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Topic: Silver leaf with ISM 500 (Read 456 times) previous topic - next topic

Silver leaf with ISM 500

I am using silver leaf vmspc with a 2006 ISM 500 and would like to find others with the same to compare performance data specifically horsepower, load and torque. Most interested in base performance pulling hills at different altitudes. With special interest above 5000'. Looking forward to any feedback.  Thanks.

2007 Foretravel Nimbus 340.

Re: Silver leaf with ISM 500

Reply #1 –
Make sure you have the correct engine specified.  Engine load is a reported value as is RPM.  Horsepower and Torque are derived (calculated/extrapolated) using reported engine data and data contained in the engine file.  It is like looking at a HP chart vs RPM and knowing RPM looking up HP.  It is not quite that simple but the engines do not report HP or Torque directly.  Maybe on later engines or these in other applications but as far as I know not for the FT coaches from this time frame.

Performance is highly dependent on the driver, the location, the elevation, wind speed and direction, tire pressures, coach weight and more. Sort of like comparing red delicious apples to honey crisp apples. They are both red but everything else is different.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Silver leaf with ISM 500

Reply #2 –
Thank you for your reply.  I am in complete agreement with you and I understand what you are saying.  What i am looking for is some rough comparison of numbers to validate within a range that my numbers are similar.  For example, my 40' nimbus weighs in at 42000 and I drive a lot in the upper Midwest.  Elevation never exceeding 2000'.  Hills are rolling with some sharper that others.  With cruise set at 65 I will hold that speed on 90% of the hills and my max HP will see 430 and torque 1440 and pedal is to the floor.  Never any higher than that.  On ramps to interstates, accelerating up to cruise speed, etc. duplicates that consistently again pedal to the floor.  That feels good and the machine is running good.  Now leave Denver going westbound on I70 as elevation starts to rise dramatically or cruise through flagstaff on I40 with cruise set at 65.  Elevations under 5500' show my consistent numbers but as I close in on 6000' the max number for HP does not exceed 370 and torque 1275.  These numbers are consistent in 5th gear at 1800 rpm.  Does this make sense?  Does someone else's 42000 coach with ISM500 cruising through the upper Midwest see approximately what I see?  That's kind of where I coming from.

Re: Silver leaf with ISM 500

Reply #3 –
I would expect another identical coach with similar variables to show similar numbers. They will react the same to the thin air. If your concern is that your engine overreacts  to 6000 ft air I think it does not.
Dub McBride 1996 270

Re: Silver leaf with ISM 500

Reply #4 –
Not sure if this helps, but it's a screen shot (see attached) of my old 2007 36 Nimbus with ISM400. Driving from Las Vegas climbing the Baker Grade. Long steep climb - "In just 19 miles Interstate 15 climbs steadily from Baker (exit 246), 960 ft. above sea level, to Halloran Summit Road (exit 265), at 4,130 ft. Engineers responsible for designing car radiators are very familiar with the Baker Grade."

Pretty much in the sweet spot and this is how it performed towing a 2016 Ford Explorer in 95* heat. This is just a snap shot in time. At several points I would down shift and try maintain my rpm and rate of climb.

Must give Roger kudos for my Silver Leaf set up. Best investment I made for my coach.

6th gear
63 mph
93% engine load
329 HP
1057 torque
32.2 lbs turbo
1638 tach.
 

Re: Silver leaf with ISM 500

Reply #5 –
Thanks