bazeng
(work in progress)
10/09/10 06:43 PM
Dog box driving tips wanted!

Hello there! I know this board had a few guys out there with dog boxes. I'm at the start of a huge learning curve as my vr4 now utilises one.

Any tips? I've read heaps online and watched a bunch of videos on youtube already. I've put them to practice and so far so good.

Basically I've gathered :
- double clutch going up gear with normal driving (i haven't attempted a normal shift yet, will this be ok?)
- flat shift at high revs works (pre load shifter, foot off gas, shifter goes into next gear and foot back on gas. Now should this be violent on engagement or should it be smooth?)
- down shift rev matching + double clutching. (i can get it to down shift nicely only if prefecty matched. Is double clutching necessary?)

So basically I would like to know of the above methods can be improved and if there are any other methods available?

what I've tried and didn't work so well:
- Flat shift down gear. It worked but it unsettled the cars motion.
- down shift without rev matching. Lots of grinding of dogs.
- shifting up slowly, lots of crunching.
- flat shift at low rpm/ high load, very big thud but goes into gear.

It is a whole new driving experience. Makes manual synchro driving feel like auto.

Feed back appreciated!


toybreaker
(it's peace of mind at 100 mph plus)
10/10/10 09:17 PM
Re: Dog box driving tips wanted!

You gotta wanna ...

That's the whole thing with dog boxes.

Once you start the shift, finish it.

Pausing a half a schosche on the way up, and double clutching (rev matching in nuetral clutch out) on the way down will give the best results.

Just visualise what the gears are doing in the box and try and match the engine and gearset speeds up before trying the shift will become second nature with time/practice.

Shifting up is all about letting the revs drop to where the next ratio just "snicks" in.

Shifting down is all about rev matching to get the engine and gearset turning the correct rpm for the box to slide into the lower gear.

The key is to match everything up the best you can and then firmly make the shift. If you let it skip along the dog edges, the sharp edges of the dogs will round off, making clean shifts progressively more difficult as the edges become worn/damaged.

Don't "force" it, just get the speeds right and it'll snick into gear every time when shifted firmly.

You'll get a feel for it fairly quickly.

Good luck, and please post a video of you bangin gears!


1badgvr4
(not even the right model )
10/10/10 11:00 PM
Re: Dog box driving tips wanted!

BAM!

bazeng
(work in progress)
10/11/10 12:09 AM
Re: Dog box driving tips wanted!

Thanks for the input!

As for that PPG video, it is good but it doesn't describe in technical detail how/what/why it needs to be done.

I noticed that there are so many styles out there of downshifting especially.
Some use left foot brake while tapping gas to down shift, others just heel / toe rev match. Some just straight slam.

What I want is detailed details..

I think at the moment it is really all about practice.

Double clutching up when on the street
Flat shift up when racing

rev match + double clutch down when on the street
rev match w/o clutch when racing

I guess I have to get used to what rev to match at in which gear etc etc.

I'll have vids up for you guys hopefully.
There really isn't anything like flatshifting and having the galant wipers come on with every shift! lol


1badgvr4
(not even the right model )
10/11/10 12:31 AM
Re: Dog box driving tips wanted!

Dont see the need for double clutching when upshifting. Speaking with subi guys that have em the best thing to do is drive it like a normal gearbox just shift like you mean it. Meaning dont slam it just make sure your ready to stick it in the gear your going to. Missing shifs will sharpen the edges of the dogs snd make it harder for you to get in gear.

belize1334
(well bread and nobly conceived)
10/11/10 01:59 AM
Re: Dog box driving tips wanted!

I've never driven a dog-box but I have driven semi tractors which have no synchros since they'd only wear out after 500,000 miles.

I think of the shift as having three distinct actions.

1) You move into neutral
2) You get the input shaft spinning at the appropriate speed so that it matches the rotation speed of the desired gear
3) You move from neutral into the desired gear

We'll start by thinking about the necessary conditions to get the trans into gear and then work backwards to engineer a procedure to prepare those conditions. Now, there are subtleties to how you do this and they depend on whether you're upshifting or downshifting.

Upshifting: Since you have no synchros, you either need everything to be moving at the right speed or you're gonna have gear teeth sliding across each other until they hook at which point the input shaft speed will be changed abruptly as it matches up with output speed. With the clutch out the entire inertial load of the engine is on the input shaft so the change in speed becomes a violent jolt. The only cushioning to this blow comes from the clutch assembly and the rubber of the tires so you'll want to have your clutch in which will decouple the engine from the transmission. If you throw it into gear at the PERFECT time then this is unnecessary but that's a pretty advanced technique and you'll want to build up to it. To get the rpms at the right point is the easy part. Even with the clutch in the input shaft will spin down on its own under friction. So you just have to get a feel for the timing and know when to throw it. Disengaging to begin with will depend on whether you're gonna have the clutch in or out when you put it back into gear. You'll have to let up on the gas (or else use a NLTS) so that the rpms start to fall. Clutch in or out, either way the input shaft spins down and you just throw it in when the time is right and then get back on the gas hard and fast so that the rpms don't continue to drop and cause engine braking. You want the rpms to dip to the exact spot where you engage and then be rising again the instant the gears hook.

Downshifting: This is a little tricker to master since the natural tendency of the input shaft is to spin down and you need it to spin up or you can't get it to engage. You'll want to take it out of gear and then you'll want the clutch out so that you can blip the throttle and raise the rpms and have the clutch pull the input shaft speed up with the rpms. You can either use the clutch as you disengage and then release it again to blip the throttle, or else just leave the clutch out while you disengage (using the throttle subtly to make this smooth). Once the rpms rise to the appropriate level you'll want to throw it back in gear. Again there's a learning curve to finding the sweet spot. And again, you can do this with the clutch in or out but using the clutch will decrease the shock to the system if you're slightly off and it slams in.

Best of luck... remember there's a learning curve so it's probably a good idea to put some time in before you get serious.


Whoodoo
(buff guys = good time but my dream is to fondle 1051)
10/11/10 03:09 AM
Re: Dog box driving tips wanted!

Ever ride a motorcycle? It should behave just like that except its not sequential. I've only driven a motorcycle engine in a racecar, so I don't have much street experience. However, you will learn the characteristics of your engine pretty quickly because it will determine how fast you shift up and where you rev match to shift down.

I'm really jealous actually. I find myself heal and toeing or left foot braking all the time just for the hell of it. I'd love to have a car that really needed it


mpt72
(Member)
10/13/10 04:56 AM
Re: Dog box driving tips wanted!

But the difference when driving a tractor vs a car is the rpms. Floating gears in a tractor is easy when its only 300 rpm incraments (no spell check sorry). It becomes rudimentary. That's why most oe clutches last damn near a million miles. In a car, however, the gear changes are 1000 rpms different, maybe more.

belize1334
(well bread and nobly conceived)
10/13/10 10:15 AM
Re: Dog box driving tips wanted!

The rpm increments are larger in a car but the transmission also has less mass. The input assembly on a tractor transmission probably weighs more than the entire long block of a 4g63. If you're off by even 100 rpm with one of those it can be damn near impossible to get it to engage.

**DONOTDELETE**
(Unregistered)
10/30/10 10:17 PM
Re: Dog box driving tips wanted!

Hi,

Came across this thread as I'm searching for a source for Ralliart Galant dogbox parts... which dogbox are you using out of interest? I'm desperately trying to find a source for parts.

As an aside, how you shift will directly affect how long the dogs on the gears last. You want to get used to matching revs on the down shift with a heel and toe or blip. It's open to debate, but using the clutch is optional. I tend to use the clutch when driving around on road/transit stages, but when on it, I don't bother with it. To me, when on it, using the clutch with a dogbox negates the whole point of having the dogbox!

You mention a flat-shift but then mention lifting off the gas - two seperate things. A flat-shift is a foot-flat-on-gas-shift. ie. no lift. This is only possible with some sort of power cut - either ignition cut or fuel cut, typically initiated electronically through a load sensor in the gearstick. Without such a system, you cannot truly flatshift. You can shift very quickly by simply lifting very slightly, very momentarily and putting the next gear in.

You can downshift without the clutch but getting the revs and such to match is a nightmare. Again, when on it/in a hurry into a corner you can, but down the box I tend to use the clutch. A lighter flywheel/clutch assembly makes this all a lot easier. I would also say a decent clutch is essential with any dogbox, strap drive clutches (ie. standard) get destroyed with the downshifts very very quickly.

Best practice is to be sure, positive, quick and exact. No lightly shifting, no granny shifting, shift like a hairy chested man with a purpose. Every time.


3rdstrikedsm
(Now mandatory for Wendy's Chili to come with cheese)
10/30/10 11:38 PM
Re: Dog box driving tips wanted!

Last I knew TRE could get parts for them.

**DONOTDELETE**
(Unregistered)
11/01/10 03:09 PM
Re: Dog box driving tips wanted!

TRE?

Barnes
(Firechicken)
11/01/10 03:14 PM
Re: Dog box driving tips wanted!

TRE = http://www.teamrip.com/

**DONOTDELETE**
(Unregistered)
11/02/10 12:09 PM
Re: Dog box driving tips wanted!

Ah, yes, already tried them, no joy

ApexHunter
(Extreme Indoor Cyclist)
11/02/10 01:54 PM
Re: Dog box driving tips wanted!

You might ask Bulletproof automotive. I really have no idea if this is something they can get, and they don't show any Ralliart products on their website, but they frequently source JDM only parts so it might be worth a shot.

ApexHunter
(Extreme Indoor Cyclist)
11/03/10 02:34 PM
Re: Dog box driving tips wanted!

Also try these guys, japan parts.com click

curtis
(Space Blanket from NASA plumbed into the attic)
11/04/10 10:49 PM
Re: Dog box driving tips wanted!

Barry one thing to do especially with the price you paid for this is go in the shifter and remove the little triangle rubber BS pad. Then weld a halo around so the front and rear has some material to mess with then drill and tap a hol in the front and rear and put the bolt in from the inside going out then install a jam nut on the inside. What you physically have created is a mechanical stop for the shifter. Now have someone go to the outside of the car and place the car in 3rd. Then inside adjust the bolt so it just touches the shifter handle then do 4th. When you to 1/2 and 5/R it may have to me adjusted a hair or the bolt be filed at with a die grinder etc but after its right you can power shift the hell out of it and never worry about over extending the shift forks which wears on the pads, brakes or bends them and passes metal into the box.

ad for mustang one



Also something else that helps and I've done it to every trans in my car. On the mid plate there's the 3 bolts with the springs and balls installed going to the notches in the shift rails. Install stiffer springs. This locks the gears in better and also gives the shifter a more ratchet feel as it drops in and also drops into neutral better.



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