digi-dash more accurate than analogue?...

[Stanley]

ive heard all sorts of performance figures from mainly pin-headed nova drivers saying 'oh my GSI did 130 in 4th' etc etc (sure youve had the same)

Does a digi-dash (with electronic speedo sender) give more of an accurate reading or are they also pants at lettign you know how fast you went by that speed camera??

heard all sorts of theories....

i.e. My speedo was reading 120mph at just below 7K (1400SR - 195/40/16's)

[Ste L]

probably just the same really i would of though

[Rich]

I had 110 on my speedo in my 1.2 4 speed lol , the astra in from had 95... I've got gsi dials in it so that might make it worse.

[Adam]

It sposed to do, seems bo**ox to me tho, revs and speed matches on both digidash, and normal clocks.

[studaman21]

tbh there is gonna be a variation when you got bigger wheels anyway

[Mr_C]

According to my old mk1 speedo it did 115mph .... 1.0 litreeee power !! Must of been the K&N and my peco big bore giving me an estimated 50bhp extra!! lol

I'm messin by the way before I get attacked by 20 posts :)

The nova I've got now, I've had 125 on my digidash at about 5000rpm in 5th and thats got a 1400 16v corsa sport engine with the standard "mods" done to it, on 15" astra sport wheels. On a private road may I add ;)

[Welsh Dan]

If you really want to know, time yourself over a known distance at a steady speed, and to the maths :).

[ade]

or have someone follow up on the mway with a more reliable modern car keeping steady distance (or up side by side) and use mobiles (on speaker phone obviously) to assess difference

[hendrix]

or compare it with a GPS system?

[Welsh Dan]

GPS isnt completely accurate, although its probably more accurate than nova clocks lol.

[loggyboy]

the lack of accuracy in a speedo comes from several things - gearing, transmision and display
Now technically the digi will only suffer from one of these as transmission cant be effected (ie no cable wear) and display will only show what the sender tells it (no needle position inacuracy, magnet wear, user error etc)
However the accuracy still relys on the gearing being right (not only after wheel size change but original gearing accuacy) and also that the programming in the dash is correct.
In short, there is no way of telling without callibration of either system.

My analouge dash showed a progressive error of +10% when tested on GPS (ie 30 at indicated 33ish, 80 at indicated 88 and 140 at indicated 155 (estimated reading based on the standard nova dash that runs out at 130!)

(incedently GPS is more than accurate enough for speed testing due the likely hood of the test being quite long (ie more than a few seconds at the speed)

[Ricky G]

i was doing 124mph down marlow bypass and got caught speeding. the letter said i was got at 123mph and i have a digi dash in my 2 litre. my mate has standard gte clocks in his 2 litre and he said it does 125 in 4th gear and i say bull****!! we both have standard 2 litres and i can only hit 117 in 4th on limiter! same gearbox's aswell. so who know coz i dont??????????

[Mr_C]

117!! My 1400 does 107 god i'm proud now haha lol

[Ash]

i tested mine when i fitted the new gearbox:-

Digidash: 112mph

Sat Nav: 103mph

oh well, they do say speedo's can be upto 10% out.

also not bad for a 1.2 carb i thought.

tested on a private road btw.

Ash

[gary_126]

havent read the whole post so this may have been mentioned.

digi dash will be more accurate, because it cuts out the paralax error from reading the analogue needle (eg if you are looking at the needle slightly squint, or completely straight on, theres gonna be a few mph difference, and you will prob round it up, giving false speed.

Apart from that id say there pretty much the same tbh

[Novadave06]

My Nova Sri, has had a Full Engine Rebuild and its only done 10,000 miles since the build and it goes off the clock at 125mph as had a race with my mates 1.8 Astra and i kicked his ass everyone didnt keep up with my Sri.. But he said he was doing around 122mph so i know my Speedo Gonna Be Almost if Not Perfect .

Cheers, DangerMouse

[Novadave06]

By The Way... Sat Nav's Like Road Angel And TomTom's Give False readings as my mate has a 2.0lr corsa and when i was doing around 140mph it was reading only 94mph on the road Angel...they do give Bad readings...

[Riggy]

i used to get 4mph difference betwwen my digi clocks and my gps