speedo
Turbo Mini Forums

after driving my car to work today i noticed that the speedometer seems to be under reading, 4k rpm and only reading 60 mph, surley this isn't right? seems to be going much faster than 60!
what needs changing?
by the way the engine and box are straight out of a metro.

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

what size wheels?

oh yeah, 13 inch wheels.

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

There is a good program called gearboxmanager that someone has written, that calculates speedo drives etc.

If admin want to host it somewhere, then I'll e-mail it to you.

I downloaded it from a german site, so its quite hard to find on the net, but if you search for gearboxmanager.zip in google and look on some german mini sites, then you might get lucky!

Else PM me and I'll send it!

coincidently, the size of wheels doent actually make that much difference, last week i was messing around with a 10" 12" and 13" and they were all within about 2-3mm rolling diameter, 12" was the biggest, 13" a little smaller, and 10" a fraction smaller.

what metro are the engine and box from? (or if you know) what diff did it have? standard 3.44, turbo 3.2 btw.

my mg lump running 12" with a 3.44 dif used to pull 60 at 3750rpm.

Pete

And on the 7th day........... God created turbochargers!

nutter driver, the engine and box straight from a 86 metro turbo, it might be me but it really seems like its not reading correct!
example; in moving traffic, speed camera in a 40 area, everybody slows down to what my speedo reads is 30 mph.

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

you could always try this...ive bought one now and it is very accurate........ http://www.turbominis.co.uk/forums/index.php?p=vt&tid=2354

mark

was thinking of that, there are so many speed cameras round my way that i would like to know exactly what speed i am doing, rather than guessing!

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

so that means it should now have a 3.2 diff. if it (the car) orignally started life with a 3.44 then the speedo would underread so what you are saying would be correct. you have basically five solutions.....

1. Get spedo recalibrated
2. get bike spedo like mark
3. get an mate with a accurate spedo to track you and mark it on the speedo
4. as above, only using a accurate rev counter, since these seem considerably more consitant than speedos in my experience, (hence i know that 3750 was 60 in my car, and just over 7000 was very illegal!)
5. forget it and drive slowly.

hth,

Personally i would go for the bike speedo, seems by far the most accurate, i will get a wired removable one when i finish building, so it is functional, but can easily be hiddemn when showing off the car. sod throwing money at someone to recalibrate my speedo!

Pete

And on the 7th day........... God created turbochargers!

gibbo, that site sounds interesting, if you could send me the link or post it up on here that would help me out, as i'm just driving everywhere slow!!
i did just find that site but its in german!

Edited by adam1330 on 11th Sep, 2004.

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson

i've gone for the bike speedo
got one on ebay, looks like quite a good one.
hopefully it will be here for the weekend!

““A turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.”” - Jeremy Clarkson