chetcpo

Well the car did OK, but the tires were less than impressive. (Avon Tech RA) I don't know if it was because they hadn't been heat cycled or properly scuffed or what, but the grip you expect from R compounds just wasn't there. It was hotter than blazes and I had to let air out throughout the day and ended up settling on 13 PSI rear and 11 front. That's what seemed to work best. Here's a couple vids. One of me (in-car) and one of my codriver. My brother in law driving it:

Thanks guys. Tonight just for goofs I let all of the air out of my front tire and to look at it you couldn't even tell. All I was worried about was the tire coming off the bead when exposed to a high lateral load. I feel better hearing you guys say you run these low pressures with no problems.

Thanks for the replies. Sorry I don't know the rim width, but the tires are 205s. And I thought stiff sidewalls were a good thing for autocross. What am I missing?

Hi guys. I'm not new to autocross, but I am new to autocrossing a 7. (locost) I am nearing completion of my scratch built 1.8 Miata based Locost. I've done about everything but paint and hang the bodywork. I thought I would give it a go at a local autocross this coming weekend. In the Locost spirit, I refuse to spend a fortune on race wheels and tires. (at this point anyway) I bought a set of VW GTI rims for $50 and some discontinued Avon Tech Ra Tires from Tire Rack for $80 each. I took them out for some testing on the local backroads. (hooliganism) and discovered that the contact patch was very narrow on the tires. I assumed this meant too much tire pressure so I let it down from 35F&R to 25F and 30R and it didn't change much of anything. The sidewalls on these tires are super stiff and about 1/2 thick and I wonder how low I can go with the pressures. I'm estimating the car to weigh around 1200lbs FWIW. Any advice? I included a pic so you can see what I'm talking about with the contact patch. http://www.locostusa.com/forums/files/kineticglass_157.jpg

I've gone up and spectated at this event before and found it less fun to watch than an autocross. Driving it is much more fun I'm sure, but I wouldn't do it without a full cage. There are some scary areas on that hill where an off would result in a rapid and massive loss in elevation.

Here's a problem I see. If the goal is for a class where you can show up in a stock Caterham and compete against others in stock trim that would make it a "stock" class. (I know, Duh-huh, bear with me) Call it Seven stock, whatever. The SCCA permits race compound tires and damper changes etc. in stock classes so your Caterham on street tires is still going to be an underdog. Your best bet may be to lobby to have them included in a street tire class like STS2. STS2 is a class for 2 seaters with 1.9 liters or less. Assuming of course your goal is to keep them on street tires for those who like "to run what ya brung." chetcpo2006-10-31 10:00:40

I don't think that's the case at all. The objective is to get the traditional sevens (including traditional locosts) a place where they can compete. Right now, a miata based locost is in the same class as a purpose built autox machine. Even if you want to run DOT tires, and the other guy is running slicks. I think I see where you are going with this, but truthfully I have no delusions that the SEB would permit me to run a car I built in my garage in a stock or street prepared class. It would be nice, but really isn't realistic based on what I know about the SCCA. The current residents in these "stockish" classes would be at my door with pitchforks, shovels, and other pointy ended thingys.

I could be wrong but after reading this thread, and the proposed "new rules" it seems to me that some of you are looking to get Locost or home-built cars out of your class. Am I mistaken?

Hello, My name is Chet Burdette and I am a Prosthetist by trade. (I design and fit artificial limbs) I'm currently building a Lotus 7 replica from scratch (no kit) with a Miata donor. I'm still a long way from finishing but I've spent the past year planning the build. I found this site when Slngsht posted an invite to your get together next summer over on the locostusa.com forums. This place is really nice, whoever put it together did a nice job.http://www.usa7s.com/aspnetforum/images/emoticons/smile5.gif" border="0" align="absmiddle">