ctdrftna

iTrader: (1)

With me on the verge of rebuilding my 6spd. I want to upgrade from synchromesh to dog engagment . To clear up a few normal questions.

NO this will not increase gear strength

YES this can be streetable if driven properly

YES this is more to maintain in the long run. You will not get 100k out of it like synchro, hence why this is in race forum.

This will help the shift ability of the transmission and eliminate mis shifts. Enable quicker shifting.

You still have to clutch, although clutchless can be done it greatly reduces the longevity of the gears.

I see it being a worthy up grade for not much, about the same price of buying new hubs and sliders and synchros.


Here is the catch. Liberty Gears only offers this for rx7 applications. They would need to see interest in it to do it to a Miata, otherwise it would be one off and cost more. I would just like to know if this is something you guys would want.

Here are some links

http://www.libertysgears.com/faceplate-proshift.htm

Some good reviews and good pics
http://honda-tech.com/showthread.php?t=2511846

http://www.youtube.com/watch?v=ArInujbVYU8&feature=youtube_gdata_player

This is a video of a t-56 faceplated on the street

Savington

iTrader: (31)

Seems like a lighter clutch is a cheaper, easier, and more reliable way to achieve the exact same goals. With my twin-disc, I can shift a stock-synchro 6-speed in <150ms.

Build a 6-speed gearset that's 50% stronger than the factory part and I'll be first in line.

ctdrftna

iTrader: (1)

Well that's another question I have is what seems to break in these things. I would rather see upgraded parts for our transmissions. Then swapping some other stock box in. Im going off my experiences. I would like something that is effortless to shift. I have to up shift mid-drift(no bashing stay on topic) and dog engagment would make that a lot easier. I have a fidanza 8lb and a act 6 puck solid

Savington

iTrader: (31)

My clutch/flywheel has 70% less rotating inertia than yours does. Your problem isn't the gearbox - it's your heavy clutch/flywheel combo.

Check out the 5-6 upshift at 3:30 in this video - I just can't see any way to shift the car much faster than that (at least when a clutch pedal is still involved).

hustler

iTrader: (6)

Kitty engagement > stupid dogs

ctdrftna

iTrader: (1)

I can totally understand the clutch after looking at 949's twin disk, I'm assuming this is what you have. Why did you choose the twin over the single ceramic ? how much tq are you running through it? I have just under 290 ftlbs to the wheels. So the single ceramic would fit my application.

FatKao

The 949 clutch is magic. The only real limit on shift speed is how quickly you can move your arm.

Savington

iTrader: (31)

I've got a ceramic twin because I never wanted to buy another clutch, regardless of my goals. I was putting ~300wtq through it last year, and I expect to do quite a bit more than that once the car is running for the winter record-setting season here in CA - enough that I may exceed the capacity of the single ceramic.

Rover will get a single organic disc at some point - I hate how slowly I have to shift that car (9lb Fidanza and an ACT HD street clutch).

ctdrftna

iTrader: (1)

well i still need to rebuild my tranny. Not sure if i will still go after the faceplated gears and have them made one-off but sounds like the clutch is a worth while investment. common sense says to go ceramic twin just because my motor can handle a **** load more power than im making and like you said, its the last clutch i will buy. but then the hardcore race car enthusiast inside of me says to do the single ceramic cause it meets my current tq and is lightest.

Leafy

iTrader: (1)

Now if it was a 5 speed gearset to hold 350ftlb of torque I'd be interested.

Why is this dog box different than normal ones though? Normal ones wear out faster when you use the clutch to shift, you're just supposed to either tap the clutch or just lift out of the throttle for a second with a normal dog engagement. Letting the input shaft spin down like synchro engagement is bad for dogs.

ctdrftna

iTrader: (1)

It's no different, it's just modifying your stock gears to be dog engagment

AkaZero

iTrader: (1)

I slam through gears fast in the stock setup (5 spd).
It's more technique than hardware I think, lighter flywheel makes it easier.

And I thought the whole point of a dog box was for stronger straight cut gears?

ctdrftna

iTrader: (1)

you can have straight cut gears and still have synchromesh, you can have helical dog, while straight cut is stronger, its louder. sure you can always say that its your technique thats wrong. All the dog engagement does is oper up the engagement window between gears, its a fool proof system so that you nearly eliminate any chance of missing. I can see that there is no support for this here, this is a very very common modification in drag racing, i guess not so much with road racing