Andy69

If I did my calculations right it sounds like someone set this car up to be soft and comfortable in the rear and handle well enough for fun on winding roads but not for any kind of track use. Looks like a set of good coil overs should fix the issue Sent from my iPad using Tapatalk

I measured the length, diameter, number of active coils, and wire diameter and used an online spring calculator. The one variable that I couldn’t get was the type of wire which didn’t make a huge difference in the end result Sent from my iPad using Tapatalk

Ok, I've got some specifics on the suspension setup on my 7. Front: 260# springs, unknown dampers, .71" ARB Rear: 90# springs (not progressive rate), Bilstein dampers, .45" adjustable ARB, set on the 2nd softest of 4 settings. Is a differential like that between front and rear springs normal on these cars? Seems to me the front is way too stiff with those springs and the bigger ARB, even accounting for the spring angle

We’ve got SCCA autocross and track days, plus a NASA region that has club racing. Jackson has a small but dedicated club that holds autocross events at Jackson Dragway. Lots of stuff going on. Give me a shout when you get here Sent from my iPad using Tapatalk

I’m right in town. Takes me about 20 minutes to get to MIR. Sent from my iPad using Tapatalk

Had my 7 out for Track Night in America yesterday for the first time. What a blast that car is to drive on the track. It was a TON of work to drive though. I'm much more tired than when I track the Honda, and it has manual steering and 225 slicks. Also, I found myself being sandblasted every time an overheating Corvette passed me on the long straight. I was picking OPR out of the cockpit between sessions. It gives plenty of warning before the front starts to slip and it's really easy to hold right at the edge. I think some suspension adjustment will make it quicker. And it absolutely LOVES trail braking. It's about equal in lap times with a Spec Miata on old tires, and a little slower than a Spec Miata on race rubber. The race Spec Miata easily passed me on the long straight, which is odd given that I have slightly more HP and way less weight. I guess the aero penalty of this design is bigger than I thought. Anyway. boring track day video below

I’m 6’1” 255 and that guy makes me look smalll Sent from my iPad using Tapatalk

I’ll take another look at that. I had seen some online but didn’t recognize them on the car Sent from my iPad using Tapatalk

I never understood why car makers make a limited run of a popular car like this. All they’re doing is leaving a million bucks per car on the table for the purchaser to have when he sells it two years latrr Sent from my iPad using Tapatalk

At some point you end up with a spring that is essentially an infinite spring rate, in that there isn't enough weight in the car for it to compress against. Still, people run upwards of 1000# springs in CRXs and Miatas, so even though the Caterham is significantly lighter, there is some room there. Depending on what the car has now, I may not even change them out. The car has no ARBs, so I can change roll resistance by adding them. I'm hoping still to model the suspension though. The thing is, you can reduce understeer by reducing roll stiffness at the front or increasing it at the rear, but my approach is to make sure the fronts are at their "happy place" first - optimal roll stiffness - and adjust the back to match. That way you are sure you are getting the most out of the car. A car can be neutral handling and still not be as fast as it could be.

I think all major manufacturers do that. Perhaps these have been refinished at some point. Sent from my iPhone using Tapatalk

I think I can get a good first kick at the cat by using an online spring rate calculator and taking a few measurements. That should tell me if I'm somewhere close to stock. I think the suspension is virtually stock which I think should put them in the 150-175 range

They are designed to transfer weight laterally, so yep. I use a setup with 8 bathroom scales, two at each wheel, and a length of 2x12 that that wheels sit on. There is enough space to roll the car back and forth. Sent from my iPad using Tapatalk

Dumb question, I know. But none of the springs currently on the car have any information on them. Fronts are red, rears are yellow. Dampers are gold. Other than that, I have no idea without putting them on a spring or shock dyno. Any way to tell or do I just need to go back to stock and start there? This is a 1992 S3 with a 1.4 k-series Sent from my iPhone using Tapatalk

The first step is to model the suspension. I have a spreadsheet I use that I got from USRT.com. There are online calculators you can buy for a period of time that are quite reasonable. I usually use more than one and compare the results just to make sure I;m on the right track. If you don't know the dynamics of the car, you're basically just guessing, and you're going to throw a lot of money at the car experimenting. And conventional wisdom is often wrong. I recently did this to my Honda, and will do it to the Caterham after I become more familiar with it. It's somewhat time consuming and garbage in garbage out but the results are rewarding. You can play around with it - what if I removed the rear ARB, what if I bumped the rear springs up, what if I did this or that. I ended up getting new stiffer dampers and adjusting the rear spring rate based on the model. After adjusting the front ride height, and then the rear to be slightly lower, I corner balanced it. The result was a car that was so neutral it would do a 4 wheel drift mid corner. I could adjust slight over or understeer by bumping tire pressures a half pound up or down. But, suspension setups are like opinions, which are like you know what. Another fellow has the same car I have and it's set up completely different, but I can't argue since he won nationals with that setup.

ugh. Makes me glad to live in TN. When I went to the DMV with my title, they ASKED ME if the title matched the VIN plate, and then I paid the $32 registration fee for a classic car, which is good in perpetuity. Technically not supposed to drive except weekends, club events, and maintenance, but I had a cop drive up to me from behind and give me the thumbs up as he went by.

I think the sidewalls of the R888Rs are too stiff and the car too light for the treadwear to line up with the diamonds, regardless of the tire pressure. I went up on pressures for Sunday. I think with this car on these tires, 10 in the front and substantially higher in the rear (eg 22) is going to balance it out as much as it can be balanced. Obviously that's not an ideal situation and is a kind of a mickey mouse fix - the proper way is going to be to model the suspension and likely increase the rear roll stiffness relative to the front. I usually shoot for 2.2-2.5 Hz spring frequency in the front and about .2 to .4 Hz higher in the rear as a starting point, so that may mean swapping out springs on all four corners, who knows. I'm honestly not sure yet if I'll both since I didn't buy this for autcross and I don't want to tear it up

Definitely a few first gear corners there. My heel-toe technique needs a bit more practice before I'm going to try that with the 7. The Honda is like a battleship and can handle a downshift like that without heel toe but I'm a bit more cautious with this car. Understeer is much more pronounced in the earlier laps. I was able to do about 10 fun runs on Saturday, which was great. I figured out I need to backside a lot more with this car because it doesn't rotate as well. On the Honda the front really digs in and gives the back a good point around which to rotate. It's super fast through a slalom if I can I can get the tail wagging I started off driving the 7 like the Honda. The Honda has nice balance - I get a little bit of mid corner oversteer and then if I'm just a hair too fast, a bit of exit understeer. About as balanced as you can be with a car that has a 62f 38r weight distribution. I like to refer to autocrossing a FWD car as the triumph of enthusiasm over physics :-) Mississippi Region has the absolute best locations for autocross. We're lucky to find a postage stamp and these guys have both Grenada airport and a section of the runway at Columbus Air Force Base. That's why I drive the 2 1/5 hours. Hands, yeah. Hand position is a challenge for me. The Honda has extremely slow steering and there are times when hand over hand steering is faster than shuffle steering. Since the 7 has a Caterham quick rack, I really don't need to do that, but it's just another habit that works with the Honda Anyway, I have to decide how serious I am with autocrossing this car. I really don't want to tear it up, but if I put the old windscreen back on and get some 200 tw tires I would be in Heritage Classic Street and I would actually be competitive .

Here was my fastest today. Terrible technique though. I probably left at least a second on the course with all that acreage between the car and the cones :-)

exit. Today I was experiencing a little bit of mid corner oversteer in a sweeper, but that was at a pretty high speed.

These are relatively new. but Im not a huge fan of Toyo in general either. Funny thing is Rivals are a much grippier tire at double the treadwear (TW number shenanigans notwithstanding). I don't think you can get them in 13, though. But the tires and the windshield are the only things keeping me out of Heritage Classic with its .79 PAX vs the .9 in D Mod. Ditto on the A7s. I ran them on the Honda. I prefer them over the Avons I currently have but I can buy an entire set of them for the price of one A7.

Thanks for the input. I was quite a bit faster today than yesterday after some practice. I'm no stranger to autocross. I've been driving a first gen Honda CRX since 2012. I can say, this car drives a lot like a FWD with respect to the understeer, usually a RWD does not like trail braking, but this car loves it. My problem was mostly with exit understeer. To cure that I ended up entering faster and trail braking much deeper into the corner than I would otherwise do. But that usually meant being pretty slow at the exit, and since the K series loves to rev, I was usually out of the power band in second by the time I was back on the gas. I have not set the corner weights yet, but it feels like they are pretty close. If they are more than a few % off, you will notice it will turn much quicker in one direction and much slower in the other. I figure if I'm serious I'll break out the plumb bob and model the suspension like I did with the Honda. The adjustments I made ended up changing the car so much I had to go down 100# on the rear springs to tighten it up. I bumped the fronts to 10 and adjusted them after each run to keep them there, set the rear at 21 and left it. That made the rear a little more loose, I think.

Took the car to the Mississippi Region autocross in Columbus today. I’m not really all that interested in racing this exclusively, since I’m not quite done kicking everyone’s butt in a 90 hp Civic, but I did want to see how it handled at the limit. It’s a 1992 with a 1.4 K-series. Toyo R888 all around, 185 front and 205 rear. I had the pressure set at 18 front and 18 rear and by the end of the day it was 9f and 8r. I think optimal is 10f and 12r But omg, push. Pushpushpushpushpush. Worse than my stock Saturn sedan. I figure it’s the combination of skinnier tires and no weight in the front. Hitting the gas does nothing except make the understeer worse. The standard fixes I think apply - more roll stiffness in the rear, less roll stiffness in the front, etc etc. Anyone manage to correct this tendency or is it just a characteristic of the design? If so how did you accomplish it? Oh and for future reference, the car is eligible for Heritage Classic Street with 200 tw tires, which has a much more advantageous PAX vs D Modified. Yes, and I cracked a rear fender hitting a cone. I was warned :-(. I used to ignore my mom’s warnings too and she would always say “the day will come when you crack a fender on your Caterham and you’ll wish you’d listened”. Lol. Sent from my iPhone using Tapatalk

It's gotten to the point where I no longer enjoy lying on the ground under a car, so for some things I'm going to start farming the work out. It's a strange feeling - I've worked on my own cars almost exclusively since I was 16. So to that end I need to find a good British car specialist within a reasonable distance of me- specifically Rover K-series. I live in Memphis. I spoke with a buddy who is connected in the odd European/German/Italian car circles, and he basically said all the guys who worked on British cars in the area have either retired or passed on. There's a German specialist, but that's about it. I found J.D.'s in Nashville but haven't called them yet. Going to try the local clubs, see what they know. Any suggestions?

and these aren't even the good sticky tires. Eventually I'll have a set of Avon slicks on there for track days.