Uprating Cat C-15

April 04, 2011, 03:36:51 pm

I have a 2003 Lexa, with a 515hp/1650lb-ft Cat C-15. Working fine now that I have the upgraded copper/brass radiator, replacing the leaking aluminum radiator.
Curious if anyone has uprated their 515/1650hp C-15 to 550/1850, and if any issues/concerns.
I called the Cat RV center to check if there were any software updates for my engine. After some initial serial # confusion (the panel in the vanity lists the engine serial # as starting with 2NZ, but it should be 6NZ), he said there have been three software updates, so I'll take it in to get those updated.
While I was on the phone, I asked if there was any hp/torque uprating that I could do. He checked, and said that I could uprate it to 550hp and 1850lb-ft with a software update only, cost would be 'about $500, depending on how much the shop charges for labour, but it's just hooking up to the computer and entering the password we provide'. He said they'd refund all (but shop labor) if I decided I didn't like it and wanted to go back down to my original tune.
He asked about tranny, I said it's an Allison 4000MH, he said that's a monster so no worries there. He said only other possible problem was cooling capacity. I told him I heading up the grapevine last week, pulled flat all the way up in 6^th gear, and if engine temps ever reached 205/206 range (and intake temp at 135 or so), the fan would kick into high gear, and within 30 seconds I'd be at 190 degrees and 105 or so on the intake. He said that sounds like plenty of spare cooling capacity, I should have no problems.
Just thought I'd check the wisdom of the Country Coach list. I'll also post this on the Cat RV forum.

Jim

2003 Lexa

Re: Uprating Cat C-15

Reply #1 – April 04, 2011, 06:17:49 pm

Yahoo Message Number: 69873

Why don't you get a hold of Gary Obermier at Premiere RV in junction city and ask him. He was CC head engineer around the time your RV was built. If he doesn't have the answer he will know who does. The coaches with 600 HP and above have communication with the transmission so that while it is shifting the output of the engine is reduced during the shift to protect the tranny.
TWI 2004 Intrigue 11731

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