No, I'm talking about the general public. Most people don't know about this. I've seen a tachometer in a dash sit at 1000 RPM while idling when the car was in fact at just under 700 RPM. All I'm saying is that tachometers on dashes are somewhat vague, and so are the other gauges, and should never(if you can help it) be used to make a proper decision until you know the raw and accurate data of that engine. Gauges on the dash are made to give the driver a somewhat general idea of how that engine is operating, nothing more. Now for the average joe that doesen't have access to the proper technology, using the dash gauges can be fine, as they usually do their job fine enough to make a close enough decision and be correct most of the time.

In English, that means ER does not know the answer to sean000's original question.

Norm

No.

Biggest factors (among many) are static compression and cam timing.


No one said they could not. They have been doing it for 50+ years.


Yes. The inaccuracy comes after the digital information is converted to the mechanical energy that drives an analog meter.


I cannot speak for Canada, but that does not happen in the US.


How did you know which reading was correct?

Norm

In your "English" can you tell us what your point is?...

I see a picture of a tachometre redlining at 5300RPM, and the engine happened to be a 3.8 too boot!!...How is this not answering the original question?

You have not identified the year, make and model of the vehicle in your pic. You have only stated that is a 3.8.

You have not demonstrated that it has, even the slightest relevance, to his question.

Norm

I did see a program on the local news here a few months back that Consumer Reports (based right near here) has found some makes (Honda was named) do design speedos that show inflated speeds when going at high speed in an effort to get the driver to not speed. If I can find an article to back this up Ill post it here.

And I'll look for a copy of the Federal law they would be violating.

Norm

Link about Honda speedometers

Im still looking for more info on this, but here is something I found that may be helpful. If you do a yahoo/google search for "honda speedometers inaccurate speed" there are thousands of similar complaints by owners.

Tell us why you would consider epinions.com (or that anonymous post) a credible source?


Me? Search the internet for accurate information? Shirley, you jest.


Founded or unfounded. Or are they just passing along another Urban legend?

Suppose it is true. Are all the "ricers" going 10% faster than they think they are?

Or, did they start the story to justify their exaggerations.

Norm

I was reading the information from a GM Tech 2 OBD 2 Scantool under the live engine monitoring mode. The tachometer on the dash was sitting at 1000 RPM(well, as well as I could see it it was) and on the Tech 2, the engine was idling just below 700 RPM. It fluctuated when idling so I couldn't get an exact reading. Now I was reading the information that the vehicle's ECU was seeing, and I'm sure it was correct.



Have you read what I have, and other members have been saying through the entire thread? 5300 is a shift point, it looks like redline, but that is just a slang term that I really prefer not to use because it is so vague. My LSS shifts at 5500 RPM, and that's right where the tachometer begins to go red(aka known as the "redline") FYI. If you want to find out how high these engines can go, put the car in park or neutral, and hit the throttle till it bounces off the rev limiter, then you see where the governor kicks in, and voila, sean000 has an answer!

Does my car even have a limiter?...I still answered the question that was at hand but some don't think it's good enough.
call it whatever, it's still happening at "the redline"...

I've had a few cars with tachs, and what I've noticed is not the acuracy of the tach that is the problem. It is the response time.

My ford probe had a quick responding tach, and I beleived it to be fairly accurate at any point in the power band. My old '95 ford F250 had a slow (dampened) tach, and would take a few seconds to even out, especially when passing on the highway, and you kick down from overdrive. Once it caught up, it was accurate. The ambient temperature had an effect on the tach's response aswell.

Not true in the least. My car, albiet not a 3.8 hits the limiter at 4000 in park, shifts at 5500 or so in drive. I'll bet that your cars are the same, or at least similar, but I don't know for sure.

Andrew

Just about any car has an RPM limiter that is either mechanically controlled or controlled by the ECU(unless it has been removed by the owner). Maufacturers don'w want pistons flying through the hood when the driver accidently puts the vehicle in neutral, or accidentally guns in when they get in thier car when it's in park, and it's a safeguard that's relatively simple yet does a lot. E.R., have you removed the rev limiter in your car? I believe your car has an ECU controlled rev limiter, so unless you have a chip in that thing, you will have a rev limiter. And we don't think it's not good enough, we know it's not good enough .



Ah, thought GM might have done something like this. What does your car rev to in Neutral?

4000 rpm, I think. I will try it and see. I think its dependant on whether or not you are moving, but I am not sure.

Not saying lots of cars dont have limiters, but there are alot of computer controlled cars that dont, so your first statement is sort of a rash generalization.

I think the manufactuers concern has more to do with speed than it has to do with engine failure. Preventing overspeeding is a part of it, thats why my car hits the limiter at 4k in park. OEM's limit the speed of their cars for safety reasons, and the eaisest way to do it is a rev limiter.

Regards,
Andrew