MAX. TOWING CAPACITY - Suburban 2500; 4x4, 6.5L Turbo Diesel

[GMC Hauler]

Would anyone out there know the MAX. Towing Capacity of my 1996 Suburban, 2500, 4x4, 6.5L Turbo Diesel?????

When towing my 9,000 lbs Travel Trailer up a hill, the truck slows down to about 30 mpH and there does not seem to be any "juice" left in her? The truck has the 4.10 Gear ratio.

Am I towing too much? What can be done in order to improve the power?

I just recently installed a aFe stage 2 Performance Air Intake Kit which helps a lot already in regards to power, I will install a 4" Exhaust system next. Will that help or does anyone have any suggestions how I can improve the power while towing any further?

Thanks in advance.

I have the same rig as you and about the same tavel trailer. Read my sig line for some of the things you will need. The proof is here: http://www.thedieselpage.com/members...es/DIY-CAC.htm

Roger

[rustyk]

For comparison, my motorhome (with the AMG 230 HP engine) can generally pull, at 16K lbs., a 6% grade at 40-45 mph (3200-3500 RPM), and is EGT-limited. I think my diffy is 4.73. That's more weight than you're pushing, but OTOH, mine is all mechanical (for a reason...)

[moondoggie]

Good Day!

You mentioned no smoke at any time, so your boost must be working - you only get smoke if air is short or fuel is too much.

There's no way you can see the radiator debris that's been described until you get stuff out of the way. My brother's a mechanic - his theory is that the oil & tranny coolers slow down the bugs & stuff, & they then stick to the front of the A/C condensor or radiator. Both my 95s had what appeared to be perfectly clean A/C condensors until I pulled off the grill & moved the coolers out of the way - the condensor was completely plugged behind both of them, & there was no way to see this until I did this work.

Bigger exhaust - about the only power mod you dare do to a 6.5 without gauges. The most important thing is getting an aftermarket 3" downpipe to replace the stock one, which looks exactly like it fell off & got run over, several times. For the rest of the exhaust system, 3 1/2" is more than adequate; 4" is overkill, but if the price is right, who cares?

Gauges - EGT & boost, minimum. With a properly-mounted EGT gauge, you can be quite sure of not melting down. You'll likely find yourself pulling hills with your eye glued to the EGT gauge, especially if you later re-flash your 'puter. (Re-flash is so named because the 'puter's program memory is flash memory. It doesn't go away when power is removed, so disconnecting the batteries has no effect on it - the program's still there.)

Now you can start to play.

Inter-After-Whatever cooler - I think Jim mentioned elsewhere that there's an article in the works that describes a ~ $400 intercooler. If this is so, it's probably the single most effective thing you can do to dramatically increase the safety margin of adding more fuel (re-flash). This will almost eliminate the 'puter defueling due to too hot intake air temps.

Foolers - you can buy a boost fooler that tells the 'puter that the boost is lower than actual, which will disallow it from defueling & dropping boost. You can buy a MAP fooler that tells the 'puter you're at high altitude when you're not, so boost comes up quicker & higher. You can (I think) get a reflash that will take care of both, although I can't name vendors - ask our advertisers, eh?

Fan - JK sells a fan clutch that comes in at a lower temp, & is calibrated, so all of them he sells reliably come in at the same lower temp. Do some searching - there's been lots written about different fans that can be used, although JK's clutch on a stock fan might at least be a good place to start. Actually, if you get your radiator, condensor, etc cleaned up & 180° 'stats in place, maybe that's enough for awhile, eh?

Keep searching, buy the old article reprints & read them (best investment I've made, other than joining the Page).

Keep us posted & Blessings!

[Jochen Woern]

Thank you very much moondoogie.

[sparkylisle]

Would anyone out there know the MAX. Towing Capacity of my 1996 Suburban, 2500, 4x4, 6.5L Turbo Diesel?????

When towing my 9,000 lbs Travel Trailer up a hill, the truck slows down to about 30 mpH and there does not seem to be any "juice" left in her? The truck has the 4.10 Gear ratio.

Thanks in advance.

I'm planning on changing the diff gears in my 1999 k2500 Suburban and I was told by the shop foreman at Truck Parts Specialists that the 14 bolt rear axle in 2500 Suburban is the 9 1/2 inch version not the 10 1/2 inch version found in trucks. If that's true, thats why our Burbs have less towing capacity than trucks.

[Jochen Woern]

One more question moondoggie:

You stated: "Bigger exhaust - about the only power mod you dare do to a 6.5without gauges."

Well, I also have installed a "afe Stage 2 Performance Air Intake Kit", will this cause a problem without the Gauges, I hope not.

In regards to the Exhaust System, is a system "turbo back" sufficient, or do I also need to change the cross over pipe?

Thanks in advance.

[moondoggie]

Good Day!

"Well, I also have installed a "afe Stage 2 Performance Air Intake Kit", will this cause a problem without the Gauges, I hope not." Oops - in a hurry. If it provides more air to the engine (which I'm sure is why you did it), it can only serve to drop EGTs, although likely only a little.

"In regards to the Exhaust System, is a system 'turbo back' sufficient, or do I also need to change the cross over pipe?" I'll defer to actual experts. Almost everything I write is parrotting others who obviously know what they're talking about that I've read here on the Page over the years. I count on positive constructive feedback when I'm wrong, & generally get it, which is good for all.

Some folks get a ceramic-coated crossover pipe, to keep more heat in the pipe; some (I suspect lots) don't. Searching might help you find the answer you want / need.


Blessings!

(signature in previous post)

[AndyL]

With the factory crossover wrapped with fiberglass heat tape I noticed no difference in spool up or EGT. When my factory crossover blew off the truck I installed a nice mandrel bent stainless piece, i again saw no difference that I could measure!

[JSSBurban]

Jochen - I see this post was a LONG time ago but I was hoping you could provide some insight. I just bought a 1999 Suburban 6.5 Turbo Diesel that has been garage kept, looks brand new inside & out and is completely stock with 73,000 miles. I'm hoping to tow a 30' travel trailer (just under 9,000lbs fully loaded) with my family of 5 and saw your post. Did you ever get your Suburban to tow your travel trailer better than what you had indicated in your original post?