xr6bt1 Member 25 Member For: 15y 9m 22d Gender: Male Location: Melbourne Posted 26/10/08 11:31 PM Share Posted 26/10/08 11:31 PM Just put a set of 20's on the car on saturday (pics to come shortly) and as expected my speedo is now out. I was thinking it would be about 4-5kays off at 100km/h. I went cruising on sunday and hooked up the GPS to see how far out it was. I found that it is actually 9kays off at 100, so speedo reads 92 but car is doing 100. Is this about normal? I have 255s on the rear and 225s on the front, rims are 8.5inch wide front and rear. Car is a BF Mk2 XR6 Turbo.Also wondering if there are any places in the western suburbs that can re-calibrate the speedo?Cheers Link to comment Share on other sites More sharing options...
senna_T Forged Member Lifetime Members 15,818 Member For: 17y 2m 11d Gender: Male Location: SW Sydney Posted 26/10/08 11:34 PM Share Posted 26/10/08 11:34 PM I drove a GT to melb. with 20s and the GPS said that was out by 6km/h - but they come standard with 18's - if your car came with 17s from the factory that could explain the increase Link to comment Share on other sites More sharing options...
YPURV4 KILL,KILL,KILL,DIE,DIE,DIE, Member 2,813 Member For: 17y 11m 14d Gender: Male Posted 26/10/08 11:41 PM Share Posted 26/10/08 11:41 PM yeah that's about right mine is 7ks out. Link to comment Share on other sites More sharing options...
XRSCAR Member 414 Member For: 16y 2m 9d Gender: Male Location: FTG, Victoria Posted 26/10/08 11:42 PM Share Posted 26/10/08 11:42 PM gone from 17" to 19" and my speedo is more accurate than ever Link to comment Share on other sites More sharing options...
xr6bt1 Member 25 Member For: 15y 9m 22d Gender: Male Location: Melbourne Posted 27/10/08 12:05 AM Author Share Posted 27/10/08 12:05 AM Yeah went from 17s to 20s. got some getting used to I guess. Link to comment Share on other sites More sharing options...
Mr Man Mad Scientist Member 816 Member For: 19y 4m 20d Gender: Male Location: Vic Posted 27/10/08 12:16 AM Share Posted 27/10/08 12:16 AM gone from 17" to 19" and my speedo is more accurate than ever :o with the 17s on, at 100km/h on the speedo it showed 97 on the gps, and now with the 19s on 100km/h on the speedo is 101 on the gps.... Link to comment Share on other sites More sharing options...
Guest Guests Posted 27/10/08 02:23 AM Share Posted 27/10/08 02:23 AM You can have your rolling diameter changed via the edit if I'm not mistaken & that will make your speedo spot on Never done it myself but pretty sure it can be done... Link to comment Share on other sites More sharing options...
RUS531 RUS531 Donating Members 410 Member For: 17y 7m 29d Gender: Male Location: Emerald QLD Posted 27/10/08 03:23 AM Share Posted 27/10/08 03:23 AM my speedo is out by about 5ks and I went from 17's to 20's Link to comment Share on other sites More sharing options...
86gav 69 - PSI Donating Members 263 Member For: 18y 6m 25d Location: Gladstone QLD Posted 04/11/08 11:22 AM Share Posted 04/11/08 11:22 AM my speedo is out by about 5ks and I went from 17's to 20'sMine is about 9k's out with 245/30'sGav Link to comment Share on other sites More sharing options...
seventytwo Still have a turbo, it's just on a diesel. Lifetime Members 5,368 Member For: 18y 9m 11d Gender: Male Location: The 8th Dimension Posted 04/11/08 11:35 AM Share Posted 04/11/08 11:35 AM Tyre calculatorTry this little gem Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now