More performance out of my 2003 8.1 Workhorse

[LETMGROW]

Originally Posted by Dutch Star Don

You might have other issues.....I had the 8.1 in a 2004 Fleetwood 32' Terra. It was a fricking beast on the hills. There wasn't a grade it couldn't pull at 55+. When towing my 5K boat, it was still stronger than many DP's on a grade.

Don has made some good points in his post. While my coach isn't going to win any stop light Grand Prix races I feel it's quite respectable. I have had more than one person ride with me and comment on the get up and go it has for a gas powered heavy vehicle.
Before running out and spending money on upgrades and add on's I would suggest you find someone with a higher end computer scan and data tool and have them go for a ride with you and look at the real time data from the onboard computer. Many of the sensors on these computer controlled engines can become "lazy" but not enough to trip the "Check Engine" light on. Checking fuel trims, MAF numbers etc. can tell you a lot of how efficiently your engine is running. A slow oxygen sensor can reduce power but still be within the parameters of operation so the sensor will pass it's test when the onboard computer calls for it.
Low fuel pressure can cut power down as it will lean out the fuel mixture but not enough to meet the threshold to trip the CEL for a lean mixture. The fuel trims will show operation on the lean side in the data screens or wave forms on the tool.
Partially clogged Catalytic Converters may show up if the tool operator is monitoring the vacuum on the tool. The vacuum will drop significantly if a converter is becoming clogged up.
This is only a partial list of what the tool's operator should be monitoring and recording but you should get the gist. The drive should be under real world conditions. Up hills, down hills, in slow traffic and at highway speeds. A through analysis will take a half hour and perhaps longer to get a true picture of the health of your engine and all the management controls.
You may need nothing more than a good tune up consisting of basics like spark plugs, wires, new air and fuel filters and a good cleaning of the Mass Air Flow sensor and correct tire pressures.
The age and mileage on the engine needs to be taken into consideration also. A higher mileage engine may be subjected to a stretched timing chain, lower compression, carbon build up etc. The mountains you climb and the elevation changes will factor in to the performance of your engine. Although the onboard computer will offer some adjustments they may not be spot on if there is something else out of range which can negate the adjustments. Everything needs to work in harmony to obtain the best performance.

[deblas]

It maybe that your expectations are above what the coach can do?

Before spending tons of cash and potentially compromising reliability, maybe share with us what your expectations are.

We had a 2003 Bounder 35e (8.1L) for 11 years, pulling a 22' enclosed toy trailer. Lets just say we were slightly overweight (don't need to hear it from the safety police).

Yes, we were slow pulling steep grades, but did just fine in most other conditions, maintaining 65+. That coach never cried on the grades, cooling stayed in check, downshifted to keep the RPMs up and just kept plugging along. That Allison did more than it was built for and never skipped a beat. We averaged around 5 mpg pulling that trailer. I couldn't give you a MPG with the coach by itself.....rarely travelled like that.

Not once did I ever think to dive into the motor.....I contemplated a Banks system but never could justify.

Oh and not pulling the trailer....that dang coach felt like a sports car!!!

Good luck!!

[Isaac-1]

Some years ago I think Brazels (or one of the other RV shops) added a twin turbo setup to a Workhorse 8.1L motorhome (I don't know if it was on a P or W series chassis). No clue how much it would cost to do or how much it helped. there are some photos in this old thread https://www.irv2.com/forums/f22/arti...ng-258069.html

[Flyer15015]

I did the Ultra RV ECM /TCM upgrade to mine, and I just put an aluminum deep pan on the TX, plus a Trans temp gauge to she how she's doing.
I also wired the 2 pancake fans up front to a 3 way toggle switch, so I can use the OEM circuit OR I can turn them on in anticipation of a high load, low speed situation such as slow traffic or mountain passes.
I'm a happy camper.........

Mike in Colorado

[Skip426]

A friend operated a speed shop in the 70’s , big sign on the parts department desk!

SPEED COSTS … HOW FAST CAN YOU AFFORD TO GO!

[dieselclacker]

With the Allison 5 speed, third gear and 3000-4000 RPM is my best friend for mountain driving in our 8.1 powered Allegro. Really versatile uphill or down. Very seldom use second gear, except on extreme grades, and still keep engine RPM within 3000-4000 range.
By watching far down the road ahead, I try to anticipate what will be necessary to negotiate it, and use the proper gear before losing RPM and momentum.

[AKIQPilot]

Originally Posted by johnwekster

This is for some of the gearheads in the group. I have a 2003 Bounder on a workhorse chassis. I struggle in the moutains and eventually, I will need to tow a vehicle.

First question: Have any of you done performance mods on your 8.1?

I was looking a RAYLOR performance products and wondered if it is worth the 5 grand and lot of labor to change out a bunch of componets. They claim 100 hp and about 50lbs of torque over stock. The only thing that scares me is replacing the camshaft. I've never done one before, but im pretty good at figuiring things out. I'm just not sure that 100 hp and 50lbs of torque is worth 5 grand.



Second question: I see a lot of people towing jeeps. Is this the best secondary vehicle? I know I want something light. I towed a small utility trailer and a golf cart and got 6.5 mpg last weekend ugh!



Thank you in advance for any light you can shine on these subjects.

Im with Dutch Star Don. You may have other issues if you’re struggling in the hills without even pulling a toad. I have 2 Workhorse chassis coaches. A W22 Itasca with every bolt on engine mod available and a W24 Adventurer that is stock except for Ultra wires and Iridium plugs. They both roll down the road right close to the max GVWR.

The W22 rips everywhere and rarely has any issue with any grade up to 9%. It gets great fuel economy driving 65mph on flat ground, 8mpg easily.

The W24 is stock and 2000lbs heavier. I rarely drive it without pulling the Wrangler so that puts us closer to 29,000 rolling down the road. It does fine on grades up to 6% but above that the extra weight really slows things down. I dont get in a hurry and try very hard to keep the RPM between 3200 and 3400 when I need the most efficient use of the power available. When in the hills out west I just tuck in with the Semis in the right lane and go whatever speed they are going. I would hold up traffic if I were to try to go up +6% grades in the left lane while loaded near the max GCWR. Ive never gotten less than about 6.5mpg completely loaded in the Adventurer. I typically get just over 7mpg completely loaded and towing on flat ground driving 63-64mph.

There is no doubt I would love an extra 100hp in the adventurer but that would come with a price tag and the economy would suffer because I will be more apt to stand on the throttle up hills instead of just taking it easy like I do now.

Your current performance sounds suspect to me. Iridium plugs an Ultra wires along with a good cleaning of the MAF would be the first thing I would do. Get a good Scan Tool to see what the ECU is doing.

[dizcom]

For your second question, the Jeeps are easy to rig for towing and to ready when it’s time to tow. Newer ones are lighter and handle better than older ones. Having one, I can say it’s very convenient and we love having it with us.