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I was at the PRI show last week, sitting in the booth with the guys from PPG and John Shepherd. We were talking and the Australians were saying that you could use the rev-limiter to shift a dogbox.

John, myself, nor my boss has ever done it, but we figured we'd trust what they had to say. So we started telling people it could be done.

We get home, and aren't totally convinced. My boss has a helical dogbox in his WRX, so he took it for a spin.

I show up at the shop yesterday, and immediately I'm sitting in the passenger seat.

Holy crap.

Accelerate hard in 1st gear and pull back on the shifter with some authority. It won't pop out of gear. When you hit the rev limiter, you are INSTANTLY in 2nd gear. The boost gauge didn't flutter, the gas pedal pushed down as hard as possible. There was a slight burble as you hit the rev limiter, then a BANG as the rear diff slams the floor behind the rear seats. There isn't a hickup in acceleration whatsoever. It's just pullllll until you let off. It's like a built automatic, but more fun to drive and you can drive it smoothly if you want.

Those Australians weren't kiddin.

We've sold dogboxes to people all over the country. I highly suggest you find someone with one of our dogboxes and ask to go for a ride. At least once, see if you can get them to do it. I giggled like a school girl for like 20 minutes.

Now we need to put a dogbox in our 94 Legacy RHD wagon....

sorry I'm confused. how does the shift light control a gearbox? That is what your saying right?

Shift light? No, I believe he's talking about wrapping the motor all the way out, to where it 'taps' and reaches maximum redline. At that point, it is technically safe to shift. . . So, THROW IT!

I'm so trying this on my NA tranny.

magicmike wrote:sorry I'm confused. how does the shift light control a gearbox? That is what your saying right?

holy jesus, wtf am I talkng about.....this is what happens when you post on only one cup of coffee. sorry i'm a fool

We're with you, Mike. My days start at 4:30 here at work . . . you sometimes have to survive on caffeine!

Yeah I sort of thought the same thing too.....and it's not even early

Would this work with a soft limiter do you think?

this only works in the dogboxes though right? that looks like what he is saying.

Project_Legacy wrote:this only works in the dogboxes though right? that looks like what he is saying.

I wouldn't do it on anything but a dogbox...because you'd probably break the tranny quickly...

It will only work in a dogbox.

Bounce off of a hard rev limit and pull back. Probably won't work on a soft limit.

isnt that clutchless shifting?

Flip_x wrote:isnt that clutchless shifting?

You can shift clutchless on a dogbox in any situation (it's that strong) but this is getting it to basically shift itself.

You normally would clutchless shift by lifting your foot off the gas breifly. I posted a video of me doing it in my car once.

With this, you use the rev-limiter to unload the dogs and all you do is bury your foot on the floor and pull on the shifter. It's badass.

You guys are having too much fun there, as usual!

Wait a sec, the shop has a 94 Legacy RHD?? say what? You like to drop those little gems as if it was nothing, don't ya?

I sent an email to Andrew and the rest of you guys a week ago. Did you see it?

Hope so. I am in Croatia now and struggling with the keyboard. They say Merry Christmas> "Sretan Bozic"

Sam

that is badass. I want to try that. Maybe I should get a spare tranny though...

It probably won't work with a synchronized transmission. If it does, it will definately break something. A dogbox is built for that kind of abuse.

That's really cool

yeah it's pretty simple, the engine hits rev limiter and freewheels for a good 20ms, unloading the transmission enough to slam the dog engagement rings into the next gear.

It's awesome stuff, but you definitely need to build a transmission out of strong shit for it, and strong selector forks too, or you'll break them yanking on the shifter.


I look forward to being able to spend that kind of money on my legacy.

that would be some awesome sh!t to have. if i get serious enough with my car i might just get a dogbox.

Ok at this point it's pretty much a wet dream, but if I can get some of my other projects done I'd HAVE to have a dogbox. What am I looking at for something like a helical dogbox made to take probably no more than 250 hp? I really like to toss my car around now and having a kickass dogbox would definitely be fun. Straight cut would be really badass but probably very annoying after a while.

One of those "other" projects is a new clutch. I'm thinking a wrx light flywheel/pressure plate/and clutch good for said hp. Any thoughts or recommendations? While that's all out I'm more than likely to do the short throw shifter and engine/tranny mounts too.

thanks

A helical dogbox will hold a LOT more than 250hp. Cost is $5400 for the gears, $750 to build the box, plus $100 for misc. install bits, and then whatever fluid you want. Plus shipping. It's totally worth it though.

For a clutch, get an Exedy Stage1. I don't like LW flywheels, so I wouldn't do that bit again.

This old timer has a story. In my last year of high school(1954) I bought a 1930 Model A Ford coupe.

It had a 3-speed non-synchro tranny that required double clutching on both up and down shifts. I'm sure it had square cut teeth.

Learning to drive it was tricky as the accelerator was a mushroom button on the top of rod sticking up through the floor. Problem was that it was very poorly damped and typically when moving off the line it would depress too quickly and do a great lurch which would pull your foot off the accelerator. This caused a sharp deceleration.

The slow down would shove your foot back down on the peddle resulting in another great lurch. This would go on with no little embarassment to a novice whose ego told him he was a terrific driver.

My Dad showed me that next to the throttle peg was a metal platform upon which you kept the left side of your foot firmly planted so that you could roll your foot and delicately depress the accelerator.

Eventually I discovered that there was a point of no forces of acceleration or its opposite when you could do a fast shift without using the clutch.

That's why I like story about dog box shifting on the slack provided by the rev limiter.