How are Dog Boxes Shifted?

 

with your hand. its the same as a regular gear box, the gears are just straight cut.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanR &raquo;</TD></TR><TR><TD CLASS="quote">with your hand.</TD></TR></TABLE>

No **** captain obvious.

They arent the same, I read they arent suppose to be shifted slow.

I need someone to elaborate for me.

 

wow, such animosity. sorry for contributing my advice. you can actually shift faster, the gears are stronger so you can jam it into gear. i know someone who had the full quaife gear set and this is what they told me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanR &raquo;</TD></TR><TR><TD CLASS="quote">wow, such animosity. sorry for contributing my advice. you can actually shift faster, the gears are stronger so you can jam it into gear. i know someone who had the full quaife gear set and this is what they told me.</TD></TR></TABLE>

common ryan I knew I had to use my hand to shift

Can it be full throttle shifted or you have to push the clutch in a little?

Double clutch for cruising?

Hard to get in 1st gear? (I dont belive this line.)

 

no clutch needed. just shove it into gear. not sure about how getting started in 1st is. since its for race cars i doubt that 1st is much of a problem.

 

The "dog box" is a setup where the gears are engaged without a syncro. This allows you to shift without the clutch, except in first gear.

 

Due to the nature of engagment, you do have to use a lot of force to get it in gear. Shifts are pretty damn fast though.

&lt;= sucks at shifting the sequential on the FSAE car.

 

"Dog boxes" are so called because instead of sychro rings - that use friction to get gears spinning at the same rate before engagement - they use "dog rings." These are like gears with big ol' ramped teeth that, once they catch, slam together, pulling the gears into engagement.

Whether the gears themselves are straight cut rather than helically ground is an entirely separate issue. Street cars use helical gears primarily because they are quieter and create some thrust, making it easy to set them up. Straight gears can be made with more meat in the teeth so are stronger so they are typically found in racing gearboxes with dog rings.

You can't sneak up on a dog box shift - they need to be poked in very firmly. Once underway, it is possible (and some would say preferable) to shift without using the clutch at all. The clutch is used in typical fashion to get the car moving.

Dog boxes can be shifted with a mechanically linked lever or often times with a pneumatic or hydraulic actuator, controlled by a switch mounted in steering wheel paddle or ring shifters, or in a sequential-style lever.

It is still necessary to match revs when shifting (up or down) but ratio splits on race 'boxes tend to be closer so that task is less obvious. Some manufacturers use "shift-while-flat" electronics that interrupt the ignition for a few microseconds when the lever is moved but it is possible to break even the stoutest box with poor technique.

K

 

and it doesnt last very long..

 

If you've ever ridden a sportbike, that's the type of tranny in question. To shift you just let off the gas slightly and it goes right into the next gear. Very sweet, I wish we'd see more sequential boxes on cars...

I've been told that a non-sychro box on the street is a PITA because it's very hard to go from neutral to first. Lots of ugly grinding and clunking noises.

 

One trick that works with many of them is to blip the throttle, then engage first as the revs drop toward idle.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
and it doesnt last very long..
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That may or may not be completely accurate. A Hewland EGT is going to last a LOT longer behind a 280hp touring car engine than would a stock Honda or VW 'box. Dog rings do wear, however - particularly if used hesitantly.

K

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinister6 &raquo;</TD></TR><TR><TD CLASS="quote">and it doesnt last very long..</TD></TR></TABLE>

If not used properly.

 

I used a straight cut, dog ring gearbox only one when I drove the Derek Daly School formula cars. Shifting up and down with only light alteration of the throttle was a great thing and it was fast. You did need to develop the proper feel for it pretty quick or you will screw it up. I took to it like a kid with a new toy on CHristmas morning but some of the other drivers there (some with more race experience than I including a previous World Challenge driver) never got the hang of it without the clutch.

It is certainly worth noting that this was on a 1000ish lb. formula car with a very close ratio gearbox on a racetrack where you alwasy knew what gear and when to be in whereas a heavier car on the street with wider spaced gearing I expect may be a whole different story. I know Jinx J. had a custom dog ring box in a racing GT5 CRX for a short time and said he loved it.

 

So you shifted without a clutch?

Did'nt let off the power?

Shifted like a theif grabbing a womens purse?

 

My race car has a dog ring Jerico. I don't use the clutch on upshifts but I do on downshifts, although it isn't quite nessasary. You don't *have* to match rev, but if you don't you better wait until deep into the brake zone to do your downshift, although this is a something that should be done anyway...
They don't like to be shifted slow, and, they rule.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paul Machan &raquo;</TD></TR><TR><TD CLASS="quote">They don't like to be shifted slow, and, they rule.
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Out of curiosity, how well do they handle skip-shifting, like going from 4th to 2nd?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Agent Smith &raquo;</TD></TR><TR><TD CLASS="quote">Out of curiosity, how well do they handle skip-shifting, like going from 4th to 2nd?
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From reading, they can take the abuse but going to 4th-2nd but a dog box would hurt the engine more than the tranny?

 

On upshifts, you don't need to use the clutch; however, even on dog boxes, most people will helltoe/revmatch on downshifts -- to be nice.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by C-Zero &raquo;</TD></TR><TR><TD CLASS="quote">So you shifted without a clutch?

Did'nt let off the power?

Shifted like a theif grabbing a womens purse?</TD></TR></TABLE>

Yes, without the clutch except from the stand still on the upshift and without the clutch on the downshift if I was right on my game or with the clutch downshifting if my confidence was maybe off.

Depends on what you call "didn't lift". Yes there was the slightest bit of lift on the upshift but barely more than perceptable because you didn't want the engine to try to free rev higher in between shifts because with an upshift the next gear will cause the revs to be lower and not higher. I would say that it was enough lift to get rid of the acceleration pressure and load and allow the gears enough slack to pull it out of gear willfully instead of yanking it out. A little mechanical sympathy for what needs to happen more than a real rev dropping lift.

I have never stolen a purse before so I don't exactly know. You don't slam it around and manhandle it but you do move positively, quickly and with confidence. Being light, slow and easy doesn't work well. It is a feel that just comes with confidence. The school car that I drove was probably under 150hp so it didn't take that much actual effort, Paul with the big V8 would better know if a tranny on a big engine needs a different touch.

 

Thanks for the info lee.


So whats was the crap about people saying about 1st gear enagement?

 

I can attest that the box behind a GT1 motor is a *little* different than the one that's behind a 150 hp neon motor.

Still, the principle is the same, and there's the bonus that red mist actually makes the shifts go better as opposed to causing a DNF due to a broken cable or some crazy production gearbox sillyness. Too bad I've only gotten to play around driving them and never actually raced anything so equipped.

 

Who makes Honda dog gearkits..?

I have only found one a while ago, and it was custom, and like 7k.

Quaife's only option is their complete universal dog+sequential box. Which is like 30k, and Honda's rotate the wrong way anyway.

You can buy frickin Ford T5 Dog boxes for under 2k, whats the story.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mattjohnston &raquo;</TD></TR><TR><TD CLASS="quote">Who makes Honda dog gearkits..?
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Houseman makes the custom sets that I have heard of. Years ago I was quoted the $5K ballpark.