Road America video - Page 3

mattr762 · #41 (**permalink**) 12-12-2003, 12:38 PM

The track is 4 miles long. It took you 2:30 minutes to go 4 miles. That equals an average of 94 MPH!

snakeeyes · #42 (**permalink**) 12-12-2003, 12:56 PM

Scott, you could do some rear ducts on the tops of the fenders, like that original 427 that appeared in several formalwear ads back a few years ago...I don't recall the CSX # but I want to say it is/was owned by a couple of brothers named Jones...

valpodoc · #43 (**permalink**) 12-12-2003, 01:33 PM

Scott, I have rear ducts under my car. Check with shelby American. Also how did you convert your analog 8mm footage to digital?
Roland

scr11 · #44 (**permalink**) 12-12-2003, 04:40 PM

Fantastic video. One of the best I've seen over the last couple of years.

Scott, SPF#1230

Morris · #45 (**permalink**) 12-13-2003, 07:34 AM

Scott

Great film.... every movement and every frame was exciting....

When you get the brakes.... you'll be surprised how your times will fall....

And Road America is one of the hardest tracks on brakes....

Did I notice you were only using 2 gears around the track except for turn 5....

What were your tire temps....

Let me know and I'll help if you ever go back to Elkhart Lake...

coyled · #46 (**permalink**) 12-15-2003, 08:26 AM

Morris, Tire temps were around 180 in back and 165 to 170 in front. Backs were at 17 pounds to start and 26 hot. Fronts at 17 to start and 24 hot. This is after they cool down and you come in at turn 5 and go through the pits. I was in third gear for the first 2 corners. I was in 4th and then down to first gear(1.94) for turn 5. The first lap of the video, I was trying to stabilize the car in the brake zone by downshifting through all the gears into turn 5. I think it was a waist of time, so I skipped it on the next lap. Second gear for turn 6, thid gear for turn 7, second gear for turn 8, third gear for the carosel, 4th for the kink, second for canada corner, third under the bridge and through turn 12, back to 4th for the front straight. Scott

Morris · #47 (**permalink**) 12-15-2003, 09:56 AM

Scott

Normally we would gear a car for the amount of time you spend in the turns....

However at Elkhart ..... your in the straight away for much of the time and you need to go to the best gear that will pull you down the straight and not peak out to soon....

Having said that ... Richard is right on when he said you need bigger brakes ..... and you need to change the gearing to something like a 3.7.... or 3.5.... with a 27" tall tire....the motor seemed to pull but then you had to feather the throttle because you weren't at the corner yet.... big loss of time at Elkhart....

Once you pick up the speed ..... then you need very large brakes and proper cooling to get you slowed for the corner.... Many of races we won when everybody else lost there brakes after 10 laps.... temp paint will help you balance the brakes front to rear...

Morris · #48 (**permalink**) 12-15-2003, 10:11 AM

Scott

As far as Tires.....

We wanted to come off the track with temp across the tire at 200-210' degrees..... with the hotter temp on the inside of the tire.... and you also want the pressure to be at 30 lbs hot when you come off the track....

Adjust your pressure going out a little higher......in your case I'd raise the backs up and try going out at 23#-LF..... 25#- RF..... 24# on both rears..... and then adjust accordingly to get to 30# when you come in....

By the way tires that have had a couple of heat cycles in them will drop down about 10-20 Degrees.....and wont' stick as welll... and I'm sure you all ready know that...

If one tire is hoter overall than the others....then suspect .....
To much weight on that corner....
To much toe-in.... or out....
Expect that tire to Blister inside of 50 miles....

Just some thoughts

coyled · #49 (**permalink**) 12-15-2003, 10:44 AM

Morris, I have spoken to goodyear about the tire preasure issue and they say the same thing, 28 to 30 hot with the bias ply slicks. I can tell you that my cobra will slide like crazy and has a lot less stick, especially in back when they come off at 28 or higher. The temps are up higher in the middle of the tire too. Maybe, its because the cobra is 2400 pounds as to why a less preasure works better. At shorter, more technical tracks, the tire temps are higher overall, regardless of preasure. I do think the tires cool aff a bit at Road America on those straights. Also, the way mine is set up or maybe just a cobra, I don't trail brake it to plant the fronts. I try to slow it in the straight line, turn it, and on the throttle at the apex or before it if I can get away with it. Were you running those tire temps on a cobra? Scott

coyled · #50 (**permalink**) 12-15-2003, 10:55 AM

Morris, I featherd the throttle for fear of not stopping in time at the corner. You can see this big time at the other side of the kink. It also had a lttle bit of hunting or a wiggle when I first went to the brakes, you can see this going into turn 5. I still don't know what it was, maybe too much toe out(1/8), or spindle flex, hot brakes, but it was making me nervous for sure. I think it slowed down my transition from throttle to brake as I didn't want to jump on them with that wiggle. Its not running out of power and would go to 8500 rpm. I actually think the gearing is just right. The driver needs the most work as always. Scott

rdorman · #51 (**permalink**) 12-15-2003, 11:01 AM

Tire pressure, only tire temps will tell the story. Forget a blanket recommended pressure except as maybe a starting point. Reading the surface of the slick is not as good as using a probe to get under the surface.

You are boiling the fluid. Try a higher temp fluid and completely change it before EVERY track event. You want your calipers to run 350F or under. While you are in there put temp sensing strips/paint on the pads and calipers so you know how hot you are running. Mass is the only thing that will build less heat. Duct air but be sure it is done right. Both sides on a solid rotor and in through the center and out the vents on a vented rotor.

Really enjoyed the video!

Rick

coyled · #52 (**permalink**) 12-15-2003, 11:08 AM

Rick, thanks for the comments. The fluid I boiled was castrol SRF. The 90.00 a quart stuff. I thought it would never boil. The temps were pretty even, 10 degree's hotter on the inside of the tires which I thought was about right. We were useing a probe. I am going to duct the rears. Scott

Morris · #53 (**permalink**) 12-15-2003, 11:16 AM

Scott

The temps and pressures were run on a 2350# GT 1 Corvette... Times were in the teen's....

But if your temps are higher in the middle of the tire... then you need more negative camber....

Many times the induced power oversteer is miss interperted for a handling issue and it is more of a driver technique issue....

28# is low and you want the tire to be at 30# so it is flat on the ground....

Also you might want to stiffen the springs or sway bar in the front to increase the wheel rate to induce less oversteer....your tire temps were higher in the back then in the front....also your pressure build up was higer in the rear indicating oversteer ... allbeit suspension or driver induced....

And yes the tires do cool down some what but not as fast as you think....

Morris · #54 (**permalink**) 12-15-2003, 11:36 AM

Scott

The wiggle or hunting when you are going into turn 5 is a Bump Steer issue.... many cars have this and you need to address this issue with a Cobra since most of them use a tie rod end that is tapered into a steering arm attached to the upright.... should be a heim with cones and washers on top and bottom so you can move the steering arm up or down as the case may need....

Turn 5 is where you will notice the loading in the front more than any other place on the track and right fully so....

Keep the bump steer down to less than .005" per inch of travel....up or down from ride height

Also use the temp paint on the rotor..... paint H's on the vent holes of the rotor next to each other starting at 900 degree's then 1000 then 1100 then 1200 degree's.... then when you take the wheel off you will know where you are with the temps..... 1000 to 1100 degree's on the front and 900 to 1000 on the rear... adjust cooling and bias as needed....

It's normal to bleed the brakes before each session.... also keep the fluid sealed....

BTW Elkhart and Blackhawk Farms are the two hardest tracks in the country on Brakes.... if you get them worked out for those tracks you can go anywhere else and feel good about your brakes....

rdorman · #55 (**permalink**) 12-15-2003, 12:26 PM

Boiling SRF, now that is working it!

Do get some cooling to your brakes. The seals don't work real well nor last real long outside their designed range.

Blackhawk farms, man I haven't thought about that place in years. Brings back memories.

Rick

coyled · #56 (**permalink**) 12-15-2003, 12:35 PM

Morris, I used to run -1 3/8 camber in back, but the cobra did not hook up very well and always wore the inside edge of the tire a lot more which was reflected in tire temps. I went down to -1.0 and the cobra hooks up much better out of the corner and actually has just as good lateral traction. There is a lot of camber(more negative) and toe change(out) on acceleration. I could run more rear spring rate to stop some of the change, which I have, but then it won't hook as well and the cobra oversteers. Right now, the way it is setup, the cobra has a pretty big push dialed into it. This is the only way I have been able to get added rear traction on corner exit. The front camber is -1 3/4. I will check the bump steer which I have not checked in a while.Thanks for the help. Scott.

Morris · #57 (**permalink**) 12-15-2003, 02:55 PM

Rick

I hope they were good memories....

Great little track to learn on.... and figure out what you had to do to a car to get it to last....

And nice folks.... taught me alot in those early day's

GeorgiaSnake · #58 (**permalink**) 12-15-2003, 05:06 PM

Morris I have been following this thread since it started and enjoyed your comments.

My memory is a bit off camber but I think I saw you run several times at Road Atlanta. I was an avid SCCA fan in the 80's and ran a bit at Road Atlanta. I ran EP (356) and had to deal with the likes of O'steen, Spruell, Cogbill etc. EP was hotly contested in those days. Wish I had been able to pick your brain back then I may have gotten into the mid 30's.

Thanks again and welcome to the nut house.

Randy

john gyann · #59 (**permalink**) 12-15-2003, 07:11 PM

Hi Scott. Great video it's inspired me to post some videos of Run & Gun soon. I can't wait to see what you do at RA next year. See you soon in Phoenix. John

Morris · #60 (**permalink**) 12-15-2003, 07:40 PM

Randy

John O and I raced at Road Atlanta for 12 hrs one night.... what a night .....

Those were some good old days.... and boy did we work hard every minute of the day....

I just happen to be very lucky and fortunate.... and there were some great races we had in GT-2 as well.... John Finger.... John Hogdall...Bob Reed all Mazda drivers.... some of the Datsun drivers were Logan Blackburn, Frank Leary, PLN, Jim Fitzgerald and Scotty Sharp.... Good time to race and learn and have some fun..... That is a great track... Road Atlanta.... and our pole time with the Corvette was under PLN times when he ran the Twin Turbo Nissan.... Ahhhhhh the old days....

We were the last one to win Road Atlanta with the dip instead of the turns they have today..... That was where they seperated the men from the boys.... and when you came out from under that bridge..... many times I slid down that hill to the finish line..... hoping I could do it just one more time..............That's enough ....my heart is getting all excited again and you'd think I just took some Viagra.........