After Market Gauges

Hello, i was wondering if it is possible to put a tach. in a '98 LeSabre Custom....i know that they are in the ltd of that year....and how to.

also, is there any way to put in a speedometer that goes higher than 100? and how hard would it be, and where could i get on if its possible??

i know that was confusing, but any help would be appreciated

thanks

John:evillol:

Speed is calculated by a speed sensor attached to the transmission. A series of pulses is then sent from the PCM to the cluster, which controls the speedometer and odometer. (I believe pulses are how it is done.)

Odds are you will not be able to tap into the stock speedometer sensor wires, as you won't find a gauge that is completely compatible. Even if you pulled the speedometer out of another GM, it probably wouldn't work. If it did, it probably wouldn't exceed the 100 MPH mark. The PCM knows that is as high as the stock speedometer goes, and likely does not read or send any signals greater than that.

Best best is to install an add on speedometer which uses an isolated, seperate, dedicated speed sensor elsewhere on the car. That's the safest, and would give you the most accurate readings. (As you really don't want to mess up your stock speedometer line and create a false speed readout... Speeding tickets suck, especially when it's your fault for messing with the speedometer. LOL)

As for a Tach. It might be possible to tap into an engine sensor, but I expect they use an equally propriatary method for obtaining readings. It likely is read directly from the Camshaft sensor (as that sensor has two parts, one the reads speed and on that reads exact position).

However, REMEMBER that the Camshaft Sensor is critical for the functioning of your engine as a whole. It determines many varibles applied to your engine systems. If you disconnect it, as soon as your car reaches temp, the engine will die because it NEEDS that sensor input to function. Thus, tapping into this sensor is also likely a bad idea.

I'm really wanting to find an engine readout that functions of data from the OBD-II connector. As when connected to an OBD-II PCM, you can monitor every varible from the engine in real-time. Fuel pressure, air/fuel mix, RPM, speed, MPG, coolant temp, transmission temp, shift point, EVERYTHING.

I'm seriously investigating combining a pile of ICs and buuld a simply 20 character LCD display that would allow you to display and scroll through the varible readouts as reported by the PCM. Any electrical engineers here that want to get involved? Any thoughts, comments, suggestions?

Hey thanks for the helpful information, where can i pick up another speedometer...like at a cheker or Auto zone?

Oh and i was looking at in-dash receivers and there was one that said it could give you all you engine info such as rpm's , speed, and g's(ok well g's are not so much engine as whole car..lol) is that anything to look in to???

Thanks agin:evillol:

I've seen the devices that you plug into your accessory power socket and they will supposedly tell you 1/4mile times, RPM, horsepower and torque. I think they had a commercial for it on Horsepower TV (Spike network)

anyway, how they hell do they work?

Here is one of the ones i was talking about.....


http://www.ultimateelectronics.com/shopping/product/detailmain.jsp?itemID=3417&itemType=PRODUCT&iMainCat=1533&iSubCat=1605&iProductID=3417#features

Unfortunately, it doesn't give much information about how it determines speed, braking, acceleration. It may calculate them all using GPS position data. The specifications do not list any inputs for any included or not included powertrain sensors.

Then again, is also doesn't even say that it is a GPS data unit. It makes it sound like it is, it uses CDs with mapping data... but it only talks about a XM satellite reciever, no mention of GPS.

It may very well be simply a glorified yellow pages on 2 DVDs with maps added. Could be useful, but quite frankly I don't often need to look up the nearest ATM or McDonalds. Annoying.

There's a Delco unit that looks to be the same size as the 1992-2002 Buick radios. Does DVDs, MP3s, CDs, is equipped with talking GPS, maps upload via DVDs... Very cool. I'd like one. I even have a place I could get one for $1500... but I don't have $1500, nor would I spend $1500 for a radio to go in a 1995 LeSabre.

Thats exactly what i was thinking as well. i does not give any explanation of how it does all that.






:evillol:J

Ok I looked in to it..i first went to the "pioneer" site then to the product site its self....i found that ..yes the maps are pre-loaded, no gps. i still did not fully explain how it did the vehicle dynamics, some it did.
here have a look your self if you r curious.....
http://www.avic-n1.com/


J:evillol:

http://www.pioneerelectronics.com/pna/article/0,,2076_3149_89180326,00.html

Here are the VDD performance gauges and what they measure:

*
Acceleration: Measures forward or backward G-Force and provides a peak hold indicator
*
Side Acceleration: Measures Lateral G-Force, indicating maximum cornering force, and provides a peak hold indicator
*
Angular Velocity: Measures turn rate
*
Speed: Measures your speed in Miles Per Hour (MPH)
*
Direction: Provides a compass with current direction: N, S, E or W
*
Slope: Indicates the incline or decline of your vehicle
*
Voltage: Keeps tabs on your vehicle’s electrical system, in volts
*
Clock: Displays the time

Most of those things could be calculated using a multi-directional accelerometer inside the stereo head unit. (Similar to what many A'pex? units use for a lot of their calculations.)

However, the speed interests me, as constant velocity could not be measured by an accelerometer... only force measurements. My guess is that it does this by monitoring the voltage supplied from the alternator. I know you can easily calculate engine RPMs using the voltage being supplied by the alternator and known alternator output varibles. By combining this with measurements from the accelerometer, it can probably loosely estimate speed. (Notice the use of non-exact analog gauge displays.)

I've looked through the specifications and the radio inputs listings. I have yet to find any listing for any external or engine sensors, so it must be built into the headunit. The installation manual would probably reveil that for sure, but I'm not going to register with Pioneer to read it nor do I have the time to read it.

Obviously, Pioneer likely does not want to reveal the specifics of how it calculates all these varibles. One, because by just not saying anything, they make the radio seem a whole lot more amazing than it likely is (and justifies the $2000 price tag.) Two, they are probably afraid another company will steal the idea or replicate the way they do it. (Though, I'm sure there's more than just one company with engineers who could make this work. I know several electrical engineers on-line who by night build circuits out of $5 of parts and sell them to people for $75.)

Yeah just as i was thinking, but if i ever win the jack pot at the casino..haha...ill buy it, thanks for the input

J

http://www.gtechpro.com/

here;s the one I saw on Speed Channel

it says it picks up RPM data from the cigarette lighter...I assume pulses from the alternator as mentioned above

It would be kinda interesting to monitor the Gforce during a high speed collision...anyone wanna try that for us?

I'm sure there are examples of data downloads from air bag DERMs/SDMs. They record all sorts of things, speed, deceleration rate, weight of the person in each seat, seat belt status, deployment status, all sorts of things. In the event the arming sensor is triggered, it records the varibles every couple milliseconds to provide a re-creation of the accident conditions.

You could calculate G-force from that data. The force of impact divided by the force of gravity in Newtons should give you G-force.

-Convert the mass of the vehicle, including passenger to kilograms.
-Convert begining and ending MPH to meters/second.
-Take the interval between the two velocities, and divide by the number of seconds between them to find acceleration.
-Mass (kg) x Acceleration (m/s/s) = Force (N)
-Force of gravity = 9.8m/s/s
-To convert the the force of gravity into terms of Newtons, multiply 9.8m/s/s times the mass of the vehicle in kg.
-The force of impact divided by the force of gravity should give you the number of G-forces encountered.