PPG Gear, dogbox, and a question

Found this the other day, thought it was cool, learned a few things:




HOWEVER, I was very surprised to hear a PPG employee say that their dogbox setup was 'ok' as a daily driver.

huh? dogbox for a daily driver? 'just get used to it'? Now, I've never driven or even been in a car w/a dogbox, so the keyboard rally-ist I am has only ever read others experiences/thoughts on this.

So what I've read is that 'yup, dogbox is fun on the street' to 'dogbox setups need to get rebuilt every 500 miles'

I figured the former was just full of shit, but then I see this PPG guy saying the same thing. Rally Anarchy is great for a no-bullshit answer, so whatchya got?


(and noooo, not planning on doing anything like this....just want to know.....'and knowing is half the battle')

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Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/



Edited 1 time(s). Last edit at 05/16/2008 11:59AM by Jon Burke.

About how much is ford type 9 or world class t5 with straight cut gears and dog engagement gonna run? Assuming you've got a stock box as a core.

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Michael LeCompte

Jon Burke Wrote:
-------------------------------------------------------
> Found this the other day, thought it was cool,
> learned a few things:
>
>
> HOWEVER, I was very surprised to hear a PPG
> employee say that their dogbox setup was 'ok' as a
> daily driver.
>
> huh? dogbox for a daily driver? 'just get used
> to it'? Now, I've never driven or even been in a
> car w/a dogbox, so the keyboard rally-ist I am has
> only ever read others experiences/thoughts on
> this.
>
> So what I've read is that 'yup, dogbox is fun on
> the street' to 'dogbox setups need to get rebuilt
> every 500 miles'
>
> I figured the former was just full of shit, but
> then I see this PPG guy saying the same thing.
> Rally Anarchy is great for a no-bullshit answer,
> so whatchya got?
>


I don't believe it. All it takes is one bad change and you can wreck a dog. Here is want Hewland has to say about shifting dog-boxes. The condensed version is that without computer intervention you better be really good to make one last.

-Tim

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Methods of Changing Gear.

William Hewland By William Hewland.
July 2000

The following is some info regarding shifting gear and face dog wear. I am in the fortunate position where I have a good amount of knowledge on the subject, as I understand the mechanical side and the user (driver) side equally well.

N.B. For succesful gear shifting, remember that it is critical to ensure that all mechanical elements between the drivers hand and the dog faces are in good order and properly set. This includes the gear linkage in the chassis!

Successful up-shifting, (defined as fast and non dog-damaging) will be achieved by fully moving the dog ring as rapidly as possible from one gear to the next, preferably with the engine's driving load removed until the shift is completed. (The opposite is true of a synchromesh gearbox as used in passenger cars, where slow movement helps). It should be remembered that it is not possible to damage the dogs when fully engaged (in gear). The damage can only take place when initiating contact during a shift, (the `danger zone`) therefore this element must be made as short as possible. If a driver moves the gear lever slowly, or if the linkage is not rigid and effective, dog wear will occur. We always recommend lightweight yet solid rod linkage, not cables ideally.

I list below the different methods of up-shifting that are used in racing most commonly. The best at the top, the worst at the bottom:

Automated (semi automated). The movement of the dog ring is powered and the engine is cut / re-instated in a co-ordinated manner. Gear-shifts take milliseconds. This system produces zero dog wear when set up well. It is not applicable to most cars, but it illustrates that speed of shift is a good thing.

Manual with engine cut. This system is almost as good as an automated one as long as the driver pulls the lever very quickly. Again it is not applicable to many cars, but it illustrates that speed of shift is a good thing. A `cheat` version of this is to shift on the engine rev limiter, which can work well. With this system it is especially important to move the lever ultra fast, otherwise the engine will be reinstated during partial dog engagement, causing damage. The damage can usually be felt by the driver.

Manual.
Best method: With no assistance from the engine management, the driver must lift off the throttle sufficiently to allow the dog ring to be pulled out of engagement. He should then stay off the throttle long enough to allow the dog ring to engage with the next gear. In practice, the driver can move the gear lever faster than he can move his foot off and back on to the throttle. Therefore the effective method is to apply load to the gear lever with your hand and then lift the throttle foot off and back on to the pedal as fast as physically possible. In lifting your foot, the loaded gear lever will almost involuntarily flick to the next gear before the foot is re-applied to the throttle.
Another method is to load the gear lever with your hand, stay flat on the throttle and dab the clutch to release the dog ring. The overall effect on the gear shift is similar to the above method, but clutch wear may become a big issue.
The worst method (most destructive and definitely slowest) is to attempt to change gear in a `passenger car / synchromesh` way, i.e. lifting off the throttle, dipping the clutch, moving the gear lever, letting the clutch up and re-instating the throttle. The method causes unnecessary clutch wear, does absolutely nothing to help come out of gear and usually causes dog wear whilst engaging the next gear. This wear is due to several reasons. Firstly, it is impossible for a driver to co-ordinate the complicated sequence of all five physical movements accurately. Consequently the engagement dogs often find themselves engaging whilst the throttle is applied. The lever is usually pulled more slowly as it was not pre-loaded, lengthening the `danger zone`.

William HewlandSuccessful down-shifting, has similar rules applied regarding speed of shift. Unloading the dogs is done in the opposite manner obviously. Whilst braking, the dogs must be unloaded by either touching the throttle pedal or- my preferred method- by dipping the clutch. However, one sharp dab of clutch or throttle is appropriate per shift. Continued pressure on either will cause dog damage for different reasons. `Blipping the throttle` just before engagement is advisable if the rev drops between gears are over 1300 rpm, as this will aid engagement and stabilise the car.

TOP TIP for ease of downshifting: Make the downshifts as late as possible in your braking zone (i.e. at lower road speed), because the rev drops between each gear are then lower. So many drivers make the mistake of downshifting as soon as they begin braking, causing gearbox wear, engine damage and `disruption` to the driving wheels.

This is a subject which can be much expanded on, but I feel that these are the basics, which I hope are of use.


William Hewland

Having some contact with the dogbox in John's fire breathing monster, I can't imagine such a thing for street use. The first and primary dealbreaker is, there you sit in neutral. Want 1st? Push clutch in and BANG into first with accompanying wheelchirp. This to me would get real old real quick.

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Jay Woodward
Snohomish, WA
'90 Mazdog Frankenprotege
Chronologically, 46...

I know plenty people who run dogboxes on the street. One let his girlfriend drive it on regular occasions. You can drive better than some 20 year old bimbo CAN'T YOU? (I am not counting motorcycles or tractor-trailer rigs)

When you're on the street, you're not racin', so you can do things like wait on the trans or even do a proper double-clutch.

And what did people do in the decades before synchromesh?

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

see? here we go again.

how about this.....I assume not all dogboxes are created equal....is it possible that PPG's design and materials (I assume state-of-the-art) have made it possible for their dogbox engagement to be easier and less prone to wear with manual shifting?

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Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

I is too iggerant to anser dat. It's entirely possible though that the Nascar-spec Jericho I'm referring to is somewhat less civilized than PPG's or the ones Pete's buddies are driving around with... I'm still waiting for Mr. Lane to find this thread and chime in.

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Jay Woodward
Snohomish, WA
'90 Mazdog Frankenprotege
Chronologically, 46...

Jon,
Watched the video, 2 things:
The spokesman had a weird Bart Simpson doo, I hate those.
And listening, I kept wondering when the mop pitch would start, sounded like HSN.

Anyway, nothing is unbreakable, ask PatR. He said he's broken them all and I believe him. The 5-speed has some design problems and parts won't cure them.

I haven't driven a dogbox on the street but I can't see how one couldn't be.
It'd be a PITA, but if you had to, I'd work.

Longevity starts with super close gear steps and a good technique.
Wider spacing makes goofs easier.

My experience has been with super tall 1st gears and having a friendly push-off is a great help for selecting the gear and saving the clutch.

I used to have 2 sets of dogs and kept one set ready to go, usually after a season.
I could flip 'em for more life.

I've had teammates who needed dogs after every session!

On a dorky machinist note I loved the video referring to their state of the art machines and then cutting to a shot of a 1980's machining center. Granted they make simple shapes and '80s/early 90's (can't remember exactly which year they changed the paint colors) vintage Mori's are great machines...but they are nowhere near modern.

Tim

What I dislike about the dogbox is that I can't sit on the clutch every time you move 14 feet in line as another car goes into a control and you are backed up in a regroup for 15 minutes. That is 15 times I go into neutral and then BANG back down to first. All the while covering about 50 yards of some parking lot at the end of a service.

Same at stoplights. Same (usually 5-10 times) at every stage ATC. Driving in downtown Portland to go to the prerally shindig was fun!

Makes me cringe sometimes, but the gears hold up well, and I have a local shop that will reweld and machine the dogs for me. The dogrings are made of harder steel, so they last longer than the gears.

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Lurch
Eric Burmeister
The west coast...of Michigan