How many have them and what brand did you use? How did you mount it in the dash? Any problems finding a good place for the antenna?

I am looking at the Speedhut as my cable driven S1 speedo/odometer is giving very erratic readings at times... tired of playing with gears and cables.

My rear end ratio of 2:88 does not correspond to any of the S1 speedo heads and I combined a S3 speedo and odometer inside my current unit...

I need a speedo that gets its information from the GPS antenna... losing the signal for a minute or so does not make any difference to me as I know
by the Tach approximately how fast I am going... but do desire a trip meter and odometer that is accurate. The 4 1/2" Speedhut looks to do all that I want and need.
Will have to adapt it to the Jaguar dash hole... the hookup and mounting of the antenna on the dash top corner is easy enough and it has turn signals and high beam
lights...

 

Curiosity here as well.


1. I seldom use my Totom GPS anymore, much less the teeny one in my antique Samsung flip cell!! I know how to get to most of the places I want to go to. And, I'm not even sure that they have a rate of travel readout?


2. Were I to look into a GPS speedo, I'd visit the Dakota Digital site. Lotsa of neat toys there. Their techs are friendly and helpful.


I'm going on errands in a bit, hopefully between showers. I just might plug in the
TOtom and see it's display and what Samantha says...


Carl

 

The speedhut gauges get good reviews on the MG forums - lots of people use them with success. I'm ready to pull the trigger on an order for a complete set for my Sprite, as it happens.

 

I use a Dakota Digital SGI-5e. Easy to configure.

GPS speed-o is not for me. Lots of Tunnels and Bridges here where that wont work.

 

The hole used for the Speedhut is about 1/2 smaller and their OD is 1/2 inch smaller or only 4.5 inches.

My plan would be to use the Jaguar speedo case, cut off the rear portion and adapt it to the Speedhut parts... That way it would install the same
way and be the same size in the dash... the Jag inner ring should cover the speedhut face. In worst case I might have to have a ring welded in
the Jag speedo case to mount their speedo parts. Their antenna will be mounted under the plastic speaker grill cover in the center of the dash
pad as there is no speaker in there and they claim the signal will pass through plastic.

Will order it soon but they take 25-30 business days for production. I am considering model GR4.5-GPS-02... no high beam light but 140 MPH. Will add a Blue LED on the left hand size of the dash and connect their wiring to it. Series 1 Jags have their turn signals in the center light quadrant.

 

the 2.88 diff was only used in the v12 cars,
so a 160mph speedo may do the trick,

 

According to my parts book, there were no 2:88's used on the Series 1 XJ. Closest ratio was 3:07 on the 4.2 engine and that would 7% difference.

Model Year Gear ratio Width
E Type 61-75 3.07,3.31,3.54 * 52"
Mk 10 61-75 3.54,3.77 * 60.5"
S Type 63-68 3.54,3.77 * 55"
420 66-68 3.54 55"
420G 66-70 3.54,3.77 * 60.5"
XJ6 4.2l 68-85 3.31,3.54,3.77 61"
XJ6 2.8 68-85 4.09,4.55 61"
XJ12 72-85 3.31 * 61"
XJ6/12 S3 79-92 2.88,3.07 61"
XJS 75-96 2.88,3.07,3.54 * 61"

The problem is the speedo heads were installed according to the rear end ratio used... not as per later cars with TPM (Turns per Mile).

Hence the need to change the internals like I already have to the S3 internals... it is odd since the speedo starts out cold being within 3% to the GPS reading (same as after I did all the conversion work) but after driving for several miles it starts reading real low...??

Will check the stupid 90 degree adapter again as it has come loose in the past... but the long time solution is to replace with a totally accurate GPS based speed head that will provide a odometer and trip meter.

I will have to adapt the slight smaller OD of the new speedo to the case for the stock speedo.. should be easy enough to weld in a metal bracket that will hold the new speedo head and make a ring that will cover the gap properly.... rear can then be covered with something....

 

a 2.88 diff from a v12 car will fit xj/xjs,

 

That is true, they all interchange...but the speedo reading correctly is my problem...

 

that looks so pretty/nice shame to drive thru a mud puddel!

 

I'll agree with that Roger...
I've had a couple Series 1 Xj12s, and all of them (plus a number of Series 2 XJ12s) have all been 3:31 lockers....

I'm always amazed at how closely my GPS speed matches my speedo...

David
shop.EverydayXJ.com

 

Actually, the 2.88 was used in many thousands of Series III 4.2 cars. All of the USA cars got that ratio circa 1982. Prior to that the USA got the 3.07

Cheers
DD

 

THANK YOU

 

I ordered the GPS speedo yesterday, GR4.5-GPS-02 or the 140 MPH model. My only concern is the push button on the front lens... how hard it will be to get it to fit into
the old speedo housing? Will add a blue LED for the high beam light off on the left hand
side of the dash panel.

 

I decided to change the original order to a flat lens with the remote push button to change the functions... it will fit where the trip meter control is now. Plus, I asked them to add the Blue high beam light in the speedo face.

Just make my fitting the new speedo much easier not having to deal with cutting a hole in the glass lens for the push button and adding the blue LED.

 

I managed to fit it into a old Jaguar tach housing (speedo housing would have worked the same) that was in my spares.. I cut out the center section on the inside leaving about 3/16" around the edges in a circle that fit the GPS cneter housing.

I had to "flatten" the inner blanking piece that is located next to the lens glass to get it to reach out a little more to cover the GPS outer ring.. then had to
grind the outer edges off since it was now wider to fit back into the outer ring that holds the glass.

I cut off a plastic container that was on my desk holding junk to get a 4 1/4 inch round ring that was about 5/16 wide adjust sanding it fit - to adjust the needed depth.. it fits around the GPS housing and then it drops in the Jag housing... forgot to take a picture of that before the final assembly.

Then I used the GPS outer screw on ring to hold it into modified Jag housing.

Next is the install.. I ordered it with a Red pointer just because I could, mine has a cable that will replace the Jag knob that adjusts the trip meter.. it controls the functions shown on the speedo face box... either trip meter, elevation, 0-60 mpg test run time/speed or 1/4 mile time/speed.

I ordered a blue light for the high beam indicator.. turn signals on Jag is in center dash housing.

This will resolve any needed tire changes in OD that would effect the speedo or odometer readings, changing trans gears, 90 degree speedo cable adapters and speedo cables. Will be 100% accurate.

First photo is finished unit, second is rear view and third shows the stock and new one side by side... stock unit is missing the outer ring and glass now.

 

Odd, me, the car or other???


1. As best as I can tell, my 83 has the 2.88 to 1 differential ratio. I conclude that was Jaguar's way of getting OD ratios at less cost to compete with the market.
As my lump trans has a .70 OD, the final drive is indeed tall. But, in practice a great match.


2. My speedo has not been accurate since the SBC install. In spite of the Dakota Digital converter. Speedo read 49. Actual 25 per police radar trailer!!!


Yet, the other day, I was driving along a tight residential street. The speedo read 25.
My SOP felt that as about right. Surely not 12.5 MPH !!!


Carl

 

Test ride was over 225 miles.. no drama at all. GPS speedo and GPS were in agreement as to distance and speed.

Great improvement... I did pull out the speedo cable so I would NOT have to hear it going round and round.

 

I just ordered a digital gauge set for my jag and it comes with a vss. Hoping that will be a good replacement for my broken mechanical cable