rallyeash 155 Posted June 21, 2011 hello, my speedo seems to be very inaccurate. for example 22mph is just over 30 and 30 is like 45 or so. what are peoples thoughts on what this could be, speedo drive cable, drive unit in the box or the actual speedometer its self? running Be3 gearbox, gti dash clocks and cable. thanks Ash Share this post Link to post Share on other sites
Anthony 1,000 Posted June 21, 2011 Are you running a matched pair of cogs in the speedo drive in the 'box, ideally both from a 205? If you start mixing and muddling the gears up, the speedo gets very inaccurate. Generally, 205 speedos are very good in my experience - I know my white '89 GTi is pretty much bang on when compared to the GPS. Share this post Link to post Share on other sites
rallyeash 155 Posted June 21, 2011 standard 1.9 gearbox just fitted with a quiafe so should be standard 1.9 drive in the box. yeah my mates speedo is bang on with the GPS also do you have those clocks spare? want to get my rev counter working and fuel gauge. Share this post Link to post Share on other sites
Ryan 99 Posted June 21, 2011 What size wheels/tyres are you using? Share this post Link to post Share on other sites
Dan! 0 Posted June 21, 2011 Have your clocks ever been taken apart? If they have, the needle for the speedo might not have been put back on properly. If its linearly wrong i.e 10mph out at 20mph, and only 11/12 mph out at 70 then moving the needle should make it alot better. Also, non standard wheels/tyre sizes? Share this post Link to post Share on other sites
rallyeash 155 Posted June 21, 2011 (edited) 185 55R14 Yokohama A048's im trying to source a good set of dials from anthony as the rev counter sometimes works and sometimes doesn't so want another set of dials and do the tacho mod too it. doesnt seem to stay a fixed speed out, although ive only compared is at low speeds Edited June 21, 2011 by rallyeash Share this post Link to post Share on other sites
SurGie 54 Posted June 21, 2011 Yeah and the GPS systems are also accurate as well I would replace both speedo cogs with a new speedo cable. Then renew the speedo housing seal as this causes many gearbox oil leaks. Hope this helps Share this post Link to post Share on other sites
welshpug 1,626 Posted June 21, 2011 should be on 185 60 not 55 Share this post Link to post Share on other sites
rallyeash 155 Posted June 21, 2011 it was on 185 60 R14 toyo R888's but there wasnt stock so got a special price on 185 55 R14 A048's instead. although this made no difference to the speedo but gave me less tyre wall flex theres one of those things which flash up your speed on a local road atm and the speedo had to read about 22 to be 30-31 mph so i know its out! Share this post Link to post Share on other sites
Bakes100 20 1 Cars Posted June 28, 2011 When i had a 6 speed box in my old 205 the speedo read approx 15% too high. I fitted a different plastic speedo cog into the gearbox housing and after that it was fine. Off the top of my head I cant remember which one i used but there is (was) a large selection available from peugeot, which i think are all different colours depending on the amount of cogs Hope this helps! Share this post Link to post Share on other sites
Weser 30 Posted June 28, 2011 I changed my dash clocks once to another second hand set and the speedo was out but 10mph. I.e 20mph indicated was 30mph actual. Bit annoying. I just replaced with another set of clocks and that solved the problem. It depends if like me you know that everything else is ok on the car? Share this post Link to post Share on other sites
marksorrento205 80 Posted June 28, 2011 Unless im missing something, your running a 1.9 gti gearbox with 185-55-14 tyres. As the 1.9 runs 195-55-15 tyres that cant help as the gears in the speedo drive are for 1.9 wheel radius or am im missing something?? When I had my vts box on my 6 engine I fitted the 1.9 speedo drive parts with the correct size tyres and the speedo was bob on. Also when I first returned the 306 rallye back to standard cyclones ( and ditched the hidious 17's it cae with) they came with 195-45-15 tyres on them and the speedo over read by around 10 mph. 50 profile ones brought it down a touch and the std 55 profile is now within 2 mph. Share this post Link to post Share on other sites
Anthony 1,000 Posted June 28, 2011 Unless im missing something, your running a 1.9 gti gearbox with 185-55-14 tyres. As the 1.9 runs 195-55-15 tyres that cant help as the gears in the speedo drive are for 1.9 wheel radius or am im missing something?? 1.9 GTi is 185/55R15's as standard - I suspect you're thinking either of 306's which run 195/55R15's, or the fact that most people run 195/50R15's on 1.9's. Share this post Link to post Share on other sites
rallyeash 155 Posted June 28, 2011 the 185 60 14 r888's i had on the front recently were still the same speedo reading and i lined them up against an old 195 50 r15 r888 and were pretty much the same diameter. my mates got these fitted on his 1.9 205 and there spot on on the speedo reading still ok to collect the speedo dials later anthony? Share this post Link to post Share on other sites
marksorrento205 80 Posted June 28, 2011 (edited) 1.9 GTi is 185/55R15's as standard - I suspect you're thinking either of 306's which run 195/55R15's, or the fact that most people run 195/50R15's on 1.9's. 185-55-15 is what I have got A slight typo Edited June 28, 2011 by marksorrento205 Share this post Link to post Share on other sites
Tesstuff 222 Posted June 28, 2011 No wonder you think it's quick if it's showing that much more on the speedo for that given speed Your choice of tyres/wheels is only making a -4.65% difference on the 1.9 box. So at 30 it would be showing on the speedo as 31.39 which is neither here nor there. So your problem isn't a rolling radius discrepancy. Share this post Link to post Share on other sites
rallyeash 155 Posted June 28, 2011 No wonder you think it's quick if it's showing that much more on the speedo for that given speed haha its annoying if driving through a 30 with a speed camera in place or somthing similar. i can appreciate it could be 5% or so out because of the different radius but not 10mph+ at such low speeds. picking a new set of dials up from anthony later which im hoping does the trick. also rev counter tends to drop off when accelerating then comes back when the throttles let off. going to do the mod again and hopefully sort that too.. Share this post Link to post Share on other sites
Grim.Badger 15 Posted July 3, 2011 It will be the small cog in the speedo housing - I'll bet you have a red 17 tooth cog, which is the one that the parts catalogue says you should have, and if you change to the 21 tooth cog your speedo will read right. I had the same problem with my old 1.6 with exactly the same miss-read; it seems that the "innacurate" clocks aren't actually broken but are set up for a different speedo cog than the "working" ones. The cogs were about £6 and a 10 mintue job to change if you fancy trying it. Share this post Link to post Share on other sites
rallyeash 155 Posted July 3, 2011 i changed my clocks now, theres definatly a difference, 30 feels about right now but it feels like its over reading at 70+. going to stick sat nav in it and take it for a spin i think Share this post Link to post Share on other sites
Tesstuff 222 Posted July 3, 2011 Can't wait for the video of you doing 30 showing 30 rather than 45 at 30 So excited Share this post Link to post Share on other sites
rallyeash 155 Posted July 3, 2011 (edited) Can't wait for the video of you doing 30 showing 30 rather than 45 at 30 So excited Edited July 3, 2011 by rallyeash Share this post Link to post Share on other sites
Redtop 14 2 Cars Posted July 3, 2011 Is this a track day car? If it is then why not get a trip meter like a monit and then calibrate the speed accurately yourself. Then you would know exactly what speed you were doing, with the size of wheels your running . Share this post Link to post Share on other sites
