Alignment / speedometer issues with bigger tires
Shayyadin
05-14-2001, 10:36 PM
First worry... I have a nice set of 17" rims coming in tomorrow, and I'm worried that my 1.5" lowering springs will combine with the bigger rims to give me camber problems in the back (where it's not adjustable) and eat (expensive) tires for breakfast.
Do I need a camber kit to go with that, or will the alignment be OK in the back?
2nd...
I never thought of this before but... a friend of mine (a physics nerd) pointed out to me that if you put bigger rims on a car, it would make sense that the spedometer would underestimate your velocity - not cool when you spot the cop and you're trying to go +under+ the limit.
I mean, traditionally the speedo taps into the driveshaft, so it doesn't give two shits what size your rims are. So if you go up to 18" rims, every 15" stock takes you 18", and you'll end up underestimating your velocity by 20%.
Is that an actual problem or am I dreaming shit up again?
Thanks for answering all my questions. I'm the "reluctant hot rodder" - I'll do it, but I'll be nervous about it for the first thousand miles!
Shayyadin
Do I need a camber kit to go with that, or will the alignment be OK in the back?
2nd...
I never thought of this before but... a friend of mine (a physics nerd) pointed out to me that if you put bigger rims on a car, it would make sense that the spedometer would underestimate your velocity - not cool when you spot the cop and you're trying to go +under+ the limit.
I mean, traditionally the speedo taps into the driveshaft, so it doesn't give two shits what size your rims are. So if you go up to 18" rims, every 15" stock takes you 18", and you'll end up underestimating your velocity by 20%.
Is that an actual problem or am I dreaming shit up again?
Thanks for answering all my questions. I'm the "reluctant hot rodder" - I'll do it, but I'll be nervous about it for the first thousand miles!
Shayyadin
MaximumBrian
05-14-2001, 10:58 PM
Since your car isn't rear wheel drive and it certainly doesn't steer with the rear wheels, than rear tires won't really wear very quickly. I'm dumped over 3" 's with 16's and I wear almost evenly.
Lordrandall
05-15-2001, 08:23 PM
Here are a few wheel/tire size calculators you can use to make sure your speedo and odo stay correct.
:)
http://members.aol.com/mx6perform/tirecal.htm
http://www.cs.fredonia.edu/~stei0302/WWW/DAKOTA/TIRECALC/tirecalc.html
http://www.powerdog.com/tiresize.cgi
Also try http://www.tirerack.com they have a link that will give you good tire sizes to stay close to stock dimensions.
Good luck!
:)
http://members.aol.com/mx6perform/tirecal.htm
http://www.cs.fredonia.edu/~stei0302/WWW/DAKOTA/TIRECALC/tirecalc.html
http://www.powerdog.com/tiresize.cgi
Also try http://www.tirerack.com they have a link that will give you good tire sizes to stay close to stock dimensions.
Good luck!
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