Speedo Calibration

MightyBoy tech questions and answers.
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Billie
Posts: 2692
Joined: Mon Aug 17, 2009 9:18 pm
Location: Brisbane

Hey, i just took the speedo drive out and im wondering what size i need to put back in. When at 60km/h my speedo reads about 60km/h and at 72km/h it reads 60 and at 95km/h it reads 80km/h. Thats out by 19.2% lol. Will i need a bigger or smaller drive? And how the F**k is it out that far.
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Billie
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Joined: Mon Aug 17, 2009 9:18 pm
Location: Brisbane

http://www.jaycar.com.au/productView.as ... rm=KEYWORD

Will that work? i allready know the % its out.
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Tez
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Joined: Wed Sep 03, 2008 9:38 pm
Location: Croydon, Vic

And how the F**k is it out that far
You've put a speedo from an entirely different vehicle (albiet a Suzuki) into your car, connected up to a non-original gearbox (F8B-box) and have over-size tyres fitted, and you wonder why your speedo is out...? :-o

Wanna have another think about that...? :-o

The Jaycar Kit might be a good solution to your miss-matching efforts tho! :lol:

Good luck! :D
Tez
So the adventure continues...
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Brayden
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The Jaycar kit only works on cars with electronic speedometers. You're shit out of luck Billie! :lol:

The only option is to try and calculate what size speedo drive you need, or take the cluster to a recalibration specialist and have them work it out and modify the speedo. To work it out you'll need figures on the rolling diameter of the wheels, the speedo drive ratio, final drive ratio and of course the cluster ratio.
F8B EFI turbo - Three pots and a snail.
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Billie
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Joined: Mon Aug 17, 2009 9:18 pm
Location: Brisbane

But the revs per km are both the same from the original unit to the alto unit.

I have all those figures except the drive one, i have the driven which is the speedo end and the revs per km and tyre size. What is the drive one?
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me217
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Joined: Mon Jul 31, 2006 11:01 pm
Location: maryborough, qld
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or put it on a dyno and get it dyno'd for a power run and ask them to get the speeds at certain speeds and then they can send that away and get an adapter thing to change the speedo to correct. this is what my dyno bloke told me when i asked about my sierra
me217

1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
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niiko
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Location: briz vegas

Just put in a digital hatch cluster and use the jaycar kit.
Works 100% :)
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gadj
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Location: Maleny, Queensland
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There is another answer, you can use a ratio box similar to those supplied by Marks Adaptors or get in touch with Lionel Otto Instruments at Salisbury http://www.ottoinstruments.com.au
So many delays to getting my MB back in order with 993cc & 5 speed transaxle... neighbor issue gone, donor shell up on rotisserie, new sheds on the way.... another project also..
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me217
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gadj wrote:There is another answer, you can use a ratio box similar to those supplied by Marks Adaptors or get in touch with Lionel Otto Instruments at Salisbury http://www.ottoinstruments.com.au
yeah thats the thing i was talking about, not sure if i made sense tho.
me217

1985 suzuki mighty boy : mods, f8b
1990 toyota mr2 gt import : mods, turbo timer, short shifter, 2.5" exhaust
1992 suzuki sierra : mods, g16b mpfi, 235's/75, snorkel & lift on the way.
mowog
Posts: 970
Joined: Sun Apr 25, 2004 2:22 am

most likely your speedo is broken.
replace it.
I have the F8 box and the speedo is not affected.
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Billie
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Joined: Mon Aug 17, 2009 9:18 pm
Location: Brisbane

I dont think the speedo is broken, just not working to well lol.

I was lookin at the digital ones, but im abit weird with things, thats why i like the alto cluster, all the rev counter, speedo, temp and fuel are in one thing, dnt like having rev counters off to the side. The hatch digi dash doesnt have a rev counter lol. I'm pretty sure its coz i have a massive wheel change, 54mm bigger than stock.

Is it possible to change the actural speedo its self? I know it comes out and all, but would another from a diff car fit?

Me thinks the skyline 300km/h would look great :P
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Jermaine
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doubt it, the skyline one would be an electronic speedo... not cable
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Billie
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Location: Brisbane

Then convert the car to digital speedo?
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mowog
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Joined: Sun Apr 25, 2004 2:22 am

you say at 60 it reads 60, at 72 it reads 60 and at 95 it reads 80.
the fact it reads 60 at both 60 and 72 indicates to me its busted.
the different tyre sizes or drives or whatever would give a consistent error not a wildly varying one.
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gadj
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That is the main reason I suggested Lionel Otto (might be another instrument repairer closer) They will most likely be able to repair, rebuild or modify your speedo thus keeping things simple
So many delays to getting my MB back in order with 993cc & 5 speed transaxle... neighbor issue gone, donor shell up on rotisserie, new sheds on the way.... another project also..
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