2018 Seneca - more power needed

MD3 · 01-22-2019, 12:20 PM

2018 Seneca here and I've already had the transmission reprogrammed to downshift when pulling the hills at 1700rpm and it will hold the downshifts until ~2500rpm before an upshift.

Did anyone try one of the aftermarket programmers or anything to increase the torque / Hp on a Seneca ?

I'm not expecting crazy power but I'd really like to be able to hold atleast 50mph on the hills in southern CA. The 40mph up the hills and zero passing power is no fun.

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SloPoke · 01-22-2019, 08:04 PM

I drove up the hill almost daily when I lived in So Cal and worked in Vegas, they are not any steeper than what we run here getting out of Salt Lake City, but we are +4,000 feet higher in elevation.

How heavy are you running GCW??? I'd be wondering if your trans-reprogram is hurting your performance?

I have not read one thread on the forum about Seneca owners using tuners... Honestly, I don't see the need for us to spend the money on one.

Robbbyr · 01-22-2019, 08:17 PM

Quote:

Originally Posted by MD3

2018 Seneca here and I've already had the transmission reprogrammed to downshift when pulling the hills at 1700rpm and it will hold the downshifts until ~2500rpm before an upshift.

Did anyone try one of the aftermarket programmers or anything to increase the torque / Hp on a Seneca ?

I'm not expecting crazy power but I'd really like to be able to hold atleast 50mph on the hills in southern CA. The 40mph up the hills and zero passing power is no fun.

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While I have never been to CA, I have traveled extensively in the northeastern part of the country. While my Seneca is no race car, I usually can top the hills here doing at least 55-60 towing my 5,000 lb. Explorer. I wonder if something might be hindering your performance?

I did some tuning research a couple of years ago and the limiting factor seems to be our 2500MH transmissions. We are right at the torque limits with our 340 HP/700 lb/ft torque engines. I think Freightliner more or less validated that argument when they upgraded to the 2018.5 horsepower/torque specs and subsequently moved up to the 3000-series Allison transmission. So I have decided to leave well enough alone.

RVermont · 01-22-2019, 11:53 PM

I shift up at 2450. And downshift at about 1450. I did a reprogram but not sure what others are getting as I know some people have a slightly different reprogram. For the most part the power is fine on 65 mph roads I can move up them okay with little speed loss as it is running fairly high rpm. But if going 55 mph the unit can drop down to 48-50 before downshift and better power band. I believe the transmission is supposed to be able to handle 2600 rpm and I wonder if there is any benefit of picking up that extra 1050 rpm, I would suspect so but haven't not investigated it. Hopefully some others can chime in with their actual shift points.

MD3 · 01-23-2019, 08:46 AM

I'm not sure my GCW, probably something I should check when I get a chance.
Anyone know the procedure or how a person uses the scales at the truck stops ? (drive on then go in, or go in then drive on, ect...)

This last weekend I was towing my trailer which claims on the tag to weigh 4300lbs with a 1800lb claimed weight toy inside and 2 of the 5 gallon gas cans full. RV had 1/4 tank of fresh water and no waste water.

I don't think I was over loaded but maybe I should check that out as to eliminate it as a possibility.

_

SloPoke · 01-23-2019, 08:47 AM

Geez... all this talk about shift points, and I am now thinking that I am totally neglecting my gauges while climbing these grades.

I honestly don't really know where my Seneca shifts at. I know that it feels much differently when in OD versus OD-OFF.

That said: Just for us to get out of town, we have to climb Parley's Canyon (7,120FT @ 6% grade) or Soldier Summit (7,477FT). At the start of the climb, I kick the Overdrive-OFF switch and from there it's eyes on the road and mirrors. Parleys canyon has a miserable entry ramp that has a max speed of 35 - so you can not get a rolling start at this climb, but our Seneca gradually builds up the forward speed until we are rolling along at 55 (truck speed limit). Soldier has two sharp curves at the mouth of the canyon that limit our speed too, but not as bad.

To be honest, my eyes are looking for which gap In the cars I can find to merge left and pass the upcoming truck in the right lane. (We are 68ft long overall, so finding a gap in the traffic is a challenge sometimes) I don't look down at the gauges that often, unless the fan stays on more than 30-seconds or so to bring the temperature back under 200F.

I guess I will have to give Stacy a note-pad and we will track our shift points on the next trip. But I know that we are not going to change what we have now... it works well!

SloPoke · 01-23-2019, 08:58 AM

Another point I might add, There are only two times we have really forced the transmission to downshift - was on the downhill of UT-143 and UT-191. Yes, UT-143 is a 13% grade. I forced the shifter to "2" with exhaust brake on and overdrive forced off - kept it at 26-28 MPH on that miserable downhill without using the service brakes. Had a few cars trying to pass along the way, but there is not many places to pass on that stretch.

RVermont · 01-23-2019, 09:13 AM

I only know my upshift point as that is what shows at the end of the day on the scan guage, the lower end on mine is much lower and maybe i need another tweek to get it shifting at 1700 instead of 1450. That would be a big plus.
The only time I feel I dont have enough power is when someone merges infront of me and they merge at 50 when the speed is 65 , then i have to reduce speed and sometimes it takes a while to regain that speed.

I think there might be a disconnect on what various people expect out their units, one person will experience the same power and speed in two different ways.

To weigh your unit it is very simple . Pull onto the scale until your cab is at the little box. Check to see that each axel is on its own scale pad and push the button. They will ask you what your company and unit number is. Just tell them private coach 1. They will then let you know to come in the office and pick up the ticket. Pay and away you go.

MD3 · 01-23-2019, 10:17 AM

Thank you for the weighing info and how too !

The only reason I have time to look at my gauges is because of the excessive time it takes to climb the long grades while being the rolling roadblock in the slow truck lane.... all while the co-pilot asking if we are going to make it up the hill while kicking her feet like she is in a Flinstone's car.

NO over drive switch in the 2018....

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SloPoke · 01-23-2019, 12:11 PM

Quote:

Originally Posted by RVermont

To weigh your unit it is very simple . Pull onto the scale until your cab is at the little box. Check to see that each axel is on its own scale pad and push the button. They will ask you what your company and unit number is. Just tell them private coach 1. They will then let you know to come in the office and pick up the ticket. Pay and away you go.

If you are like we are... constantly running with a fully loaded trailer - and running right at our maximum GCWR, we are getting our scale weight at the beginning of each significant trip. (good habits include 'Pre-trip inspection' and a trip over the scale)
We also use the CAT scale app so that we don't have to go into the office at all. They give me our weight right on the scale and send a PDF document of the Scale ticket via E-mail in about 20 seconds. Same price and the line at the fuel desk I don't have to wait in.

https://catscale.com/

and before anyone points it out - yes, we are overweight... because we were carrying extra diesel fuel on the trailer.

Robbbyr · 01-23-2019, 01:21 PM

Quote:

Originally Posted by MD3

NO over drive switch in the 2018....-

I can say I am a proactive user of my O/D cancel switch to help me maintain my speed on the grades. I even relocated my switch from its original position to make it less of a reach to use it. I really wonder why Freightliner/Jayco decided to eliminate it, I can't be the only one who uses it! I know when my O/D is off my engine will turn up to about 2,700 RPM. That is somewhere between 62-63 MPH climbing those grades. So long as I don't get boxed in and lose all my momentum I am good on all but the steepest grades. But if I do have to slow way down there is no getting the speed back uphill.

I also have no idea whether the wiring still exists in newer Senecas (pre-2018.5/Allison 3000) which would allow one to install a switch and gain more control over their transmission. I can't recall any owners commenting that they have added the switch. I know other options are available in the wiring, I added the Freightliner fog lamps.

ready2retire&drive · 01-23-2019, 10:50 PM

I use my O/D quite a bit also, the big test will be when I tow the new trailer in the spring as it is a little heaver than my old open deck one was.

SloPoke · 01-23-2019, 11:07 PM

Quote:

Originally Posted by ready2retire&drive

I use my O/D quite a bit also, the big test will be when I tow the new trailer in the spring as it is a little heaver than my old open deck one was.

Gordon, I had to look.... That trailer has an awesome look! NICE!

ready2retire&drive · 01-23-2019, 11:27 PM

It going to interesting to take her on her first run. She is a boondockers dream, two 95 gallon water tanks between the framerails,a 16 gallon hot water tank with propane and 110v water heating, the outdoor shower will keep the grey water tanks from filling. It has a 5.5 psi selve priming pump. Trailer is wired to hook up genertaor to help the propane recover the hot water faster I am sure we start out a touch on the heavy side but showers and washing off the side by side and quad will lighten the water load. Might as leave the mud there and haul home clean units. There are plenty of things loaded to make camp life easier to, small gas powered pressure washer, yamaha 3000 generator and wood splitter. Just had my second heartattck on christmas day, so splitting wood by hand is out.

McGintys924 · 01-24-2019, 04:51 PM

My reprogram did not help me at all until I received the Special Reprogram that Matt Lazier at Allison provided MarkS. Mark discussed this in his posts regarding the reprogram and how it helped some initially but when they spoke to Matt directly he provided yet another program which is wrote helped significantly increase the performance. After calling and speaking with Matt, and providing him with my service location and date, he made himself available and provided this different program. That was on a trip to Illinois with SUV on a uhaul car carrier (didn’t decide trailer or different car at that time) and I noticed a significant difference.

Steve, I also have no idea about the exact shift points

.

jrwldr · 01-30-2019, 02:43 PM

We took ours in and had the engine switched to performance. They come from the factory is economy mode and have very little pulling power.

Purdue 1 · 01-30-2019, 06:59 PM

I have good luck climbing mountains with the overdrive off and try to hit 70 MPH before beginning a climb. Keep the turbo spooled and you can maintain speed.

berwin · 01-31-2019, 06:22 AM

I have an Alante, not a Seneca but thought I'd add that you've never experienced terror until you've tried merging a fully loaded Army truck with a fully loaded trailer onto the Autobahn in Germany. :-)

RyRoRyan · 01-31-2019, 11:15 AM

Quote:

Originally Posted by jrwldr

We took ours in and had the engine switched to performance. They come from the factory is economy mode and have very little pulling power.

Do you mean you had the transmission switched to performance? I have done this, but I have not heard about different approved tunes for the engine.

johnboy · 02-04-2019, 07:40 PM

Just an FYI,
I live in northern,CO, Have a 2017 37TS

I had my Transmission reprogrammed in June before our month long trip / vacation to upstate NY / 1000 Island area .
I had Transwest do the reprogramming, here are my notes from Matt and Transwest:
On the way home after the programming I noticed a BIG difference.

Took one trip to the mountains and there was a big difference in performance compared to pre reprogramming. My wife also drives the Seneca and see too was surprised of the difference.

Going to NY pulling a Chevy Sonic on a car Dolly no issues passing many 18ers with no issue. The reprogramming to performance mode what a great help.

John, We can change your calibration. It is an hour of programming. Will be about 175$ for program.
Thanks.

Jeff Watkins
Service Manager

Toll Free: 800-909-7071

Direct: 303-684-3453
Fax:303-684-3401
jeff.watkins@transwest.com

7550 E I-25 Frontage Road Frederick, CO. 80516

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