Rowdy Sol Report post Posted June 30, 2021 I have a 2011 Tiffin Class A with a Maxxforce 7 engine detuned to 210 HP. Is there an upgrade path to improve performance on this engine? Share this post Link to post Share on other sites
dickandlois Report post Posted June 30, 2021 37 minutes ago, Rowdy Sol said: I have a 2011 Tiffin Class A with a Maxxforce 7 engine detuned to 210 HP. Is there an upgrade path to improve performance on this engine? Rowdy, Welcome to the FMCA Forum ! Think you need to offer some more information regarding the drive train! What trans mission is installed in the Coach? The biggest problem with increasing the Engine HP, is that going this way also increases the Engine Torque out put. Should the transmission not be able to handle the added HP numbers , You need to change the transmission, Drive train component's and maybe the rear axle and that can continue on and on !!! Rich. Share this post Link to post Share on other sites
rayin Report post Posted July 1, 2021 (edited) If you have an Allison A/T here are the HP and torque parameters of each one: https://www.allisontransmission.com/docs/default-source/marketing-materials/vocational-model-guide.pdf?sfvrsn=1bf83f1d_19 While searching for that I discovered many OTR truck forums with discussions of various problems with this engine in power units. Perhaps that's why your engine is de-rated. Edited July 1, 2021 by rayin Share this post Link to post Share on other sites
manholt Report post Posted July 1, 2021 The 2011 Tiffin Breeze in question, is a Maxxforce 6.4L V-8 from 2007, with 2010 EPA. 215 HP @ 2600 rpm, 560 torque @ 1400, Allison 1000. Powerglide chassis, built for economy! The max HP for that engine is 230/625 used by other coach brands! The coach comes in at 22,000/26,000 with a CCC of 2,300 and has a 60 gal fuel tank! Share this post Link to post Share on other sites
wildebill308 Report post Posted July 1, 2021 19 hours ago, Rowdy Sol said: I have a 2011 Tiffin Class A with a Maxxforce 7 engine detuned to 210 HP. Is there an upgrade path to improve performance on this engine? Welcome to the forum. Unfortunately the only upgrade I see involves upgrading the whole coach. The only good news is right now used coaches are bringing a premium price. I have friends who just sold a 2+ year old Tiffin for what they payed for it in about a week. Good luck Bill Share this post Link to post Share on other sites
jleamont Report post Posted July 2, 2021 I would trade it in as already recommended. I have had so many of those open in my previous career and none were pretty. There is an extremely weak foundation especially with its multiple piece block that bolts together and small light weight connecting rods not much heavier than a gas engine. The Ford version squeezed 350hp and 650lbft of torque but there were some bolt on differences and they didn’t stay together for long. I’d rather hang in the right lane than pick up pieces of my engine off the highway. Keep an eye on you oil, if the level starts to rise change it immediately, they are notorious for adding quarts of diesel fuel to the crankcase, this is by design. Let me explain, when it goes into regen it over fuels the two rear cylinders and it washes those cylinders with copious amounts of diesel, the intent is to flood those cylinders and push it out and down the exhaust through both turbos and into the Particulate filter. Any engine guy is cringing right now, hot turbos and exhaust don’t like liquid flowing through them nor does the crankcase like that much diesel in it. Share this post Link to post Share on other sites
Rowdy Sol Report post Posted July 6, 2021 So it appears as I look at the specs for the Allison 1000 transmission that it can safely handle a reasonable power upgrade. I am considering bumping the power from 215 to the rated 260 for the 2011 Maxxforce 7 engine. The question is whether there is any easily available upgrade route to follow. I had a duramax diesel in the past that was easily upgradeable by simply replacing the engine control computer. Is such a thing available for the Maxxforce 7? Share this post Link to post Share on other sites
manholt Report post Posted July 6, 2021 IMHO, all you'll be doing is decrease, by a couple of seconds, the time it gets you to max torque! The torque will remain the same. You get the same result by downshifting to 5th gear. Read Joe's Certifications, then re-read what he wrote! Share this post Link to post Share on other sites
rls7201 Report post Posted July 8, 2021 I believe the Maxxforce engine is the same V8 that Ford over tuned and stretched the head bolts, thus blowing head gaskets Precede with caution. Richard Share this post Link to post Share on other sites
