BUGA Community

Technical => Driveline => Topic started by: ShaneJ on December 17, 2012, 03:21:38 PM

Title: What speedo gear
Post by: ShaneJ on December 17, 2012, 03:21:38 PM

Hi guys, with the new diff and wheels my speed is now a "little" out. Anyone have any idea how to work out what speedo gear I need? I tried using some massive calculation to work it out but gave up.

3.5 diff ratio with 235/60R15(26.1inch) tyres.

Thanks

Title: Re: What speedo gear
Post by: ben on December 18, 2012, 07:46:19 AM

white out the new speeds on the dash facia works awesome!

Title: Re: What speedo gear
Post by: ShaneJ on December 18, 2012, 08:09:09 AM

haha thats an idea.  ;D Does the clear lens come off easy?

Title: Re: What speedo gear
Post by: mezzmo on December 18, 2012, 08:35:36 AM

Not as silly as it sounds Ben, if you are good on computer! - stick a piece of clear acrylic or similar to your instrument panel face - take the van for a drive using a free download app on your phone for a speedo, at each speed of 10 -15 -20 etc put a dot on your speedo with a texta. When your done, remove the clear acrylic piece and design a speedo on your computer - this is a trial and error until you get all the numbers to line up with your dots in the right spot - (i print off on crappy copy paper until i have it right), then print on a good quality photo paper or preferably vinyl and stick it over the original Beddy speedo face. This is how i did all the guages for my Corvette and it worked a treat.

hope this helps

Title: Re: What speedo gear
Post by: SkippyThBushKangeroo on December 18, 2012, 08:53:17 AM

i got mrs skippy to drive behind me in the ute, got on the mobile and got her to tell me when i was doing 50, 60, 80, 100, n 110... worked out this speedo was 20 kms out..eg 100 is 120 on the clock, when i used to just go off the speedo reading, i always wondered why it took so  long to get anywhere

Title: Re: What speedo gear
Post by: restoreid on December 18, 2012, 12:59:26 PM

I use my GPS its spot on

Title: Re: What speedo gear
Post by: ShaneJ on December 18, 2012, 01:02:30 PM

I've been using a speedo app on my Blackberry. i would prefer to the the dash though.

Title: Re: What speedo gear
Post by: willo on December 18, 2012, 02:36:46 PM

Quote from: restoreid on December 18, 2012, 12:59:26 PM

I use my GPS its spot on

I agree about the GPS but make sure you allow yourself a 'fiddle factor' in your reading.  The radars work on total accuracy so if we take away the normal speedo error then a camera might be a bit trigger happy.

ADR allows a certain percentage error but what is not generally talked about is that any error has to be on the high side by ADR rules.  That is, it shows 100kph when you are doing about 96 actual. 

Neil