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Technical => Jon's Wheel House => Topic started by: masracingtd1167 on March 27, 2022, 08:50:55 AM

Title: Tire growth
Post by: masracingtd1167 on March 27, 2022, 08:50:55 AM

Question for Jon ! I am using Th M+ H 12X33 Tire and trying to figure out how much they grow at 185 mph . The tire measures 100 inches at 5 lbs air ! Trying to figure out what gear to put in . I am thinking a 5.00 or a 4.86 ! Not really afraid of rpm this new combination is a 15 degree head rolled over to 11 degrees  and flow much better than my old 18 degree heads  ! Thanks bill !

Title: Re: Tire growth
Post by: gregm784 on March 31, 2022, 04:19:11 PM

On my combo, i am running a 4.10 gear, the M&H 12.00x16 tire that measures 100.625 at 8psi.  I run 179mph and 8050rpm on my data logger.

Title: Re: Tire growth
Post by: masracingtd1167 on April 01, 2022, 03:37:17 PM

Greg do you think it's reasonable to think they would grow to 103 inches at speed ?

Title: Re: Tire growth
Post by: Rat on April 02, 2022, 07:17:14 AM

We had an issue where the numbers didn't add up RPM v MPH, when we we reverse calculated the tire size, they were an inch & half taller than what he tire was marked. We recalculated the gear ratio using the larger diameter, replaced the gear set with the new ratio and the MPH & RPM dead on.
Gregm784, According to the Wallace calculators your tyres are growing to 101.096" or 32.18" dia @ 179 mph

Title: Re: Tire growth
Post by: JEFF/21C on April 04, 2022, 04:28:35 PM

How much changing rim width change tire height?