Costas

I posted the following on the 911 forum and it was suggested that I ask here as well. Thanks for any info!

cobalt

i have a spec book at home that will give me the numbers I owned a 74 RS clone for 19 years and made the mistake of selling it.

However, I did not see a 74 RS clone in the video. the yellow 911 is closer to a 73 RS clone, totally different than a 74. The 74 is a widebody with different suspension than the narrow body. they did make a 74 carerra which was not a race car but more of a cosmetic clone to the 73 RS with bigger bumpers.

race911

I looked at the comments over on the other forum, which were pretty helpful if not absolutely specific. I'm sure some others will see this and comment who have much, much, much more relevant and modern thoughts on what will work. First would be to know what specific tires you are using. "Slicks" can mean anything from Goodyear bias ply cantilevers to 18" radials. One alignment does not fit all.........

Costas

Anthony, you are right. People have pointed out in the other thread as well that the car is probably closer to a 73 RS. I will ask my friend for the specifics of his FIA homologation and I will post the info. In the meantime, your spec book would be a great help, thank you!

Ken I will post more info on the tires too. We are not looking for a "magical" fit-all alignment, just the base setup of the era.

Thanks again.

race911

But the tires you're using have nothing in common with what was available then, except they're round, black and hold air. Maybe someone here who vintage races on period correct treaded slicks might give some pointers. But I'll bet even THAT has changed as the cars today won't be running the same spring/t-bar rates and shock valving that was used back then. Factor in changes in ride height, roll center, etc., I doubt there's a car being used on the track today that's anywhere near similar to how they were delivered.

If you want some numbers, here's what I REMEMBER from mid-'80's "think" using 23"X8"X15" Goodyear bias ply cantilever slicks on 15X7 wheels. I think we used 21mm front, 27 or 28mm rear torsion bars, and 22mm front and rear stabilizer bars. Standard issue, raised spindle RSR struts with stock valved Bilstein sport shocks, front and rear. '73S chassis with a 2.7RS spec engine that weighed about 2300 lbs.

Now that I've laid that out, I used to shoot for .5 degree negative F&R (maybe a smidge more in the back since the paint burnthrough issue was always there), zero toe front, and 3/16" rear toe in.

It's laughable to think how underprepared and crude we ran these things, huh?

Costas

Ken, thank you for those numbers!

Here is the car's background: Originally a 1973 911S 2.4L. Converted to 1973 RS specifications (with FIA class GT27 certification). The engine, however, is the 3.0L of the 1974 model.

So you are right, it is a 73 RS. The tires it runs on are Avon (not sure which compound). The rim sizes are 7.5/21.5/15 front and 8.7/21.5/15 or 8.5/23.5/15 in the back.

The previous owner was using this setup:

It is the front toe-in that seems excessive to me. The camber looks ok for modern slicks.

Costas

An update: Using the following setup, my friend took second place today at the 30th Palladio rally here in Greece :-). Tires where Khumo's 205 up front and 225 in the back.

It is quite interesting that in the last stage (by that time he had gotten used to his new car) he was 18th overall, with only Mitsubishi's, Subaru's, and other WRC modern cars in front of him.

Thank you all for your advice and suggestions!