Monthly Archives: May 2010

School is in Session

For 2010, kicking off the National season here in the Rocky Mountain Division began with a double national at PPIR. Leading up to the event much was ado among the region muckety-mucks about the decision on whether or not to run the oval banking of NASCAR 1 and 2, rather than the pit-out apron of years past. Ideas were posed, hair was pulled, hands were wrung, panties were wadded, and ultimately the decision was made to run the banking, but with a chicane-dealie on the exit of Turn 9 to curtail speeds into T1 and T2 slightly.

For my part, I loaded everything up and headed down Thursday evening, so as to get a full day of testing in for Friday. Having made a raft of changes after a fairly disappointing outing from the previous HPR event, I wanted to see if I’d gotten the car more or less sorted, so as to be able to run well. My excitement/anticipation level was at a new high, since despite the ho-hum PPIR track, I was going to have a big group to run with, and finally, the chance to benchmark myself against one of the best in DSR.

Subscription to wings-and-things was looking good, with 21 cars registered (a lot for us!), including 4 DSR’s: Me, Paul Leonard, Tom Gonzales, and (eep) Chris Farrell.

Our only task for Thursday was to unload the car and bleed the brakes, since they were still as I came off track Sunday from HPR, i.e. boiled. Sure enough, both calipers spit plenty of
foul looking Motul and some air.

As a wonderful bonus, the PPIR garages were only $75 for the weekend, so we decided to live large and bought the last garage space so we could cast haughty looks out on the  commonersvoutside…ho ho Jeeves, fetch me a spanner! Seriously though, boy, that garage sure was nice for the weekend!

Friday

Friday showed us some good weather, windy and warm. The whole day was, thankfully, fairly uneventful.

The biggest “wow” of the day was running up on oval banking for the first time. First time in quite a while I’ve been a bit scared in the race car. Took me a couple of laps to go flat out throughvthe banking, but once I did it was “oh, well that’s not much of anything.”. Still, the sensation of looking *down* on your apex, then looking up through your visor around the banking is pretty odd, as is the funny feel of the loading downards through your body, rather than to the side.

Initial runs on the new 20×9.5 fronts were also uneventful. They didn’t make a huge change to the car, at least that I could detect, which was unexpected. Initial turn-in felt better, the car really points well. Also felt like I could *lean* on them much more mid corner, get through the corner a bit quicker. Well-used fronts and well-used rears gave a pretty reasonable balance. I took a stab at reducing the ride-height from my initial 1 5/16″ setting, but came back with some fairly rubbed rub blocks, so I raised the car back up, and basically left that alone the whole weekend.

Laptimes were consistently in the low 55’s, which felt OK. Chris reported he was in the low 54’s, so no big surprise that he was quick right away. Top speeds were similar, me around 133, and he just shy of 135.

We lost one of our four DSR’s on Friday. Paul Leonard first had a brake issue – which turned out to be no pad material left on the pads. I gave him all eight of my spare Poly A pads, but then a cracked header pipe put paid to his motivation level, so he packed up the Radical, and brought out his BMW to run the Autocross that was running in the PPIR lot outside the oval. Wish you’d been there, buddy.

Saturday

Saturday was hot. 92* ambient temperature, amplified by the sea of concrete and asphalt around us made for a really warm day. I spent a lot of time trying to stay hydrated. Lots of cars were having trouble with very high temperatures. Tom G. reported his oil in the 280’s, and the Speads FB’s were all running in the 260’s or so. Mine was also high at a steady 248 (measured in the main gallery), but not too worrisome. Even Chris changed over to his larger “warm weather” oil cooler, but reported 199* oil temps.

As a technical aside, one difference there is the measuring spot. The Speads, Tom, and I are all measuring oil in the main engine gallery, whilst Chris has his sensor in one of the oil cooler lines (not sure if it was feed or return), thus explaining some of the difference.

Practice went by quickly and uneventfully, with me testing a bit of fiddling with the shocks (less bump, more rebound) to see if I could do anything about that funny porpoising the car was doing on the infield bumps. A little better, but nothing huge. For qualifying, I put on a fresh new set of the 20×9.5’s, which I’d won back in September of last year. Thought I’d really take my best crack at seeing if I could worry Chris at all. They didn’t seem to make a huge improvement that I was able to exploit, qualifying with a 54.9 to Chris’s 54.3.

I was looking forward to the race start very much. I haven’t been off the pole in a long time, running locally, so I was curious to see how other people do it. Chris brought us up pretty slow, in first gear. Green flag dropped, and we were off! We both got pretty reasonable starts, but instantly he began to pull away, and continued to gap me, despite me being right behind in the draft. Damn. We came around the first lap, and he already had a good 4-5 car lengths on me.

As we came off the oval on lap 2, and into T5 (where are turns 2, 3, and 4??), a huge smoke cloud awaited us, along with a nice shiny patch of pavement at the apex. We both slipped and tippytoed through the corner and set off again, the origin becoming clear at T6, as Chris Waterman’s Speads sat in the infield with the firetruck nearby, smoking slightly. Tough luck for them again, and as Chris posted later “now that I’ve had two opportunities to confirm, my theory is correct: being on fire sucks.”

For the next 6-8 laps or so, I managed to stay more-or-less in touch with Chris, as he was being very careful through the oily turn 5, and was probably playing a bit of cat-and-mouse with me anyway. Made for lots of fun, trying to stay close, but in the end, he motored away. That left me to run my race, which was only punctuated with some inadvertent or assholeish moves by the Speads cars as I lapped them, one pushing me off the outside of 5 — as the corner workers put it “5 black is off….with assistance”. He tried the same thing on the next lap, so I cut back inside and quickly cleared him. The other failed to notice me coming up to lap him, so I had to dive below the white line on the oval, which turned out to be relatively uneventful.

Thus finished the race, with Chris somewhere around 30 seconds or so ahead at the checker. Best lap times were 54.3 to my 54.9. Tom finished the race, but at a reduced pace due to his overheating problems.

Post-race check of the car showed that the new fronts were wearing evently and slowly. Despite the high ambient temperature and enormous track temp, not a sign of overheating or blistering, and in fact, the wave on the rubber looked almost ideal. Very encouraging on that front. The big bummer was that the car had eaten yet another chain. Chris popped over on his bike to chat, and after filling him in on the problem, he noticed right away that it was due to the large keyed nut working its way loose on the left-hand-side of the diff, quipping that he only knew to look since he’d had one come all the way off and catastrophically fail! We took it all apart, fixed it up, and the chain was 100% for Sunday.

Sunday

Sunday was about 20* cooler than Saturday, much to the relief of everybody. Cooler temps mean that all those with marginal cooling were able to breathe a sigh of relief and go racing at full tilt again.

I went out for the morning Practice session to make sure the newly reassembled chain was going to be OK, and to see what I thought about yet another fiddly shock change, to see about dealing with those bumps. All was well. Chris and Tom sat it out.

I ran just a very quick qualifier as well, only about 5 laps. I saw a 55.0 on the dash very early on, and called that good enough. Once again, it was good enough for outside pole next to Chris, with the next closest car another second or so back.

We rolled out onto the pace lap like normal, though I noticed the cornerworkers telling us to slow down a bit. Sure enough, there must have been a mess behind us, as the first start was waved off. We drove around and tried again.

Green flag flew, and as yesterday, Chris immediately jumped ahead. I did my best to tuck into his draft. He said he had to lift slightly that first lap, and I was close enough to pull an over-under routine in T5, as he defended the inside line. However, I then had the outside again for T6, tried the same thign, and this time didn’t have enough to get myself side-by-side. And, that was about it for my challenge. Chris steadily drove away, and again, I just motored home, sore neck and sore shoulders from that darned oval. Chris lapped up to 3rd place, me about to 5th or so, content to watch Tom duke it out with an FM the last few laps of the race, which was fun to see.

Best race lap times put Chris at a 54.2, re-setting his own track record, and me about 1 second adrift, with a 55.2.

Thus finished another National race weekend in my short National career – two good finishes, and only two more to go, and it’s Wisconsin Ho!

Technical Review

Soooo, plenty o’ technical review from the weekend, as Chris was an absolute fountain of information for me, both in terms of driving, Stohr setup, and on-track comparisons.

The first interesting note was our top speeds – about 2mph or so apart. He was seeing high 134’s, me just barely edging into the 133 range. Had I more time and confidence, backing down on the Dauntless flap may have helped me make up that difference. For future reference, a 15/48 combo, the same I use at HPR, is nearly perfect for this track with the ’08 gixxer.

Second is the observation of just how quickly he pulled away at low speeds – a clear indication of just what power-to-weight ratio can do for these cars.

On the car/reliability side of things, the new routing of the dry sump vent to to the oil filler cap was a 100% success, almost no mess from the overflow bottle this weekend. As for the diff, a bunch of blue loctite and some auth-or-i-tay on tightening that nut should put an end to the car’s problem of eating chains, once again, thanks to Chris.

Despite the enormous heat, temperatures on the car were high, but tolerable. Into the 220’s on water, and into the 240’s on oil, but never higher, and stable from mid-race onwards. So, it appears the car is cooling well enough, but the real test will be Miller in August, when it is 100* or more ambient temperature.

The brakes were a total nonissue the whole weekend. Thank GOD.

Back to the suspension side of things, I made a startling realization looking at the bellcranks on Chris’s car. Despite the two of us running the same springrates, our wheel rates are wildly different. He’s running the softer/original rear motion ratio, whereas I made the update to the 1:1 rear late last year. Also, for the first time I noticed that there are two available ratios on the front bellcrank, and after confusing myself a bit, realized that the inner position (where everybody else has it) is the 1:1, higher motion ratio. My car is configured with the softer front motion ratio, meaning that my front-to-rear spring split was MUCH different than Chris’s. So, I’ll be experimenting with the normal 1:1 ratio up front, since that may explain why I’ve been unable to run the car as low as it seems like I ought to. We’ll see what that does to the balance, however. Watch this space 😉

For Next Time

So, with one more weekend behind us, what have we learned?

  • Don’t be afraid to take some wing off the car when you don’t need it, for top speed
  • Soften the damn car on bumpy tracks
  • Let’s see what the different motion ratios offer up front.
  • The new Goodyear for DSR is an excellent upgrade, if for no other reason than it really evens out the wear on the car
  • I’m not a total wank behind the wheel 😉

Overall, the car’s balance was just fine, just perhaps needed a bit of tweaking for the bumps. We’re headed back to HPR on Friday to see how the new fronts and new “baseline” feel on a known-quantity
racetrack, so it should be good to try a few things and see where it leads us.

Onward to the June Sprints!

Details, Details

One of the small issues I had at the last race weekend was persistent oil mess from the overflow fitting on the dry sump tank. The tank itself was not particularly full, so I concluded that the vapor simply wasn’t being separated all that well by my tank. I happened across a post from George Dean on the DSR forum, who mentioned that he typically runs the dry sump vent back into the motor, and lets the stock Suzuki vent do its thing. He mentioned that he’ll run either back into the valve cover, or into the factory oil filler cap. That latter seemed like a nifty solution, since it’s easily reversible, and doesn’t require any drilling/tapping/etc.

Sure enough, a 20×1.5mm adapter to -8AN male, and I have a new oil overflow line. I put the O-ring from the stock cap onto the AN fitting, since I couldn’t find M20 crush washers. We will see if it adequately seals during the first race weekend.

 

My Kingdom for some wheels

a Kodiak wheel shell cut out-of-round

a Kodiak wheel shell cut out-of-round

 

I’m not prepared to completely call them out yet, but I’ve been at the mercy of Kodiak Wheels for 13 weeks now. I placed an order for 3 wheel shells the last week in February, and still no sign of them. Customer service has been difficult. I was fortunate enough that they had one on the shelf, which I was able to assemble with a spare into a pair of 9″ front wheels, for testing the 20×9.5 front tires. However, when I tried to fit them tonight, the new shell was so out-of-round that for about a 30* arc, it would rub on the caliper and the wheel wasn’t able to turn. So, the shell is junk, and I still can’t use my 9.5″ tires. Frustrating, to say the least. Hopefully I will find some resolution soon.

Further, the 9″ set that I cobbled together from my 4th “bent” wheels are causing issue, as one of the straightened wheels will not allow the tire to fully seat. I may have to go back to Woody’s and see if they can figure out why that wheel is not allowing the tire to mount, and hopefully correct it.

Misc Else

Thanks to the SR forum for some help on my braking woes. Current thought is that it’s simply due to not bleeding the brakes. I will add that as a routine item before the race, to ensure the fluid is as fresh as possible, to avoid boiling. I’ll couple that with maybe a touch more rear bias (I’ve never even really set it?), and we’ll go from there. I will rebuild the calipers per Wayne’s suggestion, after PPIR, to see if the floaters can be made to work or not.

Taking a close look at the car, I noticed the chain had gone slack again. Sure enough, looking at it, several O-rings were missing. After looking at the UHMW “rub block” that I made over the winter, I suspect that the chain rubbed enough on the rub block, that ultimately the O-rings were damaged, so I think that one’s on me for being too stupid to keep the chain quiiiiite tight enough. Will watch that more closely as well. Wish there was more clearance on that part!

I’ve made all of the resolved changes mentioned below. The raised splitter now seems to sit much more evenly with the floor of the car, and measuring the angle, it may even be slightly nose-up. We’ll measure rub on the splitter versus the floor at PPIR, and adjust it accordingly – I suspect down just a hair – then mark it for good.

Never simple, is it?

May Update

After several more foiled attempts at trying to get out and debug the car, we finally did some debugging at our first R/R of the year, at the SCCA “May Daze” race at High Plains Raceway.
The racing went fine, and the car held up, though I definitely lost my way a bit on setup while trying to get things dialed back in from over winter.

Read all about it.

Enough Whining, so what?

So, having whined and complained about not having the car’s setup quite right, here’s what I’ve resolved to do for next time out:

  • Install the “larger” louvers from my spare nose to augment front-end downforce
  • Go with the dive planes for now.
  • Reset rake back to where it was – evidently there’s no harm in having plenty, and it sure seems to be a large-impact knob for the car’s mid/low speed turning.
  • Raise the front splitter such that it touches at the same time as the floor. Right now it is rubbing, and the floor isn’t touching at all, anywhere. This will allow me to run the car lower overall, benefitting everything.
  • We’ll be trying the 20×9.5×13 Goodyear to further augment front grip.
  • And, obviously, continue to dink with the rear wing angles and installation.

I’ve reset the heights and weights since the various adjustments at HPR, and everythig is looking like it’s at a decent start spot – 1 5/16″ front, 1 14/16″ rear, for 9/16″ of rake. With luck
the whole car can go lower, depending on how bumpy PPIR is going to be.

It looks like Chris is considering coming out to PPIR to run the N/N with us, so it’ll be fun to see where the benchmark lies, and how far from it we are. More soon!

A word about Fitness

Last year, as you may have noted from some of my race writeups, doing a race distance in the car was getting to be extremely difficult. I found myself getting out of breath, my arm muscles getting tired, and generally being tattered by the end of a race. the g-loads that these cars put through your body, combined with the low-leverage position in the cockpit, puts a bit more of a premium on conditioning. More than a few folks have mentioned getting in their DSR and being physically worn out after just a few laps.

So, in order to be able to get through a full race distance without getting fatigued, I resolved to start an excercise program over the winter. Starting in early December, I began doing a
light cardio routine – 30 minutes on an elliptical, followed by a weight workout of varying kinds, lasting 30-45 minutes. I do this three times a week as time permits.

The result is that the driver has lost about 10 pounds, and at the last race meeting, had zero issues with fatigue and soreness, even after 3 full days of racing and nearly 100 laps on track. Even something as simple as my girlfriend’s “Biggest Loser” excercise DVD was enough to get started with, so if you find yourself getting tired – you big loser you – start doing a light excercise routine. Not only does it help racing, but you’ll feel better, and look better too.

Lost in the Woods


Qualifying

With the schizophrenic state we know as Colorado finally doing its best to shuck off the cold of winter, it was finally time to head down to High Plains Raceway to begin the 2010 season.
Thus far, a spate of bad weather and bad scheduling had prevented us from getting out more than just once for a test day to try and shake down the car from winter updates.
Chiefly, I was really interested to fiddle with my homebrew Dauntless rear wing  Configuration, and see if it was better/worse/same/who-knows as my previous setup using the same Dauntless wing, from Jaremko’s 2008 Runoffs effort. So, the weekend would be primarily a long, protracted test session, to see what I could discover. With no other D’s registered, it was going to be a fairly low-stress weekend. Rob Adams in CSR Radical (with a Dauntless Wing) went home Friday with a failed engine, and Paul Leonard (Radial Prosport CSR) ran only on Saturday. Wings-and-Things was lightly subscribed, with only about 10 cars in our group.

The new rear wing in question is an approximation of Dauntless’ current low-mounted wing kit. I started with the main lower element from the bi-plane wing setup first tried on Mark Jaremko’s car at the 2008 Runoffs. It is a straightforward wing element, with a little less chord than their current kit, and without the whizzy twisted ends that help sort out the airflow coming over the rear fenders. I used that exact setup on my car to good effect at the end of last season, just barely pipping the track record that Chris Farrell set in Tim Micklos’ car. If we’re honest, lots of things went right for me to be able to catch Chris’s time, and he’ll doubtless be significantly quicker in his own car, but, being close is still a good feeling.

Atop that main element is the standard flap from Dauntless’ kit. This was an early pre-production/repaired/blem/something, that Serendipity helped find its way to me. We moved the wing forward from its previous location in the “1.0” Jaremko iteration, since that had been made for the longer WF-1 bodywork. Its new location is now approximately the same as the standard WF-1 Stohr kit, but as the 1g body is about 5″ shorter than the “long tail” WF-1″, the wing sits over open space. By contrast, the WF-1 bi-plane rear wing actually overlaps the rear deck by approximately 1/2″. Both wings are installed at about the same height, coincidentally, which differs from the current production Dauntless wing.

So, mumbo-jumbo aside, it was time to see if I could get everything sorted out. Easier said than done, as it turns out, as I did an excellent job of showing my woeful inexperience in dealing with a car as complex as this!

Friday

Friday we showed up early, and things began well. For the March test day, before the rear diff sprung a leak, I had started with about 2* of angle on the mainplane of the car, and had set the flap at a minimum ~15* angle, relative to the mainplane. We’d dropped it to 0*, then -1.5*, then -2.5*, each time picking up a bit of straightaway speed in the process, about 1mph per drop. Adjusting for ambient temperature (which in CO swings from about 40* to 80* during an early spring day), those seemed to be about the same as before, with perhaps slightly more rear-end stick.

Lap times at that test had remained constant in the mid 1:18’s, with the best coming with the mainplane at -2.0, and the flap at +15 relative. (-12.8, as it turns out). This was around two seconds better than my previous best than the run of the “West Loop” the previous September. Everybody was setting new bests though, as the asphalt seemed to have weathered in over the winter, after being brand new in 2009.

So, we began Friday with similar settings. The car was fast, immediately running under my old track record for the full course, with several laps in the low 1:41 range. Unfortunately, the
biggest problem of the weekend, and what probably offset the rest of the weekend, raised its head: the front splitter was rubbing, a LOT. In addition to picking up some grip over the winter –some estimates as much as two seconds per lap — HPR has also picked up some bumps. A lot of long right-hand corners meant the left side of hte splitter was happily leaning over and grinding away the left-side rub blocks. Wary about hurting the splitter itself, we began raising the front of the car in 1-pushrod-turn increments, hoping the problem would go away. No such luck. Over the course of the weekend, reducing the car’s rake so much ultimately resulted in a killer push, which I didn’t put together until midway through Sunday. Smart, eh?

As an aside, I also tried running the floating front rotors once again, and once again, they began to have a bad vibration after 4-5 laps. We pulled them off and ran the solids all weekend. I’m getting frustrated with the brakes on this car – see below.

Also in an effort to try and curb the, ahem, curbing of the splitter, we changed the car’s springrates from 1200/1400 to 1300/1500. As with the change from 1100/1300 to 1200/1400, the car felt a little more “propped up”, and turn-in remains excellent. No issues putting power down (i.e. wheelspin), though perhaps that’d be exacerbated without so much mid-corner understeer caused by the reduction in rake. Suffice to say, this seems to be well within the range of springrates that folks are running on their Stohrs, so it’ll do for the time being.

We played quite a bit with various wing angles, dropping the mainplane as far as -4, and the flap as high as +21 relative to the mainplane. Each adjustment definitely provides some trim effect, and has some effect on top speed, but there was enough spread in ambient temperature (40* to 90*), tire condition, car setup, and driver consistency (lacking!), that it was hard to extract any real trends, other than that ambient temperature seems to be the single biggest factor in ultimate top-speed of the car. At the moment, all I can say is that it seems to be at least as good as the previous Dauntless/Jaremko bi-plane setup, and, I suspect, better. Seems to have less drag for the amount of downforce I’m now enjoying.

It’s worth mentioning that the car in its original configuration – 1g Stohr splitter and single rear wing — was consistently 2-3mph faster down the straightaway than now, but on the order of 3-4 seconds a lap slower than it is now, other development and driver improvement notwithstanding.

We also played with adding/removing dive planes, with half an eye towards Road America in June. For sure, there was a significant effect on the front end of the car with those. Still out for better analysis is trying to determine their effect on top speed.

As you may be concluding by now, there were a lot of changes and tweaks made in an effort to try and find a balance in the car, with very little success forthcoming. I think we identified a few trends about the wing angles, dive planes, rake, and such, but as the car sits right now, I’m a bit dubious about the current setup.

We stayed Friday night in the travel-trailer RV that the parents had brought, and as it turns out, staying at the race track overnight is awful nice. Getting up in the morning, stumbling
around for a bit, and then wandering over to the race car with a hot drink in hand is a nice experience.

Saturday

Saturday dawned – if such a term could be used – cold and windy. A slight shortage of workers meant that we’d be running the shorter “West Loop”, that we had tested on back in March, with good results in the mid 1:18 range. First session of the morning, on the same practice tires as from that March day, I was quickly in the low 19’s, despite the various mishmash of changes from Friday. A fresh set of tires from last year’s national win (wow, stickers!) was good enough for a mid :18 in qualifying. The car really came alive on new rubber, and I thought that the car’s setup was quite good, especially over that short run. Feeling like I had the rear mainplane angle about where it might want to be, we went ahead and added the forward “stay” extensions to the rear endplates, and connected them to the body, which you can see in the pictures.

The race on Saturday was a bit of a mess, unfortunately. Halfway through the race, the car began its old behavior of going off progressively towards understeer, to the point where I began having to lift in the ~110mph T7, where I’ve never had to lift before. Essentially, I had a hugely rear-biased downforce – either too much rear wing, not enough front, and probably both. Post-race inspection showed that I had absolutely SCORCHED the left front tire. Granted, the West Loop is very intensive on that poor LF, but a race worth of understeer and leaning on that tire pretty hard had just shredded it. Going back to some head-scratching, a lack of rake, lack of dive planes, a healthy dose of rear flap, and maybe extra endplate area from those forward stays, had conspired to create an imbalanced setup that the fresh tires had been able to get around for a few laps, but not for a race distance. Could those forward extensions really make that much a difference to the car’s downforce? Despite consistently raising the front of the car, we just barely had some rub block left on the left side of the splitter.

Almost as an afterthought, in light of the car being two seconds off of my earlier pace, I re-set the DSR track record for the HPR West Loop at a 1:20.xx.

So, after a bit of head-scratching, tantrum-throwing, tea-leaf-reading, and crystal ball work, on Saturday evening, we raised the front splitter a hair by grinding the mounting holes, and hoped that would do the trick for rub. Further, we decided to put the dive planes back on to try and save the front, and pulled a bit of wing angle out to try and even up the aero. The flap went from +21 (i.e a lot) down to the ~17 range, relative to the mainplane.

Many kebobs and much beer was consumed to try and help sort out the confusion of the day. Barclay shouted and told stories deep into the night, and a good time was had by all.

Sunday

Sunday finally felt like a race day. We rolled out of bed, and onto the track as first session, which was now the full course, a few extra knights-in-white having been found to man the corner stations. Inexplicably, the car – or me – was dog slow on the straight – 3-4mph down from Saturday’s race, and I was only able to dip into the high :42’s, versus the test day’s low 41’s. The same was true in Qualifying. Thinking that we’d really screwed something up, we rolled the car over to the Doyle’s scales, re-set the cornerweights, and sat down to think a bit.

Fortunately, raising the splitter had reduced the rubbing enough, so we went back down a turn on the front pushrods, dialed a yet more wing out, and removed the dive planes (once again!) to see if the straightaway speed would come back. Sure enough, it did, and I definitely noticed the reduction in front grip in the high speeds T4 and T10. Since top-speeds had been high in the race with MORE rear wing than during Sunday’s practice or qualifying, I can only chalk it up to a problem with the driver during those Sunday sessions. That said, with dead tires, a dubious setup, and a weekend of changes behind me, I was mostly curious to see if the small increase in rake would regain some of the car’s low-speed balance (it did).

More worryingly, on a warmish day (85*), after about 7 laps, last year’s problem of the brakes going soft started to reappear. Over the course of a lap, the pedal got progressively worse. I
slowed my pace, and after about 3 laps, curiously, the pedal came back. I continued to push, and about 2 laps from the finish, the pedal went soft again. Once the car cooled, the pedal is
once again firm. Troublesome.

For Next Time

So, what have we learned? First, for as much as we absolutely lost our way in the woods in terms of the car’s setup, a lot went right. The new truck is working well. the 28′ Pace is turning out to be a perfect size for our operation. The engine ran flawlessly all weekend. The only niggles were too much oil from the overflow breather, an intermittent radio mike on my side, and the aforementioned vibration from the floating front rotors.

A good friend told me that he’s learned a lot more from his screwups than from his successes, so I’ll try to take that as the message for the weekend. I’m going to restore the car’s settings more or less back to where the weekend began, bar the spring change, which now that we’ve raised the splitter to its normal position, should be just fine.

For the PPIR N/N, we’ll try:

  • the 20×9.5 FA-sized Goodyear. This should help those low-and-mid speed corners, and we’ll adjust springs, rake, and shocks to match.
  • Reinstalling the dive planes, since they seem to help, and appear to have only a small effect on top speed for our lower-speed tracks.
  • Taking a page from the ALMS guys, I’ll be installing the larger/more open louvers from my spare nose, in an effort to help front downforce even more.
  • We’ll pay a lot more attention to rake, as that seems to be a big knob on the Stohr for those mid-low speed corners. Oddly, at approx 9/16″ of rake, I seem to
    be running much more than the normally indicated 1/4 or so inch?
  • changing only a few things at a time so we can figure out what the hell we’re doing!

So, lessons learned, if not a huge amount about the actual setup of the car, and particularly, setup and efficacy of the rear wing configuration. Times are getting better, and there is LOTS
of downforce to be had — more than I’ll ever be able to balance the front end with — the quesetion now is getting the car balanced, and figure out at what drag penalty – if any – that the downforce is bringing with it.