Andy, It turns out I spoke too soon! (and am now a little embarassed) Helical gear teeth can be cut on a low production basis. I just talked to one of our machinists here in the shop, and I'm going to check out a book or two and the section in Machinery's when I get a chance. I think what you're ref...

Neil, The helical cut gears are actually better handling the misalignment from the shafts not remaining perfectly parallel. With straight cut gears any misalignment will shift the loading unevenly across the face of the loaded tooth, like the little tilted box drawing above. It puts a lot more load ...

Geoff or Luke,

Do you know how much steer angle you guys see on an 'average' stage rally (I know an 'average' one doesn't exist, but an estimate?

Even better, do you know what the steer angle at the wheel is? Do you ever have it cranked over to full lock?

Best,
Drew

Jennifer, I will put up results when we get them, in the mean time, I am going to post my response in a new thread specifically about welding, I don't think that there is one here yet. It's located here: SaabRally Welding Thread On a related note, our shop at school just got a Miller Dynasty 200, an...

I don't think there's a welding thread yet, and I wanted to share some of what I have learned about welding and metallurgy over the past 3 years working on our Formula SAE team, where we do a lot of structural welding, and a lot of welding thin section 4130 tubing. This is stemming from a comment ab...

Ok, warning, go grab a cup or tea or something to prepare for this one. It's longer than my other one. FWIW, SAAB sport and rally 4 chain primaries did not use the staggered tooth design like the production gearboxes did. Presumably for ease of machining and because with the entire extra chain the s...

This thread on the FSAE forum is about loading conditions on sprockets. Sprocket loading conditions Most of the Formula SAE cars are powered by motorcycle or ATV engines, and chain drive a diff or solid rear axle using the stock bike transmissions and output sprockets. The driven sprockets on the di...

However, I highly suggest you pick up the cheapest extra C900 box you can get your hands on, broken or not (unless you have one already) and tear it down (unless you have done that already). Drew I haven't. I think this is excellent advise and I intend to follow it very shortly. I just got my hands...

Do you have one out? I don't have one I can measure here, but I'd bet that it's an even degree # taper, looks to be a 4 or 5 degree or so to me? If you have one, you could measure the dia at the small end where it transitions to threads, and the big end, and the length, and figure out the angle. Wha...

Strengthened Primary chains....not sure about these....as I said in an earlier response the Saab rally boxes ran 4 chains and both ends of the shafts were supported in a bearing....vs the 2 or 3 chains found in the 4 speeds and 5 speeds where the gear is only supported on one side. Do you know of a...

Neil, I'm glad that you are persuing this. I had aspirations when I started at engineering school here in Chicago to do some work to strengthen the 99/C900 boxes too. I've also got a good bit of CNC and modeling experience, but don't have too much free time right now, I spend it all working on our F...

Well, the only 99 I have personally seen on the road has been at Walter Wong's shop in L.A. I have never even seen Dave Kennedy's herd of them in the 6 or 8 times I've been up to his place because they're always off in storage or something somewhere. His 25k mile candy apple C900 Airflow taunts you ...

Thanks both of you. Sent you an e-mail Per.

I have been hunting around last night and this morning for a seal for a TR7, they are at least still being produced, more TR7's around than 99's I hear, which is just sillyness.

Best,
Drew

I would be for it if I had the extra money at this point, right now trying to get the car going for as little as possible. I think I am going to be able to get the later 4-speed mated up with the '73 halfshafts with all the spares I have around the garage, and I'm leaving to go back to school in Chi...

I need an early style water pump seal kit for a '73 2.0L B motor. Pump came apart fine, water seal (Pioneer aftermarket brand) is falling apart where it seals against the impellor. I'm trying to get this car running and reliable (whatever that means) by the end of next week, and have the engine out ...