Palazzo 33.2 is gutless!

[HaRVey]

I need to know if all diesel RVS are gutless or just Thor Palazzo or if something is wrong with mine.

I had a Thor ACE 29.2 before with 5 Star tune and it would kick down and accelerate just like a normal truck. Before that I had a 2006 Ram 2500 with 5.9 Cummins and towed a 16k trailer and could pass anyone, anytime and do 70 up the Grapevine (steep grade north of Los Angeles)

My new 2018 Thor Palazzo will not automatically kick down more than 1 gear (6 to 5) and I have to manually downshift to keep the RPMs at 1700 or higher to even keep 65 mph on a mild hill, and usually only maintain 55 mph!

They had to replace the turbo (VGT) before I took delivery and the Freightliner service just called and said Cummins advised there is a TSB to upgrade the turbo because of some reliability issue.

Has anyone experienced the disappointment with power and heard of this Cummins VGT replacement issue.

I'm praying the turbo is the issue with power, bUT it's not throwing any codes but this is soo gutless I can't believe everyone just accepts this.

Any thoughts?

[Beau388]

Your ACE weighed about 18,000 lbs with 320 or 371 hp Your Palazzo weighs about 26,000 lbs with 300 hp. 8,000 lbs more weight with a little less hp.

[HaRVey]

That doesn't explain why my 8,000lb 2006 Ram 2500 towing a 16,000lb trailer would run circles around this pig...
and the weight on the scales is just over 24,000 fully loaded so about the same as my 4x4 truck/trailer combo with a 3.73 final drive and 35" tires, verses the 5.13 final drive in the Palazzo and 5 speed auto verses 6 speed Allison...
By numbers, this RV should be a better performer.

[16ACE27]

Originally Posted by Beau388

Your ACE weighed about 18,000 lbs with 320 or 371 hp Your Palazzo weighs about 26,000 lbs with 300 hp. 8,000 lbs more weight with a little less hp.

But a ton more torque. What you describe does not sound normal for a DP motorhome.

[HaRVey]

That's why I'm hoping other DP owners with past diesel truck and trailer experience can weigh in and let me know if im crazy or not.
Thanks

[TurnerFam]

just crazy I suspect

85,000 miles over 4 years and no issues
but I also don’t care or concern over whether I ‘scream’
up mountains or not - I’m not in a race, and don’t know
why anyone in an RV wants to be

I’ve delivered many new coaches, both ClassA gas and diesels, and formerly
owned a Dodge turbo with 40’ fifth wheel... they all get you where you are
going - but I suppose some will never be satisfied and will charge that everyone
that owns one of ‘those’ must be somehow dissatisfied...

I am not, I am very happy : )

[captmetal]

it is a motorhome, not a corvette

[HaRVey]

Not expecting a race car, just expected something close to the same performance as a 12 year older truck/trailer with equivalent load.
Since this is my first DP, I'm hoping someone with relevant experience could give me an idea if something is wrong with mine.

[lo-tek]

I have the 36.3 with the 340hp / 700 ftlbs torque and it does ok. I've never tried to time a 0-60 stomp though.

[Bob Denman]

How many miles are on the rig?
It's a diesel; with a very healthy compression ratio.
Give it some time to "loosen-up": it may surprise you.

[brucev]

Could it possibly be partially perception? I've never owned a diesel but I believe they are known for their torque where as the gas V10 will rev at higher RPMs. Also the F53 being up front is loud and you can almost feel every moving part as they vibrate.

If you are sure it truly is underpowered, there are many performance upgrades available for diesels too.

One example for Cummins.
https://www.parleysdieselperformance...20%7C%20%24799

[Bob Denman]

I agree: the power deliveries are just about as different as they can possibly be...

[HaRVey]

Thanks to the folks who took my post for what it was meant to be, an experienced gas RV and diesel truck & trailer owner with concerns over comparable lack of power to the point I dangerously impead traffic in the slow lanes up a grade without lots of manual intervention and preparation.
I do not expect it to perform like a sports car or compete 0 to 60 with anything but comparable weight and power vehicles which it currently does not (not anything I have owned)
I was contacted by the shop that did the pre-delivery work that they received a replacement VGT from Cummins as part of a recal, so I'm hoping that is the problem and solution.
I will post an update after the repair for those that care.

[bevedfelker]

I'll be right up front and say I know squat about diesels -- but your saying it only steps down one gear sure does not seem right to me.

[brucev]

Hopefully that will do the trick. It should not be that under powered.

[Bob Denman]

As odd as it sounds : at least they found something to work on!
I hope that it solves the problem for you!

[Chuck and Mary Ann]

Was there any follow up on how the correction worked out?

[Bob Denman]

So... When are we going to start drag-racing these beasts?

[HaRVey]

The shop that did the original (pre-purchase) VGT controller replacement appearently did not use Cummins authorized OEM part so had to replace it with the correct one in order to get paid for the warranty repair (new Cummins rule since Oct. 2018). The service company was not forthcomming with why I had to bring it back, but i called Cummins and found out.
At that same time Cummins told me about the option to have the ECM prigram upgraded to the "360hp tune" which they said was a Cummins authorized and warranteed optional program and can be completed by any authorized Cummins service center using their InSite diagnostic tool.
The tune changes the hp and torque from (300/640) to (360/800) and cost me ~$500 and was worth every penny.
No drag racing or autocross for me (at least not in my RV), just stress free driving the speed limit, not holding up traffic dangerously up mountain roads, and being able to pass those that do safely and efficiently now, thanks to the Cummins "360hp tune".

[Long & Winding road]

Yeah, how did it work out for you?

Lots of computer tunes for Diesel engines these days.

Can you get one for your DP?

I bet you can and it should offer you a little more HP and a LOT more TQ. Most tuners for diesel truck engines advertize big TQ gains.