05/16/06 The camber plates finally came in yesterday so last night I set about installing them and the springs. Of course I don't have any instructions or a service manual so I just had to figure things out as I went along. Not a problem, just slows me down a little. Also the fact that many of my tools are down at the shop didn't help as I had to improvise and use adjustable wrenches a lot. The fronts took about 3.5 hours after which I had to take a bit of a break. Then the rears took another 3.

The cambered top plates are considerably thicker than stock so hopefully this will be added insurance against 'mushrooming' also. Finally, around midnight, the job was done and a quick drive reveals that the ride is not harsh at all - progressive springs are definitely a good thing. The car feels very planted although the steering feel is a little vague. This is due to the negative camber - it effectively moves the contact patch inboard and reduces the scrub radius. Overall, very happy with the changes. Even getting into the car it feels significantly lower than it was which is quite cool.

In the morning took several daylight pictures. Here's the car before and after:

Definitely an improvement, both visually and dynamically. The camber now appears to be equal in front and back.

We'll see how well it all works on Friday. The replacement Kumho is here and mounted so DarkHelmet should be ready to rumble. I'm looking forward to it. Quite a transformation so far.

05/18/06 In preparation for the trackday tomorrow I installed the track tires. Because the overall diameter is 2" smaller than the street set, the car sits even lower - so much so that I can't get my low-profile jack under the jack pads. It does look neat though (clik each picture for larger version)

A friend who also owns a Mini asked "Why does your Mini look like it's going to war and mine looks like it's going shopping?". "Because that's exactly what our cars do" was my reply. So in keeping with a militaristic theme, I found this audio clip of Dark Helmet from the Space Balls movie which I think is very appropriate for the occasion. Yeah.

05/19/06 (updated 5/20) Well, there's theory and then there's the real world. After putting all the effort and cash into springs and camber plates, I was expecting that they would a) keep the tires from blistering and b) improve lap times. Uhm... not quite. At the end of the first session, my brand-new, heat cycled left front looked like this.

Yep, another blister, in just one session. To add insult to injury my lap times were actually slower with the best of just 1:33.8. Granted, I had a passenger, but still... (Later I looked at the data and the difference is due to me not doing 10-11 as well as before, so actually a passenger makes no discernible difference to lap time). Larry dropped by to see if the club needed an extra instructor so he made a couple phone calls to racer friends and the feedback was that I should be shooting for 35 psi hot instead of 49 psi that I was getting. When your tires are overheating it's counter-intuitive to drop the pressures by over 10 psi but what the heck, they're shot anyway. So I moved the troublesome left front to the rear and dropped the pressures. The lap times got marginally worse (mostly because Larry had me trying all kinds of different lines that I wasn't used to) but guess what - the tires now seem happy. The injured one that's now the left rear did not get any worse in subsequent sessions and the one newly promoted to hazardous left front duty seems to be staying together. So, boys and girls (I can dream, right?), what did we learn? $400 worth of parts and 6.5 hours of install == zero improvement in either tire life or lap time (the car does FEEL a bit more neutral and sure looks cool, though). But 30 seconds of dropping the tire pressures in direct contradiction with conventional wisdom and bingo, at least the tire life problem seems to have been addressed. My best guess is that due to high pressure the surface of the tread was heating up much more than the carcass and that's what was causing the blistering. But I'm only guessing here. Then there's still the lap time issue but I may just have to accept that this is a 1:33 car. I might eke out a 1:32 with a good deal of practice and effort, sometime down the road. Bottom line is it's still a whole lot of fun, by no means slow, and I still get to harass and occasionally even pass all kinds of fancy machinery. In fact, on R compounds DarkHelmet is marginally faster than a stock Elise. The video (15M) shows some highlights. Sadly due to operator malfunction I did not get on video an NSX spinning directly in front of me - that would have been a nice clip. In the afternoon it started raining and the car actually did quite well on wet pavement, but all the lap times and video are from the morning sessions. Yes, both 'Vettes are C5 Z06s.

Also, in the morning I went out and drove both edges of the track so that I have a GPS outline of PIR, the better to see lines through the chicane and such. The file (for the Race Technology DL1) can be downloaded here.

Yes, my line through the chicane is a subject of much controversy and opinion, but if you look at the videos I always make up a lot of ground on people there. By hopping over the first curb and early-apexing the lefthander I can carry a good deal of speed into the chicane and get right on the bumper of the car ahead, then I use the extra pavement on the right to track out and generally get a decent enough drive out to stay with him, unless the other car has a big horsepower advantage. In fact you can see an example of that in the video above. But hey, if someone can demonstrate a better way through this bit of track I'm always eager to learn something. My datalogger is easy to move from car to car...

UPDATE:

Got some cool pictures courtesy David Birkbeck (click each for larger version). No two-wheeling with this car, definitely.

05/24/06 Another track day, this one a Porsche Club event. Mostly wet. Again instructing. It is always gratifying to be able to make a difference in someone's progress and today was no exception. Cool.

The most interesting car at the track was a Diasio D962 racecar that normally runs in DSR (same class as Stohr). This car is meant to resemble a Porsche 962 and it does, in a somewhat caricature kind of way. Quite a neat device.

Like the Stohr it is powered by a 1.0L motorcycle engine. The performance however is nowhere near being even in the same league. This particular car was only one or two seconds faster than the Mini on street tires, despite being on slicks in the dry and on rain race rubber in the wet. I ran a number of laps behind him and while he was indeed pulling away, it was rather leisurely. So he was probably running 1:35-ish in the dry. By comparison Larry has gotten into 1:10s in the Stohr. I suspect a lot of it has to do with the driver and the car ought to at least be able to see 1:25s... But it's obviously heavy, has rather primitive suspension, no downforce and a lot of drag. I can't imagine it being competitive in actual racing (there is an 'R' version powered by a 250hp rotary engine and with real suspension that ought to be a whole lot faster but still disadvantaged by being a two-seater). At any rate, it was neat to finally see one of these at a trackday. It would seem that they'd make pretty good trackday cars so I'm somewhat surprised they aren't more common. I bet you could even register one on the street in Oregon.

As far as the day's driving experience goes it was entertaining but nothing stood out. I was about a half second slower than my best pre-spring times in the dry and identical to what I was doing before in the wet. So the spring/camber plate modification improved the performance on street tires exactly as much as it did on R compounds, which is to say not at all. I don't think it was a downgrade, at least as far as I can tell, because the half second time loss was primarily due to me being more conservative in 10-11. It was prudent to back off a bit on a track that is wet or at least damp in spots. One thing that definitely needs an upgrade is the brakes - the car just doesn't want to slow down once the brakes heat up. I at least need to change the front pads but preferably upgrade the rotors as well. There is a Lotus event on Friday and the weather will be iffy for that as well. I'm not sure if I'll run it or not. Regardless, after that there is a month before the next trackday so I'll take care of the brakes in that time.

06/13/06 After all my cosmetic mods, one thing was still bugging me about how DarkHelmet looks - the tail was too busy. Too much chrome stuff. So a couple of days ago I decided to just pull all the badges off. The 'COOPER S' insignia came off very easily. The rear MINI badge wasn't too bad either but it turns out there are two holes under it. For now I installed two black plastic screws in them which looks OK but I might get the small hood badge to install there instead. The rear one was just too big. With the chrome surrounds on the taillights the car avoids looking too bland so I think now it's just about right and the tail matches the nose pretty well.

Another thing I did is take DarkHelmet to the shop and weigh it on the new scales. Below is a picture of the readout with me and a full tank of gas onboard.

Of course I did not really level the scales (I know, I know) so the cross-weights should be taken with a grain of salt. However if one were to assume that the scales are reasonably level then the indication would be that the crossweights are off by a good amount, well over 100 lbs. This would explain why it feels different cornering left and right so I think the readout is fairly accurate. It would also explain why the right rear tire rubs over bumps when there's a passenger in the back but the left rear does not. What I may need to do is shim the right rear shock a bit, maybe 1/4". I'll have to first figure out how to do that and then try it and see what effect it has on the scales and out on the track. Next trackday is June 23rd so I better do it soon. New brake pads should be in by then as well...

A quick observation - gas mileage has been improving steadily. When I did the break-in drives I was lucky to get 250 miles out of a tank and it would take the full 13 gallons to refill (about 20 MPG). Now I'm going 300 miles before the light turns on and it takes 12.5 gallons to top up which works out to 24 MPG. Not bad, the way I drive. There are now 2800 miles on the clock, nearly 500 of which was on the track.

06/23/06 Tri-club (Afla/BMW/Porsche) event at PIR. Instructing again, with Tracy in her new GTI as my sole student running in Intermediate. I didnt' even get a Novice student. Easy day - or so one would think.

Last night I installed the Hawk HPS front brake pads (rears are still on back order) and the track tires. A quick drive to break the pads in revealed some moderately odd behavior but it got better later on. So today I tested the brakes again in the morning (worked fine) and headed to the track. A beautiful day, breezy and not a cloud in the sky. There was one main task on the agenda. A while back, some may recall that I said if someone could show me a better way through the chicane I was willing to learn. It so happens that about two weeks ago I had a chance to install my GPS datalogger in a DSR driven by a very competent driver (competent enough to beat all DSR, CSR and FA cars and run 1:09 at the track taking the overall win, a pace only 5 seconds slower than the qualifying time for the factory Audi R8). What I saw in the data was a very different way of taking the chicane, shorting the first turn and making a long arc of the second, with the right-left transition being much earlier and sharper than what everyone else had been doing. So the task was to test the new line and see if it's actually an improvement on my regular one. Sure enough, the data shows this is a consistent 0.3 seconds faster, even without getting the entry speed to where it should be. The video illustrates (keep in mind this is a stock MINI vs Porsche GT3, both on R compounds, in the instructor group). The chicane is the first thing in the video.

So yes, even with well over 3,000 laps at this track I still learn something every day. I suggested the line to a friend running an M Coupe and it worked for him too. Cool. Tracy, running in the Intermediate group, got the benefit (and the challenge) of being shown 'THE' line early on. It's tricky, especially timing-wise, but eventually she got the hang of it and did quite well. Once again it's gratifying to make a difference. She ran her GTI on stock all-season tires and I got to run a few laps in it. While the car was rather handicapped by its rubber, after driving it I couldn't help but compare it to the MINI. They are pretty much direct competitors, afterall.

I've said before that driving current VWs is like driving a pillow. In the case of the GTI it's a firm pillow, but a pillow nevertheless. The suspension is soft and overdamped and steering response is a little vague (mostly having to do with tires, to be fair). We started out with 38 psi all around and it felt pretty odd. You'd make a steering input and the car would respond, a lengthy and rubbery fraction of a second later. Ugh. So I suggested 45 psi front and 40 psi rear, which helped a lot. Makes me think that with proper tires the car would be a good deal quicker and more satisfying, too. DarkHelmet, in contrast, is very direct. Turn-in is immediate, maybe even a bit twitchy but fun. Supercharger vs Turbo gives a more linear torque curve although I must say the fancy VW active differential is better at putting the power down out of turns than the MINI limited slip is. Likewise, stock VW brakes are significantly better than the MINI ones, even with Hawk pads (which didn't help much, really). After a couple of intro sessions and having fried my tires (see below), I took the GTI out in the instructor session to directly demonstrate the lines and set a moderate but reasonable pace. The Intermediate session followed immediately and Tracy really came through, greatly improving control and not only matching my target pace but exceeding it by a quarter second, for a best lap of 1:42.1. It is a full 8 seconds faster than she did in the Scion a while back. Cool :) This is when teaching is fun.

Now back to my own adventures. First, the brakes. I had ordered front and rear Hawk pads but only the fronts showed up in time so I installed those. The result? - Eeeeh. Not much different from stock, really. On quite a few occasions I was in situations where I had no brakes to use and had to throw the car sideways to slow it down for turns (fortunately it doesn't mind being abused this way even if the tires do - more on that later). So I had quite a bit of fun in the first couple of sessions, the new line through the chicane helping me set the fastest lap so far at 1:32.9. Not without some excitement, though. In one session, a Honda Civic driver thought it would be a good idea to pass me way late, UNDER YELLOW (there was a REASON we were going slow!). Half a lap later he was trying to stay ahead so desperately he spun off the track. Here's the video (candid language warning!).

Whatever the excuse, I don't expect to see this in the instructor group.. Stupid. If this were a race it wouldn't be a big deal. But this isn't a race. Well, my comment at the end sums it up - 'serves him right'.

Anyway, the tires. The first couple sessions went quite well and the tires were holding up fine, no blistering. So I thought that the pressure changes are indeed the solution and all is well. That was until the third session when the car started sliding a lot more and I started feeling a good deal of vibration in right-hand turns. Discretion being the better part of valor I pulled off the track early and went to check the tires, only to find this:

Argh. Another tire shot to hell. And the right front is not looking much better, either. I think I need a tire sponsorship! So now I have to get two new tires before the Thunderhill event on July 6. Price of having fun... How many times do I get to say this? :) As many as I choose to, I guess.