5-Speed competition gearbox.

[Luke]

I checked and we are supposed to have ruby on rails support.

[Geoff]

6:31, 14:34 intermediate and type 4 primaries will give at 7000rpm;

1st 21.7mph
2nd 37.1
3rd 56
4th 77.7
5th 98

6:31, 15:34 intermediate and type 4 primaries will give at 7000rpm;

1st 23.1mph
2nd 39.2
3rd 61
4th 83.3
5th 98

With which size tires? This is what I've got now at 7000rpms (45612 gearbox with #4 primaries) assuming tires with a 1928mm circumference.
1st 29.4mph
2nd 50.5
3rd 77
4th 106.6
5th 133.7

1st is pretty short, only good for getting rolling. I think in your setup it may be almost useless.... The rest of the setup is OK but I'd like it to be shorter.
Does anyone have the individual gear ratios for the S&R gearsets or works gearsets? I know the R&P is 6:31 but not what the rest are.

[Luke]

I have them, I also gave them to Jordan last time he was over.

[Jordan]

I have some time now before a meeting... I'll try to put up what I have, I didn't see RoR on the hosts list.. but that company is so confusing. I'll just post it and see if it works! I'll let people know the address when it's posted.

[Jordan]

I was having some problems with your host so I just put it on mine for now.

It does more stuff, but it's not really finished yet. There is an area where you can build a custom box and changing the tire size doesn't really do anything yet.. but feel free to play around with the lookup tool. I'll update it as soon as I get done with my taxes...

Saab Gearset Tool

The gear ratios that Luke gave me were:

1: 2.20
2: 1.53
3: 1.22
4: 1.0

The gearset is at the bottom of the transmission list as SR1xxxx.

[Luke]

Nice job putting that all together Jordan.

[Geoff]

this will give a much nicer spacing between the gears, in fact, using type 4 primaries will give very similar ratios in gears 2 to 5 as a competition 4 speed using special 30:35 primaries.

Hey Dave,
Are the 30:35 something that was typically used? Were those used on the gearboxes with the Sport and Rally gearset or on the boxes with the really big ring gear? Was there a difference between the gears in the Sport and Rally gearset and the gears that the boxes with the really big ring gear used?

[Luke]

this will give a much nicer spacing between the gears, in fact, using type 4 primaries will give very similar ratios in gears 2 to 5 as a competition 4 speed using special 30:35 primaries.

Hey Dave,
Are the 30:35 something that was typically used? Were those used on the gearboxes with the Sport and Rally gearset or on the boxes with the really big ring gear? Was there a difference between the gears in the Sport and Rally gearset and the gears that the boxes with the really big ring gear used?

According to Jorgen and others I've talked to the 31/30 was the standard used for the chain drive primaries. For the gear drive primary boxes there was lower gearing set availble.. 1:1.2 or something. The 6:31 is the "biggest" in terms of gearing, but the 7:34 is dimensionally larger and requires some machining of the box to fit and was mostly used on the turbo motors. I think all the ratios were the same but the later gearsets went to 14 tooth dog instead of the 27 tooth of the early ones. At least thats what I've been told.

[sonett]

6:31, 14:34 intermediate and type 4 primaries will give at 7000rpm;

1st 21.7mph
2nd 37.1
3rd 56
4th 77.7
5th 98

6:31, 15:34 intermediate and type 4 primaries will give at 7000rpm;

1st 23.1mph
2nd 39.2
3rd 61
4th 83.3
5th 98

With which size tires? This is what I've got now at 7000rpms (45612 gearbox with #4 primaries) assuming tires with a 1928mm circumference.
1st 29.4mph
2nd 50.5
3rd 77
4th 106.6
5th 133.7

1st is pretty short, only good for getting rolling. I think in your setup it may be almost useless.... The rest of the setup is OK but I'd like it to be shorter.
Does anyone have the individual gear ratios for the S&R gearsets or works gearsets? I know the R&P is 6:31 but not what the rest are.

Geoff, 1st gear will not really be used, maybe in the paddock getting to the start , in my first post i said i would only be using gears 2-5, but more often than not gears 2,3 and 4.
I think you would be hard pushed to get the gearing any lower. I had the chance of a used 4-speed gear set, but it didn't have much life left in it. When the new 6:31 5-speed final came my way it opened up extra options for me, OK i am using modified standard gears, but these are cheap and i rebuild boxes anyway, so hopefully it should be happy days.

[sonett]

this will give a much nicer spacing between the gears, in fact, using type 4 primaries will give very similar ratios in gears 2 to 5 as a competition 4 speed using special 30:35 primaries.

Hey Dave,
Are the 30:35 something that was typically used? Were those used on the gearboxes with the Sport and Rally gearset or on the boxes with the really big ring gear? Was there a difference between the gears in the Sport and Rally gearset and the gears that the boxes with the really big ring gear used?

As far as i know there was only one S&R gear set, but i am willing to be convinced otherwise, it's all fairly acedemic anyway because they are not readily available.
There were a few chain primary drives offered 30:35, 30:31 and 28:35 come to mind, i suppose any of the primaries could be used with any final drive. The big final drive needed some extra work on the gearbox to get it to fit, it stuck out of the top of the gearbox!

[sonett]

Has any progress been made into having a 4-speed dog set manufactured or even priced up? If i 'ball park' price was given it would hopefully get the ball rolling?

[Crazyswede]

I talked to a local gear cutter a year or two ago about reproducing the original S&R gear set. The tooling was going to cost about $8000...never went any farther to determine the cost of making the gears because i figured I really didn't need the crazy gearbox. However, I also discussed the option of building a cutom set of gears from straight cut gears.....would be a lot easier to do...very strong...tricky to shift....and a lot louder. But again I have been spending less time on the saab rally end of things and more time on the moto rally.

[Geoff]

The biggest issue with the stock gearing is they're so far apart, especially 3rd and 4th.

This is part of a spreadsheet I've been using for a few years to look at gear ratios. I've updated it with some info thats new to me (S&R gearset, Sonett's gearbox, different primaries).

(sorry about the width of the photo)

The gearbox I've been using works OK (2nd is perfect for rallyX) but it would be nice if the distance between the gears was closer. Its interesting to look at the S&R gearset, the difference between 2nd and 3rd is much closer than it is in the stock gearsets between 3rd and 4th. Reducing the overall ratio (different primaries) helps things. I might have to have a set of 28:35 primaries built for myself. I can't imagine those quick ratio primaries being used on a S&R box (with a S&R ring and pinion), the top speed when using a 28:35 would be 78mph at 7000 rpm!

[theoneGroo]

geoff,

nice spreadsheet.. my S&R gearbox (now Mike's) had the 6:31 ring gear and i put in a 30:30 primary , which i pulled together from a 30:27 (stock 99 turbo chainset) and 31:30 (stock na 4spd) utilising the chains from the 31:30 and the tensioner from that box as well... what are the numbers for that set-up?

[Geoff]

You got rid of your gearbox? Are you no longer building a new car? At least it went to a good home

For the 30:30 setup (which I couldn't make work in my gearbox, I think the chain I had wasn't right and I wasn't using the tensioner that you did) the speeds at 7000 rpm are pretty similar:
1st 44mph
2nd 64
3rd 80
4th 97

How did you like that setup?