Tire Help for Heads-up Manual Transmission Class

Rich osmond · 04-24-2023, 02:31 PM

I am building a car for the NMCA Coyote stock class (sealed factory engine ~500HP, 3000# min weight, and g101a transmission). The cars 60' in the mid-1.30 range, and run ~9.7's. Nearly all of the cars in the class run 26" x 10" M/T stiff all slicks, but I am wondering if there is any advantage (or disadvantage) to running a 28" tire with the appropriate gearing. Any experience is appreciated!

Ralph A Powell · 04-24-2023, 02:57 PM

What clutch and flywheel (steel or aluminum) and what 1st & 2nd gear ratio? A larger diameter will give you more contact area

Rich osmond · 04-24-2023, 03:19 PM

Thanks. Aluminum flywheel, single clutch disc 10” min, but we can run a tamer. First gear ~ 3:1, second gear ~2:1. Appreciate the help.

Jim Caughlin · 04-24-2023, 05:34 PM

Quote:

Originally Posted by Rich osmond

Thanks. Aluminum flywheel, single clutch disc 10” min, but we can run a tamer. First gear ~ 3:1, second gear ~2:1. Appreciate the help.

Oh boy, here we go again...

Rich osmond · 04-24-2023, 05:38 PM

OK. I’m just seeking a little help. Thx

1347 · 04-24-2023, 10:06 PM

why wouldn't you put a 30x9 bias tire the Stick stocker guys run? i know thats why you are asking what to use, but I would think a 30x9 would give a much better contact patch over a 26x10.

Stephen & Horace Johnson · 04-24-2023, 10:17 PM

Quote:

Originally Posted by 1347

why wouldn't you put a 30x9 bias tire the Stick stocker guys run? i know thats why you are asking what to use, but I would think a 30x9 would give a much better contact patch over a 26x10.

28s are the biggest they can run

James Hensler · 04-25-2023, 01:20 PM

I used to run the 28x10.5 Stiff in Renegade. Back then we had to weigh 3000 and made more HP 850 but with a single disk Ram and a adjustable pressure plate I 60 footed 1.25 and ran 9.0’s a DOHC 4.6

I know this isn’t your combo but it’s about as close as you’re going to get here!

Rich osmond · 04-25-2023, 01:37 PM

Thank you, James. This is very helpful and something I will consider. As you know, I will need to balance clutch slip, wheel speed, and rotating weight, so I will probably need to test with a short tire/gear package, vs a tall one. Thanks again.

Jim Caughlin · 04-25-2023, 04:50 PM

Stick to basic 'meat and potatoes' components that have been working for Stock class cars for years, Soft Lock, alum flywheel, G101 and the 10 x 28 should be plenty of tire to get you well into the 9 second range. Run the clutch as loose as you can get ways with and oh yeah, don't use the clutch to shift.

04-24-2023, 02:31 PM	#1
Rich osmond Junior Member Join Date: Jan 2016 Posts: 5 Likes: 4 Liked 0 Times in 0 Posts	Tire Help for Heads-up Manual Transmission Class I am building a car for the NMCA Coyote stock class (sealed factory engine ~500HP, 3000# min weight, and g101a transmission). The cars 60' in the mid-1.30 range, and run ~9.7's. Nearly all of the cars in the class run 26" x 10" M/T stiff all slicks, but I am wondering if there is any advantage (or disadvantage) to running a 28" tire with the appropriate gearing. Any experience is appreciated!

04-24-2023, 02:57 PM	#2
Ralph A Powell Member Join Date: Oct 2017 Location: Bay City Texas Posts: 388 Likes: 2 Liked 225 Times in 136 Posts	Re: Tire Help for Heads-up Manual Transmission Class What clutch and flywheel (steel or aluminum) and what 1st & 2nd gear ratio? A larger diameter will give you more contact area

04-24-2023, 03:19 PM	#3
Rich osmond Junior Member Join Date: Jan 2016 Posts: 5 Likes: 4 Liked 0 Times in 0 Posts	Re: Tire Help for Heads-up Manual Transmission Class Thanks. Aluminum flywheel, single clutch disc 10” min, but we can run a tamer. First gear ~ 3:1, second gear ~2:1. Appreciate the help.

04-24-2023, 05:38 PM	#5
Rich osmond Junior Member Join Date: Jan 2016 Posts: 5 Likes: 4 Liked 0 Times in 0 Posts	Re: Tire Help for Heads-up Manual Transmission Class OK. I’m just seeking a little help. Thx

04-24-2023, 10:06 PM	#6
1347 Senior Member Join Date: Aug 2007 Location: Monroe Twp NJ Posts: 503 Likes: 1,032 Liked 990 Times in 274 Posts	Re: Tire Help for Heads-up Manual Transmission Class why wouldn't you put a 30x9 bias tire the Stick stocker guys run? i know thats why you are asking what to use, but I would think a 30x9 would give a much better contact patch over a 26x10. __________________ Duane Hoven 1342 SS/GT

04-25-2023, 01:20 PM	#8
James Hensler Member Join Date: Apr 2022 Location: Noblesville,In Posts: 108 Likes: 7 Liked 58 Times in 36 Posts	Re: Tire Help for Heads-up Manual Transmission Class I used to run the 28x10.5 Stiff in Renegade. Back then we had to weigh 3000 and made more HP 850 but with a single disk Ram and a adjustable pressure plate I 60 footed 1.25 and ran 9.0’s a DOHC 4.6 I know this isn’t your combo but it’s about as close as you’re going to get here! __________________ SS/AH 328X

04-25-2023, 01:37 PM	#9
Rich osmond Junior Member Join Date: Jan 2016 Posts: 5 Likes: 4 Liked 0 Times in 0 Posts	Re: Tire Help for Heads-up Manual Transmission Class Thank you, James. This is very helpful and something I will consider. As you know, I will need to balance clutch slip, wheel speed, and rotating weight, so I will probably need to test with a short tire/gear package, vs a tall one. Thanks again.

04-25-2023, 04:50 PM	#10
Jim Caughlin Senior Member Join Date: Mar 2002 Location: Woodburn, Or Posts: 685 Likes: 82 Liked 805 Times in 245 Posts	Re: Tire Help for Heads-up Manual Transmission Class Stick to basic 'meat and potatoes' components that have been working for Stock class cars for years, Soft Lock, alum flywheel, G101 and the 10 x 28 should be plenty of tire to get you well into the 9 second range. Run the clutch as loose as you can get ways with and oh yeah, don't use the clutch to shift.