Largest tire
02-02-2007, 03:24 PM
#21
3rd Gear Member
Join Date: Nov 2006
Location: Dallas, TX area
Posts: 941
RE: Largest tire
ORIGINAL: moosestang
Besides making you lower to the ground, smaller diameter tires will increase the wheel well gap by as much as it lowers you. That's not normally what people want when lowering.
Besides making you lower to the ground, smaller diameter tires will increase the wheel well gap by as much as it lowers you. That's not normally what people want when lowering.
ORIGINAL: wthalliii
Cool.
So, you guys who know about suspension, is this a good way to lower a car without having to replace suspension parts, or do you need to do that if you get smaller diameter tires? Are there any downsides to doing this? Maybe not even wider tires, just smaller diameter tires. Can you get 235/45ZR14's instead of the stock 235/55ZR14's, maybe? That would lower the car by nearly an inch.
Smaller tires would also have the same effect as changing the rear-end ratio, too, wouldn't it? With smaller tires, you'd have increased RPM for a given speed, so you'd have more power on the low end, but lower top speed, right?
Andrew, did you retune the speedometer?
ORIGINAL: androdz
Yes you did the math right, I got 275/40/17 and I knew I was gonna reduce the diameter by around 1 inch give or take. I did it because I wanted to experiment how 3.73's will actually feel because I was let down by the 4.10 when they just died @ over 110 mph.
Andrew
Yes you did the math right, I got 275/40/17 and I knew I was gonna reduce the diameter by around 1 inch give or take. I did it because I wanted to experiment how 3.73's will actually feel because I was let down by the 4.10 when they just died @ over 110 mph.
Andrew
So, you guys who know about suspension, is this a good way to lower a car without having to replace suspension parts, or do you need to do that if you get smaller diameter tires? Are there any downsides to doing this? Maybe not even wider tires, just smaller diameter tires. Can you get 235/45ZR14's instead of the stock 235/55ZR14's, maybe? That would lower the car by nearly an inch.
Smaller tires would also have the same effect as changing the rear-end ratio, too, wouldn't it? With smaller tires, you'd have increased RPM for a given speed, so you'd have more power on the low end, but lower top speed, right?
Andrew, did you retune the speedometer?
02-03-2007, 07:37 AM
#22
I ♥ Acer
Join Date: Aug 2006
Location:
Posts: 2,090
RE: Largest tire
Yes I had to retune the speedo, it is a fairly simple task with the sct. I calculate that my rear end gearing should be anywhere around 3.7x which was what I wanted to test with the smaller diameter tires. I did this because I had a recent experience with a gt with 4.10's installed and and it dies fast after 110 mph you have to shift to 5th at around 116 or so. that means you are in overdrive at 116mph so good luck catching any speed after that; 116 mph is fairly easy to reach in the 1/4 mile with moderate mods, on street racing it is much easier to pass 116mph.
02-03-2007, 09:13 AM
#24
6th Gear Member
Join Date: Sep 2006
Location: Gainesville, FL
Posts: 11,278
RE: Largest tire
So using a taller tire will change my gearing from 3.55 to 3.73 or somewhere close to that? I thought it was the other way around.
ORIGINAL: androdz
Yes I had to retune the speedo, it is a fairly simple task with the sct. I calculate that my rear end gearing should be anywhere around 3.7x which was what I wanted to test with the smaller diameter tires. I did this because I had a recent experience with a gt with 4.10's installed and and it dies fast after 110 mph you have to shift to 5th at around 116 or so. that means you are in overdrive at 116mph so good luck catching any speed after that; 116 mph is fairly easy to reach in the 1/4 mile with moderate mods, on street racing it is much easier to pass 116mph.
Yes I had to retune the speedo, it is a fairly simple task with the sct. I calculate that my rear end gearing should be anywhere around 3.7x which was what I wanted to test with the smaller diameter tires. I did this because I had a recent experience with a gt with 4.10's installed and and it dies fast after 110 mph you have to shift to 5th at around 116 or so. that means you are in overdrive at 116mph so good luck catching any speed after that; 116 mph is fairly easy to reach in the 1/4 mile with moderate mods, on street racing it is much easier to pass 116mph.
02-03-2007, 04:38 PM
#26
4th Gear Member
Join Date: Jun 2006
Location: CA
Posts: 1,700
RE: Largest tire
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
02-04-2007, 10:09 AM
#27
3rd Gear Member
Join Date: Nov 2005
Location:
Posts: 701
RE: Largest tire
ORIGINAL: RodeoFlyer
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
02-04-2007, 11:17 PM
#28
2nd Gear Member
Join Date: Aug 2006
Location:
Posts: 305
RE: Largest tire
ORIGINAL: jbailer
I'm not sure why you think that. The section width of the tire is the physical width of the tire and does not change based on the width of the wheel. The only problem is if you get too wide a tire, it will not seat reliably on the wheel and could be a safety issue. The contact patch to the road DEFINITELY increases. -Joe
ORIGINAL: RodeoFlyer
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
02-05-2007, 01:27 AM
#29
I ♥ Acer
Join Date: Aug 2006
Location:
Posts: 2,090
RE: Largest tire
ORIGINAL: 07GT
Actually the section width does change based on the width of the wheel.The section width does change about .2 inch for every .5 inch in wheel width according to BF Goodrich. The section width does not change MUCH but more important, the tread that contacts the road does. When you run too large of a tire on too narrow of a rim it pulls the outer tread upward off the road. Not to mention your handling is worse than if the tire were on a proper sized rim because the sidewall is pulled in so much. If you use a shorter tire (with the same tread width), you lower effective gear ratio but your contact patch is less. You're better off with lower rear gears and taller tires. Don't forget your contact patch is based on width of the tire AND the height.
ORIGINAL: jbailer
I'm not sure why you think that. The section width of the tire is the physical width of the tire and does not change based on the width of the wheel. The only problem is if you get too wide a tire, it will not seat reliably on the wheel and could be a safety issue. The contact patch to the road DEFINITELY increases. -Joe
ORIGINAL: RodeoFlyer
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
shorter tires will INCREASE your gear ration - i.e , going from stock 27" tall tire to 26" tall tire will increase it from 3.55 to 3.73 (rough #'s)
for the guys running 275's on 8" wheels, there is a guy selling TORNADOS on ebay - check it out!
Andrew
PS: Do you want me to put a ruler with the pictures?
