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Main : Misc : Tech Section Race/rally box

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Race/rally box
Race/rally boxPopular
Submitter1200coupeMore Photos from 1200coupe   Last Update2005/11/11 0:23    Tell a friendTell a friend
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Pics shows the hybrid Option 1 gearbox I currently run in my rally coupe. This is a very good bit of gear and has been progressively developed over the past 7 years.

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Poster Thread
1200coupe
Posted: 2005/11/11 0:36  Updated: 2005/11/11 0:36
Home away from home
Joined: 2003/9/17
From: Canberra
Posts: 512
 Re: Race/rally box
For those technically minded members.
Modifications have been extensive and box is Option 1 close ratio dog leg 5 speed based on a 60 series front case and carrier plate because it is lighter than the 63 series boxes.Box uses Option 1 rear case and runs straight cut gearset on 3rd and 4th because they are the gears that cop the most punishment.
First and reverse selector shaft has been shortened to reduce weight.
Box has ultra light detent springs on selector shafts and runs "dead stop" circlips on selector shafts to guarantee no over selection of gears.
Where striking lever fits into selector shafts all edges have been radiused and polished for quick changes and they are welded to ends of selector shafts to ensure roll pins cant sheer.
Reverse select plunger has offset detents to lay gear lever over towards driver.
All mating syncro teeth have been ground and radiused to quick shifting.
As you can see I still run open clearance syncro's and not dog engagement because dog engagement might be a little too hard on such a light weight gearbox.
This is a very strong and well developed piece of equiptment.

Enjoy.

Poster Thread
benny
Posted: 2005/11/11 0:48  Updated: 2005/11/11 0:48
No life (a.k.a. DattoMaster)
Joined: 2002/6/14
From: Sydney
Posts: 2582
 Re: Race/rally box
Nice bit of work there Paul... Fancy doing some custom work on a certain Toyota box of mine.......should be ready by say 2010 as you are one busy person. time is everything.

Benny

Poster Thread
1200coupe
Posted: 2005/11/11 1:10  Updated: 2005/11/11 1:10
Home away from home
Joined: 2003/9/17
From: Canberra
Posts: 512
 Re: Race/rally box
Thanks Benny, Iv'e still got a few more mods to make to the selector shafts by machining another "dead stop" circlip groove on 4th/5th but its shifting very quick and accurate whilst on the bench.
I love the sound of the straight cut gears screaming through the forest and you can hear the car from miles away

Poster Thread
nzdatman
Posted: 2005/11/11 2:11  Updated: 2005/11/11 2:11
Home away from home
Joined: 2000/11/8
From: Taupo New Zealand
Posts: 595
 Re: Race/rally box
That's awesome! Did you make those gears yourself or get them made by someone?
I'm pretty keen to do the same sort of thing for the 60A in my racer. Haven't got past the thinking about it stage yet, but was wondering about whether it is feasible for someone in a machine shop to buy some cutters and have a go, or whether you reallyhave to get them made on a gear generator or something like that???

Poster Thread
1200coupe
Posted: 2005/11/11 3:54  Updated: 2005/11/11 3:54
Home away from home
Joined: 2003/9/17
From: Canberra
Posts: 512
 Re: Race/rally box
nzdatman,
Some part I have made myself and others have been sourced from aust, NZ and parts of Asia.
The layshaft was made from a billet and the 5th gear machined seperately and shrink fitted to the assembly then TIG welded into position from both sides that way its possible to pick and choose ratios, although 5th is currently 1:1.
Obviously it is possible to make the gears and shafts in a general machine shop but it takes more time than if you had access to gear generating machinery.All of the work done to the carrier plate and gear assemblies was done in lathes and mills as I dont have access to gear hobs etc.
Some of the bits have come from various A and L series gearboxes and been machined and modified to fit, the final result is a gearbox that is far better than the normal Option 1 box.
Its taken many years of developement to get this gearbox to be strong, ultra light and reliable but shifting is now super fast and reliable with the current ratios spot on for rally purposes given the power and torque characteristics of my EFi A series. Sorry but I wont be posting ratio details as I have already given away a few build secrets in above posts.
As I said before, this is one serious bit of gear and has taken heaps of development to get to this stage.
Good luck if you wish to persue a similar build up but be prepared for lots of design and machine time and of course the time consuming task of finding and modifying all the right bits.
This box if I was to ever sell would go for around $2500 - $3500 because you cant buy anything like it anywhere. I have had a few people come for a ride in the car with me and they have been seriously surprised by its efficiency and the way it is so well matched to the A series motor and final drive ratio. A gearbox like this, when mated with a button clutch and quick acting linkages is probably worth around 2 seconds per Kilometer in rally terms which is a heap of time in stage.

Good luck with your build.

Paul.

Poster Thread
A14force
Posted: 2005/11/11 19:54  Updated: 2005/11/11 19:54
No life (a.k.a. DattoMaster)
Joined: 2003/12/3
From: Christchurch NZ
Posts: 3703
 Re: Race/rally box
Morgan, Rally-a-coupe (The guy who sold you that H165 LSD) was telling me about some gearset he was gonna buy from japan. He was looking for, (And found) a 60 seires dogleg box, as he said that only a dogleg box could hold all the goodies. I belive he has since sold the car. If you have a spare two grand to throw around, you could ask him what he had, and where he got it. I know I sure don't.

Poster Thread
nzdatman
Posted: 2005/11/11 22:32  Updated: 2005/11/11 22:32
Home away from home
Joined: 2000/11/8
From: Taupo New Zealand
Posts: 595
 Re: Race/rally box
Bart, yes I could always try to save a bit of cash and buy a gearset, but one of the things I enjoy most about my coupe is making up bits and pieces myself at a fraction of the cost and making the car faster and faster on quite a limited budget.
I also think a gearbox like this would be quite a good project, I'm prepared for it to take a few years to make, and acquire all the bits I might need.

1200coupe, thanks, I don't expect you to tell me all your secrets but I am very interested in having a go and doing something like this... perhaps not to the extent you have gone to, but just a good set of ratios for the circuit, I was hoping to use 2nd gear as 1st, if I can get the car off the line with such a tall gear, but the factory option boxes were like this. Then I want to make new gears for second and third, probably straight cut.

I'm prepared for failures and whatever else comes with the development, and everybody tells me not to waste my time and to just buy a factory option box, or there is the option of the T50 gearsets for less than 2 grand, but if I always just listened to the knockers I wouldn't have achieved half of what I have already. Better to try and fail than to never have tried at all I reckon. But then there's no reason why I should fail either???

Poster Thread
Lemonhead
Posted: 2005/11/12 0:05  Updated: 2005/11/12 0:05
Home away from home
Joined: 2004/1/1
From: Brisbane
Posts: 657
 Re: Race/rally box
I like it! Nice work Paul.

I know the significance of having a close ratio gearbox in a rallycar, well worth the effort...well done.

Would love to hear the scream of the gearbox flying through the forrest. One day maybe.

Poster Thread
1200coupe
Posted: 2005/11/12 10:59  Updated: 2005/11/12 10:59
Home away from home
Joined: 2003/9/17
From: Canberra
Posts: 512
 Re: Race/rally box
Quote:
one of the things I enjoy most about my coupe is making up bits and pieces myself at a fraction of the cost and making the car faster and faster on quite a limited budget
\

Thats the absolute best way to learn - hands onn engineering. Some seriously good bits come from low budget racers working away in the shed.
Re your ratio choice - I was told many years ago - "dont consider gearbox seperately, it is important to consider ratios based on the whole package and intended use, that way the best results will come"
There might be a few failures along the way but that's what motorsport development is all about and you will learn heaps compared to "checkbook racers"

Good on you


Poster Thread
A14force
Posted: 2005/11/12 21:44  Updated: 2005/11/12 21:44
No life (a.k.a. DattoMaster)
Joined: 2003/12/3
From: Christchurch NZ
Posts: 3703
 Re: Race/rally box
I too subscribe to the low buck, ( or no buck) philosophy. I doubt there could ever be as much satisfaction in doing something if you just throw money at it untill it's fast.
nessesity is the mother of invention.