Bob's Track Friends Chat (TRAKDAWGS)

[Bob Zumbrunnen]

Wow! Could see him in the mirror for a bit, then he ran out of track right at the bridge abutment when trying to pass.

I've seen cars dart across the track in front of me, but never with quite that kind of velocity. And he passed the driver's car like it was standing still. In the dirt, even!

[OldAIMGuy]

Hey Bob, And you didn't want to ride with me! How about a ride with this guy in the Daytona Coupe???

http://www.cateseng.com/catesracing/2005_09_summit/DAN_ELAM.wmv

He was sanctioned by FAA for not filing a Flight Plan!!!



TV

[OldAIMGuy]

Thanks Bob, It would be fun to compare the two cars lean in the same corners!



I think Gary and Sheridan both had fun in the Pumpkin. Wind in the face and all!

Best regards, Tom

[Bob Zumbrunnen]

Here are a few pics from Sheridan's camera. Will snail-mail you the CD.

First, you and I on the fastest part of the track. Sheridan was standing at the 5 marker to turn 5 when he took these, so we're in the 120-140 range, though it looks like we're sitting still.




You helping Gary get strapped into the Pumpkin. Hmmm.. Familiar-looking car in the background.


Gary ready to test his neck muscles against a 100+ mph wind. Familiar-looking car gone. Likely on the grid waiting to go have fun.

[OldAIMGuy]

Hi Bob, I'm glad you made it home okay. Sounds like one tiring drive.

The Scoob looks like it's singing

Scrub a dub dub!

Yes, Looks like some camber plates are needed.

Being a former 'Stang piloto, I know how much fun those cars can be in the right place. Take good care of it.

Talked to Ryan today. He's a bit stiff and sore. I didn't have any after effects of his demonstration of the 5 mph rear bumpers! He's getting it repaired, most likely.

Best regards, Tom

[Bob Zumbrunnen]

Thanks even more for your generous hospitality and showing us how best to play on that track.

It definitely added to its fan base. What a fun (and tiring) track!

I got home at 1:30 last night and was asleep before 1:31. Drove straight through.

The Scoob definitely is a fun car on that track, but the Mustang was definitely where it belonged. It's never been on a track that so wonderfully rewarded what few really good traits it has. Felt like "home" for the car, and it's really unfortunate that it's probably the only time that particular car will see that track. It'll get retired sometime next year and I'll have my daughter help me restore it then we'll moth-ball it and hopefully it'll be pretty valuable as a one-owner when she inherits it.

And for all the grousing I was doing about an advanced student not playing well with others on the track (not pointing me by even when I was using his rear bumper to scrape the bugs off my front), an instructor in a 2002 later made me feel so much better. He passed me between a couple of turns then was quick to point me by on the straight. Too bad the session was so short. I bet he and I could've had a lot of fun just swapping positions on different parts of the track. Especially if we'd been running in the instructor session so we could actually pass mid-turn.

I really appreciated that in return for my not holding him up in the turns, he didn't make me hold back the Scoob's screaming horses as it ran up that stories-tall hill. I found and thanked him in the paddock.

Couple pictures. And I'm sure you've got some, too. :)




Really too bad the brakes started going away on the Mustang. As much fun as I was having in the Scoob, I still can't wipe off the silly grin the Mustang put on my face. What a great car for that track!!! And what a great track for that car!

Edit: Noticing in these pictures that the Mustang's suspension looks to be just about perfect, but the Scoob's camber appears to be going positive. And it's hard to tell in these pics, but though the Mustang is obviously rotating beautifully, it doesn't look like the Scoob is. And it rarely feels like it is. I could only get real rotation on it in 5 and 8.

Sheridan had mentioned that Gary's Scoob turns a lot better than mine, but visual inspection made it look like we're both running the same camber. As negative as the stock bolts will let it go.

I need to do some legwork because I'm really curious to see what differences there are between Gary's 2002 WRX and my 2004. We think his might actually be 200 lbs lighter, which would certain make a difference, especially if I'm carrying more weight over the front tires.

[OldAIMGuy]

Hey Bob, Hope you, Sheridan, Gary and Vince made it back just fine. It turned cold overnight, 49° this AM. I'm glad we had warmer weather for the weekend.

I assume all of you managed to get your right foot exercised enough this weekend. There aren't many tracks in the country where one can keep the throttle planted firmly to the floor for as long as one can at Road America.

You will have to come back for one of the pro weekends or maybe the BRIC in mid July. The place has a different feel with lots of spectators. I was glad to see Sheridan got to burn up some electrons with his camera.

Thanks again for letting the old guy hang out with all you youngsters!

Best regards, Tom

[OldAIMGuy]

I think Road America has added to its FAN base!

Welcome Bob and Allen!!!

Best regards,

Piloto Loco

[OldAIMGuy]

That's one scary warm-up lap!!!

Surprised he wasn't black flagged.

TV

[OldAIMGuy]

Hi Bob, The front rotors on the Pumpkin are nearing the end of their effective life also. It appears there's a rule change in the works for the Spec. Cobras that will allow us to use the later spindles ('95 and newer?) that have a hub separate from the rotor.

That would certainly be nice. It will make changing out the front rotors a much simpler task.

After driving Pete Wison's Stang in the early '90s, I'm amazed these rotors have held up so well. Then again, I'm only stopping 2/3s of the old Stang's weight.

Best regards, Tom

[Bob Zumbrunnen]

Sheridan,

Here's the "I Was Seventh" video you sent me.

Tom, this thing's a riot.

Sheridan also sent me several others I'll put on the ad server and give out the URL's discreetly. They're more off-color.

http://adserv.stocksite.com/images/iwasseventh.wmv

[Bob Zumbrunnen]

Hi Bob, Don't forget to bring my phone #s along.

Still have them in my cellphone.

R.A.'s not too hard on tires if you don't "flat spot" them!!!

I'm really bad about flat-spotting tires on the Mustang. No ABS, all the weight on the front, and effectively no rear brakes.

But I don't expect that to be a problem this time out. I'm sure the tires on the car have been heat-cycled enough that they've become effectively bald street tires, and I know the spares have reached that point. Not a lot of stick until just before they get so heat-soaked they get greasy.

Among the spares I'm bringing is a tire I knew for sure I'd flat-spotted going into the mini-carousel at HPT. Was ready to stick my arm out the window to come in, didn't hear anything, stayed on the track, went down the front straight, and everything was fine. When I came back around to the mini-carousel, sure enough, there was a long, dark Hoosier-shaped stripe on the track. Even upon close inspection, I couldn't find any damage on the tire.

It's harder on brakes and it demands a lot of time under full throttle.

I should be well-covered on both engines and brakes. I went ahead and replaced the Mustang's rotors because the old ones had small surface cracks all over them. Fine for spares. I do hate putting Hawk Blues on brand new rotors, though. And the Scoob will have the same problem. My first sessions in each car will likely be very short and I'll be doing nothing but bedding in the brakes. If I remember to grab the instructions for doing so that surely came with at least one set. I never can remember how the cycle goes.

[OldAIMGuy]

Hi Bob, Don't forget to bring my phone #s along.

R.A.'s not too hard on tires if you don't "flat spot" them!!!

It's harder on brakes and it demands a lot of time under full throttle.

See you soon,
Tom

[Bob Zumbrunnen]

That's kind of the impression I was getting. I knew that something like the first 60% of the long straight is uphill, so I've been looking at the map and already pitying my poor brakes for what they're going to go through at the end of two decent downhills.

I've got the Scoob ready and the Mustang on the lift. The Scoob got new brakes, including rotors and pads. A Porterfield pad that's supposed to have nearly the same torque as the Hawk Blues but not be as abusive to its relatively expensive and fragile rotors. The Scoob also has new tires/wheels on the back and the old backs got moved to the front and the old fronts are coming along as spares. They're asymetrical and directional, so I've got one spare for each side of the car.

I went ahead and put the fuel tank in the back of the truck and filled it and found my extra marine battery, so as far as the truck goes, all I need to do is semi-securely mount the battery and wire it to the fuel pump.

I'll need to buy a jack. Haven't had a good one in ages because I usually haven't worn anything out at the track, and whenever I have, I just switched fulltime to the other car. I expect I'm going to go through plenty of brakes and tires in 5 days of track time; especially the Friday instructors/advanced students day. You gonna be running Friday?

I also need to gather up all the tools needed to service brakes and tires and make sure they're all in the trailer. Have more than enough Gatorade. I'll pick up ice in EL Sunday evening.

Won't be bringing a motorcycle at all except the parts bike I'm picking up in Illinois on the way. I'll use the Scoob for commuting.

The Mustang's going to take a lot of work. I have no idea what condition the drums and rotors are in, but they acted fine last time out, so they'll come along as spares. I'll buy new ones today. And since it's got shoes on back, the brake work will take substantially longer than the Scoob did. And I need to flush/replace the brake fluid in the Stang.

Both cars will be showing up on new brakes and rotors and have a complete set of new brake pads/shoes in boxes along with one usable front and two usable rear rotors for the Scoob, and 2 of each for the Stang. I'm literally going to be bedding in my brakes at the track.

The tires are a bit hardened, especially the spares, but they'll have to do. Not really enough time to set up the rig (sawhorses and a long pipe) to HotLap them all and let them set as long as they need to. Which reminds me. I think I've got a fair amount of tire dismounting/mounting to do for the Stang. All of my spares will be on pony wheels (turns out they're just as light as the fancy aluminum ones I got), so I need to just pick out the best ones and make sure they're on the right rims.

And still need to locate my small inverter to run the laptop in the truck since I've temporarily replaced my stolen GPS unit with a much less expensive laptop one.

Heading out here soon to pick up the Stang's drums and rotors then home to get that car ready and get everything into the trailer.

I won't have enough time to do the thing I wanted to do of putting a battery isolater in the bed of the truck and tap one of the alternators to feed the trailer batteries directly rather than through the 30-amp fuse. Was really hoping to do this, as 30 amps thrown at 8 deep-cycle batteries really doesn't do much in the way of charging them. And we've found that if the batteries are drained, starting the truck doesn't provide enough power to even run the lights in the trailer. Not until the truck has charged the batteries a bit, which takes forever at less than 4 amps per battery.

Not a big deal. I doubt we'll need much juice from the trailer. It's awfully handy when needed, though.

Darn. That reminds me. The tire inflator for my little 2-gallon air compressor is screwed up, so I need to get a replacement while I'm getting my brake rotors and drums.

Got a lot of tools and clothes to pack and also need to make sure I've got pillows and blankets since I'll probably make this trip in at least 2 or maybe 3 legs, and plan to just sleep in the trailer on the air mattress. It's really pretty cool to sleep in that thing and wake up to the smell of the coffeemaker brewing up a batch.

[OldAIMGuy]

Hi Bob,
Think UPHILL from Turn 12 all the way to Turn 1.

Think DOWNHILL from Turn 1 to Turn 5.

Think UPHILL from Turn 5 to Turn 6.

Think Downhill from Turn 6 to Turn 12.

There. The short course in driving Elkhart Lake's Road America!



TV

[Bob Zumbrunnen]

http://www.roadamerica.com/2005/images/maps/map_track.pdf

<DROOL!!!>

[OldAIMGuy]

I don't remember if I mentioned it or not, but for this last weekend I'd ordered up a new set or rear springs for the Pumpkin Racer. I'm not certain what the spring rates are that ship with the current kits. Mine's an early Spec. kit (#2911SP) but seems to be different from others in that respect.

When I first got the car I'd read the little aluminum tags on the springs to see what they were. I thought I remembered the fronts being 500 and the rears being 350s. Over the last season I have brought the car up to speed in various events at various tracks and was generally pleased with the handling in the larger, faster turns, but the the car had significant "push" in the slower corners.

Choices were to attack the slow corners more slowly or do something to lessen the push. I chose to increase rear spring rate. (Note: the Spec. Challenge cars don't have either front or rear anti-sway bars. You do it all with spring rates) I didn't want to sacrifice the fine high speed stability with the change, so decided to bump up the rear rate by 50# to 400 a side. This was enough below the fronts' rate to seem logical and still a significant enough increase to be meaningful for the car's feel.

Well, the 400s arrived from FFR quickly and it was a pleasure to find that a spring swap was such an easy job. Maybe 25 minutes a side including jacking the car and removing and replacing the wheels. That's the kind of project that I like!

Well, checking the bottoms of the old springs turned out to be an education in CRS disease. The rears were 300#, not the 350s that I had "remembered." Hmmmm, well, how's this more abrupt 100 pound rate change going to affect my handling when I expected to only massage it by 50#?

I'm delighted to say this is where I wanted it to be. If the old springs had been what I had thought, probably the 50# adjustment wouldn't have been enough. As it turns out, this is just what the PUSH Doctor needed to cure the patient. I've not sacrificed any of the higher speed stability in carossels and such but the car's turn-in and balance is far better in the tighter corners. The car responds much better to throttle input as well.

Here's what impressed me. It was easy to change the springs. I'd already done frame leveling, etc. before, so that wasn't hard to repeat with the new springs. The change was meaningful and "textbook" in response to what I wanted to change.

After the change and resetting ride height and leveling the car, I then took it to the county scales (+or- 20# accuracy!) and weighed front and rear axles, left and right sides and then each corner with me in the car. I found that there was about 60# or so difference in "Cross Weights" (or the diagonal sum weights). Back to the shop and a quick 1/2 turn of the left rear and right front spring perches to lessen the pressure these were exerting. Once more across the scales showed that I was now within 20# on the diagonal sum weights. Since the County doesn't need any more accuracy when weighing trucks filled with salt, that was as close as I could get.

After years of driving ancient English roadsters and newer "showroom stock" cars the ease of making all the adjustments that I've done to this car since I bought it 2003 has been a certain pleasure. It responds appropriately to input and is very "adjustable."

I think I'm content with the handling with the current 500F/400R combination. Many of the racers have gone to much heavier rates, closer to what an autocrosser might desire. I can't fault their logic as many of these same people are running at the front of their respective groups. My experience is with cars of "vintage" character, however, and now the FFR Cobra feels right to me. I do drive mine on the street, so these lighter spring rates are kinder to my old carcass, too.

Other info:
Driver weight = 200#
Car weight = 2540 w/driver & full 22gal. tank
Cross Weights - LF-RR = 1260#, RF-LR = 1280#
Tires (street) = 245-45/17 Hankook "Ventus"
Tires (vintage racing) = 225-60/15 Hoosier TD
Steering rack = standard location (no Ackerman mod)

The car tracks essentially equally in both left and right hand turns.

Best regards,
Tom

[OldAIMGuy]

The 30th Northwoods Shelby Club invitational at Road America is now in the history books. We had spectacular weather the entire weekend and all entries enjoyed at least 4 track sessions a day.


(entering Turn 14 before the LONG Start/Finish straight)


(apex of Turn 14 before S/F Straight)

Bob, the track is calling to you!!! Can you hear it???


TV
PS: More pics from R.A. weekend........
http://www.ediecast.com/cgi-bin/edphotos.cgi?pm=GI&year=2005&date=082605&page=1

[Phil(Hot Rod Chevy)]

Found out later that the folks up north seem to really hate this and "I'm going to pass on the next straight" distance is something like 100 yards or so. I was mugging nearly half of them, and always in brake zones.

Shit, it's racing.

I say all is fair as long as you don't wreck them.

If they don't like it let them find something else to do with their spare time.

Maybe they would enjoy racing up and down the rivers and lakes in a bass boat.

Then we could call them bassholes.

I'm sure you and your friends have a nickname for the buttheads that want to make you stay 100 yards away from them before passing.

If you did that on the interstate you'd never get around anyone.

LOL

Have fun,
Phil

[Bob Zumbrunnen]

Got my Brainerd pics today. Bunches of 'em. Here are my faves.

Looks like I've got a lot more girth than I really do. In reality, I've got a thrill-seeking passenger. Would guess a buck-twenty here on the way to about 145.


Found out later that the folks up north seem to really hate this and "I'm going to pass on the next straight" distance is something like 100 yards or so. I was mugging nearly half of them, and always in brake zones.


And the Scoob all by its lonesome on the front straight. Probably pulling about a buck right here on the way to 125.

[OldAIMGuy]

Hi Bob, Re: Photos...
If JDoc could slow his shutter speed a bit and close down the aperture he'd get the wheels to look like they're turning, too!





Looks like lots of fun.

Thanks,
Tom

[OldAIMGuy]

Hi Bob, the AWD in the W8 is a 50/50 split. The only car I know of that doesn't seem to "push" like that is the baby Jag X-type. It's fore/aft split is 40/60. It's supposed to feel like a very well balanced rear driver.

Best regards, Tom

[Bob Zumbrunnen]

I'll just post the URLs to these I found.

Me in the Scoob earlier this year at MAM with a passenger.
http://public.fotki.com/jdoctor/2005_mam_events/pca_-_may_2005/saturday/_dsc1819.html

Closing in on a 2005 Mustang (likely a rental on street tires) I'm getting ready to pass.
http://public.fotki.com/jdoctor/2005_mam_events/pca_-_may_2005/saturday/_dsc1866.html

Major oops, fortunately not involving me.
http://public.fotki.com/jdoctor/2005_mam_events/pca_-_may_2005/saturday/_dsc1998.html

Me all alone in the Stang.
http://public.fotki.com/jdoctor/2005_mam_events/pca_-_may_2005/sunday/_dsc2577.html

Including this one because I just really love this Elise. And found it easy to get in and out of, though I never got to try it out on the track. Yet. <g>
http://public.fotki.com/jdoctor/2005_mam_events/pca_-_may_2005/sunday/_dsc2095.html

[Bob Zumbrunnen]

Found some pics I'm in from the Mustang Club Of Central Iowa event at MAM about a month ago.

No, I'm NOT catching him.


Think I posted this one earlier. Getting a tirely nearly airborne even with a passenger.


Apparently just passed by Paul Berg. He's a good 5 seconds a lap faster than me.


In the middle of a train.


All pics lifted from http://public.fotki.com/jdoctor/ who takes a ton of excellent pictures at that track.

Also, here's one taken by the Course Marshall this past Friday showing Sheridan, me, and Gary. To me, this picture so perfectly conveys that wonderful day. Three good friends just having a ball all day.


The Mustang crossing the start/finish line at MAM Sunday with passenger. Actually, I think this would be Gary's wife (my girlfriend/student) riding with me. Probably 100 mph at this point accelerating to 125 before the first turn.


The Scoob, probably on Saturday. Or could've been early Friday afternoon.

[Bob Zumbrunnen]

Even with all wheel drive, I found the car "pushed" in corners when pressed to the limit in the dry with the traction control off.

All of the AWD cars I've been in have pushed pretty intensely, the Subaru WRX being perhaps the worst. It plows even worse than the Taurus SHO.

[OldAIMGuy]

Hi Bob, I never bothered to try the traction control in the dry - only during the downpour at the track. In the dry, I can see how it would have inhibited the fun factor!

Even with all wheel drive, I found the car "pushed" in corners when pressed to the limit in the dry with the traction control off. The car feels more like a front driver than all wheel drive with the electronics off.

I did find that one could exceed what the Laws Of Physics would allow in the corners!


Best regards, Tom

[Bob Zumbrunnen]

I went and registered for the NASA event, not realizing it was the same weekend as RA. And also bought an old motorcycle in Omaha with the intention of picking it up when I'm at the NASA event.

I emailed the NASA event folks to pull out, though. I'm definitely doing both of those RA events.

Turns out there will be quite a few folks from down here going to RA for the Audi event, and I emailed one of them asking if he'd specifically ask for me as his instructor, since I've worked with him before and he's new to RA.

If he does, I won't be in as desperate need of your services getting me around the track. And it turns out that one of the other guys coming up is in exactly my boat. Experienced instructor, new to RA, and a bit nervous because he'll be instructing at it.

Interesting that the Passat's traction control would be so good.

When I drove Sheridan's car, I came in on the first lap and called him on the walkie-talkie to tell him the car was fuel-starving in the turns despite showing half a tank of fuel. Turned out it was the traction control. He told me how to turn it off, and the car suddenly got a whole bunch faster and wasn't trying to drive for me.

But the traction control systems have been evolving really rapidly and I'm sure the one in his 318ti is pretty crude compared to what the Passat's got.

[OldAIMGuy]

Hi Bob, I think I mentioned that I was going to put on heavier rear springs on the Pumpkin Cobra. It has tended to "push" a little in the tigher corners while being mostly neutral on higher speed sweepers. My car has the springs that came with the early kits on it. Most of the series racers are now running significantly higher spring rates than came with the kits, however.

I purchased some 400# springs to replace the coil-overs that were on it. I thought the rears were 350# springs but when I removed them, I found they were only rated for 300#. I'd hoped to only go up 50# on each spring as I didn't want to upset the car's balance on the high speed turns.

Well, I installed the new springs this weekend and then did a frame height check. The car stood a tiny bit taller at the rear and my butt tells me the extra 100# rating makes it less street worthy! So, I adjusted ride height and then set about doing some other "tuning."

I'd weighed the car before, but never bothered to do corner weights. The reason is that I use the county's scales which are only accurate to +or- 20 lbs. I guess weighing trucks loaded with Salt isn't that precise a deal!

This time I decided to see just how my "cross weight" was on the car. There's room at the scale to drive single wheels onto the platform at a time. So, I weighed each corner of the car, each side, front axle and rear axle along with total weights. I was thankful that the weights added up! I also did the same weights with me out of the car as another point of reference.

Well, I found that the "cross weight" was about 40 pounds off. It was a bit heavy "Driver's rear to Passenger's Front." While this isn't off by much (after all the scales are not very accurate) it seemed to me that maybe if I fiddled a bit I could get it closer. The driver's side of the car is 1320# vs the passenger's 1220#. This is with a very full tank of gas and my 200# in the car. I don't think the difference is going to make any difference to my lap times.

I then took the car back to the shop and took a full turn out of the spring nut on the driver's rear shock. This has the effect of reducing the pressure that that corner of the car presents to the ground. It sure is nice to be able to make these finite adjustments compared to the old English production based sports cars I've always driven.

I took the car back to the scales and remeasured. The car's now

 
          LF            RF 
         560#          520# 
  
          LR            RR 
         760#          700#

So now the cross weights are 1260 vs 1280. While side to side weight didn't change, it dropped 20 pounds off the cross weight with me in the car and about 40# off the cross weight without me in the car. So, now the car should be nicely balanced for the next track event.

It remains to be seen if this stiffening of the back of the car is going to upset the overall handling. I'll know soon enough as I'll be up at R.A. on the weenend of Aug. 26-28 with loads of track time. With 500 pound springs on the fronts and 400 pound on the rear it will be interesting to see how it drives. Most of the competitors have gone to 600 or higher on the fronts and seem to keep 100 to 200 pounds less spring on the rears. Those things must ride like bricks!

More later after some track time!

Best regards, Tom