275/40/17 VS 315/35/17 Drag Radial
01-24-2010, 03:01 AM
#21
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well, we kinda already covered that...they'll both hook great.
real world examples:
My buddy's 2000 Supercharged Camaro SS has 275's on stock rims with Nitto DR's and you can't spin the tires without power braking it on the track or on the street...plenty of hook.
I have 315's on the back of my formula with an 11 inch wide rim...they also hook great. I can't spin them unless I power brake it on DR's, and only can only chirp the tires with street tires...also plenty of hook.
real world examples:
My buddy's 2000 Supercharged Camaro SS has 275's on stock rims with Nitto DR's and you can't spin the tires without power braking it on the track or on the street...plenty of hook.
I have 315's on the back of my formula with an 11 inch wide rim...they also hook great. I can't spin them unless I power brake it on DR's, and only can only chirp the tires with street tires...also plenty of hook.
01-24-2010, 08:58 AM
#22
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I run my A4/3200 Formula w/3.73's in a Challenge Series Race about once a month for almost the past 2 yrs.
BFG DR's 255/50x16 only worked marginally at the track, were inconsistant, and spun alot on the street. Needless to say, but they were used up fast.
My M&H Racemaster 275/55x16 DR's worked well, and '60 footed better, but due to the 28" height vs. approx. 26", had my car trapping in 3rd gear just ready to shift into 4th.
I didn't like the way it felt in the car, and my MPH was about 1-2 mph off my current setup. I just sold them recently.
About 1.5 yrs ago, I bought a pair of Speedlines that happened to have "like new" Nitto 555 DR's on them. I tried them on my next trip out to the track not expecting much based on what people said.
But they ended up hooking up great. (Same as my M&H's), so I left them on all the time, and the car traps a 'lil higher as it crosses the stripe in 4th gear.
I've just installed my 2nd set of these Nitto 315/35x17 DR's on my Speedlines before last months race.
JMO, but the 275's will work based on other cars I see in our Challenge group, save a 'lil bit of weight, etc. Just don't have the "beefy look". But for a sleeper look, they'rs fine up to a certain HP level.
But now with my 315's, I don't have to swap em' each trip out and they work great, look sharp, and I just leave them on all the time.
I do have 275/40x17 GoodYear F1 street tires on the other 4 Speedlines I have, but the car is undriveable if you stab the gas with them on, (or Michelin Pilot street tires I had before the Goodyear's) Traction control goes whack...lol
01-24-2010, 08:00 PM
#27
01-25-2010, 11:54 AM
#29
I think something to take away from it is that although you have a 14.5% increase in width with 315's compared to 275's, you wont necessarily have 14.5% greater traction. It's true that friction is directly based off of weight on the tires, and 275's don't spread the weight quite as much as 315's, so each square inch of area on the road technically has more grip than on 275's than 315's.
01-25-2010, 12:01 PM
#30
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Auto Vs 6 Speed is a lot...Propper size wheel is another biggie
Iv used both..
I had better luck with the 315s..I still couldnt keep it from going sideways in 2nd and spining in 3rd..but a better track might help.
I was going to go with a 15in streetlite and slick to go with my 17s..but I think Ill get some cheap 16in wheels and just go that way....
Iv used both..
I had better luck with the 315s..I still couldnt keep it from going sideways in 2nd and spining in 3rd..but a better track might help.
I was going to go with a 15in streetlite and slick to go with my 17s..but I think Ill get some cheap 16in wheels and just go that way....
01-25-2010, 12:30 PM
#31
I think something to take away from it is that although you have a 14.5% increase in width with 315's compared to 275's, you wont necessarily have 14.5% greater traction. It's true that friction is directly based off of weight on the tires, and 275's don't spread the weight quite as much as 315's, so each square inch of area on the road technically has more grip than on 275's than 315's.
01-28-2010, 11:32 PM
#32
in my experiences I have had better luck as far as 60' times trap speeds and ets
315s are over kill in my opinion. Have taken my 275 down to a 6.2 with 1.37-1.45 60' turned around in about a month and ran same setup with a little bit warmer weather and best 60' was a 1.50-1.67 et went to 6.4-6.7. and trap speeds were off by more than a handfull. In my opinion 315s are for IRS cats really now some of these guys are correct as far as lb per square inch deal goes and that has alot to do with it. Also a 275 is a tad bit better in the ran for not having the 40mm more of tire on the ground if you get caught in the rain. I do ride around on the street with 315's because like everyone else says the look SWEET but swapem out for 275s at the track
315s are over kill in my opinion. Have taken my 275 down to a 6.2 with 1.37-1.45 60' turned around in about a month and ran same setup with a little bit warmer weather and best 60' was a 1.50-1.67 et went to 6.4-6.7. and trap speeds were off by more than a handfull. In my opinion 315s are for IRS cats really now some of these guys are correct as far as lb per square inch deal goes and that has alot to do with it. Also a 275 is a tad bit better in the ran for not having the 40mm more of tire on the ground if you get caught in the rain. I do ride around on the street with 315's because like everyone else says the look SWEET but swapem out for 275s at the track
01-28-2010, 11:39 PM
#33
in my experiences I have had better luck as far as 60' times trap speeds and ets
315s are over kill in my opinion. Have taken my 275 down to a 6.2 with 1.37-1.45 60' turned around in about a month and ran same setup with a little bit warmer weather and best 60' was a 1.50-1.67 et went to 6.4-6.7. and trap speeds were off by more than a handfull. In my opinion 315s are for IRS cats really now some of these guys are correct as far as lb per square inch deal goes and that has alot to do with it. Also a 275 is a tad bit better in the ran for not having the 40mm more of tire on the ground if you get caught in the rain. I do ride around on the street with 315's because like everyone else says the look SWEET but swapem out for 275s at the track
315s are over kill in my opinion. Have taken my 275 down to a 6.2 with 1.37-1.45 60' turned around in about a month and ran same setup with a little bit warmer weather and best 60' was a 1.50-1.67 et went to 6.4-6.7. and trap speeds were off by more than a handfull. In my opinion 315s are for IRS cats really now some of these guys are correct as far as lb per square inch deal goes and that has alot to do with it. Also a 275 is a tad bit better in the ran for not having the 40mm more of tire on the ground if you get caught in the rain. I do ride around on the street with 315's because like everyone else says the look SWEET but swapem out for 275s at the track
01-28-2010, 11:53 PM
#34
TECH Enthusiast
Great thread, I am looking into new rims and DR's... but out of the current rims available in 17x11, I don't like any of them. Think I'm just gonna get 17x9.5 with some 275 DRs. I do love the look of a fat tire out back though 
oh well can't have cake and eat it too... or something like that
oh well can't have cake and eat it too... or something like that
01-29-2010, 07:00 AM
#35
Launching!
I think something to take away from it is that although you have a 14.5% increase in width with 315's compared to 275's, you wont necessarily have 14.5% greater traction. It's true that friction is directly based off of weight on the tires, and 275's don't spread the weight quite as much as 315's, so each square inch of area on the road technically has more grip than on 275's than 315's.
1) Friction is calculated by taking weight (pounds) times the coefficient of friction. Friction is not calculated using pressure therefore friction is not dependant on area.
2) With that said, the friction generated by a 275 wide tire and a 315 wide tire will be the same.
3) Getting down to the molecular level....When a tire is making contact with asphalt or concrete, the rubber of the tire will be pressed into the pavement voids at the surface. As the tire spins, there will be a shearing force that tries to shear (cut) these embedded portions of rubber off at the face of the pavement. With a wider tire, this shearing force is reduced thereby preventing the rubber from being sheared. As a result, the rubber pushes off the pavement as opposed to being sheared off and the vehicle staying stationary. Although the friction generated by a 275 and 315 wide tire are the same, the 315 wide tire will be able to handle more power until it is broken loose.
01-30-2010, 12:40 AM
#36
I've thought about this and came up with these conclusions:
1) Friction is calculated by taking weight (pounds) times the coefficient of friction. Friction is not calculated using pressure therefore friction is not dependant on area.
2) With that said, the friction generated by a 275 wide tire and a 315 wide tire will be the same.
3) Getting down to the molecular level....When a tire is making contact with asphalt or concrete, the rubber of the tire will be pressed into the pavement voids at the surface. As the tire spins, there will be a shearing force that tries to shear (cut) these embedded portions of rubber off at the face of the pavement. With a wider tire, this shearing force is reduced thereby preventing the rubber from being sheared. As a result, the rubber pushes off the pavement as opposed to being sheared off and the vehicle staying stationary. Although the friction generated by a 275 and 315 wide tire are the same, the 315 wide tire will be able to handle more power until it is broken loose.
1) Friction is calculated by taking weight (pounds) times the coefficient of friction. Friction is not calculated using pressure therefore friction is not dependant on area.
2) With that said, the friction generated by a 275 wide tire and a 315 wide tire will be the same.
3) Getting down to the molecular level....When a tire is making contact with asphalt or concrete, the rubber of the tire will be pressed into the pavement voids at the surface. As the tire spins, there will be a shearing force that tries to shear (cut) these embedded portions of rubber off at the face of the pavement. With a wider tire, this shearing force is reduced thereby preventing the rubber from being sheared. As a result, the rubber pushes off the pavement as opposed to being sheared off and the vehicle staying stationary. Although the friction generated by a 275 and 315 wide tire are the same, the 315 wide tire will be able to handle more power until it is broken loose.
01-30-2010, 09:28 AM
#37
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Bottom Line is what he's basically talking about is "the Footprint". What racer's find out about, and have known for many, many years.
As an example, if you have a taller tire, then more of the "arc" touches the pavement. A shorter tire has a smaller "arc" (or "Footprint on the pavement)
Given the 275 & 315's in question are the same basic height, tho you may have the same size "arc" hitting the pavement, you also have more rubber based on the 315's extra width of rubber hitting the ground.
Sidewall size playa a big role in tire flex for launching as well. You always see more sidewall size area as you view faster cars at the track.
The most optimum tires for traction and hookup wouldnt be a 35 & 40 series sidewall such as these 275/40x17 & 315/35 x 17's anyway. But in a streetcar, etc. they do fine up to a certain HP level.
But between these two, if the 275's hook on your car, they are lighter and a better way to go.
If not, then the 315/35x17's will have "more footprint"
As an example, if you have a taller tire, then more of the "arc" touches the pavement. A shorter tire has a smaller "arc" (or "Footprint on the pavement)
Given the 275 & 315's in question are the same basic height, tho you may have the same size "arc" hitting the pavement, you also have more rubber based on the 315's extra width of rubber hitting the ground.
Sidewall size playa a big role in tire flex for launching as well. You always see more sidewall size area as you view faster cars at the track.
The most optimum tires for traction and hookup wouldnt be a 35 & 40 series sidewall such as these 275/40x17 & 315/35 x 17's anyway. But in a streetcar, etc. they do fine up to a certain HP level.
But between these two, if the 275's hook on your car, they are lighter and a better way to go.
If not, then the 315/35x17's will have "more footprint"
01-30-2010, 10:19 AM
#38
Bottom Line is what he's basically talking about is "the Footprint". What racer's find out about, and have known for many, many years.
As an example, if you have a taller tire, then more of the "arc" touches the pavement. A shorter tire has a smaller "arc" (or "Footprint on the pavement)
Given the 275 & 315's in question are the same basic height, tho you may have the same size "arc" hitting the pavement, you also have more rubber based on the 315's extra width of rubber hitting the ground.
Sidewall size playa a big role in tire flex for launching as well. You always see more sidewall size area as you view faster cars at the track.
The most optimum tires for traction and hookup wouldnt be a 35 & 40 series sidewall such as these 275/40x17 & 315/35 x 17's anyway. But in a streetcar, etc. they do fine up to a certain HP level.
But between these two, if the 275's hook on your car, they are lighter and a better way to go.
If not, then the 315/35x17's will have "more footprint"
As an example, if you have a taller tire, then more of the "arc" touches the pavement. A shorter tire has a smaller "arc" (or "Footprint on the pavement)
Given the 275 & 315's in question are the same basic height, tho you may have the same size "arc" hitting the pavement, you also have more rubber based on the 315's extra width of rubber hitting the ground.
Sidewall size playa a big role in tire flex for launching as well. You always see more sidewall size area as you view faster cars at the track.
The most optimum tires for traction and hookup wouldnt be a 35 & 40 series sidewall such as these 275/40x17 & 315/35 x 17's anyway. But in a streetcar, etc. they do fine up to a certain HP level.
But between these two, if the 275's hook on your car, they are lighter and a better way to go.
If not, then the 315/35x17's will have "more footprint"
09-25-2011, 12:42 AM
#39
11 Second Club
275's has more side wall and will hook better than a stiff *** 315 tire...
09-25-2011, 02:33 AM
#40
In almost any case it is easier hooking a taller tire that is thinner, with more sidewall, then it is hooking a short tire that is wider, less sidewall.
I watched a few weeks ago several cars running 5s in the 1/8 and 7s in The 1/4.. all fbodys and all on a 275 radial.
I watched a few weeks ago several cars running 5s in the 1/8 and 7s in The 1/4.. all fbodys and all on a 275 radial.