Guages--mechanical versus electrical

[Michael Oritt]

In addition to the wiring I am also redoing the dash and instruments. Auto Meter makes OT, OP and WT guages in both mechanical and electrical configurations. Is there any real difference between the two in either accuracy or reliability?

Best--Michael Oritt, Elva Courier

 

[Deleted member 3577]

Can't think of anything better than the stock MGA gage for the Elva.

Mechanical is far better...

1) No guessing.....Fast response and reliability
2) No voltage regulators, no adapters, no wires & easy trouble-shooting.
3) Ease of installation.
4) One gage to look at.

Second best would be Racetech.....(Pegasus)

 

[tr8todd]

Mechanical gauges are better. That being said, I run both. The mechanical sit in front of me and the electrical off to the side. With a British car, it offers piece of mind. If you run mechanical gauges, make sure you run metal or braided stainless lines into the cockpit. Those plastic ones are not alowed for racing. Nothing worse than having hot oil spray on your legs when you are out on the track.

 

[Deleted member 3577]

[ QUOTE ]
Nothing worse than having hot oil spray on your legs when you are out on the track.

[/ QUOTE ]
Great!.....Another sneaky little trick for my Pinto to pull.

Or that will be next years tech-peeve /ubbthreads/images/graemlins/nonono.gif

 

[aeronca65t]

You can buy low-cost mechanical gauges in discount stores like AutoZone. I bought a mech. temp gauge for under $20. It came with a number of engine block adapters (none of them fit, but I was able to modify one using a lathe).
They have low-cost mech oil pressure gauges too but I used a spare aircraft gauge and homemade adapter that allows me to use an oil pressure warning light as well.(be sure to use copper line to the oil pressure gauge....not plastic line).
If you are running total-loss electrical (no alternator), a voltage gauge is a good idea too. My favorite gauge is the big red shift light I bought from Summit Racing. Under $35 and easy to adjust. I still have the teeny-tiny '78 Midget tach in the dash, but I never look at it.

 

[JerryB]

Depends on two things....(at least in my mind).
1) packaging constraints
2)level of prep

Mechanical gages usually have 270* sweep while electric gages have 90* sweep. Therefore mech. have more defined visual reading points.

Electric guages have large transducers/sending units and might be problematic as to fit.

If you have a cheap motor, you might use cheap gages. That doesn't mean that a cheap gage is not doable. For my $ its Autometer (e-bay is a good cheap source of NEW) or Stewart Warner. Pretesting whatever you use might be advantageous. Clocking the gages are a good help.

Water pressure and oil pressure lights (big ones) are a help also.

 

[Hap Waldrop]

I use mechanical gauge (Autometer) except for the tach, it's electric. I agree with Jerryb, buy the best and largest you can, I use on most of my cars 2 5/8" temp and pressure gauges, have notice no real difference in fluid filled vs not, use the 4" in dash Autometer tach, in the past I went for the memory feature, but then noticed I nevered used it, so the last Autometer tach I bought was the 4" in dash without memory. I like Autometer Sport Comp with black faces in roadsters.

Here's a pic of the gauges in Speedracer
www.acmespeedshop.com/_images/100-0004_IMG.JPG

 

[Eric]

[ QUOTE ]
Those plastic ones are not alowed for racing. Nothing worse than having hot oil spray on your legs when you are out on the track.

[/ QUOTE ]

I'm not sure that's universally true. I crew for a guy running CASC and SCCA races in GT3 (BMW 2002) who uses a plastic tube oil pressure gauge, clearly visible through the windshield and under the hood, and it has never occasioned comment at tech.

 

[Tim Hollister]

[ QUOTE ]
[ QUOTE ]
Those plastic ones are not alowed for racing. Nothing worse than having hot oil spray on your legs when you are out on the track.

[/ QUOTE ]

I'm not sure that's universally true. I crew for a guy running CASC and SCCA races in GT3 (BMW 2002) who uses a plastic tube oil pressure gauge, clearly visible through the windshield and under the hood, and it has never occasioned comment at tech.

[/ QUOTE ]

From the SCCA's 2007 General Competition Rules (GCR):

9.3.27. FUEL, OIL, AND WATER LINES
All fuel, oil, and water lines, including gauge and vent lines, that pass into or through the driver/passenger compartment, shall be of steel tube or metal braided hoses or bulkheaded. The driver shall not be exposed to header tanks.



I've only been doing this a few years now but that rule has been there since at least 2001, and for good reason in my eyes. The rule applies unless something in the GT specs allows otherwise. I know it applies in the Production category.

Best wishes, and be safe!

Tim

 

[JerryB]

"""""Best wishes, and be safe!

Tim """"" /ubbthreads/images/graemlins/iagree.gif

Common sense should prevail when something like this is not spelled out in the rule book.

Kinda like my story I always tell of arm restraints...asking which hand the driver writes his bank checks with......

I wouldnt use plastic or even the so-called "good" labeled nylon for manual oil pressure guages in my scooter!!

We still see cars with fuel gages in the drivers compartment also......famous words "I've been racing 15 years and never had a fire"

 

[aeronca65t]

[ QUOTE ]
Here's a pic of the gauges in Speedracer
www.acmespeedshop.com/_images/100-0004_IMG.JPG

[/ QUOTE ]


OK, that is nice.
Mine's more of a patchwork of cast-off or existing parts.
Steering wheel (10") is cheapie from JC Whitney. I cut the center out of an old Midget steering wheel and made an adapter from that. The column is shortened about 5" or so. Water temp (mechanical) is under $20 from AutoZone. Oil pressure gauge is old one from Aeronca. Stock tach and cheap Summit shift-light. The button on the right is for the Fiamm air horns....flaggers like 'em. Dash is home-brew "engine-turned". Shifter is made from a bed frame caster (price was right). Toggle swiches are freebies from local company (Allied Signal) and are high quality, US made. I'd like to mount the fuse box on the dash (like in plane).

We're required to wear arm restraints and I would anyway.....but I am not understanding the point of the "bank checks" comment at all??? /ubbthreads/images/graemlins/confused.gif

 

[Deleted member 3577]

here is the Pinto ......Impressive ain't it?

 

[aeronca65t]

[ QUOTE ]
here is the Pinto ......Impressive ain't it?....

[/ QUOTE ]

Dave: I see you have a "mascot" riding along with you too. Mine's "The Lucky Lizard", strapped to the cage with zip-ties.

 

[foxtrapper]

[ QUOTE ]
In addition to the wiring I am also redoing the dash and instruments. Auto Meter makes OT, OP and WT guages in both mechanical and electrical configurations. Is there any real difference between the two in either accuracy or reliability?

Best--Michael Oritt, Elva Courier

[/ QUOTE ]

Mechanical gauges carry the myth of superiority as a legacy from about half a century ago, when electric gauges were indeed pretty bad. Today, that's not the case.

I'd run electric, given the choice. The installation is much easier and neater. The price is usually higher though.

In the Autometer line, the low end is the autogage. The electric units have a smaller sweep than the mechanic, but that's normally not an issue for driving. The higher end that you're probably considering is the pro-comp. In this series the electric is the same wide sweep as the mechanical gauges.

 

[DrEntropy]

For the application, my pref has always been mechanicals. Mostly for the sweep range difference. A quick glance at the 'short' sweep electric ones has always had me going back for another look as confirmation... not the best thing. And Dave said it: the dual WT/OP Smith's is a one-shot confirm. Nice vertical white line; press on. And I s'pose electric ones are reliable enough now, but I'm still of the linear, Newtonian school when it comes to a racing app. Just my 2p worth.

...and as soon as I saw Dave's blue critter I thought of Nial's lizard... then scrolled down and there he was! heh.

 

[Deleted member 3577]

[ QUOTE ]
I see you have a "mascot" riding along with you too. Mine's "The Lucky Lizard"

[/ QUOTE ]
Yep...Cpt. Sparkles dot thought I should have it.....

Gonna have to ask her what its name is again. /ubbthreads/images/graemlins/confused.gif

I usually give it a pat on the head before I leave grid. /ubbthreads/images/graemlins/grin.gif

 

[JerryB]

Kinda like my story I always tell of arm restraints...asking which hand the driver writes his bank checks with......

Nial wrote..........
""""We're required to wear arm restraints and I would anyway.....but I am not understanding the point of the "bank checks" comment at all??? """""""

It goes like this.....the loss of a hand or worse in the case of a severe roll over or crash due to an arm(s) flailing around might preclude the driver from writing a check (or worse) on Monday. When dialoging with a driver about this they really remember the story of writing checks then. /ubbthreads/images/graemlins/rolleyes.gif

 

[aeronca65t]

Ah! OK...got it!

 

[Michael Oritt]

Dave--

I like the Pinto's dash--very functional. Attached is a picture of my initial template for a new dash for the Courier. I'm using the small Auto Meter guages and the 5" Monster tach.

Best--Michael

 

[Deleted member 3577]

I wouldn't say I'm a gauge hawk or anything.
(I check them once per lap after exiting the last turn)

I really never look at the tach either.
I just hold her to the floor until it is out of cam. (about 5800)

Looks like your spending some quality time in the garage this winter. /ubbthreads/images/graemlins/yesnod.gif /ubbthreads/images/graemlins/thumbsup.gif