small 1/4mile oval tips, transitioning from road racing

[rob burgoon]

Gonna reduce the RR upper angle one big hole for saturday. I'll order a second chain if this doesn't go the way I expect.

[rob burgoon]

Lots of crashing this time around. These cars are amazingly tough or I'm just amazingly lucky. All the crashing made it hard to focus on setup.

http://youtu.be/upp-VDbcqzM

http://youtu.be/1sPYMz49pVU

The track blacked over pretty fast in the main. Very tricky to drive the car in the black. Do you guys have any theories on how the car's behavior changes in the black? Does tread depth matter in the black? Sipes help? Hurt? Bring out the worn tires for the black maybe?

When cornering does having the tire press down still increase grip in the black, or does it flip-flop since the surface is harder?

Lateral G and weight transfer seems to go down in the slick, does that mean we want to increase on-throttle dynamic weight on RR a little when we hit the gas? Maybe incline a RRU a little in the slick and lower it a little in the tacky to adjust for this?

[drtrkr244]

Your car looked very loose in and off. The track looked fairly hard and slick. Generally, you have to increase weight transfer to the right side tires to generate more side bite and forward bite, esp when using harder tires.

My go to adj for those conditions are 1) lower jbar on pinion 2) lower right bottom bar 3) lower right top bar 4) lengthen drop on LR. Just be careful not to get too tight as that would kill a crate car. Hope this helps.

[rob burgoon]

You race with some idiots. Wow, talk about talentless haha. These guys can't even keep the cars under them! I wouldn't race there unless you plan on getting wrecked weekly. Looked like every car except 1st and 2nd spun hahaha 

Eh, I can't really complain. A car got wiped for the night from one of my spins in the heat, and then I managed to back into someone's undamaged panel. Oops. Still adjusting to the no mirror thing haha, thought I had seen every car involved, but was mistaken.

More lessons learned.

[rob burgoon]

Your car looked very loose in and off. The track looked fairly hard and slick. Generally, you have to increase weight transfer to the right side tires to generate more side bite and forward bite, esp when using harder tires.

My go to adj for those conditions are 1) lower jbar on pinion 2) lower right bottom bar 3) lower right top bar 4) lengthen drop on LR. Just be careful not to get too tight as that would kill a crate car. Hope this helps.

Here's my guess at the primary effects of each of those:
1) lower rear roll center, more body roll, more weight transfer to RR when cornering
2) less rear steer, does something to entry maybe?
3) less weight on RR when on gas, less rear steer
4) more rear steer, more weight on LR

Lot going on there if I have it right.

Also, after that race that was 2 nights on the same tires, LF 5/32, RF 4/32, LR 3/32, RR 2/32 tread depth of the paddles. add 2/32 for tread depth of the circumference cuts. I was running about 13 psi cold all around, tire wear suggests less pressure on right side tires and a little less on left side. I might try 11 on the right sides, 12 on the left.

[oldtrackchamp4x]

RF 12 RR 11 LF 10 LR 8 Dry slick only.JMO.

[rob burgoon]

RF 12 RR 11 LF 10 LR 8 Dry slick only.JMO.

Do you have a theory on why the lower pressures on the left side? Do the rights have to be higher to keep the tire on the bead or something?

3 psi split on the rear tires to add stagger?

[oldtrackchamp4x]

This is what Hoosier tire recommends for their G-60 IMCA tires on a dry slick track. Except the RR. They say 12 but I run the RR at 11 and it works for me. JMO.

[stock car driver]

This has to be a joke, you've got the internet and found this forum but you cant find shaw, jet or many of the other chassis websites with set up and tech adj guides?

[rob burgoon]

This is what Hoosier tire recommends for their G-60 IMCA tires on a dry slick track. Except the RR. They say 12 but I run the RR at 11 and it works for me. JMO.

Fair enough.

This has to be a joke, you've got the internet and found this forum but you cant find shaw, jet or many of the other chassis websites with set up and tech adj guides?

How many setup guides describe why lower pressures on the left side are favored? Do post a link if you can find one that says *why* lower pressures on the left are better.

[stock car driver]

Fair enough.



How many setup guides describe why lower pressures on the left side are favored? Do post a link if you can find one that says *why* lower pressures on the left are better.

really? you need someone to tell you that. like I said I hope your just screwing with everyone on here, nobody can be that out of it.

[stock car driver]

http://www.hoosiertire.com/otdtire.htm

12. IMCA Air Pressure Siping & Grinding Tips

1) What is the proper air pressure for the IMCA tire?
a. Temperature profile across the tire is the best indicator
- If your temperatures are even across the tread, your pressures are correct
b. We always recommend running the most pressure possible
- Under inflated tires will feel soft, squirmy, unresponsive
- Over inflated tires will be loose with little traction, “on top of the track”
c. Standard IMCA Modified setup:
- Heavy Track - 15 right side, 12 left side
- Slick Track – 14 right front, 10 left front, 13 right rear, 8 left rear

2) How should I sipe my IMCA tires?
a. Why do we sipe?
- To build or remove heat
1. We sipe across a tire to increase wear and build heat. We sipe around a tire to reduce heat and increase sidebite when additional traction is not necessary.
- Reduce block stiffness and increase wear on tires too hard for track conditions
b. Siping tips
- We generally never sipe more than ½ depth of any block. 1/3rd the depth of the block, or 3/32nds, is preferred in most situations.
- The more sipes you apply, the shallower they should be. In turn, the less sipes you use, the deeper you can cut while still minimizing the risk of chunking.
- The more evenly you can space your sipes within a block, the better their performance will be. You should always try and limit the amount of small, unsupported corners of a block to reduce tread chunking.
- Unless facing severe track conditions, IMCA tires seem to like aggressive siping, both across and around, the tire. In turn, if the track is severe, only shallow, circumferential sipes should be used to help reduce temperature and possible tread blistering. Taylor your quantity and location of sipes to the track conditions; the easier the track, the more sipes and vise versa.

[rob burgoon]

Don't mind this idiot ^ he can't keep his car consistent if his life depended on it. Just time the moron and you'll see this. He is way behind. His stock car days makes his head all big and mighty when in reality he only bully's over the Internet and a coward in person. He unlocks and blocks me regularly because he wants to know what I say. That should tell you Enough about the creep.On another note tire pressures we personally even out when track slicks off. Close up rear pressures and fronts. Stock car doesn't know his RR temp or pressure when he gets off track and likes cooking it cuz he has no talent obviously. Like I said time the talentless idiot who has no one backing him.

Yeah, he doesn't seem to play nice in other threads either. He sent some abuse my way in private messages.

At any rate, the tentative plan for next week is to rotate the tires around, buy a belt sander, and try to knock off some shine. It will be night 3 on that set, and I expect the track to get blacker in the main. I'll add some stagger to try to remove the desire to slide in the middle of the corner. Driver will try to take up the gas again earlier to stabilize the handling.

[stock car driver]

Yeah, he doesn't seem to play nice in other threads either. He sent some abuse my way in private messages.

At any rate, the tentative plan for next week is to rotate the tires around, buy a belt sander, and try to knock off some shine. It will be night 3 on that set, and I expect the track to get blacker in the main. I'll add some stagger to try to remove the desire to slide in the middle of the corner. Driver will try to take up the gas again earlier to stabilize the handling.

Your funny. I tried to help you. CLEARLY your just screwing with people on here nobody is stupid enough to not know why the left side air pressure is lower on a car turning left.

9x cant make up his mind, first hes a old old wise crew chief, then hes a crew guy whos been around dirt track racing longer than Ive been alive, now hes a driver, he needs to try and keep his lies straight hes posting on here.

[rob burgoon]

Your funny. I tried to help you. CLEARLY your just screwing with people on here nobody is stupid enough to not know why the left side air pressure is lower on a car turning left.

You have no idea either, so beat it.