6.5 TURBO IN MOTORHOME

[FENCE MAN]

I RECENTLY JOINED THIS FORUM AND JUST PURCHASED A 1996 MOTORHOME WITH A 6.5 TURBO DIESEL

I HAVE A 2002 DURAMAX AND ALLISON IN MY 3/4 T. 4X4 AND GOT A PROGRAM FROM HYPERTECH

HYPERTECH DOES NOT OFFER A PROGRAM FOR THE P30 CHEVY CHASSIS IN A MOTORHOME

ANY IDEAS????

BILL :rolleyes:

[markrinker]

Lots of 'em! You have come to the right place!

If you haven't already, start here:

1) Search and read forum postings on performance enhancements here.

2) Read the numerous articles posted about getting MORE POWER out of your 6.5 on www.thedieselpage.com (http://www.thedieselpage.com)

3) Buy bound reprints of previous year articles on same, you'll find everything you'll need to know to make 10%-30% more torque/horsepower. It all depends on what you want to spend. turbo@thedieselpage.com will help you find the right articles to read.

Some givens:

1) Unless you have AT LEAST 3.5" inch exhaust with mandrel bends, you can do better in that department. With the length of a motorhome exhaust, 4" is probably a good bet. Certainly its already been done, and somebody can give you the right answer for your make/model.

If GM supplied the stock downtube (crimpled, flattened, and contorted) from the turbo, it needs to GO first. Chuck your cat if you aren't required to be inspected. Chuck the stock muffler unless you know it to be a high-flowing piece, which is unlikely from the factory.

www.heathdiesel.com (http://www.heathdiesel.com) or www.kennedydiesel.com (http://www.kennedydiesel.com) both sell good replacement downtubes. Not sure about who you'll find to bend you a custom 4" exhaust system - probably www.bankspower.com (http://www.bankspower.com) would be a good place to start.

2) If you don't have gauges for boost and exhaust gas temps, add them. Everything else you do will need the information they provide. Ditto on suppliers listed above.

3) The 6.5 responds well to additional fuel and air when it has someplace to go - i.e. good exhaust already in place. Both shops listed above sell replacement chips or reflashed computers with more aggressive timing curves and fuel delivery, depending on your setup.

4) Depending on who's chip you buy, you should follow their lead on boost management. Your turbo is probably set very conservatively, making 5-7lbs on a level cruise. Your GM-8 can easily make 12-14lbs (nominal) to match lots more fuel supplied by a good design chip. (You'll need gauges in place before experimenting in this department.)

5) Cooling mods to keep water temps in check while towing or running hills should be similar to 3500 series trucks that tow. You may need some new hardware in the water pump, crossover neck, fan clutch and thermostat department. Depending on how much room you have up front, the 6.5 will also respond well to air-to-air intercooling, once the previously mentioned mods (fuel and air flow) are in place.

Have fun, ask lots of questions, be ready to explore as there are few motorhome-heads here.

p.s. Buy a spare FSD, remote cooler, and extension harness and mount it in a cool spot where the harness can reach your injection pump (in the hot intake valley of your engine). Find a tool that will help you with the inevitable swap from injection pump mounted FSD to the new FSD you'll have waiting and ready for the day that yours dies and threatens to ruin an otherwise relaxing vacation.

Extra credit: Buy a spare injection pump and learn to install it. You'll probably do that eventually, as well, depending on your luck and whether your motorhome ever received a warranty pump upgrade from Standyne...unlikely...!

[ 09-20-2004, 06:10 PM: Message edited by: Mark Rinker ]

[dstoops]

Mark is RIGHT ON! I would recommend to do the cooling mods first. I didn't and ended up with a blown head gasket @ 130,000 miles. I got my '97 style cooling "kit" from Peninsular Diesel. Check their web-site for contact info. http://www.peninsulardiesel.com/

[rjwest]

You will need to determine if your MH is
OBD2 PCM or the older tpye PCM.

The reason I say this is Moterhomes are givin the
Year that the Moterhome was manufactured, not the
Chassis year. Do not know if this is true in your case. It is possible to have 95 or older chassis.

If The PCM( Powertrain Control Module ) is
OBD2, there is no " chip " upgrade.

The Module needs to be sent away to br reprogrammed.

If 95 or older, a PROM(CHIP ) is available.
The 95 and older has a small cover plate on top
where the prom is installed.

Note, there is a big differance in Diagnostic codes for the 96 newer vs 95 and older.

[FENCE MAN]

I bought this unit from a retired farmer -- it has 39,000 miles and is in like new condition

The unit is a FIRAN COVINGTON LX 32 FT.-- Firan only made this coach for one year -- all weled alumium framework and full artic insulation package

I assume that the P30 Chassis is a 1995

Bill

[markrinker]

Is there a diagnostics port under the dash, below the steering column? You can trace the harness to find the ECM (computer). If it has a small 2" x 2" plate with 2 screws, you have the early model and can buy a replacement chip. If the box (cigar box size) does not have the removable plate, and has two modular plugs, thats the new style, and you'll have to have it reflashed with the new curves.

[FENCE MAN]

It does have the plug in diagnostic port below the dash and to the left of the steering colum

I'll check out the box when I pick it up -- I have it at the chevy dealer right now to replace all the hoses, belts, fluids, etc. -- with 10 years on the rubber age -- I want to make sure all of it is fresh, including the fluids, (engine,trans, and rearend)

Bill

[markrinker]

Sounds like a good idea. Anytime I buy a used vehicle, thats where I start as well. Just the condition of the fluids can tell you alot of the history.

Did you determine the size of your current exhaust? Does it have a cat and muffler combo? What does the downtube from the turbo look like?

[BillCarry]

Bill,

I have a 94 motor home (30 ft. about 14500 lbs loaded)which I bought new (actually ordered built) with a 6.5 turbo. Now has about 118000 miles on it. It was a very early build - I think one of the first P-30 6.5 turbos. Had all sorts of Inj. Pump problems the first couple of years that Chevy tried to fix with various degrees of success. Got a warranty pump at about 85,000 miles and six or seven yars.
PMD was replaced about 45,000 and with the new pump at 85. No problems since.

The exhaust system on the P-30 has nice straight pipes - no crinkles, etc from the tube bender.

Do the cooliong system upgrade - the high flow water pump and associated crossover, etc. The original thermostat is not the dual set up as on the pickups but a single larger thermostat and outlet. Chevy did not change that in '97 when they went to the high capacity pump on the motor home engine. I didn't do the water pump upgrade until I had cracked a cylinder head. Also clean your radiator front behind the A/C condenser.

In general I've very happy with the performance and delighted with the fuel consumption. Consistenly get 11.5 to 12 mpg. Oil consumption has been 1600-1800 miles per quart from day one and has not changed. I use Rotella and change it every 2500-3000 miles. I've thought about power improvements but have always intended to keep this thing a long time and have stayed conservative. One of the first things I did was install boost, EGT and tansmission temp. gages.