Why in the heck is my speedo off.....

Old 07-12-2007, 07:42 PM
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Default Why in the heck is my speedo off.....

Why in the heck is my speedo off by 10 mph. My car has factory size tires and the factory wheels. It has been lowered, but I didn't think that would matter. Am I wrong? It is supposed to have stock gears. At 70 mph I am right at 2K rpm. Any thoughts?
Old 07-12-2007, 07:46 PM
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lowering it might affect it . when i had my 65 chevy shortwide i had to get the speedo recalibrated after lowering it 5 in the front 6 in the back. Seems like it threw it off a bit.
Old 07-12-2007, 07:53 PM
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is your's auto?

im not at 2k rpm's till around 90mph
Old 07-12-2007, 07:55 PM
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did u change rear ends or somthineg? thats what happened with mine. either that or the previous owner never tuned it back after he pulled the gears out of it.


btw lowering it will NOT effect ur speedo.
Old 07-12-2007, 07:56 PM
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Originally Posted by Reznor
is your's auto?

im not at 2k rpm's till around 90mph
Nope M6
Old 07-12-2007, 07:56 PM
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lowering it has no affect on your speedometer. You obviously have aftermarket gears.

Brent
Old 07-12-2007, 07:57 PM
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2k at 90mph? What the heck gearing do you have?
Old 07-12-2007, 07:57 PM
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Originally Posted by LightEmUpLs1
did u change rear ends or somthineg? thats what happened with mine. either that or the previous owner never tuned it back after he pulled the gears out of it.


btw lowering it will NOT effect ur speedo.
Well, I think 2 owners ago put a new rear end in it. I guess that could be it. It is supposed to be stock though, but if he didn't have it tuned like you said.
Old 07-12-2007, 08:04 PM
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Originally Posted by MikeD101898
2k at 90mph? What the heck gearing do you have?
stock m6 gears 3.42(?)
Old 07-12-2007, 08:08 PM
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Originally Posted by Reznor
stock m6 gears 3.42(?)
Are you sure ur speedo's not off?
Old 07-12-2007, 08:10 PM
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Originally Posted by FastB
Are you sure ur speedo's not off?
i have a big cam too

245/250 .611/.615

its more like 2100-2150rpm
Old 07-12-2007, 08:10 PM
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Originally Posted by MikeD101898
2k at 90mph? What the heck gearing do you have?
btw, quick price/info on the mkiv?
Old 07-12-2007, 08:13 PM
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Stock Z was right at 80 at 1900-2K all stock. Go to the dealer they will let you use there emissions dyno to verify the speedo atleast the did for me or even a regular dyno to confirm your guess.
Old 07-12-2007, 08:34 PM
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Originally Posted by LightEmUpLs1
did u change rear ends or somthineg? thats what happened with mine. either that or the previous owner never tuned it back after he pulled the gears out of it.


btw lowering it will NOT effect ur speedo.
i did change the rear end to posi. in my truck too when i lowered guess that's probably what threw the speedo off


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