increase gas mileage, power and torque

[flytyer]

  Has anyone tried the addition of headders, mufflers,air filters and the newer mufflers to increase the HP, torque, and gas mileage on the work horse chassis(allison transmission 4speed with the chev 8.1, and did it do as they claim.
  Did anyone find a way t increase the gas mileage otherthan by slowing down?

 

[John From Detroit]

Has anyone tried them.. Yes, Workhorse on the 2006 models (Believe it or not)

And dozens if not hundreds of Banks Power Pack customers

Do they increase HP, Performance, torque and Millage:  Yes

Do they increase it enough to justify the cost of the mod:  Well.... Generally, no,  I imagine if you keep the rig long enough and make enough trips cross country and the gas price hits 4.00-5.00/gallon... Perhaps, but at this time, no

 

[Shayne]

John is right.  However we do have a Banks Pak and are very pleased with it, even tho we only have 29K miles on a 98 MH 460 Ford 37 ft.  but we like it and glad we have it.  A friend of ours has the same coach as us without the BP and wishes he did have it.  Cost wise,  wow lot of bucks but if you are satisfied, it's probably worth it  it not  is isn't  matter of choice. Same as cars  I wouldn't;t drive a small car across the street,  yet a lot of people do  matter of choice.

 

[Gary RV_Wizard]

Flytyer,
Which Workhorse chassis do you have? You mentioned a 4 speed Allison transmisson, but the Workhorse with an Allison is a 5 speed or now a 6 speed (in the W20/W22 series Workhorse).  Workhorse also makes a P32 chassis with a 4 speed GM Hydramatic transmission and the same 8.1L engine as the W series, but that's not an Allison.

In either case, there are several sources for improved headers and such that give some degree of performance enhancement to this chassis.  Banks is one and  Gibson is another.  Most of the power gains occur in the high RPM range, i.e. maximum engine output.  I have not seen any first hand reports of increased fuel mileage - in fact, most reports say there was no change at all in economy - just more responsive power.

There are also multiple vendors of "chips" that purport to increases perfromance.  I am somewhat skeptical of the results of these on a motorhome chassis (which is tuned differently to begin with), but there are reportedly benefits in pick-ups and SUV's with the 8.1L engine.