Author Topic: tire speed vs low gear ratio  (Read 663 times)

Offline wideopen231

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tire speed vs low gear ratio
« on: June 20, 2020, 08:47:30 AM »
Maybe my thinking is off base.After 7 months of job I am doing its highly possible.

 Wouldn't a higher(lower number) ratio give you more wheel speed at the hit?Provided you have enough power to get it rolling. Part of another thread and did not want to derail it. I had advice from a old guy in Kansas not to go 1.80 low but rather the 1.69 low because of shake. Hard to argue with those guys. LOL  So far only shake I have had was from stupid tune.which goes back to under powered thing.Always a probleM. NEED MORE POWER!!!!!!!
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline buickfed

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Re: tire speed vs low gear ratio
« Reply #1 on: June 20, 2020, 10:50:46 AM »
good question. bought an altered and we will run al least one v6 in it. the tires are 36x17-16. a lot of diameter for the v6. BUT, my tranny guy likes R&D and has built a t350 modified with a 700r4 first gear, but no changes for 2-3.  that first is 3.08. add a 4.56 and you get a wild granny gear. now the decision is what rear gear to use.
normal stuff is so boring......  ;D

Offline THE FRENCHTOWN FLYER

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Re: tire speed vs low gear ratio
« Reply #2 on: June 20, 2020, 12:17:10 PM »
Let me respectfully suggest your tire us WAAAaaay too big for a V6. I switched from a 15 x 12 x 31.5 to a 15 x 10.5 x 28S last Sunday and ran my best 60' - 1.18 in years, down .13 sec from the previous 12 x 31.5s.

This is with a 305 ci inline six bracket engine (around 550 HP).
« Last Edit: June 20, 2020, 12:18:49 PM by THE FRENCHTOWN FLYER »

Offline buickfed

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Re: tire speed vs low gear ratio
« Reply #3 on: June 20, 2020, 02:08:33 PM »
it had a bbc in it. that's the tire/rim combo that came with the car. if i went smaller it wouldn't look right. ;D

Offline THE FRENCHTOWN FLYER

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Re: tire speed vs low gear ratio
« Reply #4 on: June 20, 2020, 04:53:13 PM »
My big tires looked baddass.
The littles looked goofy.
But it ran like JackTheBear with them on.
Now I realize how beautiful they look.

Offline wideopen231

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Re: tire speed vs low gear ratio
« Reply #5 on: June 20, 2020, 06:16:31 PM »
Best looking thing for race car is ET slip with small numbers and big mph numbers. IMO
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline JrFuel Hayden

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Re: tire speed vs low gear ratio
« Reply #6 on: June 20, 2020, 10:47:43 PM »
WideOpen; the reason I suggested a 1.80 gear was he had trouble with tire shake so I thought the 1.80 gear would help getting the tire up to speed at the hit. More gear is a torque multiplier , so it multipies the HP, again more power helps with tire shake. Another option is to go with a lower [ bigger number] rear gear.
when I 1'st started JF racing I too met that "old guy from Kansas, he turned me onto a 1.68 1'st gear to slow up the tire speed some , now most of the jF guys are running 1.68 or 1.69 gear with one team running a 1.54.
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Offline wideopen231

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Re: tire speed vs low gear ratio
« Reply #7 on: June 21, 2020, 04:28:56 AM »
Oh . I understand your reasoning and was not replying to your suggestion,  Heck I agree that if not enough power or too much tire(same effect) you may have to hit it harder to break it loose. Main reason that I stated earlier that if I run into shake that I can not tune out other wise I will drop about 25 to 30% load in tank and see if that will get tire some more speed at hit, Hey even at 27 bucks a gallon its a cheap attempt to see if more power would help. Poor boy can't carry 3 or 4 sets of tires to swap arond.LOL
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot