Gateway Test and Tune 04/20

S

Steve Fehr

Member # 017
GCC Member
Location
Ellisville
First Name
Steve
Last Name
Fehr
I'll be heading over to Gateway this afternoon. Hope to be there in time for the gates to open at 5:00. Racing starts at 6:00. Assuming no delays due to problems on the track, I hope to leave between 7:00 and 7:30.

Steve
 
Good luck, keep trying for that elusive 11.93. I don't need to know when you beat it :rolleyes: :D
 
Purple Venom said:
Good luck, keep trying for that elusive 11.93. I don't need to know when you beat it :rolleyes: :D
Click to expand...

Tim:

Your time is still good. I should have been bracket racing. A 12.17 followed by three 12.06s. Was having a hard time getting hooked up. Speed through the traps was between 114 and 116.

Steve
 
STL Mark said:
Good Job Bud!
How was the crowd?

Kate OK?
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Mark:

The crowd was relatively light. Like last year, they have combined the street tire, slicks and motorcycles all into a single night. I was #4 in line at 6:00 when racing started and got two runs in by 6:30. It took an hour for the next 2 because of a problem on the track. I was told that the turnout had been light all year long.

Kate ran well. Even with feathering the throttle out of the hole and short shifting 1/2 and 3/4 the tires were coming loose. I was running 18lbs of pressure. I'm concerned about going any lower.

My objective last night wasn't to beat Tim (even though it would have been nice :)) but merely to warmup for Muncie. It will be much more interesting in that environement where you're actually "racing". At Gateway I was matched up against a stock pickup truck twice and some little rice rocket on the last run. Neither were a challange. I suspect I'd peddle just a little faster if Tim was lined up next to me.

Steve
 
Ok tire experts, chime in here, but is he really gaining anything by lowering his air pressure on street tires? I ran my best time with 32lbs of air in my rear tires. I've learned and read that the front tires should be aired up to 38 or max to make them harder to reduce rolling resistance. My point is, street tires obtain their maximum grip at the right air pressure for the tires. I don't think lowering the air pressure is really helping you Steve, and may actually be contributing to your loose feel going down the track. Next time you go, try running your rears at 22-24 and see what that does. My .02 worth.

Race, there is going to be racing at Muncie! :eek: I thought it was just for fun :D Guess I'll have to put the slicks on :D
 
Purple Venom said:
Next time you go, try running your rears at 22-24 and see what that does. My .02 worth.
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Tim:

I've run them that high before and haven't had any luck. All the folks at the track suggest lowering the pressures. I emailed Scott Holley last night and he replied that I should stick with the 18 lbs but to soften my front shocks up to a setting of 0, while stiffening the rears with a setting of 7 or 8 (out of 12). I guess I'll give that a try between now and Muncie.

Isn't Paul a drag racer?

Steve
PS: Hell yes its a race.
 
Take a piece of chalk and mark the tire and rim...if pressure is too low the tire will spin on the rim. This is the way we did it in the old days...or sometimes screwed the bead to the rim.Still have a set of slicks mounted and they are screwed to the rim all the way around.
 
I ran 3.5 lbs of air in the rear Goodyear 11" wide car slick on the funnybike and ran over 162 MPH in the quarter. Thats...three and a half lbs. of air. The air gauge was calibrated in tenths and 1/4 to a 1/2 lb variation could be seen in the tires footprint.

Yes, a slick needs to be screwed to the rim with sheet metal screws and yes it feels squirley especially when the tire shakes really hard. However the way to determine correct pressure is to watch the footprint after doing a short chirp of the tires. Not a full burnout...but just a about a foot or two of rubber. Watch the center of the footprint and the edges of the footprint. If the rubber being left is concentrated in the center of the tire...decrease pressure. If the rubber is concentrated on the edges...increase the pressure. If you see both a dark center and dark edges with light band inbetween...the tire to rim width combination is wrong....usually the rim is too narrow. You are looking for a uniform patch across 100% of the width of the tire.

For a heavier car obviously the pressure will be higher...but the principal to find the optimum pressure for your vehicle and tire remains the same. I agree with Mike that if your going to be serious and run slicks....definitely screw the tire to the rim and use the white shoe polish (or a yellow crayon) to mark the position of the tire to the rim to determine if the tire is trying to slip on the rim. I also am a firm believer in running a tube inside the rear slick even if it's rated as tubeless. A rear tire shake can be very violent and relying on only the tire bead to hold air after screwing 20 or more sheet metal screws into it... is IMHO too risky.

Oh...we also ran 60lbs of air in the front tire...but it didn't see much contact on the track....:)

Kerry
 
Kerry & Kathy said:
...Yes, a slick needs to be screwed to the rim with sheet metal screws...
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Kerry:

I'm running on street tires - Michelin PS2s. Slicks aren't on the radar for me.

Where did you do your mini-burnouts? Leaving rubber on the driveway isn't going to fly with Pam and I doubt if the pedestrians at the strip will want me dumping the clutch in the parking lot.

Steve
 
Steve, Pam will get over it, Linda did :D Thanks Kerry. I will just have to beat Steve with my little ole street tires :rolleyes: :D
 
Steve Fehr said:
Kerry:

I'm running on street tires - Michelin PS2s. Slicks aren't on the radar for me.

Where did you do your mini-burnouts? Leaving rubber on the driveway isn't going to fly with Pam and I doubt if the pedestrians at the strip will want me dumping the clutch in the parking lot.

Steve
Click to expand...

Mostly between the bleach box and the starting line during time trials for any needed adjustments or on the far end of the return road. However, any good (remote) smooth blacktop or concrete will do. Concrete is definitely easier to read but harder on the driveline.

For street tires... screws are out of the question so you'll have to run more pressure to keep from spinning the tire. Actually a street radial works better with more air anyway since you don't have as flat a tread area as you do with a slick. However adjusting tire pressure can help what is already limited traction. An old street racer trick is when your tires are off the rims you can use a spring loaded center punch to dimple the inside of the rim sealing area above the bead. The bead should be untouched to maintain a seal but just above you can dimple the rim to resist spinning the tire and get away with a little less pressure.

I really think with street tires you could gain more with launching technique. Get the tires hot in the bleach box with a second gear start and spin the tires pretty good until they want to start pulling you out of the box. Then do a short dry chirp going to the starting line to remove any remaining water and loose rubber balling on the tire...then stage. When you leave...Keep from spinning the tires excessively by slipping the clutch to keep the engine rpm up while keeping the tires just on the verge of breaking loose. This is where a lot of practice getting the launch right can pay off in lower ET's.

Get the tire pressure close and then practice your clutch technique until you can leave hard...and consistently.

Anyway...what do I know...I'm just an old fart. :D
 
:D Dream on Stever. Street tires will not pull a wheel off the ground. But, think what ya want, you SPF guys usually do :D
 
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