SCCA STR Autocross Carrera Build

[Flieger]

My dad subscribes to Vintage Motorsport and I have seen the Richard Newton columns. I really don't know anything about him- he could have worked with Aryton Senna for all I know. The columns generally seem accurate but with nothing really new. Occasionally a tidbit to chew on.

That said, I don't think he's worthy of hatin' on just because he plugs his articles in every post (why I don't know, since he's in a magazine).

[winders]

All he is doing is promoting his blog any chance he gets. His articles are total fluff with no meat. All they do is fill some space.

[Driven97]

Originally Posted by msterling

Hey Matt,

It was nice to meet you last Sat. at Pitt Race.

Nice meeting you too Mark, apologies our conversation was so short. We'll have to do an event where we can both bring our cars out and battle for air cooled superiority.

Thanks for the pics too, my car was definitely on two wheels!



And also used up 100% of the rear compression travel:

[jamesjedi]

+1 for the Flieger response.

[Randy W]

Post #164: This Dwight Mitchell?

That's Pat Costin, current owner of Dwight's '71 911. Here's Dwight Mitchell two years ago with the car. He ran 22/28 or 23/29 torsion bars. He developed specially machined bushings that had no binding - that was one of his secrets. He adjusted shocks, sway bars and tire pressures for each course. You need compliance in an autocross car. Best to spend money on tires and shocks if allowed. The driver is the most important factor!

[panzerfaust]

Originally Posted by emptyo

Here's my car on 15 X 7 & 8 (Soon to be 9 & 10) on Hoosier R6 225/275.

If only they made street tires in 275-35/15!





This was originally built to be a BSP autocross car.

I realize it's kinda hard to see the contrast because of the murdered out wheels. Sorry 'bout it.

nice car...are u running the taller profile 15's hoosiiers or the shorter ones? hard to tell from the picture with black wheels

[jamesjedi]

Randy, all this talk of 15 inch wheels and their benefits, did you not run 16's? It is sometimes difficult to tell from a photo, is Costin running 15 - 8/9's? I am guessing 15's.

[rennch]

Originally Posted by panzerfaust

nice car...are u running the taller profile 15's hoosiiers or the shorter ones? hard to tell from the picture with black wheels

I ended up going with Avon historic rubber on 15 x 9-11, which were amazing for the 2 months they lasted. Now I've got michelins on there. I haven't autocross sd them yet but I will soon.



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[BaEdwte]

Bummer that you have to keep the cat. What are your plans there - keep the stock?

[panzerfaust]

Originally Posted by emptyo

I ended up going with Avon historic rubber on 15 x 9-11, which were amazing for the 2 months they lasted. Now I've got michelins on there. I haven't autocross sd them yet but I will soon.



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i like the avons too...what size are you running? i also have 9-11x15s

both TB's and Avons are $$$$ thats why im leaning towards hoosiers.

britex hopefully will help on the cost of the Avons?

[Randy W]

Originally Posted by jamesjedi

Randy, all this talk of 15 inch wheels and their benefits, did you not run 16's? It is sometimes difficult to tell from a photo, is Costin running 15 - 8/9's? I am guessing 15's.

I've run on 15s, 16s, and 17s for autocross. My preference is for the lightest unsprung weight, however you need to balance that with what grip is needed for the power and weight of your car. I settled on 16 x 9 Fuchs with Hoosier race slicks for my own 911T/ST with 3.6L.

Dwight ran on 15x7 Revolution wheels with 225 tires on his 2.7L powered early 911 with RS flares - the same ones in my photograph. His style of sliding the car suited this set up.

[Driven97]

Originally Posted by Randy W

Post #164: This Dwight Mitchell?

That's Pat Costin, current owner of Dwight's '70 911. Here's Dwight Mitchell last year with the car. He ran 22/28 or 23/29 torsion bars. He developed specially machined bushings that had no binding - that was one of his secrets. He adjusted shocks, sway bars and tire pressures for each course. You need compliance in an autocross car. Best to spend money on tires and shocks if allowed. The driver is the most important factor!

Yes! Last I can tell Dwight was National Champion in ASP 22 years ago in that car, battling against a Lotus Elan - yikes! Things sure have changed since then.

These days ASP is Lancer Evolutions and BMW M3s. Now there's an SSP above ASP that's C6 z06 Corvette land, though there is a well prepared and driven 997 turbo that's got a shot this year. Dwight's car would be BSP today, which again runs into a large S2000 problem...

Looks like Dwight's car was probably about 450lb lighter than my car or more, which would put his ride frequencies not far off from where my car is with the big stonking bars, actually maybe firmer than my car in roll since I don't run a rear sway. I would love, love, love to be at that weight but it's just not possible under the rules.

Also yeah, going through and really loving on my Delrin bushings to eliminate bind was the best thing I did for the handling of my car. Poly is the devil.

The unfortunate truth is that the modern cars are indeed actually better than the old stuff, at least under SCCA Street Touring rules, for autocross. Maybe positive progress isn't such a bad thing anyways.