: How do you prefer your tachometer?



Night Wolf
09-12-10, 01:48 AM
Gauges interest me, and of them is the tachometer - especially importantly in a performance car w/ manual transmission. As a whole, the gauges, design, layout and backlights play a major role in how I feel about a car.

One of the biggest differences is - tachometer to the left or right of the speedometer, in cars with a "normal" dash (not Mini etc...)

This first poped in my head many years ago when I was interested in the 1995 Eldorado ETC, but for a while preferred the '96+ interior. At the time, I thought the tachometer looked better on the left, mostly because when idling and stopped, the gauges looked more "natural"

http://i.ebayimg.com/15/!!fczqhQBmE~$(KGrHqMH-CMEsK43JK42BLFcUBC4-Q~~_4.JPG

http://i.ebayimg.com/03/!B2iIZmwCWk~$(KGrHqYOKjIE)OJ1,T!ZBMi7lGFrWw~~_3.JP G

After having a vehicle with both, for whatever reason I much prefer the tach on the right. Perhaps because that is the way the BMW is setup and I am used to driving it spirited, but I'm not sure. As for the above two Caddys, I now very much prefer the eariler dash design over the newer, with the ECC and FDC alongside the cluster, tho if it were me I would paint the needles red.

It's to the point where I now no longer like the tach on the left.... it sort of bothers me. The new Jeep Wrangler JK has the tach on the right and I have read comments about it where people have said it is on the wrong side. I wonder if it is an import or domestic thing? I remember my fathers Fiero having the tach on the right side.

While I installed an aftermarket tach in the '79 DeVille and Isuzu (same tach... still have it) the only vehicles I've owned with factory tachs were the (2) e30s and Jeep

http://i43.photobucket.com/albums/e363/InoventionsEast/Jeep/1-24-10%20--%201%20year/IMG_0022.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-23-09016.jpg

77CDV
09-12-10, 01:56 AM
That top pic looks awfully familiar.... :lol:

I have to say that I'm indifferent to the whole left/right thing. A tach on an automatic is rather useless anyway. Now on a manual, it's indespensible, but as long as the tach is one of the two dominant gauges and is clear and legible in all lighting (as it is on Nicole), it makes little difference whether it's on the right or left.

gary88
09-12-10, 02:00 AM
Preferably in the center. When it comes to gauges I think Porsche is hard to beat.
http://i1005.photobucket.com/albums/af175/gheb882/911gauges1.jpg

What I really don't like though is how GM

77CDV
09-12-10, 02:06 AM
Don't leave us hanging, Gary!

ga_etc
09-12-10, 02:13 AM
I don't feel that it really matters which side it's on as long as my car has one. I prefer my vehicles, automatic or straight shift, to have FULL instrumentation. I like to know what's going on with the vitals of the car. I am accustomed to it being on the left though. Most things that I have driven with one, it's on the left side. Of course Buick had to be different and put it on the right.
http://i685.photobucket.com/albums/vv220/austin99etc/0903101749a.jpg
It threw me off a little at first, but I'm used to it now. I don't think either way is "correct", it's just whatever you are used to.

gdwriter
09-12-10, 02:14 AM
A tach on an automatic is rather useless anyway.I may not need it to tell when to shift (and after a while, you can do it by feel and sound), but it's still fun to watch it climb when you're hooning on it. And even when you're not.

I've had them on the left and right, and it doesn't really matter to me. But I do like it when the speedometer and tach are the same size. That's something I didn't like about the gauge cluster in my '99 Accord.

ga_etc
09-12-10, 02:18 AM
But I do like it when the speedometer and tach are the same size. That's something I didn't like about the gauge cluster in my '99 Accord.

I'm sure you would love the speedo/tach in the first gen xB then.
http://www.jbcarpages.com/scion/xb/2004/pictures/images/2004_scion_xb_picture%20%2831%29.jpg

gdwriter
09-12-10, 02:24 AM
I'm sure you would love the speedo/tach in the first gen xB then.Ick. Poo. Gack. Not just the instrument cluster, but the whole freakin' car.

ga_etc
09-12-10, 02:29 AM
I strangely like both generations of them. Tons of room in them and I think they have a lot of personality (for a Toyota product).

Jesda
09-12-10, 02:37 AM
I've never thought about this. I do wish temp gauges were more accurate. They're all heavily damped and dont budge until the car finally overheats.

Night Wolf
09-12-10, 02:45 AM
I've never thought about this. I do wish temp gauges were more accurate. They're all heavily damped and dont budge until the car finally overheats.

That is entirely dependent on the gauge setup.

Older cars used a much more direct gauge. Not old enough to be mechanical, but still electronic. Example would be my BMW. Those gauges are so freakin accurate it's crazy. The slightest RPM variation is shown on the tach, and the simplest change in temp is also shown. They did use high quality VDO gauges though.

OTOH the Jeep's gauges are dummed down - they are sent thru the PCM first which then tells the gauge what to do. On my '05 for example, besides the oil pressure gauge being nothing more then a glorified idiot light, the temp is sent thru the PCM as is the RPM.

The RPM is the worst, because it is so slow to respond. Not that the AMC 4.0 is a fast revving engine, but if I am stopped with the trans in neutral and hit the gas wide open, the engine will bounce off the rev limiter while the tach is still climbing. Same thing when shifting, if I up shift and accelerate, the tach is still decreasing in RPM while the engine is obviously gaining in RPM (from both sound and mph). It is annoying.

Sadly, more and more newer vehicles are using such a dumbed down version of gauges. They are not direct, nor accurate, but more what the PCM actually wants displayed.

I don't know the truth to it but I heard in the mid 90's the tach on Northstars was calibrated to show less then actual RPM as the engine would shift near 7k yet it was not displayed on the tach for insurance and possibly warranty reasons.... haven't heard about it in a long time though.

Jesda
09-12-10, 02:50 AM
The temp gauge on my 1990 M20 E34 was worthless. It would just sit there doing nothing, steam coming out of the hood, until the temperature finally got to a critical point. It would then spike from the center to full red like an on/off switch. They might as well have replaced the piece of junk with a bright red light.

Never did find out if the gauge on the E46 was any better. I came to learn that the low coolant light worked well.

Night Wolf
09-12-10, 03:39 AM
Did you loose coolant first? Did the water pump belt or water pump itself fail?

Temp gauges are misleading. It tells the temp of the coolant - at the location of the coolant sensor.

If you loose coolant due to a leak, chances are the temp gauge will not pick it up in time and once coolant is gone, the temp sensor is no longer in the coolant because there is no coolant to sense, but engine keeps running - it overheats.

Same thing with a failure of the water pump or belt. If the coolant is not circulating the engine will be overheating in certain locations but not others, and typically not others would be where the sensor is located.

Oh my Jeep when I changed the coolant one time but did not properly bleed the system of air, all was well and the temp guage stayed fairly low so I drove it down the road then all of a sudden the check gauges light came on and the temp gauge pegged out in the red. Turns out there was a lot of air still in the engine but blocked by the thermostat, once I got the air bled off and the themostat opened from being exposed to the hot coolant, it circulated and was fine after that.

I had a similar problem with my Lincoln. I don't remember the specific problem, but the engine was overheating to the point that it would no longer stay running, yet the temp gauge was registering normal, I forgot what it was that was blocking the coolant flow.

Did the M20 run well after the overheat? the aluminum head dosen't take well to overheats - that and letting the timing belt go are about the only things that'll kill one.

Jesda
09-12-10, 04:50 AM
The sensor was working -- it stayed in the center then suddenly shot up to H. It never dropped to C the way a bad sensor or dangerously low coolant situation would. I pulled over, saw the steam, and noticed that a clamp fell off a major coolant hose at the top, so I popped the hose back on, limped home, and replaced the clamp. It still drove perfectly.

That M20 was completely gutless for a big sedan but it was a joy to work on thanks to the simplicity and space in that big E34 engine bay. Car had 230k when I bought it, sold it with 231k. Broke even and had a lot of fun.

Night Wolf
09-12-10, 07:51 AM
The cooling system on the M20 is a bit overly complicated then what it should be - though not nearly as bad as the M42. If it is one of the hoses I am thinking of, then it makes sense that there would be steam as coolant was sprayed onto and hitting various parts of the engine, especially near/around the exhaust - yet there would not be an overheat condition yet.

When the throttle body heater plate developed a crack in my 325i, a pinhole leak on the drivers side. I didn't know anything was wrong but the low coolant light came on. I pulled over to look at it and when I opened the hood, there was steam. The coolant was just getting sprayed around and ending up on hot engine parts, even though it was on the other side of the exhaust manifolds.

With the then-new 5-series, it was asking a lot out of the old M20, especially when paired with an automatic. It was among the last applications the engine was used in. Next meet you can check out the M20 in a 3-series and see if it feels the same way :cool:

I~LUV~Caddys8792
09-12-10, 08:02 AM
The placement doesn't really matter to me, as long as it's legible. In the Regal, it's to the left of the speedometer, and in the S320, it's to the right.

gary88
09-12-10, 01:00 PM
Don't leave us hanging, Gary!

Forgot to finish that last part :lol:

But what I was saying was I don't like the kind of half gauge GM used to put in their trucks (and still in the Corvette). Just not as cool to me when the tach needle doesn't do a full sweep around the gauge face.

http://i1005.photobucket.com/albums/af175/gheb882/CadillacEscaladeGaugeClusterInstall2.jpg

http://i1005.photobucket.com/albums/af175/gheb882/zr1dashjpg.jpg

Stingroo
09-12-10, 01:06 PM
Yeah I don't like the half or 3/4 tachs either.


You know, I've never thought about this. One thing I miss is seeing RPM's measured x100. I don't know why, I just thought seeing it that way was cooler to me.

That xB setup - oh my lord. When I drove my friend's it confused the shit out of me. It was so annoying. Also that Porsche one would drive me nuts too. Speedometer should be front and center in a layout like that, IMO.

And on the subject of gauges in general, especially in that ZR1 instrument cluster that Gary just posted - what's with the fuel gauge? I never understood that. It says 0 (should just be E), 1/2, and then 1. One what? It's not one gallon, and I obviously know it means full, but damn. Use an F. lol

orconn
09-12-10, 01:26 PM
The gauge laout used by BMW adn Alfa Romeo are the most useful to me .... and the most esthetic. I think the whole design of the 4th generation Seville dashboard is the best I have ever scene. Digital gauges don't get it for me I like analog guages that include full temperature (Oil and Water), electrical, oil and gas.

ted tcb
09-12-10, 01:35 PM
The temp gauge in my 91 Miata is very accurate, and sometimes disconcerting.
In heavy traffic on a hot day, the temp may rise to 3/4 at idle.
As soon as I drive away, the temp needle settles back down.
If this happened in my STS, I'd have a heart attack ... I understand why the engineers dampen the
gauges, to reduce owner anxiety.

Rick, something about the gauges on your 21 year old BMW ... I don't know if its the number font or the cool
backlighting, but the guages look very high end and precise for an old car. BMW sure got it right.

By comparison, the typeface on the Jeep gauges look ridiculously large, almost like it was made for a Buick's
octogenarian owner, one with poor vision. To coin a phrase, those guages look like they came from a toddler's
playset.

I loved the instruments on the 97 STS .... kind of backlit like the newer STS models, and the secondary guages
were very readable. Conversely, on my 95 STS, the gauges to the left and right of the main pod were completely
obscured by the steering wheel. I'd have to duck down or peer over the wheel to read my DIC info ... worst placement of any guages in any car I've driven.

Funny, I've never even noticed which side my tach's are located on.
When you showed the poor segment spacing on the Grand Prix's tach, I was surprised.
I'd probably look at that tach for 20 years and never pick up on the irregularities .... but, once noticed,
it would drive me nuts.

Nice post.

Jesda
09-12-10, 02:02 PM
I really really hate the red/orange lighting BMW has been using since forever. It looks dull and puts me to sleep.

Worst ever:
http://www.car-list.com/newcars/2008/image/navl_misc.jpg

Night Wolf
09-12-10, 02:08 PM
Rick, something about the gauges on your 21 year old BMW ... I don't know if its the number font or the cool
backlighting, but the guages look very high end and precise for an old car. BMW sure got it right.

By comparison, the typeface on the Jeep gauges look ridiculously large, almost like it was made for a Buick's
octogenarian owner, one with poor vision. To coin a phrase, those guages look like they came from a toddler's
playset.

Funny, I've never even noticed which side my tach's are located on.
When you showed the poor segment spacing on the Grand Prix's tach, I was surprised.
I'd probably look at that tach for 20 years and never pick up on the irregularities .... but, once noticed,
it would drive me nuts.

Nice post.

Yeah, the tach on the GP I noticed when my father first bought the car and it drove me crazy!

As for the Jeep... yeah, the numbers are on the big side, but I do prefer them (and the red needles) over the eariler design - though the early TJ had a real oil pressure gauge.

To just show how picky I get with things... if you notice, the font size is bigger for the tach then the speedometer.... that bugs me.

Early TJ:

http://i.ebayimg.com/21/!B2FSN,!!mk~$(KGrHqYOKjQE)UfLJHN+BMhBsu8kPw~~_3.JP G

That has the real oil pressure gauge. It goes rather low at idle and up high at cruise etc... On '03-'06 TJ it is nothing more then a dummy light. Basically there is an on/off sender (just like a light) It is set at something crazy low, like 8psi. As long as it detects pressure, it tells the computer "GOOD" the computer then makes the oil gauge dance around to make it look like it is actually doing something. It'll sit at halfway when idling, then raise a bit as you increase RPM etc... The only time it does something else is when for that sender detects lower then 8psi, it tells the computer "BAD" the computer then makes the gauge go to L, the check gauges light comes on along with the chime.

To show how bad it really is, once the engine is running, you can unplug the sender switch - and the gauge will continue to dance around with RPM.

The gauge is capable of displaying full range of motion, because I can put the cluster in diagnostic mode and it'll run all the gauges/lights through a series of tests. I plan on adding an oil temp and oil pressure gauge to both the BMW and Jeep, but I want to see what I can setup using the factory oil pressure gauge and either an early TJ sending unit or an aftermarket unit. Either way it would have to be custom wired in directly tot he gauge itself and bypass the computer.

I agree, the BMW gauges look nice. Stock they are very bland, but I added the carbon fiber backing, the stainless trim rings, painted the needles red and blacked-out the icons. They are so complex, I have yet to see a cars gauges built to that level of detail. They are so accurate though, the tach is a direct reading from the distrubutor - the slightest change in RPM is displayed, such as a bad shift and the engine is forced to raise/lower RPM rapidly etc... The Jeep is all buffered by the PCM which is annoying.

The needles are actually metal, and the gauges are all tilted within the cluster so they are directly facing the driver. This was when I did a makeover to the cluster and replaced the broken odometer gears.

Stock:

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09003.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09015.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09016.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09018.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09021.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09023.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-15-09028.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW/gauge%20cluster/1-23-09005.jpg

I can't seem to find quality pictures of it actually in the car.

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW92/Bringing%20home/Ashleigh132.jpg

http://i43.photobucket.com/albums/e363/InoventionsEast/BMW92/12-9-09/IMG_0052.jpg

Gauges are a big thing to me, the design and way they look etc... It is just something I get nit picky about. My friend had an '01 Jetta 1.8T and I really liked those gauges - especially the vivid red and blue at night. As I said before, the inteiror, and interior backlighting of a car to me are a big deal.... Many new Hyundais have beautiful backlight gauges and interiors at night.

ted tcb
09-12-10, 02:20 PM
I forgot that you altered the display on your BMW ... love the trim rings, same as on my old Miata.

I also like interesting lighting techniques .... I have a 2010 Mazda3 GT manual, and the radio controls
pulse when volume is adjusted. A little thing, but a nice touch which takes place outside your main field of
vision.

I~LUV~Caddys8792
09-12-10, 02:22 PM
Worst ever:
http://www.car-list.com/newcars/2008/image/navl_misc.jpg


I love those square FoMoCo gauges from the '70s and early '80s. So ostentatious. I love the woodgrain, chrome trim and aluminum.

'79 Mark V.
http://i.ebayimg.com/15/!!gMq(bgBGE~$(KGrHqUOKnIEvyFrzKsmBMLe(Odl(g~~_4.JP G

orconn
09-12-10, 03:29 PM
Any car company that puts a large clock to the right sight of the steering column is in need of serious ergometric design help! ThsoseL Lincoln (other Ford products) instrument really looked cheap ... nothing like fake wood and fake chrystal lenses to scream "I am cheap and don't care if everyone know's it!"

I~LUV~Caddys8792
09-12-10, 03:34 PM
Hey! It was the '70s, the decade that taste forgot!

http://i278.photobucket.com/albums/kk92/caliboypsychobillykid/l_3d8b4f16bb9d28c3682a185bd7dedabe.jpg

gdwriter
09-12-10, 03:45 PM
I really like my gauge cluster. Big speedo and tach, back lit, with long, red needles. Classy and even a little sporty:

http://sphotos.ak.fbcdn.net/photos-ak-snc1/v2384/117/61/776743093/n776743093_1299341_255.jpg

I'm not sure about the trend in current cars going back to the gauges split into two or three pods. Don't have enough drive time in one to know if that would bother me or not. Probably not, as long as the gauges are there, I can get used to it. But grouping the gauges under one binnacle seems simpler.

Sevillian273
09-12-10, 04:58 PM
I tend to favor aftermarket gauges since they are unbiased by the car maker. This is especially important to me concerning a temp gauge. 'Cold', 'Warm', and 'Hot' arent good enough. I like to know the actual temperature. I have to have an oil pressure and coolant temperature gauge in all my cars so that in the event of a loss of either, I can quickly make the right decision and save the engine. I have seen several engines get destroyed because the driver didnt know anything was wrong.

As far as the tach goes, I pretty much use it for diagnostic reasons since I have only automatics. It doesnt influence my driving much however there have been a couple occasions where I had the stereo up high and forgot that I was in overdrive lockout and was cruising down the highway at almost 4 grand!

For factory tachometers, I like the centered position in the classic full circle style. I dont much care for the half or quarter circle style. And I HATE digital tachs including the factory one in the driver info center.

http://i106.photobucket.com/albums/m280/merc892003/P7130020.jpg

Of course the biggest issue with aftermarket gauges is placement...

Night Wolf
09-12-10, 05:05 PM
Personally when I mod my vehicle, I like to keep a clean "could be factory" look... and the thing about aftermarket gauges is that they usually just do not fit that bill at all.

In the Jeep I have been thinking about putting an oil temp and oil press gauge on the "A-pillar", I would use gauges that blended well with the Jeep. Though since it is OBDII I may also get a Scan Gauge.

The BMW would be more tricky. e30M3 replaced the econometer in the tach with an oil temp gauge. But for me to place two seperate gauges, I just don't know where I would put them that would offer a clean look that blends with the interior well.

Now if I was building a dedicated performance vehicle be it a track car or off-road machine, none of that really matters and I would put things where ever I felt.

I~LUV~Caddys8792
09-12-10, 05:27 PM
I like digital dashes for the amount of information they generally offer and how precise that information is, but I never liked how digital dashes look. It's straight out of the '80s, and not in the best way. I like watching the needles move like a clock, not numbers marching up like on a calculator or adding machine.

Sevillian273
09-12-10, 07:10 PM
^^^ Indeed. Especially concerning a tach however I do like a digital speedo because you can glance down ever so quickly and get you exact speed rather than compare the needle to the nearest notch. Also it's nice to see exactly how many gallons of gas are in the tank... I've always wanted to build a custom sheetmetal dash with all individual hand picked gauges like in alot of resto-mod/street machines.

Late 80's early 90's GM sedans had some epic digital dashes:


http://www.youtube.com/watch?v=PLaDOBptFlY

I~LUV~Caddys8792
09-12-10, 07:39 PM
I agree, GM had some pretty wacky stuff from about 1988 to about 1993.

gdwriter
09-13-10, 01:00 AM
After driving Cruella for several years, I got used to the digital speedometer, so while there's the option to turn it off in the Seville, I keep it on. I still prefer analog gauges, but it's handy having both.

Playdrv4me
09-13-10, 10:21 PM
BMW has been notorious for their overly damped gauges for A LONG time, especially among BMW master techs. The reason that BMW gets picked on in particular is because they were one of the first high end brands to move to plastic cooling system fittings and components (radiator end tanks etc.). So you'd have the ages old scenario... coolant fitting busts, coolant starts spraying out all over the place and engine temp rapidly begins to climb, BUT, it climbs much more quickly than the gauge can keep up with. Suddenly, as Jesda stated, the temp needle shoots from 1/2 to 3/4 and then all the way to RED, driver attempts to save the situation by pulling over as soon as he/she can, and by this time the engine has been too hot for too long. Thousands of E39 528i Sedans and Wagons found their fate via cracked blocks in the late 90s and early 2000s as a result of this very stupid and very preventable problem.

The argument could be made that the owner should have changed these fragile components out sooner, but to the best of my knowledge BMW never published any directive instructing owners that coolant fittings and couplings needed any particularly special maintenance. Most owners who re-hab their cooling systems do so because seasoned BMW techs keep an eye out for them and direct them to replace them at x number of mile intervals. So unlike the N* HG issue, where you could really take a long-shot at blaming owners who perhaps weren't religious with coolant changes... in the case of the BMW overheating failures, there wasn't really much the owner could have done.

I believe that BMW and the rest of the industry in turn, continued to use more and more plastic components in cooling systems as the years passed, but I suppose by now materials have been created that get brittle far less quickly and are far more durable. Those '90s 2.8L years were pretty terrible unless you kept your eye on your cooling system, and those uber-damped needles only served to magnify the problem to a much greater extent. That's a shame, because outside of the achilles heel in the cooling systems, the engines themselves were no less world class than any other legendary BMW inline six.

Night Wolf
09-14-10, 01:11 AM
I haven't heard of that, it is interesting to know.

Outside of the e30 world, I don't follow BMW *too* much, and the two sites I go to are e30-specific. Atleast with the M20 in the e30 there is not a big concern over the cooling system being problematic other then the standard maintenace items on any vehicle.

I will say that the M42 4cyl in the '92 318iC was a mess of a cooling system. So overly complex just too much. While handling what is known as the "under intake manifold mess" I was able to remove a bunch of stuff and re-route other things, but still - whoever designed that cooling system must have been crazy. Perhaps it was just a picture of what was to come at BMW in the 90s? I dunno. With the exception of more hoses then needed, the M20 and e30 haven't been problems.

A *properly* designed cooling system in a vehicle should only need 4 hoses. 2 going to the radiator and 2 going to the heater core. The Jeep has - 4 hoses. Actually as much of a gas hog the AMC 4.0 is, it really dosen't matter. In almost all circles of vehicles the related engines usually have atleast a few common problems, things to look out for ot things to replace by a certain time etc... I must say the AMC 4.0 dosen't have any of that. The darn things just keep going and going. No head gasket problems, timing related issues, plastic manifolds to deal with, crazy cooling system designs. About the only thing that is know to sometimes be a problem is the rear main seal leaking. Even then, because it is a two piece design it can be changed just by dropping the oil pan.

The BMW M42 was the worst. Such a great little engine but the whole thing was put together using bolts that were 1-2 sizes smaller then they should have been, everything was torqued to 10-20% less then what it should be. The engine had some quirky engineering - like HALF a thrust bearing, the crazy cooling system and a timing chain system that was more tempramental, more expenive and required more maintenace then a timing belt system. There are atleast 3 ways that engine is just waiting to kill itself at any time from design flaws. The good thing is that Metric Mechanic not only sells all the parts to address all the issues if you are rebuilding one yourself - but also sells rebuilt engines using their parts from stock to wild.

ga_etc
09-14-10, 01:16 AM
I loved the digital dash that was in my '88 Cutlass Supreme.

http://www.youtube.com/watch?v=JQQe_fI75eA&feature=related

Night Wolf
09-14-10, 01:23 AM
I really like digital dashes

Night Wolf
09-17-10, 11:33 PM
Some support equipment at work...

backwards tach:

http://i43.photobucket.com/albums/e363/InoventionsEast/misc/cid__0914102130_01.jpg

tach w/ pictogram:

http://i43.photobucket.com/albums/e363/InoventionsEast/misc/cid__0914102150.jpg

Night Wolf
09-18-10, 01:47 AM
BMW has been notorious for their overly damped gauges for A LONG time, especially among BMW master techs. The reason that BMW gets picked on in particular is because they were one of the first high end brands to move to plastic cooling system fittings and components (radiator end tanks etc.). So you'd have the ages old scenario... coolant fitting busts, coolant starts spraying out all over the place and engine temp rapidly begins to climb, BUT, it climbs much more quickly than the gauge can keep up with. Suddenly, as Jesda stated, the temp needle shoots from 1/2 to 3/4 and then all the way to RED, driver attempts to save the situation by pulling over as soon as he/she can, and by this time the engine has been too hot for too long. Thousands of E39 528i Sedans and Wagons found their fate via cracked blocks in the late 90s and early 2000s as a result of this very stupid and very preventable problem.

The argument could be made that the owner should have changed these fragile components out sooner, but to the best of my knowledge BMW never published any directive instructing owners that coolant fittings and couplings needed any particularly special maintenance. Most owners who re-hab their cooling systems do so because seasoned BMW techs keep an eye out for them and direct them to replace them at x number of mile intervals. So unlike the N* HG issue, where you could really take a long-shot at blaming owners who perhaps weren't religious with coolant changes... in the case of the BMW overheating failures, there wasn't really much the owner could have done.

I believe that BMW and the rest of the industry in turn, continued to use more and more plastic components in cooling systems as the years passed, but I suppose by now materials have been created that get brittle far less quickly and are far more durable. Those '90s 2.8L years were pretty terrible unless you kept your eye on your cooling system, and those uber-damped needles only served to magnify the problem to a much greater extent. That's a shame, because outside of the achilles heel in the cooling systems, the engines themselves were no less world class than any other legendary BMW inline six.

While browsing various things at one of the e30 sites, I saw this...

http://r3vlimited.com/board/showthread.php?t=125657

Seems to be exactly what you and Jesda are talking about too. Seems to have really started right after the e30 too... with the e34 such as the one Jesda owned being the start.

Since being into BMW, I am kinda stuck in the 80's BMW - which is a vastly different world then the modern BMW. The more I read and hear about modern BMW - the more it seems to be more hassle then it's worth. I'm sure the timeframe of the cars I like will progress as time goes on and new becomes old, but there seems to be a definite difference in build quality between 80s and 90s BMW.

Submariner409
09-18-10, 10:25 AM
For automotive and motorcycle tachs, especially when racing, I prefer a 270 degree sweep unit: You don't need to "read" it - your RPM and redline are graphic so there's no mental lag.

Digital tachs are useful for carburetor, timing, and steady state engine work. By "steady state" I mean marine or stationary diesel or gas applications where the engine runs at one steady rpm for hours, maybe days. BUT in automotive or racing use you have to "read" the instrument: 6 - 3 - 5 - 0 rpm.

Those two tachs shown a couple of posts back are common in diesel applications. They take their input from either a trigger wheel or mechanical drive tip. VDO makes some great diesel tachs. I use them - 5,000 rpm - on my Olds455 boat engines - they're built to turn a maximum rpm of 5,000 and generally run, heavily loaded, at 2,500 rpm for 6 - 8 hours at a time.

If your vehicle engine has/is controlled to a redline of say, 6300 rpm, then a tach that goes to 10,000 is strictly eye candy. The last 45 degrees of sweep is graphically wasted.

BTW, Many instrument companies make hour meters - very simple to wire into an ignition circuit so the meter totals only while the engine is running - good trick for keeping track of maintenance times. Practically every internal combustion on earth, except those in cars, uses an hour meter.

I~LUV~Caddys8792
09-18-10, 11:37 AM
What makes VDO tachs & other instruments different and why are they better?

Submariner409
09-18-10, 12:43 PM
What makes VDO tachs & other instruments different and why are they better?

The reference was to VDO diesel tachometers - low RPM types, usually 0 - 4,500 rpm, so the individual graduations can be seen with greater precision. VDO does make some fine automotive instruments though......made in Germany, not China. To clarify my earlier post, there are low-rpm tachs which take their trigger from an ignition system - points or magnetic - they're just not as common as the 6-8-10 thousand rpm units.

Get into the Stewart Warner or Gaffrig catalogs for some nice instruments.

I~LUV~Caddys8792
09-18-10, 01:06 PM
AFAIK, all german cars use VDO, right? Atleast the older ones?

Jesda
09-18-10, 02:37 PM
Just realized my old 900 uses VDO.

Night Wolf
09-18-10, 09:16 PM
AFAIK, all german cars use VDO, right? Atleast the older ones?

e30s used VDO and MotoMeter. Both look the same from the outside, but the internals are slightly different. Some of the components are interchangeable. The cluster I built for my e30 is a mix of MotoMeter and VDO. The car had VDO facoy but I fired the PCB, and the MotoMeter PCB swapped right in. Some other components were swapped as well.

For the most part older BMW used VDO. From my experience they make high quality stuff.

Those two tachs in my previous reply are indeed diesel powered equipement. The one with the backwards tach is a huge NA Detroit V6 and the other is a smaller turbocharged John Deere I4.