Wanted 6" and 8" 13" Caterham wheel

[O Racer]

Doing track days with my 90's Seven on 14" wheels with old Kumhos and with the lack of 14" race tires decided to go to 13" wheels

 

Anyone have two 6" x 13" and two 8" x 13" Caterham used wheels for sale?

 

Thinking of new Avon CR500 tires for new wheel set up. Any advise on that...choice of compounds.

 

If not Avons any advise on other race tires and how they may compare to the Avons

 

Having too much fun now cannot imagine the difference with the new set up

[Kitcat]

I had good luck w/my '97 Xflow Cat on 15" Prisoner wheels w/Toyo RA1's (205x50). I put a set of Avon CR 500's on the front (after a flat) and they were no better than the Toyos wh/cost abt 1/3. They were 195x15x45, I think. The 13" wheels mite give you better acceleration tho.

[O Racer]

Kitcat, Thanks for the tip on 15's, I ran those Toyos in Spec Miata and for the money definitely a great tire

 

Does anyone have experience with Goodyear or Hoosier slicks, will save my 14" setup for street so slicks will only be for track use

[yellowss7]

I've been using 13 inch Hoosiers bias ply slicks in the softest R25B compound. They stick great, and because our cars are so light, they wear well.

 

Tom

[O Racer]

Thanks for the input, if I can ask, I appreciate knowing the size tires you are using assuming 6" fronts and 8" rears

 

Have not raced on bias ply tires since the mid 70's, how does the handling differ from radial race tires, one thing I do know is that they need to be warmed up before any hot laps

 

My Seven is yellow/aluminum I built it in '91, its the last car I sell

 

BTW running in Northern CA, you?

[yellowss7]

I'm in Pennsylvania. While I do have standard sized rims with Toyo R888's on them that I use on the street and occasionally on the track, the Slicks are mounted on 10 inch wide Kodiak 3 piece rims on all four corners, a holdover from my autoxing days.

 

While that is probably way over kill, it is very neutral in handling. No push, no oversteer. I know some like to be able to drift their cars a bit. I have 195 hp at the flywheel.

 

Prior to this year, I ran, 20 x9 x13 Hoosiers that had a circumference of approx 64 inches. This year I bought 22.5 x10 x 13 hooiers that have a 71 inch circumference and obviously a taller sidewall. I was running out of revs in some corners that I hope the taller profile tire will resovle the problem. I am doing a trackday on Sunday so I'll let you know if the taller profile is a better match for our gearing.

 

As for bia ply slicks, they are very progressive compared to Radials, They tend to be more predictable in their feel vs radials that just let go. In my experience, all tires need to have some heat in them before they work, as evidenced by the number of knuckleheads that bend their cars on the first lap or two of the day or session. The R25 compound is very soft and sticky, but I still take it easy for a few laps. I do trackdays, not races.

 

I have the Caterham 6speed with a 3.62 rear. Mine is a 2000 superlight that I assembled, and I can't ever imagine selling it.

 

Tom

[Croc]

The R300 I 'borrow' for track use in UK/Europe has 13 inch rims with CR500. I prefer the 13 inch rims over the 15 inchers that I run with CR500s on track with my CSR. I find the 13 inch wheels are more communicative and progressive on breakaway and prefer them. I have not tested other brands back to back like Kitcat though. Their smaller diameter does restrict top speed 135mph down to about 125mph - so that is an issue on long straights which may be a factor for you?

 

The CR500 is a nicely light tire - lighter than the Toyo. They are frustrating to source at times though and can be expensive. Roger Krause in CA is always a good source along with Sasco Sports in VA.

 

Another idea - have you looked at ACB10s? Bias ply so you will need to tweak your suspension set up but similar compound to CR500 with a better tread pattern and usable for road although I would not want to drive in the wet. More consistent grip over the life of the tire than a slick. Easier to source than CR500s as the Miata racing fraternity use them on the east coast a lot.

[Kitcat]

Some X-flow owners have had oil starvation/engine failure w/stock wet sump using the super-sticky racing slicks. Mite be a reason to add an accusump? Dry sump is ideal. Or just stick w/Toyos, CR500's, etc (street legal race tires).

[O Racer]

Thanks Tom, Kitcat and Croc for the advise, further info from me might lead to more ideas from followers of this site so here goes.

 

My Seven was a bone stock '91 chassis with 1700 AX cross flow, Sierra 5 speed and Dedion rear, I raced other cars over the last 20 years so this car was used sparingly with about 12,000 miles. Sold the last race car and have done 3 track days since late Nov. all at Laguna and have had more fun than I have had 'real' racing in years.So the grand plan...I have a 4/4 Morgan with a non cross flow 1500 and a push-pull 4 speed that has been crying out for an engine swap for 22 years. I found an identical AX based low mileage Super Sprint that needs pistons, machining and assembly. The plan is to put my Seven engine and Trans in the Morgan as is and do a build out of the new engine, not in any way to full race specs but something more than my stock 130HP engine for some more straight away speed and some more torque for the upgrades where I get pulled. I am down to 1:49 second laps at Laguna on 10+ year old Kumho 185-60-14 radials so with the extra power and 13" race tires I will be even happier

 

Kitcat, I like the idea of a dry sump on the rebuild as Laguna has some high G up and down hill turns

 

I am also still using the stock original brake pads and rotors, that is next in line to change

 

So starting from a stock Seven is like a clean sheet of paper, I want some more speed, grip and handling but not too radical for the street

 

Anyone like to chime in and give me ideas all appreciated. Perhaps this thread should get moved to another subject, if someone knows how, please do

 

John

 

#18 yellow/aluminum 1991 Caterham Seven

[O Racer]

I moved this to the general technical thread

[yellowss7]

Had a great day on track today, and I'm happy to report that the new taller sized Hoosier slicks made a significant difference in my top speed and speed in each gear. I had been using 20x9x13 hoosiers with a circumference of 64 inches. The sets I ordered this year had the same width, but were 22.5 x10 x 13 and have a circumference of 71 inches which is closer to the original CR500 tires that orignally came with the car.

 

I did not notice any loss of accelration as I could stay with GT3s, and Z06's up to 100mph no problem. And with the taller profile I certainly had more speed in each gear.

 

 

Only thing I have to do now is lower the ride height an inch or so as the car now sit up higher.

 

The 10 inch wide slicks are really too much tire for the car as I don't get anywhere near the hear into them compared to Blubarisax on narrower slicks.

Fresh Rubber. My new mantra.

 

Tom

[O Racer]

Hi Tom

 

Glad to hear the new size slicks worked so well for you, nothing like new tires, cannot wait to treat myself to new slicks and see the results to my lap time.

 

I run Lotus and Shelby club track days, both do a good job controlling the run groups and the drivers seem to drive well and watch their mirrors. Without the straight away speed I need for cars to back off at the start of the straight to get past then I disappear by the track out of the first turn, cannot wait for a few more HP and new 13's and slicks

 

With my plan to upgrade engine from 130 to 160 or so HP and with 13" wheels what wheel width would you recommend? My first choice was 6"fronts and 8" rears using the Cat wheels

 

Any suggestions for wheel width and wheel brands that the fast guys are using on your side of the country

 

My two main tracks Laguna Seca and Sears Point have short straights so top speed is not as much an issue, handling yes very much

 

Thanks

 

John

[sdca7]

I've used Kumho V710's, Hoosier and Avon bias ply slicks, CR500s, ACB10's, and now am using Hoosier A6's for track days. The A6's have a very progressive feel at the limit, warm up quickly, and don't get greasy easily on light cars like ours. It may be my driving style, but I like the feel of the radial tires better than the bias ply. Could be car setup as well. The newer radial ply slicks are very progressive compared to the older ones, and the "DOT" A6's have a very sticky compound. I didn't have any big problems with any of these tires, but I tend to like the A6's for track days. Just so !!! expensive! Fortunately, they don't heat cycle out very fast on my car.

 

Justin

[yellowss7]

John, I don't know about the fast guys, but the wheels used by the Caterhams at NJMP range from the Stock Caterham 8 spoke, to Rial's, Kodiak's and BBS.

 

All pricey! all light.

[supersportsp]

I have the multispoke Caterham 13" wheels on my '97 Caterham. I bought them from Karl (blubarisax) with Avon ZZRs. They are quite sticky and resulted in a 7+ second lap improvement over my 15" wheel/Toyo T1R set-up.

[blubarisax]

7+ seconds??? I want them back! Just kidding!

[supersportsp]

7+ seconds??? I want them back! Just kidding!

 

Very tight track with hardly any straights. You are pretty much cornering 70% of the time.

[Croc]

I have the multispoke Caterham 13" wheels on my '97 Caterham. I bought them from Karl (blubarisax) with Avon ZZRs. They are quite sticky and resulted in a 7+ second lap improvement over my 15" wheel/Toyo T1R set-up.

 

Excellent news (and excellent driving by you!) - I just bought some Avon ZZRs and 13 inch rims for my car!

[Kitcat]

Croc:

Why? And will you lose top speed? If so how much (not relevant at NJMP?)?

What size rear/front wheels did your car come with (15x9 and 15x7?)?

[blubarisax]

I'm sure the 13" wheels will be better for your off road work! As I recall, the diameter is the same or close to it.