I have stock 3:23 gears out back. I have the factory 15x7 rims that came on 92 rs's. I put Goodyears 225/70/15. I believe these tires are much bigger than what came from the factory. Since i added these tires, my launch is more quicker, Is it true since i added bigger tires, its as if my rear end ration increased. If so how high did it go since i added bigger tires.

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92' camaro
New 305 block TPI conversion, Flat top pistons,Bore over .30 Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads, accel cam,52mm throttle bodie, SLP runners Home aid cold air induction, Air foil,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods MSD 8.5 mm wires, bosch plattinum plugs, hypertech cap & rotor and coil, Edelbrock TES headers, free flowing catalytic converter and a 3 inch force II flowmaster exhaust system, and a 3 inch cutout,Zoom multi friction clutch, T-5 tranny,billenstien shocks&struts.
Soon to come!!!
Procharger system 12lbs o boost.
New paint job(hawaiin orchid purple)Cast alluminum ZR1 rims w/ 275 tires.
Favorite quote: "where ever u go, there u are"

Other car;
1971 plymouth Duster
Mods:340,edelbrock victor jr. intake, 650 4 barrel holley, heddman headers,40 series dual flowmasters, cold air intake,4:10 gears, just got a new paint job and cragar rims with 315 tires in the back.
:Yeah its not a chevy but damn how many 71' dusters have u seen in the streets.

 

Taller tires hurt your 'effective' gear ratio. Maybe your getting more traction?


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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

Im sure that hurt the gear ration, but i was told by someone, that if u install taller tires, ur ratio increases is that true if so how high has mine gotten from 3:23

 

Smaller tires effectivly reduce the ratio. If your stock tires were 26" and you went to those 27.4" tall tires then your 3.23 ratio would be like having 3.08 gears instead.

To make your 3.23 gears feel like 3.45 you need to go to a smaller tire hieght than stock but going smaller than 26" will give you very little traction.

Chances are that the taller tire just allowed you to have more rubber on the ground and you're not spinning as much now.

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87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

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87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

So then the key, theoretically would be too have the tallest tires that would fit for traction. Then you would buy a really high gear ration to counter-act the tall tires?

~Arnold

 

Just to clear up the confusion, I would like to add that when people talk about rear end gear ratios, lower ratio usually means a NUMERICALLY higher ratio, i.e. more revolutions of the driveshaft are required for one revolution of the axleshaft. Conversely, a higher ratio implies a NUMERICALLY lower ratio, i.e. less turns of the driveshaft are required for one revolution of the axleshaft.

Numerically higher ratios are called lower ratios because they effectively lower top speed, and hence also reduce vehicle speed at all given engine rpms. Of course this is a trade off for increased acceleration. Numerically lower ratios increase top speed and are thus referred to as high ratios. They increase vehicle speed at all given engine rpms while reducing acceleration.

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'88 IROC 305 TPI
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[This message has been edited by 88irocz28 (edited May 14, 2001).]

 

Hey steve, How does having a Taller Tire, Increase contact patch ?


Im Honestly asking, Not being a smartass



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

hmmmmm i actually have less traction than what i had when i had my stock tires, but the car runs like its a$$ is on fire.

 

Taller tires have a longer contact patch than a shorter tire, assuming you don't have it pumped up hard as a rock. Just because. I'm too beat from actually doing work to give you a better explanation, lol.

 

The distance from the front to the back of the tire that contacts the ground is greater on a taller tire.

Going to a taller tire then putting in a low gear like 4.10's also increases the torque multiplication with the lower gears.

Not considering tranny gear ratios. 300 lb of torque through 3.23 gears multiplies to 969 lb. 300 lb of torque through 4.10 gears equals 1230 lb. You can't make 261 lb of torque in the engine as cheaply as you can with gears. Now bring down the rpm with taller tires and the car will be quicker off the line with the increased torque and you can still drive on the highway.

It's not uncommon for a prostreet type car to have 4.56 gears and 33" tall tires.

 

umm yeah

 

Thanks Man, Its lucid Now

Never really Considerd it, I guess it makes sense Tho.


So going to a Taller Tire is really a fairly Good way to Lower RPM at the end of the 1/4, Or shorter tire to bring them up ?


As far as the contact patch, true, But I could argue with you all day that a "longer" Contact patch dosent equate to more friction, IE traction


And Ive got My Physicis textbook right here to back me up, too




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

Thanks Man, Its lucid Now

Never really Considerd it, I guess it makes sense Tho.


So going to a Taller Tire is really a fairly Good way to Lower RPM at the end of the 1/4, Or shorter tire to bring them up ?


As far as the contact patch, true, But I could argue with you all day that a "longer" Contact patch dosent equate to more friction, IE traction


And Ive got My Physicis textbook right here to back me up, too




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

When you consider stock eliminator cars are limited to a 9" wide tire and a maximum of 30" tall, they all try to squeeze that 30" tire into the fenders to get as much rubber on the ground. Just a few weeks ago an A/SA car run the first 9.99 at sea level on a 9" tire.

Since we don't race in stock eliminator, we can put a wider tire on. You also need to consider how much rolling resistance is increased from a wider tire when compared to a skinier tire.

Yes a taller tire will lower the rpm at the finish line as long as the gears haven't been changed. Without lowering the gears though, the car can be a bit of a dog off the line. This can usually be seen a slower 60 foot time and ET but higher MPH.