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Re: RPM at 100km/h?
My Manual Exy sits on 2600rpm @100k's in saying this I did do this test when the first post went up for this and I was doing 2500rpm @100k's in the mean time I have changed oil, oil filter & air filter I also have 17" wheels and run 5w/30 oil synhetic all these factors come into play as my tyres have a 7mm rolling diameter differance compared to original tyres.
Dave
--- (Dave Newcastle 2004 ST
ID: X211
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23/Feb/2006, 3:46 pm
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Re: RPM at 100km/h?
would not the RPM be decided on the road you were driving?! i.e flat incline or decline?!
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2004 ST-X Limited
Alloys, Bull Bar, Roof Racks
Sun Roof & Baby Seat.
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23/Feb/2006, 7:08 pm
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Re: RPM at 100km/h?
So true its called torque loading. To get a true comparison everyone would have to use the same road and conditions with the same varibles but thankfully we have accessories some more than others not mentioning any names but I think we know who Im talking about.Its just never ending.
Cheers Dave
--- (Dave Newcastle 2004 ST
ID: X211
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24/Feb/2006, 6:22 am
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Re: RPM at 100km/h?
quote:
Dave4x4 wrote:
So true its called torque loading. To get a true comparison everyone would have to use the same road and conditions with the same varibles [snip] Dave
Interested in how this torque loading works. My series 1 auto shows pretty close to 2400 rpm at 100kph. Most of the time the torque converter is locked and I assume that the engine and wheels must follow the same ratio up slope or down (0.694 according to the book; on a manual, 5th gear is 0.733 for comparison).
Driving at 100kph using cruise control, going up slope often I observe that the engine revs increase to about 2700 which I assume results from the torque convertor unlocking, introducing a certain amount of slip and allowing the engine to increase revs to pick up the speed in higher power band. The vehicle either then accelerates and the revs drop back fairly rapidly to 2400, or on a steeper hill, the overdrive kicks out and engine revs go to around 3500 in 3rd gear (ratio 1.0) (This usually results in flying over the top of the hill about 6 or 7 kays over the limit before the cruise reacts sufficiently for engine braking to take effect).
So is this "torque loading" double speak for allowing slippage so the engine can run at higher revs?
--- David M (X095)
 ST Auto (series 1) 165,000 kms
Nissan nudge, fog lights, towbar, floor mats, K&N filter, Dunlop RV501's did 85,000 kms, now on Cooper CS4s |
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27/Feb/2006, 12:35 pm
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Re: RPM at 100km/h?
Torque loading is only on auto's. Manuals have fixed ratio's unless your clutch is slipping. Easy way to explain is drive your Exy auto with one person in the car & pay attention to the tacho then load it up with people or put a trailer on the back and you will be doing the same speed going through the gears but with more RPM's with the load. For the torque converter locking up at freeway speed this is true unless like you said you over run you current speed , accelerate or go up hill as for a manual fixed ratio going in fixed ratio going out big varible 15" 16" 17" tyres with different rolling diameter just means your different to the next exy in speed & RPM's and fuel economy up or down
Dave
--- (Dave Newcastle 2004 ST
ID: X211
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28/Feb/2006, 7:15 pm
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Re: RPM at 100km/h?
Will have to watch the tacho more the next few trips - I have not noticed small changes in revs according to load apart from my example above. I have been assuming that the torque converter is basically locked up once you get moving for economy reasons. I think you're saying it slips a little under load?
--- David M (X095)
ST Auto (series 1) 165,000 kms
Nissan nudge, fog lights, towbar, floor mats, K&N filter, Dunlop RV501's did 85,000 kms, now on Cooper CS4s |
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1/Mar/2006, 8:15 am
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Re: RPM at 100km/h?
Yes thats correct the torque converter will be in catch up mode when accelorating as more and more fluid is pumped in and at times will be turning the veins in the torque converter faster than what speed you are actualy doing at this point it should lock up thats the reason auto's do not get good fuel economy compared to manuals
Dave
--- (Dave Newcastle 2004 ST
ID: X211
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1/Mar/2006, 9:50 pm
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Re: RPM at 100km/h?
Locking torque converters is why recent autos can get much closer to manuals. I'm guessing that the ECU limits the engine revs (e.g. to 2700 at 100kph) so the slippage isn't too great.
--- David M (X095)
ST Auto (series 1) 165,000 kms
Nissan nudge, fog lights, towbar, floor mats, K&N filter, Dunlop RV501's did 85,000 kms, now on Cooper CS4s |
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2/Mar/2006, 9:43 am
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Re: RPM at 100km/h?
Drove over to sister inlaw's at Orange last night - noticed that at 100km/h (basically) on the highway it was about 2400rpm.
My exy is basically standard except for the compulsory mod of a k&n filter lol
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9/Mar/2006, 6:29 pm
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