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Re: 997 Carrera on 19 inches
Quote:
MMD said:
As you probably know, it's just for looks; the serious drawbacks are a possibly harsher ride more expenses for suspension maintenance. Do it to make a fashion statement.
And we are talking from experience?
A fashion statement? Is that why they put on the S?
The ride quality is fine. It is not harsh. The 997 was designed for 19 inch tires. Plus you get wider tires so it handles better. I would stay with the same width tires that Porsche recommends.
Mar 27, 2005 4:05:15 PM
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Carlos from Spain
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Re: 997 Carrera on 19 inches
Quote:
Dilinger said:
its just that with 18 inches, the gap until flares is big and also the tire profile is bigger, On the 997 the 18inch looks like 17 inch
Are you sure that outside diameter of 19" tires (=rolling diameter of tread profile) is really that much bigger than 18" tires fitted to the same model?
I have my doubts, because it would mean having to use different electronic software depending on wheel size to compensate for different tire diameters to maintain speedometer accuracy within acceptable legal limits.
Generally, larger "nominal diameter" tires have wider tread but smaller "aspect ratio". (For instance, 285/30 = 30% aspect ratio, instead of 265/35 = 35%). This allows the outside tread diameter to be kept very close to that of the "smaller" tire also offered on the same model.
If the tires look like they "fill" the wheel arches better, then it is generally because the car has been lowered, not because tires are really larger in outside diameter.
Mar 27, 2005 9:30:54 PM
- Leong
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Reply to:
Carlos from Spain
Re: 997 Carrera on 19 inches
Quote:
Carlos from Spain said:
Doesn't Porsche have a 19" wheel/tire option for the base 997? then just put those on and with the same tire sizes and you should be OK.
Yes, and at least half the base 997 models at my dealer have had this option fitted. And it cost $NZ3500 which is ridiculously cheap...
Mar 27, 2005 9:40:43 PM
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Carlos from Spain
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Re: 997 Carrera on 19 inches
Maybe its the visual effect of the tire wall being black like the gap between wheel arch and tire, and therefore blends somewhat with it visually and the eye uses more the shinny wheel as a reference so the larger wheel "looks" like it fills the gap more yet the total diameter of the tire is the same 
Mar 27, 2005 10:36:46 PM
- fritz
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Reply to:
Carlos from Spain
Re: 997 Carrera on 19 inches
Quote:
Carlos from Spain said:
Maybe its the visual effect of the tire wall being black like the gap between wheel arch and tire, and therefore blends somewhat with it visually and the eye uses more the shinny wheel as a reference so the larger wheel "looks" like it fills the gap more yet the total diameter of the tire is the same
I think there is an "optical illusion" effect as you described.
One thing is for sure; larger diameter wheels certainly make most brake disks look "Mickey Mouse".
Re: 997 Carrera on 19 inches
Quote:
Brian E said:
Use this to calculate tire diamter, it works great.
http://www.rx7.org/Robinette/tire_diameter.htm
Interesting Link. Thanks!
Re: 997 Carrera on 19 inches
Quote:
fritz said:
One thing is for sure; larger diameter wheels certainly make most brake disks look "Mickey Mouse".
This is so true. You can see this effect most likely on SUVs with 22'' wheels. I saw a Cadillac Escalade with 22'' wheels during my Florida vacation and the brake calipers and especially the discs looked really tiny, tiny, tiny.
Which remembers me of a story of somebody with large trousers but a tiny...well, sorry, it is late.
Mar 28, 2005 2:48:00 AM
- Jeff (in SF)
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Re: 997 Carrera on 19 inches
I bet you'd be fine with 265's on the back but here's what I think is the more preferred set up = stick with the OEM recommended rear widths and instead, increase the width of the front tires by 10mm on each side. Since it doesn't have AWD, you don't have to sweat the small difference in overall wheel diameter/circumference. On my 996, I kept 265 (18") on the back and went up to 235/40's on the front and the car understeered MUCH less than the stock setup. I assume less understeer is what you're trying to accomplish.
Mar 28, 2005 7:51:36 AM
- Raptor
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Re: 997 Carrera on 19 inches
Quote:
Raptor said:
Can you use, for example, 18 inch rims for winter tires and 19 inch rims for summer tires without modifying the suspension each time you change them?
If both wheel sizes are "officially recommended" dimensions, no suspension mods are needed. You just may need to use spacers with one and not with the other, but that will be specified in a TSB. Your dealer should have copies of all TSBs.
Mar 29, 2005 5:45:45 AM
- 911Carrera05
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Re: 997 Carrera on 19 inches
I tested the base 997 with 18s and also with optional 19s. The 19s (5 spoke) looked better, but the much lower profile gave a noticably harsher ride. I opted for the standard 18s, which so far prove to be plenty "sticky" through the SoCal canyons. I love this car!
Re: 997 Carrera on 19 inches
I think the 19" wheels are the way to go. I bought a Porsche not a Mercedes, I can put up with a little bit of extra harshness in the ride. As far as traction goes I can't spin the tires on good pavement from a dead stop. But, during cornering it's very easy to get the back end to slide out. I would have to say that the 295 tires will improve handling on slick public roads. They will enable you to get on the gas earlier with out sliding sideways. On a race track it may be a different story. I'm not a race car driver I bought my car for public roads and I love the way the 19" wheels look.
Re: 997 Carrera on 19 inches
Quote:
Jonas said:
I think the 19" wheels are the way to go.
...
I'm not a race car driver I bought my car for public roads and I love the way the 19" wheels look.
These SportDesign do look alright even if they are 19", as their design hides a lot of the tiny brake discs.
19 inches vs 18 inches INTERESTING !
Well using the link of another member i calculated some figures for 18 inches and 19 inches....here are the results
18 inches:
Front Tyres - 235/40 18
Tire Diameter=25.401574803149607
Tire Section Width(inches)=9.25196850393701
Tire Sidewall=3.7007874015748037
Rear Tyres - 265/40 18
Tire Diameter=26.346456692913385
Tire Section=10.433070866141733
Tire Sidewall=4.1732283464566935
19 inches:
Front Tyres 235/35 19
Tire Diameter=25.476377952755907
Tire Section Width(inches)=9.25196850393701
Tire Sidewall=3.238188976377953
Rear Tyres 295/30 19
Tire Diameter=25.968503937007874
Tire Section Width(inches)=11.614173228346457
Tire Sidewall=3.484251968503937
Interesting info,if you consider that it would be more the case that 19 inches had larger diameter BUT instead on the front the 19 inches are slightly bigger in diameter, and on the REAR the 19 inches are smaller!! i expected them to be bigger.First because they are 19 inches-despite the lower profile- and second because visually they look like they fill the back flares more than the 18 inches!! but the 18 inches are bigger..
Just a note: Smaller diameter wheel, on moving axle means better acceleration less max. speed.
Biger diameter means slower 0-60 but bigger max. speed.
Comment if you care
18 inches:
Front Tyres - 235/40 18
Tire Diameter=25.401574803149607
Tire Section Width(inches)=9.25196850393701
Tire Sidewall=3.7007874015748037
Rear Tyres - 265/40 18
Tire Diameter=26.346456692913385
Tire Section=10.433070866141733
Tire Sidewall=4.1732283464566935
19 inches:
Front Tyres 235/35 19
Tire Diameter=25.476377952755907
Tire Section Width(inches)=9.25196850393701
Tire Sidewall=3.238188976377953
Rear Tyres 295/30 19
Tire Diameter=25.968503937007874
Tire Section Width(inches)=11.614173228346457
Tire Sidewall=3.484251968503937
Interesting info,if you consider that it would be more the case that 19 inches had larger diameter BUT instead on the front the 19 inches are slightly bigger in diameter, and on the REAR the 19 inches are smaller!! i expected them to be bigger.First because they are 19 inches-despite the lower profile- and second because visually they look like they fill the back flares more than the 18 inches!! but the 18 inches are bigger..
Just a note: Smaller diameter wheel, on moving axle means better acceleration less max. speed.
Biger diameter means slower 0-60 but bigger max. speed.
Comment if you care
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