Alfa race transmissions

alfabender · #1 (**permalink**) 07-05-2005, 12:43 PM

When I bought my race car it had an ultra-close-ratio transmission claimed to be a Switters box. Gear ratios were: 1.99, 1.46, 1.14, 1.0. 0.85. The configuration of the box was this: It was a stock-type box, with stock synchros. The gears were made up by combining various gears from early and late boxes, and then swapping gears between the input and lay shafts. This is harder than it sounds because one of the shafts (I think the layshaft) is just one solid piece, to swap a gear onto it requires cutting the old gear off, cutting the inside out of the gear you want to swap on, and welding it on. The metal is very hard, and when you do all the cutting and welding you would likely ruin the heat treatment. I have a bunch of notes about which gears to use to do all this. When the trans worked (see below) it was a joy to run, very close ratios and well matched to my peaky race motor.

So my question is, does this sound like a description of a Switters box? It's kind of a home made approach to building a c.r. box. I have never seen any advertising literature or a website for Switters, and I don't know how to get hold of him or even what city he lives in (I think I might have heard Phoenix), so I was never able to ask him about it.

The swapping and welding in my box was nicely done, but after hearing some funny noises I took it apart and two of the gears in there had failed (teeth broken off). Looking closely, it's clear that, even though the welding was done pretty well, the gears were not 100% straight--the wear was only across about a third of the gear surface. I will try to take some digital photos and post them when I get home.

I am now running a close-ratio Colotti dog box, which I am very happy with. Its gears are fully interchangeable and designed that way from the factory, while it uses a stock Alfa casing and shift forks, everything inside is quite different, even the shift pattern is different.

Doug Bender

borrani · #2 (**permalink**) 07-05-2005, 03:16 PM

Several people are building those types of gearboxes. I think Tom Sahines will as well?

A colotti box, my dream. Yes you have interchangeable gears, but not 5th, is that correct? Isn't 5th a 1:1 gear on that box?

Schwitters is in my hometown of Rockford, IL, I believe. http://www.alfabb.com/bb/forums/printthread.php?t=8066

Steve S.

genericwood · #3 (**permalink**) 07-05-2005, 03:43 PM

Yes, Schwitters makes a box like the one you describe. I run one in my GTV and love it. He also makes dog boxes with Hewland gears in an Alfa case. If gear alignment is off in your old box, I would tend to doubt it came from Steve, though. He is quite a perfectionist! Send him your pictures and I'm sure he will help you either way. His email is SWS4Alfa@aol.com. And yes, he is still in Rockford, IL. He will be at the BRIC at Road America helping me out in a week and a half if anyone wants to talk transmissions. He's one of truly nice guys I have learned a ton from. Oh, by the way, he also does great cylinder head work using a flow bench in his basement!

Erik Wood

alfabender · #4 (**permalink**) 07-05-2005, 03:45 PM

Steve

Yes, 5th gear is 1:1. So I am in the process of replacing the 5.12 rear axle with a 4.56.

alfafredly · #5 (**permalink**) 07-13-2005, 08:45 PM

Quote:

Originally Posted by genericwood

He also makes dog boxes with Hewland gears in an Alfa case.

Erik Wood

Jr. Z · #6 (**permalink**) 07-13-2005, 10:14 PM

Dog boxes are what motorcycles use. They have square peg like protrusions that engage slightly larger square holes in the gear you're engaging. No synchro ring, so a bit faster shifting. I have a bud with a Hewland 5 spd dog box conversion in a Ford Cortina 4 spd case. He has it in a Lotus Super 7. When he pulled it apart he called me to ask what those funny square peg shaped things were, he'd never been into a dog box & didn't know what he had. I took a look @ it & almost fell over, Hewland made very few of these thing in the late 60s. Now very desired. Bruce

alfafredly · #7 (**permalink**) 07-13-2005, 10:48 PM

Thanks Bruce now I know!

BigSwede · #8 (**permalink**) 07-14-2005, 12:13 AM

550 Maranello dogbox

genericwood · #9 (**permalink**) 07-17-2005, 05:26 PM

Doug, just to add some closure to your original question, Steve Schwitters helped me at the track this weekend. I asked him about your box and he reminded me that his ultra-close box does not require any welding. I guess he does it all with machining. So the box you have must not be one of his. Again, I'm sure he can help you with it if you'd like. Mine worked great at Road America for the B.R.I.C. this weekend. I ended up 7/32 in Group 8C. The only cars in front were Porsches and Lotus Elan's. Damn those things are fast!

Erik

justcallmefred · #10 (**permalink**) 07-18-2005, 10:51 AM

I've been busy with back-back race weekends, your trans was probably made by an outfit called Arizona Twin Cam, I think his name is Bruce- nice guy. He does as you describe- cuts the centers out and welds different gears together. When I was helping David Wall it did not take long before we were shucking teeth off left and right with his 2.0 litre Gtv (by the way now yellow and for sale by you know who for $65K !) Repaired it works to this day in his 58 spider 1300 with about 125-130 h.p. I imagine it would handle up to around 170-180 but not much more. I probably still have his phone # if you want. Fred.

gtvracer · #11 (**permalink**) 06-05-2006, 01:45 PM

Hello all,

I have just posted a thread asking if someone has an old 4 speed I can get to Schwitters so he can build my close ratio 5 speed. Can anyone help?

geh458 · #12 (**permalink**) 06-05-2006, 03:52 PM

Can't help you with your situation, but I'm considering this setup in a spare transmission I've got in the garage.

http://www.ar-racingproducts.com/Des...aspx?tabid=626

genericwood · #13 (**permalink**) 06-05-2006, 08:42 PM

I'm sure the OS Giken stuff is top quality. But Schwitters gear sets are only a little over half the price. And the gears are closer. The Schwitters box I run has 1.99 / 1.47 / 1.17 / 1.00 / 0.85 gears. While the tall first is a bit of a pain in the paddock, the ratios are great on the track!

Sorry I no longer have a 4-speed to contribute!

Erik

gtvracer · #14 (**permalink**) 06-06-2006, 07:12 AM

Thank you both for your replies. I do want the Schwitters ratios but I am stuck w/o a 4 speed core. My buddy at Pinnacle Autosports is going with a full bore Schwitters dog box with the Hewland gears but with 2 kids, that is out of my budget! Thank you geh458 for the OS Giken info. I may have to go that route.

turbolarespider · #15 (**permalink**) 06-06-2006, 07:16 AM

Quote:

Originally Posted by gtvracer

Thank you both for your replies. I do want the Schwitters ratios but I am stuck w/o a 4 speed core. My buddy at Pinnacle Autosports is going with a full bore Schwitters dog box with the Hewland gears but with 2 kids, that is out of my budget! Thank you geh458 for the OS Giken info. I may have to go that route.