03-31-2017, 01:42 AM
|
#1 (permalink)
|
|
EcoModding flying lizard
Join Date: May 2012
Location: Georgia
Posts: 743
Thanks: 618
Thanked 263 Times in 175 Posts
|
Low RPM load limits? Lugging?
What load limits do you use when you are at low rpms? I find that below 1500 rpm, operating at too high a load makes the engine sound and feel rough, which I assume is nearing the lugging point.
idle-1300: 40% load(sometimes a little more)
1300-1400: 50% load
1500-infinity and beyond: No limits
__________________
-Kaze o tatakaimasen-
Best trip in V6: 52.0
Best tank in V6: 46.0
Best tank in Mazda: 49.9
Best tank in CBR: 61.3
Best tank in SV: 83.9
Quote:
Originally Posted by MetroMPG
You can lead a fashion-conscious horse to unusual-looking water...
|
|
|
|
|
 Today
|
|
|
|
Other popular topics in this forum...
|
|
|
|
|
03-31-2017, 02:03 AM
|
#2 (permalink)
|
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
|
Below 1500 is probably always too low for flooring it for any purpose at all. But above that, in a naturally aspirated and relatively low-power engine that is also in good working order, there is not much chance of damage. ECUs will adjust timing and AFR as needed to avoid pre-detonation. Nonetheless, 1500 is my absolute bottom for relatively high load (75%, which is a long way from WOT). But generally I am at 1700 or higher as I accelerate. Been doing this for years all the time and have 248,000 miles on the original engine now. 
Great video here:
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
|
|
|
|
|
03-31-2017, 03:08 PM
|
#3 (permalink)
|
|
Master EcoModder
Join Date: Dec 2011
Location: New Zealand
Posts: 5,077
Thanks: 2,903
Thanked 2,560 Times in 1,586 Posts
|
In my Insight, the engine feels fine wide open down to maybe 1200rpm. At those low revs, even barely touching the pedal is enough to give it 100% load, because it needs so little air.
Edit: Recently passed 220k and it still runs like a brand new engine.
|
|
|
|
|
The Following User Says Thank You to Ecky For This Useful Post:
|
|
|
03-31-2017, 08:56 PM
|
#4 (permalink)
|
|
Master EcoModder
Join Date: May 2009
Location: Australia
Posts: 1,510
Thanks: 325
Thanked 452 Times in 319 Posts
|
Drive by wire throttle won't let you do anything that's bad for the engine, IMO.
|
|
|
|
|
03-31-2017, 09:04 PM
|
#5 (permalink)
|
|
Corporate imperialist
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,265
Thanks: 273
Thanked 3,569 Times in 2,833 Posts
|
For my 8L engine build I would like to cruse along at 70mph turning 1,400rpm. If the engine doesn't like that I will have to change rear end gears.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
|
|
|
|
|
04-01-2017, 01:20 AM
|
#6 (permalink)
|
|
Master EcoModder
Join Date: Dec 2014
Location: Butte, Montana
Posts: 726
Thanks: 208
Thanked 428 Times in 279 Posts
|
Quote:
Originally Posted by Daschicken
What load limits do you use when you are at low rpms? I find that below 1500 rpm, operating at too high a load makes the engine sound and feel rough, which I assume is nearing the lugging point.
|
Not nearing . It is the indicator of lugging. Roughness is lugging beyond what the computer is able to maintain smooth operation.
__________________
1st gen cummins 91.5 dodge d250 ,HX35W/12/6 QSV
ehxsost manafulld wrap, Aero Tonto
best tank: distance 649gps mi 24.04 mpg 27.011usg
Best mpg : 31.32mpg 100mi 3.193 USG 5/2/20
Former
'83 GMC S-15 Jimmy 2door 2wd O/D auto 3.73R&P
'79 Chevy K20 4X4 350ci 400hp msd custom th400 /np205. 7.5-new 14mpg modded befor modding was a thing
87' Hyundai Excel
83 ranger w/87 2.9 L FI2wd auto 18mpg on the floor
04 Mitsubishi Gallant 2.4L auto 26mpg
06 Subaru Forrester XT(WRX PACKAGE) MT AWD Turbocharged 18 plying dirty best of 26mpg@70mph
95Chevy Blazer 4x4 auto 14-18mpg
04 Chevy Blazer 4x4 auto 16-22mpg
|
|
|
|
|
04-01-2017, 02:25 AM
|
#7 (permalink)
|
|
Master EcoModder
Join Date: Sep 2012
Location: Victoria, BC
Posts: 1,747
Thanks: 75
Thanked 577 Times in 426 Posts
|
Number of cylinders and/or displacement count, imo.
My 3 cylinder Geo isn't much good under 2000rpm at heavy load, whereas my wife's V6 happily chuggs down the the highway at 1500rpm. My Miata (read: DOHC/high-revving) is a turd below about 2500 rpm.
|
|
|
|
|
04-01-2017, 12:13 PM
|
#8 (permalink)
|
|
Eco Sol
Join Date: May 2009
Location: Paradise, TX
Posts: 343
Thanks: 24
Thanked 88 Times in 52 Posts
|
That guy does such great tutorials. My head feels funny, did I just learned something?!!
__________________
Best Tank = 42.72 mpg (in the 94 Del Sol)
CR-Z Current Mods:
Max Sidewall PSI
|
|
|
|
|
04-01-2017, 03:01 PM
|
#9 (permalink)
|
|
Master EcoModder
Join Date: Jun 2008
Location: Earth
Posts: 5,209
Thanks: 225
Thanked 811 Times in 594 Posts
|
Have I missed something here? All the BSFC graphs I see seem to show that the engine is less efficient at low RPM & higher load.
|
|
|
|
|
04-01-2017, 03:24 PM
|
#10 (permalink)
|
|
Master EcoModder
Join Date: Dec 2011
Location: New Zealand
Posts: 5,077
Thanks: 2,903
Thanked 2,560 Times in 1,586 Posts
|
Here's mine:
|
|
|
|
|
