photo's of all round 295/40/20's

[SERBS_HEMI_C]

Originally Posted by vvv90

Yup!


In fact, we should plagiarize the page and put it in the tech-tip FAQ section. There's SOOOO much good info on that page.

I totally bookmarked it.

did you totally? just like for sure, i think you totally did...

[vvv90]

Originally Posted by SERBS_HEMI_C

did you totally? just like for sure, i think you totally did...

Like like like ..... OH .... MUH .... GAWD did I just totally bookmark that.

[330toSRT8]

Originally Posted by JMatt

Fair enough!! A big thank you then from me to you!!!

I first "figured it out" when my father explained how they set tire pressures on his 727 based on total weight of the aircraft and contact patch for the tires. I thought he was nuts when he said 10,000 pounds of weight yields a 100 square inch contact patch at 100 psi.......

Like this thread, it took some explaining and convincing before I relized my dad wasn't nuts.

Hopefully this thread will prove educational.

Thanks again.

Ok, your explanation was beautiful and the math works out perfectly. Most of us are looking for grip during acceleration and hard cornering, both of which involve some sort of weight transfer from front-to-back or side-to-side. Based on the many posts above I've drawn the conclusion that a wider tire provides the exact same contact patch while sitting still, but during acceleration the wider tire provides more grip. Is this correct? I don't really care how much grip I have at 0 MPH.

[JMatt]

Originally Posted by 330toSRT8

Ok, your explanation was beautiful and the math works out perfectly. Most of us are looking for grip during acceleration and hard cornering, both of which involve some sort of weight transfer from front-to-back or side-to-side. Based on the many posts above I've drawn the conclusion that a wider tire provides the exact same contact patch while sitting still, but during acceleration the wider tire provides more grip. Is this correct? I don't really care how much grip I have at 0 MPH.

I think (but google searching wasn't proven to my satisfaction yet) that we can run a lower pressure at the starting line with a wider rear tire. THIS is what I think is the source of extra traction. I used to run about 28psi with my F-1's. I plan on dropping to 25 psi with my new 275's. In theory, I'll have 10% more contact patch at launch and 10% more traction +/- differences in tire brand.

We'll see.......

I wish I were more of an expert, but I must admit we're at the end of my knowledge level. We need someone else to step up who's even more technical than me.

[JMatt]

Originally Posted by 330toSRT8

. . . Based on the many posts above I've drawn the conclusion that a wider tire provides the exact same contact patch while sitting still, but during acceleration the wider tire provides more grip. Is this correct?

I believe you are 100% correct.

The physics on the whole slip angle, yadda yadda was making my head hurt. Clearly beyond my knowledge level.

[mjr5150]

As I just put 295's on the rear and have yet to hit the track......this thread was an awesome learning tool as to what I thought I had and didn't have ...regarding newfound traction . Kudos guys and thanks .





The tires are pirelli scorpions 265-35-22 in the front on 22x9 wheels .........and 295-30-22 in the back on 22x10.5 wheels .

I'm going in about three weeks to see if they hook any better than my f-1's did . I used to play with the pressure a bit in the rears down to about 20psi . I'm going to try to bring down the 295's to around 25 to start out with . By the way HD...the car looks good to me . Thanks again for the great read here and the tire info JMatt .

[JMatt]

Originally Posted by mjr5150

The tires are pirelli scorpions 265-35-22 in the front on 22x9 wheels .........and 295-30-22 in the back on 22x10.5 wheels .

I'm going in about three weeks to see if they hook any better than my f-1's did . I used to play with the pressure a bit in the rears down to about 20psi . I'm going to try to bring down the 295's to around 25 to start out with . By the way HD...the car looks good to me . Thanks again for the great read here and the tire info JMatt .

You're welcome!

I'm surprised no one has commented on your wheels/tires yet. For the record, I think they look SWEEEEET!!!

(or as Dubster would say "they're siiiiiiiick!")

[HalV48]

Most drag racers know about contact patch.

JMatt is right.

In drag racing the contact patch is determined by car weight, weight transfer, torque, tire width, tire heighth, tire sidewall construction, tire cross section construction, tire materials, tire pressure, and traction.