Desyncronizing a subie 5 speed

[benebob]

Has anybody done it? Are the parts readily available?

[dynomatt]

Do you mean removing them altogether, or converting them to a dog box?

[BAC5.2]

I'm not sure why you would want to. It can be done, but it won't be pretty. It will NEVER go into gear, and it WILL break. The design of the stock gears and shift collars are not conducive to quick shifts without syncronizers. There are about 70 dog teeth on the collar and on the gear. There is no margin for error on shifting if you had no syncros. So you remove the stock syncro and unless things are going EXACTLY the right speed you aren't getting into gear. Even 1 RPM makes the difference.

If you are interested in a dogbox, shoot me a PM. We have PPG Straight and helical cut dog engagement gears in stock. Gearsets designed from the getgo to be shifted as fast as an automatic.

Phil

[benebob]

Yeah, just thinking about a dog box. Not in a hurry as we aren't even 3 pedal yet but I need to plan ahead price wise (not a clue on cost). I know some trannies you can buy replacement gears and all that are made for it or can go the machined route. Just figuring out which would need to be done for a subie 5 speed.

[dynomatt]

You'll get a few naysayers along soon no doubt (or at least you do in the other forums I'm a part of).

I've driven a few cars with dog boxes.

On the road, as a daily driver, they are not very good.

However, as a competition vehicle, they are excellent. I've rallied with dog boxes in the last two cars, and they are excellent.

As to brands, I can highly recommend the PPG stuff. However, they are not as flexible on ratios and, given your car is a race car, you'd want to have a long look at ratios.

The other option that I've used is Albins (www.albinsgear.com.au). They do a really good ratio set which has a 2.69 1st gear up to a 1:1 fifth using the 4.11 diff ratios. This would be perfect.

Having said that, I've gone down the path of a six speed for mine. The ratios aren't as tight, but the inherent strength (offset a little by the extra weight) of the 6 speed makes it a longer term, lower cost option.

Dogboxes have to be rebuilt same as synchro boxes. The dogs do wear, and when they were it becomes like a worn synchro, so selecting gears is hard. But like synchro boxes, dog wear is related to how the box is used. Jam gears in fast, with no regard for rev-matching, and the dogs will wear quicker...same as synchros. However, dog rings are often part of the gear, so replacement sometimes means new gears, rather than just synchros.

If you're looking for recommendations, what's your budget? That often determines what options you've got. If you're just after closer ratios, then any of the JDM STi boxes (particularly the RA ones if you can find them) are a good choice. They aren't made of glass, it's just they won't last as long as the 6 speeds.

Let me know if you want more info.

Matt

[benebob]

Thanks man,
weight is more of an issue for us as our minimum is 2400 and most cars in our class can get down to the 2200 range (we have a 10% awd penalty as it is). Plus $3500+ for a 6 speed vs $35 for a 5 speed makes it an obvious choice in my opinion.

[dynomatt]

Ahhh...it's a budget thing then.

$35 for a 5 speed? damn that's cheap.

If that's the case, don't pursue a dog box. It will cost you heaps to buy and heaps to maintain.

If you can keep a 5 speed going, and replace them for $35 then you're on a winner...no further questions required!!

Matt

[benebob]

Originally Posted by dynomatt

Ahhh...it's a budget thing then.

$35 for a 5 speed? damn that's cheap.

If that's the case, don't pursue a dog box. It will cost you heaps to buy and heaps to maintain.

If you can keep a 5 speed going, and replace them for $35 then you're on a winner...no further questions required!!

Matt

Yip local pull a part is a nice thing to have! Ah but that's why I'm looking now. Its definately years away but I don't have a huge influx of cash so I need to think on the 5 year plan.

[BAC5.2]

Driving a dogbox is not nearly as uncomfortable as the general public would like to think.

They can, and are, driven daily. I've got one in my other car. I drive it often.

Rebuild time and maintainence also aren't as often as some people would like you to think. We had the same helical dogbox in a professional time-attack car for 4 years. That's 4 years of 680whp and 10 second drag passes. It's the most abused car we've ever seen. We recently replaced it with a straight cut dogbox, to take advantage of the gear ratios. When we tore it down, it looked fantastic. A little heat wear, but no damage to the rings or the dog teeth.

There is the potential for wear if you are unfamiliar with driving a dogbox, but once you know what you are doing, you should have no issues. Shift fast, shift hard, and enjoy it.

The first clutchless, wide-open-throttle shift I did with my car, all 4 tires broke loose and the car jumped sideways a few feet. It's an experience I highly recommend to everyone who enjoys fast cars.