I have seen that a lot of you with the ISM's have posted positive results with the resonator/Aero muffler change. But not much feedback on the 400ISL. Has anyone with the ISL that has done this mod. seen worthwhile results? Would you do it again in hindsight?
I have been told that there isn't a lot you can do to to the ISL to "pep" it up but if the exhaust mod would help without making it too obnoxious sounding I might consider it.
Thanks, Dean
Anytime you reduce back pressure on a turbo it improves efficiency.
Call Cummins with your engine Serial # and the CPL#,ask if it can be reprogramed to to 450 Hp.
The ISL will go to 450 HP per Cummins last printing, but who knows it is a horsepower race I guess. I included a link to the Cummins RV engine list with HP & Torque.
I am for getting every bit of power that is available with out "Hot Rodding" it, why I went with the Cummins upgrade to the 500, which is the max with Cummins blessing.
It just cost a little more to do it correct vs hot rodding on the cheap.
The resonator sure is a winner.
As usual MO
Dave M
http://cumminsengines.com/showcase.aspx (http://cumminsengines.com/showcase.aspx)
Bill & Dave, I did a little digging and it appears that the ISL 400 could be reprogramed to 425 or 450hp but it will not increase the torque. It will only change the HP/torque curve. Not much gain there.
So it sounds like the resonator/free-flow muffler change may be a better and cheaper option if it does make a difference. I had not seen much feedback about the ISL and resonator and am curious if anyone had any input on having done it and if they found it worthwhile?
Thanks, Dean
I just added an Aero 5050XL to my 2004 that has the ISL. (See my entry in the "What did you do in your coach today" thread.}
I'll post what I find regarding performance improvement.
Thanks Larry. Curious to know how much louder it is too, if at all, from behind and in the seat.
Dean
Actually I just split it out as its own topic here Installed Aero resonator (http://www.foreforums.com/index.php?topic=17109.0)