GPS Speedometers

[mutantZ]

I've been noticing alot more people have been installing the GPS speedometer from Speedhut. I found some older threads in other sections from a few years back talking about how slow these gauges are to respond, or how they won't work in a tunnel , etc. Has a couple years in tech development made a big difference with these types of gauge's accuracy? Just curious as it would make installation of a new speedometer a snap.

[kj280z]

I've been noticing alot more people have been installing the GPS speedometer from Speedhut. I found some older threads in other sections from a few years back talking about how slow these gauges are to respond, or how they won't work in a tunnel , etc. Has a couple years in tech development made a big difference with these types of gauge's accuracy? Just curious as it would make installation of a new speedometer a snap.

 

I have just received mine from Speedhut and will provide feedback as soon as it is installed

[S130Z]

Same here, I'll let you know my opinions on it. I have talked to the guy at SpeedHut a couple times and he tells me the GPS speedo is his favorite product they sell.

[RTz]

I'd be interested in hearing a first hand report as well. One of the drawbacks of my BMW swap is that there is no VSS in the transmission (BMW puts them in the diff.) I have a workaround for it, but the GPS may be a more elegant solution.

[MONGO510]

Yeah! What RTz said.

 

Mongo

[randy 77zt]

i dont know anything about the speed hut units but gps speedos have been used in offshore race boats for many years.most modern cars use some kind of electronic speedo and andthe old drive cables havent been used for years.

[RTz]

I don't suspect too many offshore race boats drive through tunnels or between rows of 20 story buildings?

[cygnusx1]

One thing to note about GPS speed.  Unless the GPS unit has a built in correction for descent and ascent angle, the speed will only be accurate when you are on level ground.  Boats are obviously always on level paths.  Hills cause significant error on the GPS speed readings.

 

Sine Cosine Tangent.

 

 

Edited July 18, 2010 by cygnusx1

[stony]

The 2 speed powerglide im running as no speed hookup... been considering this option myself. subscribed!!

[kj280z]

Here is a picture of mine - You'll notice it is the newest from Speedhut in the larger 4.25" configuration. I think I'm one of the first to get one...

 

I also had them customize it for a blue light in the center for the high beam indicator, the left red light is to replace the brake light, and I had them put in a temp light.

 

It's about as simple an installation as you can imagine - power and ground to the gauge, running the GPS antenna (can't be stuck to a metal surface), then run the wires to the lights from the old guage (except for the custom wire for the temp light which I have wired separately).

 

The greatest part about all of this is that their Tach is also a work of art and EASY to wire in replacement of any of the old Z tachs and the mounting on the old bezel is really easy.

 

My tach also has custom lights for the blinkers and a check engine light which turns on off of my LS1 PCM...

 

All the indiglo stuff matches the guage faces for my other guages so everything will match perfectly. I also had Speedhut change my Amp Meter face to a Volt Meter and I got a volt meter from a later 280z to replace my old gauge... I will post more pics when it's all done, but this whole setup certainly has my endorsement.

 

Edited July 18, 2010 by kjones

[S130Z]

One thing to note about GPS speed.  Unless the GPS unit has a built in correction for descent and ascent angle, the speed will only be accurate when you are on level ground.  Boats are obviously always on level paths.  Hills cause significant error on the GPS speed readings.

 

Sine Cosine Tangent.

 

The Speehut Revolution GPS speedo does have a feature where it tells you your altitude. I wonder if it has a correction factor incorporated with the altimeter. I will do some tests if I ever get my car back.

[S130Z]

Here is a picture of mine - You'll notice it is the newest from Speedhut in the larger 4.25" configuration. I think I'm one of the first to get one...

 

 

This REALLY pisses me off.....BIG TIME! I just purchased mine a week ago and really wanted a 4.25" tach and speedo........FML

[kj280z]

This REALLY pisses me off.....BIG TIME! I just purchased mine a week ago and really wanted a 4.25" tach and speedo........FML

 

Give them a call! They may exchange it for you - I have found them to be awesome in that regard...

[BRAAP]

The Speehut Revolution GPS speedo does have a feature where it tells you your altitude. I wonder if it has a correction factor incorporated with the altimeter. I will do some tests if I ever get my car back.

 

 

Correction factor, for like density alt etc? GPS uses the satellites to determine altitude, no barometric sensors so it indicates true altitude above sea level regardless of weather, pressures, etc, so long as it has multiple sats to get its data. Or did you mean an indication of approximation error due to weak or minimal GPS satellite coverage like a deep canyon?

 

 

GPS works great for the power boats, flat relatively level surface, full access to the sky, any lag to them is inconsequential. Now start zig zagging around town, (especially down town where tall buildings are blocking and uncovering line of sight to the sats as you move), neighbor hoods or windy mountainous back-roads in canyons. My concern would be accuracy and lag, in those zig zag situations, as someone else mentioned, Sine Cosine Tangent, not only going up and down, but also around corners, etc. I wonder if like on skid pad if it would keep a consistent accurate speed? Better yet, a slalom. Would it record average speed across the mean path covered, (like a stop watch would record) due to margin of accuracy being approx 5-10 feet, i.e. the offset of the slalom course or would it truly read speed based on ground covered which will be higher, like a tire driven speedo?. If the accuracy is about the distance of the slalom offset, it could end up exaggerating the speed by estimating it as wider swing around the slalom... None of that really matter entirely on the road to try and stay within the law, but lag, zig zag accuracy etc could have an affect which will also affect the ODO reading, i.e. actual ground traveled wont be as accurate the tighter and twisty the route taken vs just driving in a straight line.

[S130Z]

Paul......you know what I meant. But I'm really more concerned about going the speed limit as I drive around town. But I will let you know how things end up.

[kj280z]

My current Garmin GPS has a separate screen for speed and trip time, ect... I keep an eye on it all the time and it has never not matched my speedo in the car.

 

Based on my conversations with the guys at speedhut related to all your concerns I am very confident this is going to be a great solution... And I'll never have to worry about changing the speedo gear in the tranny or any re-calibrations ever again!

 

If it doesn't work in a tunnel (there aren't any around here anyway) who cares?!

Edited July 18, 2010 by kjones

[garvice]

If it doesn't work in a tunnel (there aren't any around here anyway) who cares?!

I do since the exhaust sounds so beautiful in the tunnels around me and yet the council has decided that it is a good idea to have speed cameras in them.

That is just mean. You are so tempted to give a spurt of power to hear the exhaust but yet you really know you shouldn't so you are always looking at your speedo when the cameras come up.

[rallyeo]

I've been using an app for my phone (droid) called SpeedView that is free, looks great, and is quite accurate. It has a lot of other cool features too, like distance traveled, keeps a log of my speed, and has a compass. Highly recommended if you have an android os phone.. check out the Dynomaster and Trapster apps while you're at it .

[kj280z]

I got around to mounting the GPS Speedo in the bezel tonight and will install in the dash tomorrow - It will be about a week before I install the whole dash - depending on when my new heater core and other parts arrive, but here's a look...

 

I might actually hook it up temporarily in my daily driver since it only requires power and ground and do some testing prior to final install in my Z.

 

Also, notice the 3 lights that were added, Bright light indicator, Brake and Temp

 

 

[kj280z]

I got around to mounting the GPS Speedo in the bezel tonight and will install in the dash tomorrow - It will be about a week before I install the whole dash - depending on when my new heater core and other parts arrive, but here's a look...

 

I might actually hook it up temporarily in my daily driver since it only requires power and ground and do some testing prior to final install in my Z.

 

Also, notice the 3 lights that were added, Bright light indicator, Brake and Temp

 

 

 

Since I'm convinced that I'm gonna like this GPS Speedo SO much along with all the other nifty features in it, I have decided to sell my Speedo converter and the stock Speedometer with the Speedhut gauge faces! I'm committed!! Anyway - check out the classifieds if you're interested in the other unit since some of you have already asked...