Upgrading 350 Cummins ISL

[ricere]

I have a 2006 Kountry Star DP with a Spartan Chassis and a 350 Cummins ISL. I talked with a gentleman with a similar coach as mine who had his 350 hp and 1050 pounds of torque ISL increased to 400 hp and 1200 pounds of torque with simply a computer program change. He claimed much more power and increased fuel mileage.

Is it that simple? Is it possible I can have that done to my coach and not void the warranty?

Thanks for any info on this subject.

[ricere]

I have a 2006 Kountry Star DP with a Spartan Chassis and a 350 Cummins ISL. I talked with a gentleman with a similar coach as mine who had his 350 hp and 1050 pounds of torque ISL increased to 400 hp and 1200 pounds of torque with simply a computer program change. He claimed much more power and increased fuel mileage.

Is it that simple? Is it possible I can have that done to my coach and not void the warranty?

Thanks for any info on this subject.

[Route 66]

In many cases reprogramming the ECU is all that's required.

If Cummins does it, it will probably cost a couple of thousand dollars, and they will warranty it.

If not done by Cummins, it will be cheaper, but there could be warranty issues.

I suggest investigating both ways.

[ricere]

Thanks Dirk.

[Ed-Deb]

Dirk is correct.

Cummins can uprate the ECU (increase power and torque) on most models. You will pay for this service and also pay an additional fee for retaining the warranty.

You can use after market products to acheive similiar results. Some products will be cheaper than the Cummins uprate and some will be more expensive.

The real difference is that with the Cummins ECU uprate you can retain your warranty on the engine.

My preference would be to use the Cummins ECU reflash and maintain my warranty.

Ed

[ricere]

I talked to a Cummins tech this morning and he informed me they could indeed reprogram my 350 hp ISL and make it a 400 hp ISL and keep full warranty. The cost, $2,500.

But, if my engine was out of warranty, they would do the exact same programming and the cost would be $350.

Upon questioning him about the differences in price of increasing the hp of an ISL in warranty vs one out of warranty, I reminded him that the 400 ISL is virtually the same engine as the 350 ISL and the increased power should not affect the engine life or reliability. He agreed with that, but added the 400 ISL sells for least $2,500 more than the 350, and you can't get that extra power without paying the price.

I guess if you want power, you have to pay.

[Route 66]

The higher the horsepower output of the engine, the more stress is placed on the engine, and there is a greater chance of engine failure.

That's the warranty issue.

[Scottsdale]

When you go to Lee's RV and build a Kountry Star, the Spartan Mountain Master chassis w/400HP Cummins ISL engine is listed at an option cost of $6,821.

Are you getting more than just the computer program change for this amount?

[Route 66]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> When you go to Lee's RV and build a Kountry Star, the Spartan Mountain Master chassis w/400HP Cummins ISL engine is listed at an option cost of $6,821.

Are you getting more than just the computer program change for this amount? </div></BLOCKQUOTE>

You are getting an entirely different engine.

The standard KSDP engine is the 8.3 L ISC rated at 360 hp and 1050 lb-ft of torque.

The optional ISL is 8.9 L and rated at 400 hp and 1200 lb-ft of torque.

[ajbjrvers]

To; Ricere

Re; 350 to 400 hp ISL

Right after I took delivery back in 2002, the Cummins tech put the computer on my 400 ISL.
the read-out showed 370 hp, I had paid a lot extra for the 400 hp.

After checking with factory re; upgrade, it was determed that the new turbo and many other new parts were installed, but the computer was not re-programed for the 400 hp.

Bottom line, it was more than a re-program to inrease hp.

Hope this info helps

Thanks and Happy New Year

--- Aime--

[ricere]

In 2005 the KSDPs came with an 8.3 Cummins with 330 horsepower.

However, in 2006, I understand the KSDPs had two engines. 36 feet and under had the 8.3 330 hp, and the 39 foot units had the 350 horsepower 8.9 engines. Mine is 39 ft.

All I know for sure is that my motorhome came from the factory with an 8.9 liter ISL Cummins with 350 horsepower and 1050 lbs of torque.
I gave the cummins technician the serial number of my engine, and he said the main difference between my engine, the 370, and the 400 horsepower versions is the computer program. I understand that one other difference (newer 400 hp version from factory) is the exhaust brake, but that doesn't have anything to do with horsepower.

He stated that he could make my engine a 400 horsepower 1200 pounds of torque in about an hour without an appointment. I am not going to tell him he doesn't know what he's talking about.

Also, I met a gentlemen with a 2006 KSDP 3910 who claimed he had this done to his coach and was very happy with the results.

I plan on getting this done, but I may wait until the warranty is gone first.

[Ecker]

What gets lost in these discussions is the impact that increasing HP has on cooling system and transmission. Ignoring the increased fees required for engine mods within warranty, the software uprate can be done. However, the cooling system may not be able to handle heat or the torque converter may not match the tranny P/N. The chassis manufacturer needs to be in the approval loop.

I'll give an example. In 2000, the ISB was raised from 275 to 300 in response to the HP race by motorhome manufacturers sales. This minimal rise in HP required Cummins to produce a more robust block (and thus deny permission to upgrade the existing 275's) and FCOC to change the radiator to a larger capacity radiator and the driveshaft.