Electrical or Mechanical Gauges? [Merged 9-6]

[TSiAWD91]

Ok i ordered an autometer mechanical oil pressure gauge today on accident.i wanted to get the electrical,but for some reason i picked the mechanical.anyways,i was wondering if the mechanical gauge is a PITA to install and if i should send back the one i ordered to get the electrical gauge,or if its not too bad of an install.thanks for any help!!

 

[Defiant]

yeah, so by time oil reaches the line, pressure is lost anyhow, right?

Not at all. Pressure in a closed system is the same throughout. A restriction such as an orifice or otherwise-tiny passage will reduce reaction time, but the pressure will -given the chance- remain the same.

Mechanical gauges need to be connected through tubing (well, or linkages if you get something like a Model A or Piper Cub fuel level gauge) to the system they're measuring. In some cases, such as oil and fuel pressure, you don't really want those fluids running up a tube to your dashboard. It doesn't matter much for a manifold pressure gauge, since air's all over everything anyhow.

Electronic gauges -such as the factory oil pressure, fuel level, and water temperature gauges- have a sensor which is pressed on, heated by, or otherwise affected by the quantity they're measuring. It tends to keep the messiness in one place that way. The drawback is that you also have to buy the sensor along with the gauge, and in come cases the sensor can cost as much as the gauge.

 

[miden]

Another option for mechanical gauges is translator. I know that autometer (and probably every other gauge place too...) makes them and summit sells them. It's a fluid filled line that goes between the system and the gauge. So oil or fuel or trans fluid pressure raises, which puts pressure on the line which put pressure on the gauge. Keeps engine fluids out of the cockpit but still gives you the speed and accuracy of mechanical gauges. They do cost about $100, though so at that point you're up to electrical gauge prices...

-M

 

[my97mitsGSX]

right now i'm looking at the HKS CAMP stuff.. i dont' see to many people using it, but I like the idea of not having gauges and just a 7" tv screen (which can be used for watching tv and display the gauges that way)

 

[BoostNV]

everything I have looked at for the Defi Guages that use the link system there is a unit that bolt on at the oil filter that has the sensor in it. The the sensor is wired to the link unit. The same thing goes for the fuel pressure. Is this right or did I read somthing wrong?

 

[ECLIPSE95]

I bought a mechanical Oil pressure guage and I was wondering how I am suppose to install this gauge...I know I have to tap some kinda oil line but where is that? would it just be easier to buy an electric oil pressure guage? so i dont have the fear of busting that line that goes to the gauge?

 

[DSM-ZERO]

Yes there is always a chance of the line busting and making a big mess
If you plan on putting the guage in your cab I would get an Electric one

 

[miamieclipse]

Shoot i have a mechanical one .....Do you know what line it needs to be installed in? I got mine and have it in the piller (b/c i needed the a/f for tuning) but i don't have the oil press. hooked up yet? Do you know where/how it is supposed to be installed?

 

[Doug99RS]

I would check with some of the NT-gone turbo guys. If I'm not mistaken you can remove the oil pressure sending unit gauge and put in a splice fitting that will allow you to run the gauge you purchased as well as use the stock dummy light sending unit. The stock sending unit is the lime green connector on the back side of the block about straight down from the throttle body.
Doug

 

[ECLIPSE95]

Doug, are you talking about an electric gauge?

well since I have already have the mechanical gauge I guess I will use that...I want to get the steel braded line which I think is a -4 fitting? whatever that means and how would I run that braded line into a T-fitting? and where do I put that T-fitting?~Dustin

 

[Doug99RS]

I'm referring to the factory sending unit spot on the backside of the block.

Regardless of which after-market gauge kit you buy there will be some part of it that will physically need to come in contact with an oil passage that is under pressure. One kind of pressure gauge will fill a tube up with oil all the way up to the gauge you look at. The other will convert the oil pressure itself, under the hood, in to an electrical signal to be sent in to the car. But both types need access to oil pressure and that's why I mentioned tapping in at the factory sending unit.
Doug

 

[ECLIPSE95]

gotcha, thankz doug

 

[asexton6969]

Ok, i searched this topic to no avail. I was wondering which is better to get. An electric or mechanical transmission temperature gauge? Sorry if the question has been asked alot.

 

[transdude]

Ok, i searched this topic to no avail. I was wondering which is better to get. An electric or manual transmission temperature gauge? Sorry if the question has been asked alot.

To my knowledge, there are no mechanical temp gauges so an electrical one would be the only choice.

-John

 

[Jehu]

Autometer has mechanical ones. A capillary tube type. I chose that over the electrical gauges because I like the 270 deg. sweep better than the 90 deg. on the electrical one. I also wanted one that said "Trans temp" rather than oil temp. The full sweep electrical gauges only say "Oil temp" . The capillary tube is a little more of a pain to deal with though...You can't disconnect the end from the gauge, so you basically have to thread the big bulb through the entire hose route.

 

[asexton6969]

Thanks alot guys, I read the first reply and I thought that I had gone crazy. I wondered if I had just imgained a mechanical tranny temp gauge. Thanks.

 

[96N/TalonLP]

I have a autometer mechanical water temp gauge and I was wondering how exactly to install it. I have searched many times and i have found a little info. I recall reading some where that there is a coolant sensor on the back of the block near the oil pressure unit. I am not exactly sure of this though. any help would be great thaks!

 

[dalatinromeo]

I just ordered a boost controller and now looking to order a Greddy Boost Controller(mechanical). I have been searching all day for a mechanical boost gauge in 52 mm size, but all I have found are electrical ones that are 52mm. Does anyone know if they make Greddy mechanical boost gauges 52mm or do they only come in 60mm.

And if they do make them in 52 mm can anyone post the link. Thanks.

 

[Slipstream]

I'd highly advise against a mechanical water temp gauge for the same reasons I object to mechanical oil pressure gauges. hot, nasty fluid inside the cabin if it breaks. However, if you insist, your gauge should have come with a temp sensor and you will either need to find an available tap in an existing water passage or drill and tap your own hole into a water passage.(I'm not certain if there are pre tapped locations on the 420a). Instead of detailing this all out, how about I just send you to autometer's generic mechanical temp installs http://hp.autometer.com/instructions/004431_instruction.pdf
That will take care of all the basics, now all you need to do is find the right location to tap.

 

[dave99gst]

52mm = 2.04" fyi
in other words... standarde size.
http://www.google.com/search?hl=en&lr=&q=greddy+boost+52mm

 

[Defiant]

I'd highly advise against a mechanical water temp gauge for the same reasons I object to mechanical oil pressure gauges. hot, nasty fluid inside the cabin if it breaks.

Not for water- they usually use alcohol or ether in a sealed tube-and-bulb. Coming from the days that they were common, breaks weren't a problem of note. Leaking oil pressure gauges were, but usually no more than a drip.

 

[Dsmboost4g63]

Well, Im not too sure how diffrent the 420a is but on the water neck/thermostat area there are 2 sensors.....a small one on the side and a larger one right on the back...(at least on 4g63).....what i did i didnt wanna cancel any sensor or nothing so i made a "T" type fitting that runs from the larger sensor whole then i just connect the original sensor in one hole and my autometer in the other....sorry if this isnt so clear...ima at school......but yea it worked fin for me....i dunno bout other people but this was a kind of a struggle for me as well but its working good now....make sure you use that leak tape stuff...(forgot what its called) on all the connections.....also, i used thos brass water type fittings and made my own "t"...hope it helps......

 

[Slipstream]

Not for water- they usually use alcohol or ether in a sealed tube-and-bulb. Coming from the days that they were common, breaks weren't a problem of note. Leaking oil pressure gauges were, but usually no more than a drip.

Agreed, alcohol filled tubes, I remember those days. I guess I just choose to air on the side of caution. Anything leaking in fluid in my cabin is cause to ruin my day. Also agreed that often the oil gauges never leaked more than a few drops, but there is always the case of the old Datsun I shoved one in...which later split the tubing and successfully left its foul funk all over the dash, carpet etc. Probably an installation error...maybe inferior materials, but it still wasn't fun.

Autometer appears to use a sealed bulb type for their gauges, so at worst you'd leak the alcohol and the gauge wouldn't work anymore.

 

[Defiant]

agreed that often the oil gauges never leaked more than a few drops, but there is always the case of the old Datsun I shoved one in...

My 2000 has one the factory "shoved" in, right in the cluster. I found it when it started to drip. Snugging it got it to stop. The Zs were notorious for electronic senders that always read low, and drove the owners nuts. They finally sold all of them to Mitsubishi.

 

[luv2rallye]

So that's why I went nuts with my 260 & 280Z's. :laugh:

 

[CyberEye]

Does Autometer (preferably) or anyone else make an electronic fuel pressure gauge? And how acurate are they as compared to a mechanical one? I want to mount it in the cabin, hence the need for the electric.