Autobox Gearing

Post by **docchevron** » Thu Nov 05, 2009 2:28 pm

Blimey! That aint bad then..

Ok, so, to complete testing here, you'll need a meter with a calibrated tacho (the guys in your workshop should have one I'm sure) and test the rev counter in the car against the calibrated tacho and see if there is any difference.

If there isn't, then the car clearly has the worng autobox in it.
If there is, you know the rev counter is a bit wayward.

Post by **Tim Leech** » Thu Nov 05, 2009 2:50 pm

OK Doc, will get it looked at, the accleration is good but its not what what you would call "frugal"

Post by **docchevron** » Fri Nov 06, 2009 2:45 am

They never are, whilst NO-ONE makes a better auto transmission than Zahnradfabrik Friedrichshafen unless you can keep it in top gear all the time, it's still limited by a fluid coupling, albeit with a very clever planetary gear set..

IMHO for most BX applications I always thought the final drive ratio was too low...
Thats why I had my own built for Phoenix, shame Citroen never quite got it right there...

Either way, if your tacho is accurate it must have the wrong box in it, I'm fairly sure it shouldn't be lower geared than a valver, thats just wrong!

Way2go · Post by **Way2go** » Fri Nov 06, 2009 6:13 am

Jaba wrote: My tables show 22.3mph per 1000 for the GTi Auto - that means 3580 revs at a true 80mph.

My gauges would agree with that!

My speedo is spot on accurate against the SatNav and at 80mph shows 3600 on the rev counter!