 |
The Oldsmobile Connection The Site For Oldsmobile Enthusiasts
|
| View previous topic :: View next topic |
| Author |
Message |
TheLSS
Joined: 10 Jan 2007
Posts: 30
Location: Canada
|
| Posted: Wed Jan 17, 2007 7:43 pm Post subject: Re: MAX RPM...3.8L? |
|
|
Erroneous Restrictionism! wrote: TheLSS wrote:
Contrary to popular beleif, the guages on your dash are not as accurate as you may think they are.
Who's belief?....Auto techs?....auto makers?....aftermarket companies?...
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. |
|
| Back to top |
|
88 Coupe
Joined: 15 Feb 2004
Posts: 2963
Location: Southern California
|
| Posted: Wed Jan 17, 2007 9:59 pm Post subject: Re: MAX RPM...3.8L? |
|
|
Erroneous Restrictionism! wrote: sean000 wrote: Thanks, where did you find that?
I have pic of a 3.8 with a tach, looked at a pic of the tach.
In English, that means ER does not know the answer to sean000's original question.
Norm |
|
| Back to top |
|
88 Coupe
Joined: 15 Feb 2004
Posts: 2963
Location: Southern California
|
| Posted: Wed Jan 17, 2007 10:51 pm Post subject: Re: MAX RPM...3.8L? |
|
|
85cieraholiday wrote: ........ Would the fact that the 83 is rear wheel drive have any effect here?
No.
Biggest factors (among many) are static compression and cam timing.
Erroneous Restrictionism! wrote: TheLSS wrote: And to add to that the stock tachometers on cars are nowhere near accurate.
It's hard to imagine that car manufactures couldn't figure out a simple.."timing sequence"!
No one said they could not. They have been doing it for 50+ years.
TheLSS wrote: ........ unless the tach is an accurate digital display ........
Yes. The inaccuracy comes after the digital information is converted to the mechanical energy that drives an analog meter.
TheLSS wrote: ........ Manufacturers put the speedos so they read ahead that 15% to keep people from speeding and not even knowing it ........
I cannot speak for Canada, but that does not happen in the US.
TheLSS wrote: ........ 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 ........
How did you know which reading was correct?
Norm |
|
| Back to top |
|
Erroneous Restrictionism!
Joined: 02 Jun 2004
Posts: 266
|
| Posted: Wed Jan 17, 2007 11:41 pm Post subject: Re: MAX RPM...3.8L? |
|
|
88 Coupe wrote: Erroneous Restrictionism! wrote: sean000 wrote: Thanks, where did you find that?
I have pic of a 3.8 with a tach, looked at a pic of the tach.
In English, that means ER does not know the answer to sean000's original question.
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? |
|
| Back to top |
|
88 Coupe
Joined: 15 Feb 2004
Posts: 2963
Location: Southern California
|
| Posted: Thu Jan 18, 2007 12:29 am Post subject: Re: MAX RPM...3.8L? |
|
|
Erroneous Restrictionism! wrote: ........ 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 |
|
| Back to top |
|
85cieraholiday
Joined: 04 Jan 2004
Posts: 1043
Location: West Haven Connecticut
|
| Posted: Thu Jan 18, 2007 2:36 am Post subject: Re: MAX RPM...3.8L? |
|
|
88 Coupe wrote:
TheLSS wrote: ........ Manufacturers put the speedos so they read ahead that 15% to keep people from speeding and not even knowing it ........
I cannot speak for Canada, but that does not happen in the US.
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. |
|
| Back to top |
|
88 Coupe
Joined: 15 Feb 2004
Posts: 2963
Location: Southern California
|
| Posted: Thu Jan 18, 2007 3:58 am Post subject: Re: MAX RPM...3.8L? |
|
|
85cieraholiday wrote: ........ 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 |
|
| Back to top |
|
85cieraholiday
Joined: 04 Jan 2004
Posts: 1043
Location: West Haven Connecticut
|
| Posted: Thu Jan 18, 2007 11:40 am Post subject: Re: MAX RPM...3.8L? |
|
|
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. |
|
| Back to top |
|
88 Coupe
Joined: 15 Feb 2004
Posts: 2963
Location: Southern California
|
| Posted: Fri Jan 19, 2007 12:34 am Post subject: Re: MAX RPM...3.8L? |
|
|
85cieraholiday wrote: Link about Honda speedometers
Tell us why you would consider epinions.com (or that anonymous post) a credible source?
Quote: ........ If you do a Yahoo/Google search ........
Me? Search the internet for accurate information? Shirley, you jest.
Quote: ........ there are thousands of similar complaints by owners.
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 |
|
| Back to top |
|
TheLSS
Joined: 10 Jan 2007
Posts: 30
Location: Canada
|
| Posted: Fri Jan 19, 2007 9:05 am Post subject: Re: MAX RPM...3.8L? |
|
|
88 Coupe wrote:
TheLSS wrote: ........ 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 ........
How did you know which reading was correct?
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.
Erroneous Restrictionism! wrote:
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?
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! |
|
| Back to top |
|
Erroneous Restrictionism!
Joined: 02 Jun 2004
Posts: 266
|
| Posted: Fri Jan 19, 2007 9:48 am Post subject: Re: MAX RPM...3.8L? |
|
|
TheLSS wrote:
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"... |
|
| Back to top |
|
88delta88
Joined: 09 Jun 2003
Posts: 2407
Location: Canada
|
| Posted: Fri Jan 19, 2007 10:46 am Post subject: Re: MAX RPM...3.8L? |
|
|
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. |
|
| Back to top |
|
andrewk
Joined: 18 May 2005
Posts: 1246
Location: Ames, IA
|
| Posted: Fri Jan 19, 2007 12:02 pm Post subject: Re: MAX RPM...3.8L? |
|
|
Erroneous Restrictionism! wrote: TheLSS wrote:
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"...
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 |
|
| Back to top |
|
TheLSS
Joined: 10 Jan 2007
Posts: 30
Location: Canada
|
| Posted: Fri Jan 19, 2007 12:02 pm Post subject: Re: MAX RPM...3.8L? |
|
|
Erroneous Restrictionism! wrote: TheLSS wrote:
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"...
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 :wink: .
andrewk wrote:
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
Ah, thought GM might have done something like this. What does your car rev to in Neutral? |
|
| Back to top |
|
andrewk
Joined: 18 May 2005
Posts: 1246
Location: Ames, IA
|
| Posted: Fri Jan 19, 2007 12:24 pm Post subject: Re: MAX RPM...3.8L? |
|
|
TheLSS wrote: Erroneous Restrictionism! wrote: TheLSS wrote:
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"...
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 :wink: .
andrewk wrote:
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
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 |
|
| Back to top |
|
| |
|