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Location:
Sydney
Registered:
May 2004
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Rim sizes & effect on speed
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Sun, 19 June 2005 06:11
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Just out of curiosity,
i have an ae92 sx.
Im not sure what the factory standard rim size is...but right now i got 15" rims on them.
I know that bigger rims will make your car go slower...
Im just wondering if smaller rims will make your car go faster?
If i downgrade my size from 15" to 14", would my car go faster?
Reason i ask is because i cant really afford to have 15" rims atm...so just wondering if having 14" rims would make an advantage...
Cheers
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Location:
Kilsyth, Melbourne
Registered:
September 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 06:18
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smaller rims will give you more accelaration but less top speed and bigger rims will do the opposite
-Calvin
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Registered:
May 2002
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 06:18
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The only dofference would be in rolling circumference. I.E. If you change your wheel-tire combo to have a smaller circumference it will have better acceleration and less top speed. It will also throw your speedo out of whack.
It's much like gear ratios, changing the circumference changes the relationship between engine revs and road speed. If you follow...
Chances are, when they put 15's on they would have fit a thinner tire so the circumference is the same.
In reality, it's not worth considering for performance benifits. Gains would be negligible and your speedo would be inaccurate.
Tim.
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Location:
brisbane
Registered:
December 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 07:08
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lol i woudlnt bother about putting smaller tyres on to go faster... as has been stated above.. there would be abigger difference in getting ur mate in the passenger seat to row the car along
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Location:
Perth, WA
Registered:
December 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 07:15
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changing rim sizes doesn't necessarily mean that the circumference will change.
bigger rims, lower profile..
Eldar.O.
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Location:
Sydney
Registered:
May 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 07:22
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Speedo out of whack?
What is the correct circumference or wheel/tyre combo for an accurate speedo reading?
The 15" rims now have 195/50R15 rubber on them...is this the right tyre/rim combo for a correct speedo reading?
How about 14" rims? wout would be the correct tyre combo? 185/60R14?
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Location:
Dandenong Ranges, VIC
Registered:
July 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 11:21
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| kwayzivietnamese wrote on Sun, 19 June 2005 17:22 |
What is the correct circumference or wheel/tyre combo for an accurate speedo reading?
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Whatever the car came with originally is going to be correct.
http://www.ae92gts.com/ae92gts_wheel_fit.html
I must be bored 
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 12:51
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What you want is SENSIBLE sized wheels - i.e. 12s or 20s are both going to look quite stupid on an AE92. Within the range of sensible (15-17 in my opinion), then choose tyres that come close to the rolling diameter of what's on the tyre placard - you can either measure, work out, or look up in a tyre brochure to find out what size your tyres are. For the sake of performance, you want the LIGHTEST wheel/tyre combo - i.e. no rolling-mirror chromies.
Then again, maybe the whole diameter thing has some truth. Maybe that's why drag cars to a burnout - to reduce the diameter of the tyre  
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Location:
Sydney
Registered:
May 2004
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Re: Rim sizes & effect on speed
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Sun, 19 June 2005 16:08
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Mmmm...
the factory rims i just found out are 14".
And most of them are fitted with pretty thick as tyres...
That means if im to get 14" rims/alloys, then its pretty much certain that if i had lowish profile on them...speedo will be wrong?
Crap....having fat tyres is sooo uncool..
And there are a nice set of 14" alloys that i mite wanna get...but its got 185/60R14....crap crap crap 
How much of a speedo whacko reading diff are we talking here? Just so that i know how much to give way at speed cameras...
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Registered:
October 2004
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Location:
Melbourne
Registered:
January 2005
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Re: Rim sizes & effect on speed
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Mon, 20 June 2005 01:19
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I found a tyre size calculator on the web. Was very helpful when getting new rims to make sure the diamater didn't change much. Here is the link:
http://www.rochfordtyres.co.uk/TyreCalc.asp
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Location:
Campbelltown
Registered:
November 2003
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Re: Rim sizes & effect on speed
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Mon, 20 June 2005 01:29
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its easy to work out yourself and i actually found this calc while searching for info and came up on the old toymods egroups.
Tyre width eg 195 times the aspect ratio (profile) eg 50 x 2 gives you the height of both side walls on the tyre top and bottom, then multiply the size of the rim by 25.4 and you have the diameter of the rim, compare with other sizes until you get a match and then choose that size.
PS my speedo is out by 6% by my calculations and as yet after nearly two years of driving i have gone past many radars and never been pinged so i guess its right
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Location:
Sydney
Registered:
May 2004
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Re: Rim sizes & effect on speed
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Mon, 20 June 2005 01:34
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ahhh...
cheers man that site is great! 
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