| conevadr | 03-21-2006 09:34 PM |
Is bigger always better?
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Since it didn't get any replies in the V710 thread, I figured I'd give the question it's own thread.
If Kumho comes out with a 255/40 V710, would it be preferred over the current 275 for Astock? In other words, is bigger always better? Is it possible that for an 8 inch rim, that the 275 is actually a little too large, and the lighter weight, shorter sidewall, and better fit of the 255 would work as well or better? Has anyone tested the 255 Victoracer against the 275?
If Kumho comes out with a 255/40 V710, would it be preferred over the current 275 for Astock? In other words, is bigger always better? Is it possible that for an 8 inch rim, that the 275 is actually a little too large, and the lighter weight, shorter sidewall, and better fit of the 255 would work as well or better? Has anyone tested the 255 Victoracer against the 275?
| sciolist | 03-21-2006 09:37 PM |
My money would be on the 255 for an 8" wheel. I'm using 275's on 8.5" wheels, and I'll probably switch to 255's if they produce them this season.
| solo-x | 03-21-2006 10:31 PM |
doubtful. HS honda guys are stuffing 225 tires onto 5" wheels. super balloon style, but faster none the less.
nate
nate
| leecea | 03-21-2006 11:13 PM |
I am always told that 215/40x16s will be faster on my WRX than 225/50x16s, so bigger isn't always faster. However, with the STi's shorter 2nd gear, the acceleration gains of a shorter tire may not help.
| KC | 03-22-2006 08:03 AM |
A 255/40-17 would be ~.7" shorter than the 275/40-17. You pick up a bit of gearing in those .7"... you'd be acellerating a little faster than the 275s... with power not really being a problem with the STi even on 275s, I would still go with the 255s as just that little bit, if you can retain the grip, would be just marginally faster. They're only a tad skinnier too.
--kC
--kC
| KC | 03-22-2006 08:08 AM |
[QUOTE=leecea]I am always told that 215/40x16s will be faster on my WRX than 225/50x16s, so bigger isn't always faster. However, with the STi's shorter 2nd gear, the acceleration gains of a shorter tire may not help.[/QUOTE]
That's because the boost lag in a WRX cen be lessened to a certain extent by shortening the gearing. You're getting up to speed much faster with a shorter sidewall tire.
Example... when I ran 225/35-17 Falken FK451s, those tires were about 1.5" shorter than stock. I would hit top of 2nd around 57mph vs the stock 62. But I also got there faster as shorter gearing on tires acts like a HP/TQ multiplier. (Can't remember the math on this one). Think about a 10 speed bike. If you were pedaling, and the chain was on the smaller cog, and were doing the same amount of revolutions in the same amount of time as you would on the bigger cog, the speed of the bike is much faster.
--kC
That's because the boost lag in a WRX cen be lessened to a certain extent by shortening the gearing. You're getting up to speed much faster with a shorter sidewall tire.
Example... when I ran 225/35-17 Falken FK451s, those tires were about 1.5" shorter than stock. I would hit top of 2nd around 57mph vs the stock 62. But I also got there faster as shorter gearing on tires acts like a HP/TQ multiplier. (Can't remember the math on this one). Think about a 10 speed bike. If you were pedaling, and the chain was on the smaller cog, and were doing the same amount of revolutions in the same amount of time as you would on the bigger cog, the speed of the bike is much faster.
--kC
| conevadr | 03-22-2006 08:37 AM |
A couple of other things that I was thinking about in the favor of the 255s...
shorter sidewall - lowers the CG of the entire car
shorter sidewall - better transitional response
better fit - better sidewall support, less rollover, better transitional response, better wear
less weight - less rotational mass, better acceleration
275-255 != 20 - due to the additional pull in, the real usable tread width advantage is maybe a half inch, possibly less if you consider actual difference is change in contact patch shape, not size
So has anyone tested 255 vs 275 Victos, or what about 275/40 vs 245/40 in the V710s or Hoosiers?
shorter sidewall - lowers the CG of the entire car
shorter sidewall - better transitional response
better fit - better sidewall support, less rollover, better transitional response, better wear
less weight - less rotational mass, better acceleration
275-255 != 20 - due to the additional pull in, the real usable tread width advantage is maybe a half inch, possibly less if you consider actual difference is change in contact patch shape, not size
So has anyone tested 255 vs 275 Victos, or what about 275/40 vs 245/40 in the V710s or Hoosiers?
| thrdeye | 03-22-2006 09:25 AM |
Robert Carpenter tested this theory on the Miata he ran last year. It was between a 205 and a 225. He told me he actually got more USEABLE rubber on the ground with the smaller tire.
YMMV
YMMV
| ratt_finkel | 03-22-2006 10:38 AM |
Miatas are a different beast. He is not the only one to come to that conclusion. I personaly fall under the "find the biggest tire that can fit" camp.
| KC | 03-22-2006 10:56 AM |
I'm going though the same thing right now with the release of the 265/35-18 V710s...
I don't know if they'd fit on an 18x8 or not. 245/35-18s do... barely... and the 265/35s will have a slightly taller sidewall.
I don't know if they'd fit on an 18x8 or not. 245/35-18s do... barely... and the 265/35s will have a slightly taller sidewall.
| ratt_finkel | 03-22-2006 12:43 PM |
[QUOTE=KC]I'm going though the same thing right now with the release of the 265/35-18 V710s...
I don't know if they'd fit on an 18x8 or not. 245/35-18s do... barely... and the 265/35s will have a slightly taller sidewall.[/QUOTE]
Where did you hear they were releasing that size?
I don't know if they'd fit on an 18x8 or not. 245/35-18s do... barely... and the 265/35s will have a slightly taller sidewall.[/QUOTE]
Where did you hear they were releasing that size?
| KC | 03-22-2006 03:04 PM |
[QUOTE=ratt_finkel]Where did you hear they were releasing that size?[/QUOTE]
Oh... umm... :confused:
--kC
Oh... umm... :confused:
--kC
| AUTOwrXER | 03-22-2006 03:49 PM |
There are all sorts of reasons why a smaller size could be better, but I have yet to see the smaller tire prove faster on course*
My money would be on the 275 in this scenario.
*Given the same compound tire
My money would be on the 275 in this scenario.
*Given the same compound tire
| KC | 03-22-2006 04:39 PM |
[QUOTE=AUTOwrXER]There are all sorts of reasons why a smaller size could be better, but I have yet to see the smaller tire prove faster on course*
My money would be on the 275 in this scenario.
*Given the same compound tire[/QUOTE]
Gearing plays a big part... if you don't lose much contact patch...
My money would be on the 275 in this scenario.
*Given the same compound tire[/QUOTE]
Gearing plays a big part... if you don't lose much contact patch...
| AUTOwrXER | 03-22-2006 04:57 PM |
[QUOTE=KC]Gearing plays a big part... if you don't lose much contact patch...[/QUOTE]
Sure, but I think lowering the center of gravity via the shorter tire is even more beneficial than the gearing advantage. Still, I have yet to experience a smaller tire being faster than a larger tire on the STi. Contact patch is king, it seems, even over:
Gearing
CG Height
Scrub Radius
Extra overall width
Weight
Just IMHO, with data aquisition to back me up...
Sure, but I think lowering the center of gravity via the shorter tire is even more beneficial than the gearing advantage. Still, I have yet to experience a smaller tire being faster than a larger tire on the STi. Contact patch is king, it seems, even over:
Gearing
CG Height
Scrub Radius
Extra overall width
Weight
Just IMHO, with data aquisition to back me up...
| sciolist | 03-22-2006 11:01 PM |
[QUOTE=AUTOwrXER]Contact patch is king, it seems, even over:
Gearing
CG Height
Scrub Radius
Extra overall width
Weight
Just IMHO, with data aquisition to back me up...[/QUOTE]
Yes, I can imagine that's true, but my question is this: We're talking about a 275 on an 8" wheel vs. a 255 on an 8" wheel. The 275 is going to be pretty convex. The 255 significantly less so. Let's assume the car has adequate camber to take advantage of either tire. Even the 255 is wider than what would be considered optimum for an 8" wheel.
So, which tire atually has the larger *effective* contact patch? The 275 is obviously wider, but the 255 is more nearly normal to the wheel. I honestly don't know.
Gearing
CG Height
Scrub Radius
Extra overall width
Weight
Just IMHO, with data aquisition to back me up...[/QUOTE]
Yes, I can imagine that's true, but my question is this: We're talking about a 275 on an 8" wheel vs. a 255 on an 8" wheel. The 275 is going to be pretty convex. The 255 significantly less so. Let's assume the car has adequate camber to take advantage of either tire. Even the 255 is wider than what would be considered optimum for an 8" wheel.
So, which tire atually has the larger *effective* contact patch? The 275 is obviously wider, but the 255 is more nearly normal to the wheel. I honestly don't know.
| KC | 03-23-2006 07:44 AM |
[QUOTE=AUTOwrXER]
Just IMHO, with data aquisition to back me up...[/QUOTE]
Yeah.. but what do you know? :devil: You're just an auto-xer.. not a Road Racer like Hoppe is. :lol:
Just IMHO, with data aquisition to back me up...[/QUOTE]
Yeah.. but what do you know? :devil: You're just an auto-xer.. not a Road Racer like Hoppe is. :lol:
| enduroshark | 03-23-2006 08:17 AM |
As long a you can get them warm enough and have enough power to move them along, contact patch is king.
| AUTOwrXER | 03-23-2006 09:51 AM |
[QUOTE=KC]Yeah.. but what do you know? :devil: You're just an auto-xer.. not a Road Racer like Hoppe is. :lol:[/QUOTE]
:lol:
:lol:
| Scooby South | 03-23-2006 09:52 AM |
[QUOTE=KC]Yeah.. but what do you know? :devil: You're just an auto-xer.. not a Road Racer like Hoppe is. :lol:[/QUOTE]
:lol: :lol: [I]Psuedo[/I]???
Bill
:lol: :lol: [I]Psuedo[/I]???
Bill
| AUTOwrXER | 03-23-2006 09:53 AM |
[QUOTE=sciolist]Yes, I can imagine that's true, but my question is this: We're talking about a 275 on an 8" wheel vs. a 255 on an 8" wheel. The 275 is going to be pretty convex. The 255 significantly less so. Let's assume the car has adequate camber to take advantage of either tire. Even the 255 is wider than what would be considered optimum for an 8" wheel.
So, which tire atually has the larger *effective* contact patch? The 275 is obviously wider, but the 255 is more nearly normal to the wheel. I honestly don't know.[/QUOTE]
Since you mentioned this tire selection for AS, you are making a mistake in the assumption that the car will have adequate camber. Having the tire buldge at the sidewall is not a bad idea when you are leaning on the outer half of the wheel while cornering. I'd bet that the 275 has more contact patch (and a more useful patch) in that scenario than the 255 that mearly fits on the (poorly cambered) wheel better.
So, which tire atually has the larger *effective* contact patch? The 275 is obviously wider, but the 255 is more nearly normal to the wheel. I honestly don't know.[/QUOTE]
Since you mentioned this tire selection for AS, you are making a mistake in the assumption that the car will have adequate camber. Having the tire buldge at the sidewall is not a bad idea when you are leaning on the outer half of the wheel while cornering. I'd bet that the 275 has more contact patch (and a more useful patch) in that scenario than the 255 that mearly fits on the (poorly cambered) wheel better.
| sciolist | 03-23-2006 10:10 AM |
[QUOTE=AUTOwrXER]Since you mentioned this tire selection for AS, you are making a mistake in the assumption that the car will have adequate camber. Having the tire buldge at the sidewall is not a bad idea when you are leaning on the outer half of the wheel while cornering. I'd bet that the 275 has more contact patch (and a more useful patch) in that scenario than the 255 that mearly fits on the (poorly cambered) wheel better.[/QUOTE]
The original poster was the one who specified AS, not me. I'm mainly interested in the "absolute width" vs. "width considering fit on the wheel" question.
So let's move this over to BSP, where they'll let us have race tires *and* camber. :) Let's say a 255/40-17 710 materializes, and let's assume the wheel is fixed at 17x8.5. Is the 255 going to have a bigger effective contact patch than the 275?
The original poster was the one who specified AS, not me. I'm mainly interested in the "absolute width" vs. "width considering fit on the wheel" question.
So let's move this over to BSP, where they'll let us have race tires *and* camber. :) Let's say a 255/40-17 710 materializes, and let's assume the wheel is fixed at 17x8.5. Is the 255 going to have a bigger effective contact patch than the 275?
| WJM | 03-23-2006 10:11 AM |
[QUOTE=KC]Yeah.. but what do you know? :devil: You're just an auto-xer.. not a Road Racer like Hoppe is. :lol:[/QUOTE]
Hoppe is a road racer? show me t3h resultz!~!!!one!!1! :banana:
Hoppe is a road racer? show me t3h resultz!~!!!one!!1! :banana:
| WJM | 03-23-2006 10:11 AM |
BTW I'd go for the 275's over the 255's any day.
225>215>205 for my RX...even on the SAME 5" wide rim. The RX was FASTEST on the 225's over anything else I previously had on it. Unfortunatly the 225's were also the SHORTEST tire and I had to shoft more often.
But now I have 15x8's, bye bye 13x5's... :devil:
225>215>205 for my RX...even on the SAME 5" wide rim. The RX was FASTEST on the 225's over anything else I previously had on it. Unfortunatly the 225's were also the SHORTEST tire and I had to shoft more often.
But now I have 15x8's, bye bye 13x5's... :devil:
| rankink | 03-23-2006 11:03 AM |
Being that I have run on the 255 victos and 275 v710's I think even with a v710 in 255 size the 275 will be faster. The grip is different because of the compounds, but I did not really see any decrease in response from one tire to the next.
Here is a picture of a 255 victo next to a 275 v710 on the same 8 inch wheel.
[IMG]http://img.villagephotos.com/p/2004-11/896075/255vs2752.jpg[/IMG]
I am sticking with the 275's.
Here is a picture of a 255 victo next to a 275 v710 on the same 8 inch wheel.
[IMG]http://img.villagephotos.com/p/2004-11/896075/255vs2752.jpg[/IMG]
I am sticking with the 275's.
| trhoppe | 03-23-2006 12:27 PM |
How did I get dragged into this?
On a WRX, its a different world as the car is a dog with a 225/50 on the stock 16" wheel. Its the only scenario where "thinner" is better, especially since its WAY shorter.
On an STi, stuff the widest tire you can regardless of the height. 275/40 > * for AS.
-Tom
On a WRX, its a different world as the car is a dog with a 225/50 on the stock 16" wheel. Its the only scenario where "thinner" is better, especially since its WAY shorter.
On an STi, stuff the widest tire you can regardless of the height. 275/40 > * for AS.
-Tom
| conevadr | 03-23-2006 08:11 PM |
[QUOTE=rankink]
Here is a picture of a 255 victo next to a 275 v710 on the same 8 inch wheel.
[IMG]http://img.villagephotos.com/p/2004-11/896075/255vs2752.jpg[/IMG]
I am sticking with the 275's.[/QUOTE]
A picture's worth a 1000 internet opinions...
From my measurements, a 255 Victo has a section width of 9.8 on an 8 inch rim. From what I've been told, a 275 V710 on an 8 inch rim has a section width of 10.3 inches. That in the pic, the difference looks like more than .5 inch.
Anyone have an accurate measurement of the section width of a 275 V710 on an 8 inch rim?
Here is a picture of a 255 victo next to a 275 v710 on the same 8 inch wheel.
[IMG]http://img.villagephotos.com/p/2004-11/896075/255vs2752.jpg[/IMG]
I am sticking with the 275's.[/QUOTE]
A picture's worth a 1000 internet opinions...
From my measurements, a 255 Victo has a section width of 9.8 on an 8 inch rim. From what I've been told, a 275 V710 on an 8 inch rim has a section width of 10.3 inches. That in the pic, the difference looks like more than .5 inch.
Anyone have an accurate measurement of the section width of a 275 V710 on an 8 inch rim?
| conevadr | 03-23-2006 08:14 PM |
[QUOTE=AUTOwrXER]
Just IMHO, with data aquisition to back me up...[/QUOTE]
Any actual times, or readings that you can share? Was it so close as to be an almost unmeasurable difference - or was the difference significant?
Just IMHO, with data aquisition to back me up...[/QUOTE]
Any actual times, or readings that you can share? Was it so close as to be an almost unmeasurable difference - or was the difference significant?
| AUTOwrXER | 03-23-2006 11:41 PM |
[QUOTE=conevadr]Any actual times, or readings that you can share? Was it so close as to be an almost unmeasurable difference - or was the difference significant?[/QUOTE]
I don't have any data on this yet-to-be-released tire (obviously), but I do have some data that I would be willing to share on 275s, 285s and 315s. You can dowload the free Traqmate sw and I'll send you my files.
I don't have any data on this yet-to-be-released tire (obviously), but I do have some data that I would be willing to share on 275s, 285s and 315s. You can dowload the free Traqmate sw and I'll send you my files.
| fc3s7 | 03-24-2006 07:10 AM |
[QUOTE=AUTOwrXER]I don't have any data on this yet-to-be-released tire (obviously), but I do have some data that I would be willing to share on 275s, 285s and 315s. You can dowload the free Traqmate sw and I'll send you my files.[/QUOTE]
Did you keep the track width the same for the difference size tires? ie..spacers.
Did you keep the track width the same for the difference size tires? ie..spacers.
| AUTOwrXER | 03-24-2006 12:03 PM |
[QUOTE=fc3s7]Did you keep the track width the same for the difference size tires? ie..spacers.[/QUOTE]
No. All the tires I have tested are pulled in as close to the strut (in the front) or trailing arm (in the rear) as possible. Therefore, the wider tires stick further out and increase the track width. While that may help with weight transfer, IMO you give up more in transitions because you need to move the car further side-to-side.
No. All the tires I have tested are pulled in as close to the strut (in the front) or trailing arm (in the rear) as possible. Therefore, the wider tires stick further out and increase the track width. While that may help with weight transfer, IMO you give up more in transitions because you need to move the car further side-to-side.
| ratt_finkel | 03-24-2006 12:41 PM |
[QUOTE=AUTOwrXER]No. All the tires I have tested are pulled in as close to the strut (in the front) or trailing arm (in the rear) as possible. Therefore, the wider tires stick further out and increase the track width. While that may help with weight transfer, IMO you give up more in transitions because you need to move the car further side-to-side.[/QUOTE]
Not to mention the car is physically wider.
Not to mention the car is physically wider.
| AUTOwrXER | 03-24-2006 02:38 PM |
[QUOTE=ratt_finkel]Not to mention the car is physically wider.[/QUOTE]
Which would be the reason why you need to move the car further ;)
Which would be the reason why you need to move the car further ;)
| rich728 | 03-24-2006 04:15 PM |
is kumho really making a 265/35/18 or is that just speculation?
| rich728 | 03-27-2006 12:18 PM |
anyone have any update on this?
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