By Chris Tropea
Sep 2, 2024
|
Caterham,
Mazda,
Mazda MX-5 Cup
How does a Caterham 7, with an old-school suspension, compare with a Mazda MX-5 Cup race car with a more modern setup? They're closer than you might think. Our test driver J.G. Pasterjak took one around the Grassroots Motorsports official test track, the Florida International Rally & Motorsport Park (FIRM), to find out.
9/2/24 2:15 p.m.
Not surprised by the result given the lightweight of the Caterham. I'd love to see you guys test some single seat race cars there as they are even lighter than the Caterham.
9/2/24 2:26 p.m.
Fine piece, although I'd like to see them on the same rubber. Going from Falken Azenis to Avon slicks on my 7 was worth at least 2 seconds a lap,
9/3/24 5:39 p.m.
I really enjoyed getting JG's feedback and seeing a competent driver drive my car. I have a extensive racing back ground, but it hasn't been behind the wheel other than go-karts when I was a kid. JG suggest the technology is 70 years old, and while I may be in that class, Caterhams have seen significant improvements sense Colin Chapman did his seventh design in 1956. This car was built in 1999 and what Caterham calls a S-3 has been built the same from the mid 1990's. Chapman's concept for the car, was a car you could drive to the race track and drive home. This car does not have tags, but is street legal. The cops might not like the sound, but that is a easy fix. The car is also set up for me, and I am not a good driver. The brakes could be better. I am not as good as I should be at down shifting and matching engine speed. I could increase the rear brake bias if I was a better driver. JG might like the pads in the car, I don't. I like pads with more friction. JG talks about the compliance, and I believe the key to Caterham handling is the very stiff chassis and soft springs. This car has road springs, but even SCCA nationally competitive E production Caterhams use soft spring rates. One of the comments here was you could take two seconds off the time with slicks. I agree, and would add this: Increase the spring rates some, change the brake bias, Put some rake in the car, ( I have it set up for me and I wanted to stay away from oversteer). Trail braking makes these cars turn quicker because of the short wheelbase and allow you to get on the power earlier. To do that you have to be a much better driver than me, but this car has a lot more in it, than what JG drove. I have one correction to what JG said. The car weighs exactly 1300 LBS as he drove it. When I corner weighted the car the scales were flipping between 1300 and 1301. That is with a iron block engine, a full cage, and a rear bumper. I have been lucky enough to have driven a number of purpose built race cars ( I haven't raced them) and spent some time in very good Formula Fords. Light cars with stiff chassis and no compliance in the joints have a feel that can not be duplicated in a production car. a Caterham is like that and has enough power to point the car with the throttle. A good friend of mine was a SCCA national champion for Group 44 (John Kelly). John was not married until much later in life and had just about every type of car you could have. He told me don't get something with a V-8. Get a Caterham. They will teach you haw to drive and they are the most fun you can have driving.
9/3/24 7:56 p.m.
A buddy drove an Ariel Atom and a BMW M5 at Portland raceway on the same day. The M5 was faster because the track is not very twisty and the M5 has far better aero. Same factors will apply here.
9/3/24 10:10 p.m.
I ran with an early Lotus 7 - the fenders were air brakes and once we hit anywhere near top speed, my MG walked away from it. A fender that went further down at the front would be more aerodynamic. Of course you can minimize that by installing louvers in the top of the fenders to let the air out.
9/3/24 10:33 p.m.
The entire car is an air brake. I used to say that it was a supercar 0-60, a S2000 to 85, an Accord to 100, and a civic to 120, at which time it was all over.
9/4/24 8:53 a.m.
WOW, Karl B's Caterham! I built the rollcage for the car back in early 2023. Cool to see it here getting some love.
9/4/24 10:46 a.m.
Still proves the best thing you can do if you want to go fast is simplify, then add lightness.
9/4/24 11:18 a.m.
Car and Driver did acceleration testing on my 7. I had the windshield in place. I don't remember the specifics, but I do recall that it hit an aero wall at about 90 and acceleration fell off dramatically. My car had cycle fenders.
Around our local kart track, it was very quick. At Thunderhill, less so.
9/4/24 11:30 a.m.
Yeah even on our data traces at the FIRM—which tops out around 100-110 for a moderately powered car—you can see the acceleration curves really tailing off toward the top. I think this is a clear indication that it needs an LS swap (or at least a turbo K).
For real, though, everyone needs to try one of these cars at least once. They're super predictable and accessible way out at the limit in a kind of counter intuitive way. there's just nothing else out there with th ekind of balance and layout that these things have, so it's hard to even make comparisons to normal cars.
Big thanks to Carl for letting us toss it around.
Displaying 1-10 of 27 commentsView all comments on the GRM forums
You'll need to Log in to post comments.