It looks like these guys are definitely looking out for us rally guys, and not just aiming on the corporate events.

http://up2mtns.blogspot.com/2010/12/dirtfish-dogbox.html

Want to thrash a dogbox for a few hours, just to learn how? Apparently you can at DirtFish. Really cool for them!

Seems backwards from what I was told on how to drive a dogbox. Curious what others have heard on how to drive them.

I was told by a couple people that if you're out to lessen the wear you should clutch on the downshifts. On the upshift since the revs are wanting to fall as you bang another gear that it already lessens some of the wear. Regardless of clutch or not, it seems the faster/harder you bang gears, the more the gearbox likes it under racing conditions.

Dave

That sounds different than my experience with non syncromesh and dog drive gear boxes.

I spent a bit of time testing a Nissan 240RS factory rally car in Kenya. The dogs in this transmission must have been worn because it only needed a "blip" on the throttle to change gears.

On the up shift you needed to take the pressure off of the lugs by reducing the throttle some. Then it was only a matter of sharply engaging the next gear. This was difficult for me to learn. Any hesitation on the up shift would result in getting stuck in neutral.

Down shifting was easy. Reduce throttle to take the pressure off of the lugs so that you could disengage the gear. Give the throttle a blip and mash into the next lower gear. This sequence occurred very quickly.

I know very little about Subarus but the description sounds backwards to me.

---

Robert.

"You are way too normal to be on Rally Anarchy." Eddie Fiorelli.

This seems VERY familiar to shifting motorcycles. Well I guess they are the same style of transmission...
Slight lift on upshift to unload the gears/dogs, or use an ignition cut. The key on older bikes was to slam it into gear or else you'd find neutral between gears, not much of a problem on newer Japanese bikes.
Down shifting is just a blip and jab with the foot. On pavement I like to use just a hint of clutch to keep the back end from coming out, unless I want the that

Could someone add a cush drive or a rubber damper to limit drive train shocks?
It seems that would allow more abusive shifting with less wear.

Tim, thanks for reposting my link over here...you beat me to it!

Quote
DaveK
Seems backwards from what I was told on how to drive a dogbox. Curious what others have heard on how to drive them.

I was told by a couple people that if you're out to lessen the wear you should clutch on the downshifts. On the upshift since the revs are wanting to fall as you bang another gear that it already lessens some of the wear. Regardless of clutch or not, it seems the faster/harder you bang gears, the more the gearbox likes it under racing conditions.

Dave

I was told/understood the same thing, but under the conditions I described it makes sense, here's why:

For downshifting, this is under HEAVY braking (think racing conditions).....so you're trailbraking/threshhold braking, so if you don't clutch in, the wheels are almost locked up and they slow down the engine faster with the drivetrain fully connected (no clutch) so the gears are already moving fairly slowly and its just easier to pop in/out of gears at that point.

Its definitely a 'feeling' kind of thing...and I messed it up plenty of times. and on tarmac, with stickier tires that keep the drivetrain connected to the road, I think it would be a different technique.


If you're not HARD on the brake, then yes.....clutch and a blip of the throttle to rev match.


For upshifting, its simply less drive train shock to jab the clutch. When you upshift, unless you really wait for the revs to fall and 100% match, there's still a delta between the gears. If you shift w/o the clutch, the force of that delta is higher because its still connected to the engine and its all absorbed by just the gears as engine revs down to match. If you hit the clutch, any force from the engine is removed and then its just the weight of the rotating mass of the gearset, and then the clutch takes the rest of it when re-engaged.


here's Pat Richard demonstrating it better than I ever could.

No problem, Jon! I'm really liking the stories I've heard about Dirtfish so far, and the responses I've gotten from the guys running it when I've talked with them! Happy to share! And its a good story

Is your dog engagement box a 5 or 6 speed?

And did you break a 2nd in a 5mt or a 6mt?

And, can I drive it if we ever end up an the same race???! Hehe

---

Brap Brap.

Quote
biggreen96
Is your dog engagement box a 5 or 6 speed?

And did you break a 2nd in a 5mt or a 6mt?

And, can I drive it if we ever end up an the same race???! Hehe

after a lot of research/consideration, I'm staying with the 5speed platform

I broke 2nd gear in my stock WRX 5mt. I had over 117K miles on it, so I wasn't too surprised when it happened.

Can you drive it? Sure! but you break it, you buy it!

Quote
Jon Burke
Can you drive it? Sure! but you break it, you buy it!

Does that go for everyone you know?

I like the part where he describes a Modena dogbox as "top of the line, world class". That was pretty funny, gave me a chuckle.

Quote
Jon Burke
I was told/understood the same thing, but under the conditions I described it makes sense, here's why:

For downshifting, this is under HEAVY braking (think racing conditions).....so you're trailbraking/threshhold braking, so if you don't clutch in, the wheels are almost locked up and they slow down the engine faster with the drivetrain fully connected (no clutch) so the gears are already moving fairly slowly and its just easier to pop in/out of gears at that point.

Gotcha, makes a bit more sense now. On the rev-drop thing, I suppose my car is slightly different as I'm not running a restrictor, so my powerband is much higher in the rev range. When I'm dropping gears if I'm doing it right my car shouldn't really dip much below 5000rpm whereas on a restricted car with antilag, I'll bet you guys are closer to 2500rpm.

If I can find the $$ to get my box repaired, I'll have to mess around with driving it this way too.

Thanks,

Dave

Quote
Doivi Clarkinen
I like the part where he describes a Modena dogbox as "top of the line, world class". That was pretty funny, gave me a chuckle.

hey, it is to me!!!

I knew one of you guys would give me crap for that, haha...I know, I know, its not a Hollinger or $50K tranny, but relatively speaking, its pretty damned nice. Even nicer that Frank at Modena gave me a screaming deal on it so I could even consider buying it and still afford to actually run events this year.

ok, so maybe I threw a LITTLE marketing hype in there guilty as charged.



Edited 1 time(s). Last edit at 12/27/2010 01:48PM by Jon Burke.

Although it was cool of them to allow you to bang around in their car a while to gain some hands on experience(and a hardon), I think you've received some common misinformation regarding the dogbox and it's operation. I'm curious if your instructor has ever driven in anger, built, or maintained a dogbox(or dogboxes) of his own or for other drivers over the course of many seasons. If not he's probably the last guy you should be getting advice from. He might be a good entry level driving instructor but he's most likely never sat with many different drivers, experienced the different driving/shift styles, and then personally torn down the box to see what has happened... much less 100's of times using different boxes.

First off I believe their cars are equipped with the KAPS dogchange system which has a very unique dog design so the feel and operation will be entirely different in your box. In the KAPS box the surfaces that can collide (zing/buzz/grind) during a missed shift are NOT the surfaces that hold the gear in as a conventional box like the Modena. So you can zing the shit out of them(KAPS) without too much damage, the KAPS is fragile in other ways. Every single dogbox manufacture has a slighly different dog profile and use a different amount of dogs, so they all feel different. In general the fewer the dogs the faster the shift and the easier they are to mesh, but it comes at a cost of dog surface area so they are more fragile.

Best advice I can give you is; Once moving never-ever use the clutch, that will do more damage as the entire assembly will be unloaded and although it might not make noise and balk you will be skipping dogs like crazy (can't hear or feel if the clutch is in) and once the dogs find their pocket they will bounce back and forth hammering them to shit before taking a drive load. The entire point of dogchange is seamless power transfer via CLUTCHLESS shifting, they are designed to be used clutchless. A bonus is it frees up your left foot so you can be on the brakes 99% of the time to keep the engine/turbo and more so, the diffs loaded up. To shift all you need to do is apply pressure to the gear lever and blip the throttle 10-15%, be fast/swift with the gearlever, not forceful. Same up or down, think swift and deliberate. I've data logged for several years a number of cars/drivers and the ones that did the least box damage blipped the throttle the least, a consistent 10-15% is all it takes. The drivers that were doing 100% lift a tad more damage and the guys clutching it were trashing the box every event.

I’m assuming your gearbox is a wrx 5spd, whatever you do don’t reuse the case that had the failure, it’s effed toss it as once a gear breaks the missing teeth allow the remaining teeth to climb/bind each other, this will make the shafts deflect and damage the case. The 5spd case is barely strong enough for stock use and the brgs bores will for sure be elongated after a gear breaks. Find a “seasoned” case that has never seen a failure.

Before you even put it together take a look at the gears and dogs, pair them up and make sure the machining is dead on. Put the dog ring to the matching gear and inspect the dogs and their mesh, make sure when you load them all the dogs are touching equally… I’ve seen the dogs not clocked, so out of the 4-5-6 dogs only half of them are actually touching. If they do not all touch at the same time send them back. I’ve also seen on the Modena and the PPG the 5th gears dogs are on a ring/sleeve that is welded to the gear then the weld machined flat (why I have no idea). If you have one like this inspect it to make sure the weld was not ground all the way off. One way to tell is to mix a table spoon of Drano into a half cup of water, use a small paint brush to paint the paste onto the welded area and let it sit for 5 minutes, rince it off with water and you will be able to see the filler metal and the base material, see of it’s a full weld or if it’s only have way.

When you set up the box, make the gearshafts as loose as you can in the preload range so they spin as freely as possible. Also most important is the make damn sure you set it up so that when the fork moves between gears you get equal engagement in both directions, you might see that in one direction you get full dog purchase, in the other you don’t. Subaru makes different rails with the fork position adjusted to center the ring between the gears equally.

Dave had a chuckle as he like me has played paddycake a time or two with a Modena, not the best by any means but it will work if you set it up and drive it correctly. As everything in life, you get what you pay for, machine time, material, quality inspection. In my experience the 4 worst (entry level) dogboxes are Quaife, Modena, Albins and PPG. All three companies use material one step up from cream cheese, real soft steel so if you zing a dog ring once there will be nothing left of it. The best dogboxes are KAPS, BRENA Clemente, and Drenth, not the prettiest finished product but dead nuts machining and best quality materials available.



Edited 1 time(s). Last edit at 12/27/2010 02:21PM by Gravel Spray.

Quote
Gravel Spray
As everything in life, you get what you pay for and in my experience the 3 worst (entry level) dogboxes are Quaife, Modena and PPG. All three companies use material one step up from cream cheese, real soft steel so if you zing a dog ring once there will be nothing left of it. The best dogboxes are KAPS, BRENA Clemente, and Drenth, not the prettiest finished product but dead nuts machining and best quality materials available.

Thanks for sharing that info relating datalogging to gearbox wear. Really interesting!

Was just curious if you guys have worked with Hollinger ones and where they'd rate as they didn't make the best or worst list.

Dave

Quote
Gravel Spray
Although it was cool of them to allow you to bang around in their car a while to gain some hands on experience(and a hardon), I think you've received some common misinformation regarding the dogbox and it's operation. I'm curious if your instructor has ever driven in anger, built, or maintained a dogbox(or dogboxes) of his own or for other drivers over the course of many seasons. If not he's probably the last guy you should be getting advice from. He might be a good entry level driving instructor but he's most likely never sat with many different drivers, experienced the different driving/shift styles, and then personally torn down the box to see what has happened... much less 100's of times using different boxes.

First off I believe their cars are equipped with the KAPS dogchange system which has a very unique dog design so the feel and operation will be entirely different in your box. In the KAPS box the surfaces that can collide (zing/buzz/grind) during a missed shift are NOT the surfaces that hold the gear in as a conventional box like the Modena. So you can zing the shit out of them(KAPS) without too much damage, the KAPS is fragile in other ways. Every single dogbox manufacture has a slighly different dog profile and use a different amount of dogs, so they all feel different. In general the fewer the dogs the faster the shift and the easier they are to mesh, but it comes at a cost of dog surface area so they are more fragile.

Best advice I can give you is; Once moving never-ever use the clutch, that will do more damage as the entire assembly will be unloaded and although it might not make noise and balk you will be skipping dogs like crazy (can't hear or feel if the clutch is in) and once the dogs find their pocket they will bounce back and forth hammering them to shit before taking a drive load. The entire point of dogchange is seamless power transfer via CLUTCHLESS shifting, they are designed to be used clutchless. A bonus is it frees up your left foot so you can be on the brakes 99% of the time to keep the engine/turbo and more so, the diffs loaded up. To shift all you need to do is apply pressure to the gear lever and blip the throttle 10-15%, be fast/swift with the gearlever, not forceful. Same up or down, think swift and deliberate. I've data logged for several years a number of cars/drivers and the ones that did the least box damage blipped the throttle the least, a consistent 10-15% is all it takes. The drivers that were doing 100% lift a tad more damage and the guys clutching it were trashing the box every event.

I’m assuming your gearbox is a wrx 5spd, whatever you do don’t reuse the case that had the failure, it’s effed toss it as once a gear breaks the missing teeth allow the remaining teeth to climb/bind each other, this will make the shafts deflect and damage the case. The 5spd case is barely strong enough for stock use and the brgs bores will for sure be elongated after a gear breaks. Find a “seasoned” case that has never seen a failure.

Before you even put it together take a look at the gears and dogs, pair them up and make sure the machining is dead on. Put the dog ring to the matching gear and inspect the dogs and their mesh, make sure when you load them all the dogs are touching equally… I’ve seen the dogs not clocked, so out of the 4-5-6 dogs only half of them are actually touching. If they do not all touch at the same time send them back. I’ve also seen on the Modena and the PPG the 5th gears dogs are on a ring/sleeve that is welded to the gear then the weld machined flat (why I have no idea). If you have one like this inspect it to make sure the weld was not ground all the way off. One way to tell is to mix a table spoon of Drano into a half cup of water, use a small paint brush to paint the paste onto the welded area and let it sit for 5 minutes, rince it off with water and you will be able to see the filler metal and the base material, see of it’s a full weld or if it’s only have way.

When you set up the box, make the gearshafts as loose as you can in the preload range so they spin as freely as possible. Also most important is the make damn sure you set it up so that when the fork moves between gears you get equal engagement in both directions, you might see that in one direction you get full dog purchase, in the other you don’t. Subaru makes different rails with the fork position adjusted to center the ring between the gears equally.

Dave had a chuckle as he like me has played paddycake a time or two with a Modena, not the best by any means but it will work if you set it up and drive it correctly. As everything in life, you get what you pay for, machine time, material, quality inspection. In my experience the 4 worst (entry level) dogboxes are Quaife, Modena, Albins and PPG. All three companies use material one step up from cream cheese, real soft steel so if you zing a dog ring once there will be nothing left of it. The best dogboxes are KAPS, BRENA Clemente, and Drenth, not the prettiest finished product but dead nuts machining and best quality materials available.

Thanks for the contribution Pete! Great information for sure!

What would you suggest for checking the engagement and making sure the dogs all touch? Plastigauge or similar?