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Newbie Question on RPM's

Discussion in 'Z3 Roadster & Coupé' started by Scott, Nov 17, 2014.

  1. Scott

    Scott Newbie
    American Zeds

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    And forgive me in advance if this has been addresses before or I posted in the wrong forum. I have a 1998,
    2.8 L - Automatic Z3 and at 80 mph my RPM's are approx. 3200. is this normal? Thanks for any insight! Scott
     
  2. FRANKIE

    FRANKIE Zorg Guru (V)
    American Zeds The M44 Massive

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    None of us drive below 90.

    Sorry for that. I just couldn't help it. Welcome to the forum from New Jersey. I personally can't answer that because I have a '96 1.9l stick shift. However, there are many members of this forum that have the same model that can answer that question. It might take a short time as they probably are reluctant to take their eyes off the road at 80.to LOOK at the tach. Its wonderful to hear that you're regard for the D.C. police allows you to do 80. Actually, if you know the right spots, you can do this on the Atlantic City expressway or the Garden State Parkway. And any time in traffic on 295 or the Jersey Turnpike. Some times, to go slower might be risking your life. A big welcome to the forum to you. There are many members from all over the world, but most of them reside in the UK. A really GREAT BUNCH OF GUYS with a wonderful sense of humor. You'll find a lot of information about your Z or Zed as they say and plenty of the guys (and girls) are just fun to talk to. I had a week off in June and went over to the UK to meet many of them. I had the time of my life. I almost felt like a kid again. Well, enough of bending your ear. I know that soon you'll have your answer.
    P.S. They're probably out on the road looking at their tacks while doing 80 so they can give you an accurate answer. Frankie
     
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  3. David Cullen

    David Cullen Zorg Legend
    Supporter The M44 Massive

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    Thanks I have not owed a Z3 and just didnt know what was acceptable for rpms

    Force
    I have a dodge van that at 70 it is about 2500 so I just didnt know
    Thanks
    To both of you
    tohbi
    01-19-2012, 11:07 AM
    i'm not real familiar with the 1.9. is this an undersquare engine like the 6 cylinder engines?

    i like undersquare engines [stroke longer than piston diameter] because they tend to give good torque, meaning good power down low on the rpm band. for a street car this is optimum, imho. for the track, high rpm narrow powerband is usually best.

    long stroke means higher piston speeds than short stroke designs at same rpm. this means greater piston wear and/or damage over time. but pistons are so well designed today that we seldom hear of problems.

    your little 4-banger engine has a short enough crankshaft that you shouldn't need to worry about distortion at high rpm. the 6 cylinder is more problematic but this is compensated by numerous and wide crank bearings. the great thing about the 6 cylinder is that we can drive them at fairly low rpm because they make such good power down low, thereby giving less wear and better mileage. but the ability to rev when needed is still there.

    imho, my car could do well with an overdrive. i don't prefer cruising over 3k rpm and our freeways put me at 3500 at 75mph but the engine is designed for it.
    nfunk
    01-19-2012, 04:10 PM
    I have a 1998 Z3 2.8 L and I get 3500 rpm doing 80 MPH while my Toyota Highlander 3.0L gets 3000 RPM at 80 MPH. Bottom line, the Z3 is a lot more fun to drive!
    tohbi
    01-19-2012, 05:15 PM
    my speedo says 80, too, at 3500 rpm but these speedometers are notoriously optimistic, they say 5-7 mph.
    nfunk
    01-19-2012, 05:56 PM
    True, next time I will have to check it with my Garmin GPS for accuracy.
    nfunk
    01-21-2012, 04:34 PM
    Ok, just checked the speedometer against a Garmin GPS. Doing a constant 80 mph the GPS showed 77 mph, which isn't bad, and I like the error to be on the low side then high side.
     
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  4. David Cullen

    David Cullen Zorg Legend
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    one or two variables may came in to play, ie. wheel size and tyre wall but will play close enough to above quotes ;-)
     
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  5. miller1098

    miller1098 Zorg Guru (V)
    Supporter British Zeds

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    We have a 2.8 manual an have just been out in it .its hard to take a pic image.jpg image.jpg
     
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  6. hard top

    hard top Zorg Expert (I)
    Dutch Zeds The M44 Massive

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    Give or take that is about spot on in answering the question @miller1098
     
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