2015 Winnebago Forza 34T, 340 HP enough?

[FrontRangeRVer]

Hi, we recently ordered a 2015 Winnebago Forza 34T (actual length is 35'6"), and it has the Cummins ISB 340 hp, 660 lbs torque with the Alison 2100 series six-speed transmission.

It is due to arrive soon, and we are very excited that we ordered this, as Winnie is now including some more standard features than the (already produced) 2015 Forza's, like Auto Generator start (temp,timer,voltage), gas and elec WH, and a new tiltable and swivel TV above the fireplace.

The main question I have is this. We live at 8,600 feet in Colorado, and tow a Jeep Wrangler Rubicon. Is this engine going to make me happy with the power going over all these high mountain passes? I haven't been very happy with my current gas unit with the 8.1 big block.

Thanks in advance!

[Daveinet]

FrontRangeRVer wrote:

Gjac wrote:

FrontRangeRVer wrote:
Yep....after a year of owning the 6.7 turbocharged Cummins, it screams up and down the ALTITUDE induced mountains up here compaired to my 8.1 big block with headers, ECM tune, CAI, Dual exhaust with dual Magnaflows.

And to the guy above that said....you want to drag? Yeah....bring it on up here in the mountains. I will even give your v-8 gas unit a head start. :B

I think Dave has moved on, haven't seen any of his posts lately but he put a 502 CI Chevy which had over 500 HP in his 13,000 lb Revcon, I don't think a 6.7 L with 340 hp and weights 30,000 lbs can get high enough to win that drag race.

at Altitude? A naturally gas engine is a dog up here compared to ANY turbo charged diesel......especially with the torque advantage. HP doesn't do it up here.

Well, since you woke up an old thread, I suppose I'll respond.
I've been at 8000+ ft before - traveling up S St Vrain HWY to AllensPark. DW was following in the Grand Cherokee and complained she had trouble keeping up. Power to weight ratio, and a well designed intake still flows pretty reasonable, even at high altitude. Only thing that slowed me was the corners, and those not much.

If you want to do the math, I loose about 100 hp at 8000 feet. That still leaves me at 320-340 HP pulling 13K lbs. So yah, bring it on.

[DazedNConfused]

DazedNConfused wrote:

FrontRangeRVer wrote:
I am the OP, and after driving our new unit up and down some of these mountain passes here in Colorado, the 340 HP from the deisel wins hands down over my hopped up 8.1 Workhorse. My 8.1 I traded in had the Banks full headers system, dual exhaust with Magnaflows, and an UltraPower ECM tune, and this new deisel blows it out of the water....at least in these high altitudes.

Anyone that says their gas unit is as good as a deisel pusher (in high altitudes) are crazy!

I would totally believe this. When the air gets thin, there ain't much a normally aspirated engine can do to overcome that. The turbo will really help.

I've towed my 12,000 lb fiver up the steepest stuff I have access to in the NC mountains. It isn't as gnarly or high elevation as the Rockies...but there is one 8-mile stretch of an 8% grade that I pulled up this past summer with my 3/4 ton 2012 Super Duty pickup. I didn't know what to expect. It was a total non-event. I tow in tow/haul mode with the cruise control at 67mph while on the highway. Ford engineers are smarter than I am...so I let the truck make the decisions on gear selection and such. On steep grades my truck will downshift out of 6th into 5th...and can accelerate up anything. On the above mentioned grade, when it got really steep, the truck downshifted into 4th gear. There was power and torque to spare...and I had plenty of acceleration. I actually enjoyed towing up that big steep hill at the same 67mph that I always run on the highway -- passing every Class A and tractor trailer that was in front of me. Would like to have seen what one of the big horsepower (500+) big boy class As could do up that hill. Guessing it would have also been a non-event for them.

Anyway...I bring this up...because part of the reason I am entertaining a Class A is to simplify the setup/teardown in hopes of doing more trips...including frequent summer trips to our NC mountains. I'll be hitting that 8-mile 8% grade every time I head into the mountains. I'm looking at a gasser Tiffin. Am sure it will make it up the hill...but was trying to figure out what pace it would be capable of. Guessing engine screaming all the way up...and about 30-35mph will be all it can muster. I'm sure I'll love the Class A -- but heading into the mountains I'll wish I had my old setup. 🙂 Just wish big boy diesel rigs weren't so pricey. College for my girls is on the horizon...and given the choice between sending them off the college and having a gasser Class A or getting a big boy diesel rig and local community college....well...you get the point. 🙂

Of note, when I sent my above message, we were sans motorhome. We ended up ordering a Tiffin Allegro Red 38QBA. It's a diesel pusher bunk model that came with a Cummins 340HP, but was given a chance to get in early on a 360HP engine upgrade that also came with an Allison 3000 instead of the 2500. This is not an option on the 2016, but wasn't on the 2015. of note, the extra 20HP is nice, but where this engine makes a big difference is the extra 50ish ft lbs of torque all across the rev range. It really rips and is a rock star on all but the steepest hills and still gets 9.5 - 11.5 mpg depending on terrain.

[FrontRangeRVer]

Gjac wrote:

FrontRangeRVer wrote:
Yep....after a year of owning the 6.7 turbocharged Cummins, it screams up and down the ALTITUDE induced mountains up here compaired to my 8.1 big block with headers, ECM tune, CAI, Dual exhaust with dual Magnaflows.

And to the guy above that said....you want to drag? Yeah....bring it on up here in the mountains. I will even give your v-8 gas unit a head start. :B

I think Dave has moved on, haven't seen any of his posts lately but he put a 502 CI Chevy which had over 500 HP in his 13,000 lb Revcon, I don't think a 6.7 L with 340 hp and weights 30,000 lbs can get high enough to win that drag race.

at Altitude? A naturally gas engine is a dog up here compared to ANY turbo charged diesel......especially with the torque advantage. HP doesn't do it up here.

[Gjac]

FrontRangeRVer wrote:
Yep....after a year of owning the 6.7 turbocharged Cummins, it screams up and down the ALTITUDE induced mountains up here compaired to my 8.1 big block with headers, ECM tune, CAI, Dual exhaust with dual Magnaflows.

And to the guy above that said....you want to drag? Yeah....bring it on up here in the mountains. I will even give your v-8 gas unit a head start. :B

I think Dave has moved on, haven't seen any of his posts lately but he put a 502 CI Chevy which had over 500 HP in his 13,000 lb Revcon, I don't think a 6.7 L with 340 hp and weights 30,000 lbs can get high enough to win that drag race.

[FrontRangeRVer]

Yep....after a year of owning the 6.7 turbocharged Cummins, it screams up and down the ALTITUDE induced mountains up here compaired to my 8.1 big block with headers, ECM tune, CAI, Dual exhaust with dual Magnaflows.

And to the guy above that said....you want to drag? Yeah....bring it on up here in the mountains. I will even give your v-8 gas unit a head start. :B

[DanTheRVMan]

My experience is the isb is as fast as the isl up hill when no one is around, which makes sense as the weight/hp ratio are similar. The isl does better if you get stuck behind a slow truck the isl accelerates around and back up to speed quicker. I have been happy with both engines.

[Ruf-n-it]

I have had my 2016 Forza 36G with 340 HP Cummins since August. I tow a 2011 Ford Edge and my unit will maintain 55 MPH going up a pretty steep grade. I have no issue with the power which is much better that my gaser. It also gets 2-3 MPH more that the gas model

[Daveinet]

FrontRangeRVer wrote:

Anyone that says their gas unit is as good as a diesel pusher (in high altitudes) are crazy!

You wanna drag?

[alkillion]

Hey FrontRangeRVer, good to see you got your new Forza.
My dealer says they can't keep them in stock, and even offered to buy mine back.
Enjoy

[DazedNConfused]

FrontRangeRVer wrote:
I am the OP, and after driving our new unit up and down some of these mountain passes here in Colorado, the 340 HP from the deisel wins hands down over my hopped up 8.1 Workhorse. My 8.1 I traded in had the Banks full headers system, dual exhaust with Magnaflows, and an UltraPower ECM tune, and this new deisel blows it out of the water....at least in these high altitudes.

Anyone that says their gas unit is as good as a deisel pusher (in high altitudes) are crazy!

I would totally believe this. When the air gets thin, there ain't much a normally aspirated engine can do to overcome that. The turbo will really help.

I've towed my 12,000 lb fiver up the steepest stuff I have access to in the NC mountains. It isn't as gnarly or high elevation as the Rockies...but there is one 8-mile stretch of an 8% grade that I pulled up this past summer with my 3/4 ton 2012 Super Duty pickup. I didn't know what to expect. It was a total non-event. I tow in tow/haul mode with the cruise control at 67mph while on the highway. Ford engineers are smarter than I am...so I let the truck make the decisions on gear selection and such. On steep grades my truck will downshift out of 6th into 5th...and can accelerate up anything. On the above mentioned grade, when it got really steep, the truck downshifted into 4th gear. There was power and torque to spare...and I had plenty of acceleration. I actually enjoyed towing up that big steep hill at the same 67mph that I always run on the highway -- passing every Class A and tractor trailer that was in front of me. Would like to have seen what one of the big horsepower (500+) big boy class As could do up that hill. Guessing it would have also been a non-event for them.

Anyway...I bring this up...because part of the reason I am entertaining a Class A is to simplify the setup/teardown in hopes of doing more trips...including frequent summer trips to our NC mountains. I'll be hitting that 8-mile 8% grade every time I head into the mountains. I'm looking at a gasser Tiffin. Am sure it will make it up the hill...but was trying to figure out what pace it would be capable of. Guessing engine screaming all the way up...and about 30-35mph will be all it can muster. I'm sure I'll love the Class A -- but heading into the mountains I'll wish I had my old setup. 🙂 Just wish big boy diesel rigs weren't so pricey. College for my girls is on the horizon...and given the choice between sending them off the college and having a gasser Class A or getting a big boy diesel rig and local community college....well...you get the point. 🙂

[FrontRangeRVer]

I am the OP, and after driving our new unit up and down some of these mountain passes here in Colorado, the 340 HP from the deisel wins hands down over my hopped up 8.1 Workhorse. My 8.1 I traded in had the Banks full headers system, dual exhaust with Magnaflows, and an UltraPower ECM tune, and this new deisel blows it out of the water....at least in these high altitudes.

Anyone that says their gas unit is as good as a deisel pusher (in high altitudes) are crazy!

[zman-az]

To me, I don't think there is enough power but I drive a 3/4 Diesel and spoiled when pulling loads up grades. My experience is with my 2014 Journey 34B which is about the same weight and driveline combo as the Forenza. I have not done Vail pass but have done 6-7% Grades at 3-7,000ft elevation though out the west. If you expect to be screaming up steep mountain grades, even in the low elevations 40-45mph is about what to expect, and that is in 3rd gear. You will love the quite rear engine and airbag suspension and that is a plus.

[eheading]

Last spring we went from a 40' motorhome with the CAT c-9, 400 hp engine to a 34' Newmar with the little 6.7 liter Cummins. Sure, on a long hill it is slower than the CAT was, but overall we are VERY pleased with the performance, to say nothing of the improved fuel economy!!

Ed Headington

[uralman]

I just traded in a 2009 Monaco on a ford chassis for a 2015 Berkshire with the 340 Cummings. Much smoother ride, even though its much heavier there is more power at much lower RPMs than the ford. much more pleasant to drive. mostly the freightliner chassis rides smoother without the ford buggy springs that feel like no springs at all.