. Everyone else copied them.

 

Yes. We have helical cut gears to quiet down the gear train - under rotation though, helical cut gears have "thrust" forces.. it pushes the shaft front to back as the gear turns - with straight cut gears, you have only torsion on the shaft so theres less movement there. The thrust forces do create losses so straight cut gears will actually give you more pwoer to the floor. Straight cut gears also have better power holding capacity.

 

It will handle the abuse, we used a BTCC spec Tractive Seq in a 600hp turbo car and died on us first day.
The gears were very thin and better suited for low torque, stupid of us but didn't know better.
Right now we're using Sellhom for the first time (pic I posted) and that tranny is good for 1500-2000hp.

Quaife is really good, I bet this gearbox will shave off a few sec and on top of that easy/cheap to change gear ratio if needed.