Daz Posted July 25, 2014 Report Share Posted July 25, 2014 So at 2000 rpm in 4th O/D just how fast am I going ? Its a 1975 standard car, standard tyres. No need to go into great detail about gear ratios tyres sizes and stuff, just give or take a few mph, how fast am I going? I need to fit a fag lighter then I could plug in Bat Nav. Thanks Quote Link to post Share on other sites
Austin Branson Posted July 25, 2014 Report Share Posted July 25, 2014 (edited) Depending on tyres, I would say about 52 or 53mph, if it's a CF, maybe 56 or 57 if it's a CP. Austin Edited July 25, 2014 by Austin Branson Quote Link to post Share on other sites
Johncracknell Posted July 25, 2014 Report Share Posted July 25, 2014 There's some good speed aps on mobile phones that will give an accurate speed via GPS these days Quote Link to post Share on other sites
simonjrwinter Posted July 25, 2014 Report Share Posted July 25, 2014 Some of them even have a HUD mode so you can see a reflection in your screen Quote Link to post Share on other sites
Don H. Posted July 25, 2014 Report Share Posted July 25, 2014 There's some good speed aps on mobile phones that will give an accurate speed via GPS these days Some of them even have a HUD mode so you can see a reflection in your screen I use an app called SpeedHUD on my iPhone. The heads-up display is useful and of course the GPS precision is perfect. Quote Link to post Share on other sites
North London Mike Posted July 25, 2014 Report Share Posted July 25, 2014 (edited) 24 mph per 1000 = 48 mph (depending on stuff............Doris Nav agrees.) feels faster though more like 52 ! Edited July 25, 2014 by North London Mike Quote Link to post Share on other sites
Alec Pringle Posted July 25, 2014 Report Share Posted July 25, 2014 Bear in mind that your tacho could well be significantly awry . . . . . Cheers Alec Quote Link to post Share on other sites
Daz Posted July 26, 2014 Author Report Share Posted July 26, 2014 Thanks, I have downloaded a Speedo app to my phone and will try it out later,don't know why I didn't think of that!! Quote Link to post Share on other sites
jamesStag Posted July 26, 2014 Report Share Posted July 26, 2014 (edited) Daz, +1 on Alec's comment. Don't trust the tacho unless it been checked. I had the feeling that my engine tacho was well out. So borrowed an optical digital tacho to check on the engine pulley. At an indicated 4000 rpm, the engine was doing nearer 3000rpm!! The tacho has since been off to JDO instruments, and now reads correctly... cheers, J. Edited July 26, 2014 by jamesStag Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 26, 2014 Report Share Posted July 26, 2014 (edited) Yes, we all know the addition of a tacho to a tuned up, first car, was responsible for many an engine rebuild.... Mini owners used to claim valve bounce was the best rev limiter. Edited July 26, 2014 by BlueTR3A-5EKT Quote Link to post Share on other sites
john.r.davies Posted July 26, 2014 Report Share Posted July 26, 2014 Apps! We didn't have "apps" when I were a lad! But we did have a few motorways, and we have lot more now. Take a passenger who wears a watch for a drive on one, at a constant speed according to your speedo They count how long it takes to pass ten of then (1 kilometer). Then, simple arithmetic will reveal your velocity, in Kms/hour, easily converted to Miles/hr. Google will do it for you! Apps! Pah! John Quote Link to post Share on other sites
Alec Pringle Posted July 27, 2014 Report Share Posted July 27, 2014 " They count how long it takes to pass ten of then " Aye lad, gradely, now try explaining that on a sober Sunday morning . . . . Cheers Alec Quote Link to post Share on other sites
Don H. Posted July 27, 2014 Report Share Posted July 27, 2014 Apps! We didn't have "apps" when I were a lad!... ...Google will do it for you! Apps! Pah! What's wrong with this picture? Quote Link to post Share on other sites
AlanT Posted July 27, 2014 Report Share Posted July 27, 2014 Remember the difference between fence-panels and fence-posts. You will pass elevern posts in a km, kind of. Quote Link to post Share on other sites
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