How much power would i lose by putting 17s or 18s on?
12-17-2003, 10:44 PM
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How much power would i lose by putting 17s or 18s on?
I used to have a 94 Accord and i went from a stock 15" rim to 18" Racing Hart C2s w/ 225/40 Pirelli p7000s... The lack of power afterwards was really noticeable. I currently have a 04 WRX sedan with the stock 16" on it. I was wondering if i went up to a 17" wheel how much power would i be losing? and will it be fairly noticeable? I also wanted to make sure that the lug pattern is 5x100 right? Any info will be greatly appreciated.
12-17-2003, 11:11 PM
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depends on what wheels and tires you get
the thing that slows you down is the weight, a few pounds of rotational inertia can make a big difference
get some lightweight wheels and a light tire and larger wheels can possibly make you a little faster. its all in the weights. wheels are more noticable than tires cause wheels vary more than tires.
17" wheels vary between 13.xx pounds and 24+ pounds, huge difference, while different 17" tires will range from 22 pounds to 25 pounds
of course those numbers are pretty rough, just an example to show the differences
the thing that slows you down is the weight, a few pounds of rotational inertia can make a big difference
get some lightweight wheels and a light tire and larger wheels can possibly make you a little faster. its all in the weights. wheels are more noticable than tires cause wheels vary more than tires.
17" wheels vary between 13.xx pounds and 24+ pounds, huge difference, while different 17" tires will range from 22 pounds to 25 pounds
of course those numbers are pretty rough, just an example to show the differences
12-18-2003, 01:28 AM
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Your WRX has much more power than the Accord did, and going to 17s is a much smaller change. Your car will be a little slower with the few extra pounds on each wheel, but you can make that up by going with a slightly smaller diameter, like 215/40R17.
12-18-2003, 06:36 AM
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I agree that the wheel/tire combination is somewhat importaint. The most importain consideration is the torque applied to the ground. If you keep the same tire overall diameter then you will lose little or no power. Look up your present tire/rim size and then go to a +1 or +2 size. You will find that as the rim size goes from 16 inch to a 17 or 18 that the + 1 or +2 tire size will have a smaller cross sectional diamention. The tire might go from a 60 series to a 50 or 40 series cross section. This way the rolling diameter will be the same and no power will be lost. eddie
12-18-2003, 04:04 PM
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Also, the much improved handling should make up for any nominal power losses. Like erhayes said, if you keep the overall tire diameter closer to the stocker (ie you get a 215 or so), it should help.
12-18-2003, 04:05 PM
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Also, the much improved handling should make up for any nominal power losses. Like erhayes said, if you keep the overall tire diameter closer to the stocker it should help. Just be careful since a little less tire sidewall makes it easier to scratch up your wheels on the curb or potholes.
Last edited by Choku Dori; 12-18-2003 at 04:52 PM.
12-18-2003, 04:24 PM
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my stock wheel tire = 37lbs (tread was down to the wear bars)
rota actions(19lbs) w/ 225-45-17's Goodyear Eagle F1's = 42 lbs
only about 5 lbs but much more rubber
the stocker feel a bit faster in a straight line but turns suck.
rota actions(19lbs) w/ 225-45-17's Goodyear Eagle F1's = 42 lbs
only about 5 lbs but much more rubber
the stocker feel a bit faster in a straight line but turns suck.
12-19-2003, 06:47 AM
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I would be interested in the calculation which arrived at a loss of 2.7 HP for each pound of additional wheel weight. Did you pick a nominal distance from the axel center to establish the weight? I ran a rough calculation on HP loss if you increase the tire radius by 1/2 inch and the power loss is approc 6%; so on a 220 hp WRX the loss will be 13.2 HP. eddie
12-19-2003, 07:01 AM
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I didnt pick a distance from the axle or anything. I know that the 2.7 is accurate for the flywheel and pullys. Just assumed was the same for wheels too. Since they are rotational mass. If I am wrong please correct me so that I can know the truth. "You cant handle the truth." <- sorry I couldnt resist.
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12-19-2003, 08:27 AM
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Originally posted by erhayes
I would be interested in the calculation which arrived at a loss of 2.7 HP for each pound of additional wheel weight. Did you pick a nominal distance from the axel center to establish the weight? I ran a rough calculation on HP loss if you increase the tire radius by 1/2 inch and the power loss is approc 6%; so on a 220 hp WRX the loss will be 13.2 HP. eddie
I would be interested in the calculation which arrived at a loss of 2.7 HP for each pound of additional wheel weight. Did you pick a nominal distance from the axel center to establish the weight? I ran a rough calculation on HP loss if you increase the tire radius by 1/2 inch and the power loss is approc 6%; so on a 220 hp WRX the loss will be 13.2 HP. eddie
12-20-2003, 03:25 AM
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Wow, lots of info! thanks guys. Well I'm thinking of going with 17"... now i just have to come up with the money! I really want some Volks but god... 450 a wheel is so expensive...
12-20-2003, 03:27 AM
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Originally posted by Kosoku
Wow, lots of info! thanks guys. Well I'm thinking of going with 17"... now i just have to come up with the money! I really want some Volks but god... 450 a wheel is so expensive...
Wow, lots of info! thanks guys. Well I'm thinking of going with 17"... now i just have to come up with the money! I really want some Volks but god... 450 a wheel is so expensive...
12-20-2003, 04:35 AM
#14
ive had the same worries, and now i have 17's that weigh 19lbs, and tires that weigh 24 or 25lb each. there is a noticable change in speed and stopping distance. the speed im not too worried about, but the stopping distance worried me a bit. it takes a bit more effort to stop, not much but there still is a difference. itll take awhile but you'll get used to it.
and plus the difference in handling makes up for alot!
and plus the difference in handling makes up for alot!
12-20-2003, 10:03 AM
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Why not get lighter wheels? Am I blind or has no one suggested that outright? Yeah pricey... but my Volks weigh ~16lb each. Then I have less tire than stock. So it should come out lighter. Being that its all plus-sized, there's no torque difference. In the end I bet I "gained back" some power
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