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Engine Specific Info and Questions => TDI Engine -General Info => Topic started by: oldskool rich on May 17, 2008, 02:31:03 pm

Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 17, 2008, 02:31:03 pm
i have just dropped a mk5 golf 2.0 GT TDI 6speed box into a mk1, i would like to have a working speedo, but what i thort was the right plug tuns out to be the reverse lights

there is not anymore out puts, so how the hell does it work?

how am i supposed to know how fast im going?

 :?
Title: how does the speedo work on a late mk5 box?
Post by: jtanguay on May 17, 2008, 02:36:30 pm
GPS???  :lol:

i think you're stuck...  as far as i know it uses the ECU to do all the calculations etc...  but i'm sure someone has found a way to do it.
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 17, 2008, 04:29:00 pm
doesn't it have a electronic sensor somewhere? probably shares the plug of the reverse lights?
Title: how does the speedo work on a late mk5 box?
Post by: RabbitGTDguy on May 17, 2008, 04:44:52 pm
Should still use a VSS pickup off the differential. They are usually "black" in color...stick up maybe 3 inches or so...and would have a plug on the top of it (unless someone unscrewed the actually VSS sensor and all that is there is the bottom portion of the speedo gear assembly (which VSS screws onto or on early o2a cars (same VSS as 02j) you could hook a non electronic speedo up there...
 Check and see there.

The 2 plug on the shift mech is def. the reverse lights...

Joe
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 17, 2008, 06:01:59 pm
i know what you meen cus ive seen one of these vss connectors on a different box, this box was made in april 2007 it is totaly differnt to anything else ive seen, it has no connection or any hole for a connection, all it has is the reverse lights :(
Title: how does the speedo work on a late mk5 box?
Post by: RabbitGTDguy on May 17, 2008, 07:52:14 pm
Hmm...
i wonder if it uses a magnetic pickup from somewhere then...good question for investigation. that might be the answer though.

If you can't figure it out...the above is the way to go about getting the signal working for the speedo cluster... there are systems out there... *i.e. buying an aftermarket electronic speedo* that use magnet pickup systems to register speed or can pull a VSS signal.

If I come across the answer...I will let you know.

Joe
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 18, 2008, 12:57:50 am
i dont realy wana buy gps, its well expensive

if you know where i can get an aftermarket one from, that wud be amazing :wink:
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 18, 2008, 03:25:37 am
make your own ;)

do you have ABS pickups on the hubs? or can you fit them cheaply?

thats a good way to sense speed, and if you have two, you can also calculate speed accurately while cornering.

if its just to sense speed you can fit just one sensor to a rear wheel, and have a custom dial to show speed on the dash.

wont you have problems with such a system? here I can modify what I want, but by law I cannot mess with the mileage counter.
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 18, 2008, 03:47:06 am
thinking about it.. its how VW senses speed:D
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 18, 2008, 06:22:15 pm
ye i cud probly set sumthin up off a rear wheel, but im not an electrical person, is there anything i can buy to fit on?

dont care about legality, just dont wana get caught by cameras

is there anyway i cud attach a mk1 speedo cable sum how then i cud use the standard mk1 dials
Title: how does the speedo work on a late mk5 box?
Post by: RabbitGTDguy on May 18, 2008, 06:34:33 pm
http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=287/home_id=59/mode=prod/prd126.htm

http://www.wildhorses4x4.com/downloads/8280%2008-08-06.pdf

Just a few products out there...

Joe
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 19, 2008, 02:58:07 am
those are electronic to electronic adapter and mechanical to signal.

for making a speedo off a abs signal, you only need an integrator to get the pulse in the right shape, then a counter is reset by a known fixed pulse generator.
 
I could get you a rough schematic, but you would have to implement it with somebody with background in electronics.

another thought: LED sucks, not visible during the daytime. using LCD a microcontroller could do all the work.
Title: how does the speedo work on a late mk5 box?
Post by: RabbitGTDguy on May 19, 2008, 04:13:58 am
generic search just looking for one of several different variations, options and products out there...

Didn't spend a lot of time on it honestly...

Where would you find an ABS signal on an MK1? Install the ABS sensor and pickup wheel on the hub would be quite the job (though, you could convert to a mk2/3 suspension in doing so...would take some work...) but might yield good results. You'd have to get your ABS bits from a b3,  a 'rado or similar with ABS. I don't think I'd go above b3, 'rado or mk3 hub/spindles. B3 ABS spindles will come in two variaties since there are some 16v cars (4 lug hubs) that had ABS...your choices in 'rado and Mk3 would be similar.
I think you'd have to use the entire spindle as late mk2 and on hubs use a larger bearing, of course 100mm axles, etc...so in order to get the ABS hub in, you'd have to run the larger wheel bearing.
Just thinking off the top of my head.

There are several simple methods out there...many of the ones used for adding aftermarket speedos would work as well. Many of them (like this example) use Hall sensors...or in your case...maybe better...a magnetic sensor to allow for speedo readout...
http://www.marshallinstruments.com/speedometers.cfm

guess I'm wondering as well. You just have the 6 speed box in the mk1? Mated to what as far as an engine goes? Maybe I missed that. I remember reading it a while back but can't remember at this point.

Joe
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 19, 2008, 04:40:17 am
those are some sweet dials :D

I swapped all hubs/trasmissions from a mk3 vr6 into my mk2.
 but before that I swapped for mk3 TD abs parts.
I noticed that the abs sender was a add on, as it fell down when I took it apart, so were the front senders.

I guess one can order the parts from vw, just the hub and sender, then improvise a way to secure the sender.

or use a magnet glued to the transmission and a hall sender.
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 19, 2008, 05:51:39 pm
the engine is a heavily modified AAZ.

things hav changed slightly. i ended up removing my caddy dash and destroyed it in the process. now im using a mk1 scirocco dash which wasnt easy and i dont want to spoil it with a digital speedo.

is there any way i can get the standard speedo cable to work without being in the gear box?

i was thinking of taking the gear out of my old box that operates the speedo and welding it onto my half shaft and just run the cable off that?

wud that work? :?
Title: how does the speedo work on a late mk5 box?
Post by: gigaz2 on May 20, 2008, 05:48:47 am
thats some serious mod, a lot of risk for almost no return.

cheap and dirty way for a geek to do it: bicycle computer with the sensor coupled to the passenger side transmission (the part that doesn't move with the suspension).

I achieved to take mine to 85Km/h on a very steep incline :D so it doesn't seem to have a limit and you could avoid speed cams with that.

the accuracy increases a lot if you glue it to a rim, and have the sender in the caliper for instance.
Title: how does the speedo work on a late mk5 box?
Post by: RabbitGTDguy on May 20, 2008, 07:00:29 am
There are kits for custom motorcycles out there as well that use the same idea. Would be an easy install...

I wouldn't go the route that you were talking...err...cutting....welding....on the box itself...much easier ways to do it...

Joe
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 21, 2008, 03:28:17 pm
ok so i could use a bike speedo, trouble is that i need to then go from the pulse sensor to my anolog style clocks.

i know its alot of effort for nothing back, i spent the whole day hiding my aftermarket tacho metre inside the standard clocks of a mk1 scirocco, theres no way i did that for nothing. i need all the dials working. i want this to look totaly standard.
Title: how does the speedo work on a late mk5 box?
Post by: snakemaster on May 21, 2008, 03:57:12 pm
Hey man get a speedo cable of a beetle cos it goes to the front hub and the greese cap got a pin in it whitch turns the cable , you could mod this to fit the rear hub of your pickup need a bit longer cable thro , have a look at a beetle to see what i meen  :)
Title: how does the speedo work on a late mk5 box?
Post by: oldskool rich on May 21, 2008, 06:09:24 pm
safe, ill look into that

thanx