Siping question

[latemodel86]

I've seen tires siped across and some siped along with the tire. My question is, what direction will I sipe under certain conditions and why?

[fast_crew]

Across to let the tread flex alittle, build heat and provide edges until the tire fires, usually done to hard tires on a hard surface. Around helps to get side bite, and disipates alittle heat down the straights, small grooves work better for heat disipation though.

[latemodel86]

So, let's say, if I had a D55, it might be a good idea to sipe the tires across and then get a #1 head and blade, and then put a groove in the middle of the tread block going along with the tire?

[joedoozer]

We don't run a D55, but we did run a SD48 spec tire for a season. And they are also hard as stones. For the front tires I used a #1 and cut each block into 1/4's. Instead of 1 big block I now had 4 smaller ones. And then siped each block into 1/4's. For the rears I used the same #1 but only cut the blocks across. Making thinner wider blocks. And siped those around the tire. It really does depend on the track type, driver style, and the race. Does the track tend to have long green flag runs, or is it a crash fest and the caution is out every 2 laps. Knowing what the sipes and grooves will do, will help you decide what is best for you.

[hpmaster]

I like the side bite from lots of radial sipes on dry slick but I sorta think that over 5 or 10 laps on a green the tire might give up more than I gained with too many sipes. Doing this I have been able to go out as far as half a lap ahead only to have folks catch back up as the tire gives up. This is what I think it fires the tires up fast but it don't take long to give it all back. Is 24 not enough or 42 too many? Ok you tires Guru's whats your suggestions. Less radial sipes or more what?

[talclipse]

I like the side bite from lots of radial sipes on dry slick but I sorta think that over 5 or 10 laps on a green the tire might give up more than I gained with too many sipes. Doing this I have been able to go out as far as half a lap ahead only to have folks catch back up as the tire gives up. This is what I think it fires the tires up fast but it don't take long to give it all back. Is 24 not enough or 42 too many? Ok you tires Guru's whats your suggestions. Less radial sipes or more what?

What does the tire look like after a race? Are you on a tire rule? If not how does your compound selection compare to the competitions? What happens to your car to allow the competitors to catch up (are you slowing down or are they speeding up??)?

[joedoozer]

What does the tire look like after a race? Are you on a tire rule? If not how does your compound selection compare to the competitions? What happens to your car to allow the competitors to catch up (are you slowing down or are they speeding up??)?

I was thinking the same thing. Maybe you have a better grooving and siping technique than everyone else. Maybe its taking their tires more laps to fire. This would something to test at a practice session. Go out with your "race" tires all siped and grooved and have someone on a stop watch. As soon as the lap times drop off, pull in and look at the tires.

[Egoracing]

Sipes create heat, they allow the tires rubber to rub and create friction. I agree with the above, you could be getting a great start because the tires fire faster but the friction you area adding is causing heat to build and after a few laps the tires get to hot and start falling off. I know for a FACT that I sipe different for a qualifying run than a heat race and different still for a feature.

[latemodel86]

I knew you had to sipe and groove according to track conditions and the distances of the races, but unfortunately I don't have extra wheels and tires. So when I go to sipe and groove those tires, I'm stuck with them until I go buy extra wheels and tires. I always run D21's in practice and the heat race on a local night. Then depending on the track, I'll change to some D55's wherever I need to put them. So I guess what I'm saying is that, I've got to pick a good siping and grooving combinations, or just one of them for a D55, that'll last me in a 20 lap, dry, slick, rubbered up feature.

[hpmaster]

I was thinking the same thing. Maybe you have a better grooving and siping technique than everyone else. Maybe its taking their tires more laps to fire. This would something to test at a practice session. Go out with your "race" tires all siped and grooved and have someone on a stop watch. As soon as the lap times drop off, pull in and look at the tires.

What was happening is my corner times were consistant but my drive off was suffering, indicating to me at least that my rear tires were giving up but my fronts were doing the job. Sipe less than I was on rears and block and drill the blocks to cool more on rears? I too am in a limited money situation, general broke, thus limited on sets of tires. We have to race on md 56 American Racers. Used to run UMP tracks but I refuse to play Hosers, Hoosier, bankrupt the little guy policies.

[Egoracing]

The BIG questions that you are the only one that can answer is: Are they dropping off because you are over heating them OR are they dropping off because you are burning the edges off OR are they dropping off because the sipes were shallow and you burned them off.

[4bangerhotrod]

if your racing weekly running 20-25lap features im sure your spinning the tires for them to be going away. it takes a really abrasive track to wear a 56 out in a 50-75 lap race and even then they dont really fall off to much. just the track slowing down. you need to get a temp gun and check tire temps before you pull off the track surface after the race cant remember the max temp for a 56 but im thinkin its around 200*, 210* maybe check with AR. once you have tire temps you should be able to tell excactly whats goin on with the car and they will tell you what changes need to be made. and you should be able to adjust your groving and siping according to what the temps and tire surface look like.

[mab475]

Just because your tires are to hot doesn't necessarily mean your spinning them.

[latemodel86]

Have another grooving question. If I groove the tire to where the blocks are 4 little squares, what does this do and why?

[joedoozer]

I groove my fronts like this. Gives you more edges. I then sipe each little block into 1/4's.

[grt74]

im reading this and i think something that is a factor is heat,if your good for a few laps and they catch back up to you something you need to check is heat and stagger but youll have to do it on the track in a test,check your stagger before and after i think youll be surprised,also check you air tank for water or moisture,these are factors too

[AmickRacing]

This could be an old wives tale, but an old timer once told me that if you're spinning your tires, they will almost never over heat (normal spinning, not boiling them off really bad of course), but if the tire is working hard and loaded up good, it'll create a lot of heat.

Makes sense to me, a tire that's locked down and working hard would have to build more heat than a tire that's spinning a bit because it won't have the traction to build heat.

That sound plausible?

[mab475]

This could be an old wives tale, but an old timer once told me that if you're spinning your tires, they will almost never over heat (normal spinning, not boiling them off really bad of course), but if the tire is working hard and loaded up good, it'll create a lot of heat.

Makes sense to me, a tire that's locked down and working hard would have to build more heat than a tire that's spinning a bit because it won't have the traction to build heat.

That sound plausible?

Exactly what I meant earlier. Not an old wives tale it's actually true.

[4bangerhotrod]

if your spinning your tires you will rip the edges off though and on a hard tire your running on your edges. you can grind them to keep from doing this as bad. but you should try to keep from spinning your tires, some tires if you slip them one time there junk for the rest of the race. it shows up alot at eldora during heat races.

[jrkracing54]

I ran a brand new D55 at Ocala last year for the Thanksgiving race. I was great for about 5-6 laps and then the car went loose. After the race talked to winner Ivadent Lloyd and told him what happened. He said did you spin the tires. I said "probably". He said "you tore all the edges off". He was right tire was junk. He said you gotta baby them until you get heat in them. Lesson learned for me. John 1*