newbie questions 96 6.5 stock...want more umph for towing

[KTM Mike]

Hi all - I own a 96 6.5 - totally stock, running the 4:10 gearing. We bought it used about 5 or 6 years ago - been quite reliable. Prior owner towed a 35 foot 5th wheel with it, logging around 60,000 miles. Since we have owned it, it has not seen the load of a big 5th wheel, - but has done a bit of lighter towing (under 5,000 lbs). Truck currently has about 135,000 miles on it.

We just bought a large(?) travel trailer - that I know is likely seriously pushing, or exceeding the tow ratings of this truck. We need to live with this one for a while before we can manage to replace it, so want to do what we can to get it set up right for it. the trailer is a 06 Weekend Warrior FSC2800 toy hauler, with a stickered weight of 7,800 empty. Assuming that is accurate (not likely I realize), i suspect our loaded weight will be 9,500 ish.

With that as back ground, here are my questions:

1) what would actual tow rating be for my truck (96 6.5 TD, 4:10, Silverado HD, towing package, long bed extended cab 4x4

2) what low cost, bolt on easy type mods can we start with to help this old beast out? I know with off road motorcycles there are normally a million little tweeks you can make for cheap and often get lots of benefit. I know my way around a bike well, but wrenching on the truck would be new territory for me. (not that I cant do it...just new to me)

3) stepping away from low or no cost mods, I did find out about the SSDiesel reprogrammed ECMs - seem to make sense. But what impact on fuel economy can I expect? What are the trade offs to doing such a mod? Go with the +40 hp or +80 hp version?

4) recognizing its miles, any preventive type things to keep in mind? Really no mechanical issues in the past except (pardon my ignorance here!) a warranty item, something related to the injection system? not exactly sure what it was! Common failure item from what i recall.

Thanks in advance! I am glad i found this web site!

Mike

[Hubert]

Welcome to the forum.

Read read read a bit to start. FAQ's are at the top. Decide if you really want to try and upgrade the truck or sell and buy a heavier hauler. And you have to describe either your willingness to do the work or pay for the upgrades. No you don't have to be a mechanic. Most guys like me are average Joes with a decent tool box. Some guys and girls on here are full out gearheads. Just be honest and describe yourself so as to set the pace.

1 Exhaust upgrade
2. Gauges

Tough call which first but no "power" mods w/o gauges. Probably since you are towing that weight I would do gauges first and that way you can see benefit of mods. Gauges are also good for diagnosing things. But the exhaust is fairly safe upgrade and the starting point.

Then a little more boost are all reasonable and cost effective upgrades. Then see if you like performance and reevaluate. More potential but by then you kind of see the picture.

At ~120,000 + miles you are near the bigger maintenance items injectors, timing, and glowplugs. Will still be a good daily driver and decent worker as is for a long while yet but to tow that weight probably needs some maintenance for performance.

[Hubert]

I didn't really answer your questions. The truck will pull that weight ok on level ground. Hills will slow you way down. Even with the basic mods hills will still hurt a good bit. Mountains will be slow going and not recommended w/o gauges and basic mods. Really shouldn't tow that weight w/o gauges.

Gauges being boost, exhaust gas temperature, and transmission fluid temperature (auto).

Also describe how much frontal wind area you have and experience pulling bigger trailers and some expectations. Do you want to set cruise on 75 mph with ac, and forget about it?

[KTM Mike]

Hubert

thanks for the reply. At this point, I guess if i can do some basic mods for under $1,000 that is my plan. We likely will need to use this truck to tow with for at least 1 1/2 to 2 years of about 5,000 to 7,000 max miles per year towing this trailer. After that time frame, we will look to upgrade.

I will continue to look at the FAQ stuff as well.

Willingness to do the work...guess it depends on the nature of it! The basic bolt on stuff - no problemo. I am far from a gear head (two wheel related I am..), but can easily do the basic bolt on stuff.

As I am about to have some routine exhaust work done anyhow, I think i will go down the exhaust path first from the sounds of it. When you say guages first, are you saying even if just exhaust work?

Increasing boost - now that i can see the need for guages. Having not yet read that topic in the FAQ, what is involved there? Is this accomplished with the ECM upgrade perhaps?

Bigger maintenance items - yep...does sound like we need to address some of that stuff as well. Off hand, I suspect we will rely on our local GM dealer f or most of that (ie plugs, injectors etc.)

Thanks again! I am sure i will have more dumb questions!

Mike

[KTM Mike]

Hubert

You posted your second post while I was responding to the first!

We are in Michigan, so mountains not likely an issue! (unless I make a mountain out of a mole hill...).

Frontal area...boy not sure how to describe that. This is not a tall 5th wheel or anything, but it is a tall(Er) tow behind trailer - I think max height is around 12' (with the AC if i recall right) , with the front much lower, gradually sloping to the rear.

Towing experience...not much actually. About the biggest I have towed is our 8x16 enclosed trailer full of dirt bikes etc. (this next comment also goes to expectations) I used to tow that on occassion with a seriously over worked Class C motorhome (92) with a Chevy 350 V8 - yup...it was slow...yup, it dragged waaaay down on hills (the stuff we have here in Michigan) .... but I was OK with it. My hope is to be no worse off, maybe a tick better with our truck and this new trailer than what I was with that old motorhome and our old enclosed trailer.

Expectations...gee what you describe would be nice! But, I am realistic. I have no issue at all setting the cruise on at 65 ish, and pokin along. Would be nice to still have AC...though! Much of our driving is NOT interstates - so we would be doing 55 ish there.

[ronniejoe]

Read the articles in my signature for a good starting foundation for understanding the 6.5 and its performance.

Don't believe the advertised HP claims on any of the chips or reflashes out there. There is no way that a chip alone can give you 60 or 80 hp. See the dyno plots in article 1 and what it took to get to each step. Even if they could deliver that level of power alone, it would not be available for long. High intake air temperatures, high egts and high coolant temp will limit its use.

The 6.5 can be made to tow very well. However, it isn't cheap to do it (much cheaper than a new Duramax, though).

[Hubert]

OK I think that kind of sets the pace. You should be fine with the truck. Just read up a litte about it. Indirect injection, compression ratio, boost exhaust gas temperature etc. Ronniejoe describes things very well and has great talent.

Sorry to waffle a bit. Gauges are important. Probably should be first add on as you shouldn't tow that much weight w/o them. Even stock the truck can melt itself down towing heavy.

The stock exhaust is restrictive. Upgrading that will boost performance and is generally safe if all else is stock. But it won't save you if towing heavy gauges will (like mentioned above stock the truck can melt down towing hard).

Before you spend money on fixing stock exhaust look into aftermarket downpipe and bigger exhaust. Several vendors and sizes to choose from.

I'd say 3" downpipe and 4" exhaust if you don't mind a little extra noise. No it won't be real loud but thats subjective. The turbo will muffle most of the noise. If passangers on vacation are less forgiving then compare other systems. If you have emissions testing and they look for soot trap look into aftermarket systems suited for that. Some gut it out.

I don't know what it really does after 100,000 miles and in comparison to better breathing performance vs what ever oxides its suppose to reduce.

[DmaxMaverick]

Welcome to the Forums!

I suggest picking a vendor, and stay with him/her for the duration of your upgrade. Heath, Kennedy, SSDiesel, etc. All of them have excellent end product solutions, and can be found HERE (http://www.thedieselpage.com/vendors/main.htm). Problems we are seeing is the mix/match attempts, with dissapointing results.

I'll echo much of what has already been said above. Gages! Get the pyro and boost gages in BEFORE you do any power upgrades. Before or after exhaust. Exhaust alone won't cure anything. It will facilitate the other upgrades. A 3" downpipe with a free flowing 3.5" system would be fine for a daily driver and tow vehicle. More power will require more airflow, but a 4" system is at the extreme end. You'll also want to look into the high volume cooling system, if yours doesn't already have it. It depends on when your '96 was built.

If you are handy with tools, consider doing most of the maintenance work yourself. The dealer will cost you many more times in labor than the parts (unless you get them from the dealer). Injectors and glow plugs are like replacing spark plugs. The injectors are simple, and require a special (or not) 30mm socket. Glow plugs are easier than spark plugs. Water pump and timing components are not much different than their gasser counterparts. Parts through the vendors will cost you 25-50% of the dealer cost, and usually for better parts.

[moondoggie]

Good Day!

1st purchase: Gauges. If you can only afford one gauge, EGT. RJ was shocked when he found out what EGT's he'd been unknowingly running.

2nd purchase: exhaust. Consensus seems to be 3 1/2" is adequate for virtually anything you might ever want to do with a 6.5. That's what RJ's got, & he just set the 6.5 Power Pull record, running within 1 mph of an 06 PS & an 02 DMax. Obviously 4" might be unnecessary, but if that's what you gotta have, go for it. (BTW, if you're one of the extremely few folks that doesn't really care for loud exhaust, do a search in this forum for "muffler" - I posted recently about a muffler that is quite a bit quieter than Kennedy's muffler - can't hear it with the windows up, but still has a little rap to it if the windows are all down.)

Then I'd be looking into what everyone here calls "cooling mods." In 97 (?) GM upgraded to a MUCH higher output water pump & dual thermostats; Kennedy & others carry all the parts.

In this modern age, we all immediately think about reflash and/or EPROM replacement for quick More Power. The problem is, you do that with a 6.5 & you'll be glad you've got a motorcycle along - you can roll it out of the trailer & ride for help when your 6.5 grenades. RJ & others have proved that the 6.5 can make very good power with excellent reliability, but you've gotta be careful & do it in the right order.

Blessings!

[sturgeon-phish]

I'm referencing the '96 dealer brochure trailering data. Is your truck a 3500 or 2500? A K3500 ball hitch towing - 8000#, K2500 ball hitch 7000#. K3500 fifth wheel 8000# w/3000 on the king pin, K2500 7000# (or 8000# if you have the optional 8600 upgrade) and 2500# on the king pin.

I am right at the limit towing my fifth. Upgrading the exhaust was a huge improvement. Gauges a must. I ordering mine soon. I have drove very easy because while towing I'm esentially blind to the load I'm putting on the truck. If you have a later '96 you may have the upgraded cooling. look at the thermostat and see if you have two or four bolts. The upgrade will have four bolts for two thermostats. Upgrade to a 97 up intake. Almost as good as the aftermarkets and a lot cheaper. Exchange the air inlets at the turn signals.
Jim

[Robyn]

Let me relate a sad story.
Back in 93 I purchased a 3/4 ton GMC stretch cab 4x4 and it was a great little truck.
It became obvious that with the family and doing HORSE SHOWS we needed a crew cab,
The following season we stopped by the GMC dealer and came home with a new 94 1 ton dually crew cab with the 6.5 in it and 4.10 gears.
We pull a featherlight 4 horse slant load trailer. With all the horses, tack, people ect the truck and trailer weigh in at just slightly under 19K.

The little 6.5 was so overwhelmed it was pathetic. I did the exhaust thing and a few other items that were available at the time but to no avail.
This was a losing battle.
I traded the GMC off for a Dodge with a V10. Much more power but could not keep trannies behind that 8L monster. Went through 5 before warranty ran out. Got rid of the "DOG" (Dodge) and got a Stroke Ford. UUUUUUUUGH what a disaster that was. Just a POS.
All told I spent a truck load of money on trucks, Modifications to make them better and such and then all for nothing. There was not a one of them that could handle the job reliably.
Since that time the Stroke is long gone and I have an old 86 GMC Dually 4x4 that I stuffed a Hand built (BY ME) long stroke 503 in with a well endowed 400 behind it.
We dont use the trailer much now that the kids are gone so the dually usually sits holding the driveway from blowing away.
Anyway, here is what I learned from 3 years of heart ache and loss of thousands of $$$$$$
For not nearly what I spent on pickups I could have specd out a really nice Freightliner Business class hauler with a 310 horse Kitty in it with a 13 speed Road ranger.
This truck would have been 6 place + seating with all the creature comforts too.
No need to modify, no need to sweat the mountains, just hook up and go.
I realize that not everyone can afford to buy a new one of these but they do come up for sale used when folks die off or the kids leave home or someone who needs a tax writeoff gets a new one.
Bottom line, Our little trucks were never meant to do what we ask of them in many cases. I love the 6.5/6.2 diesels but these are not heavy duty beasts of burden they are light duty passenger car, pickup engines and should be looked at with this in mind. If you keep your max gross to around 10K (truck and trailer,camper) they can hack it fairly well with some mods.
You push into the land we were going into and it just isn't going to happen without trouble.
Being in the trucking business I do have some connections. My neighbor asked me to help him get a truck set up to pull his HUUUUUUUUUUUUUUUUUUUUUUUUUGE house trailer. OMG this thing is the biggest 5th wheel I think I have ever seen.
I turned him onto the idea of a Business class truck. I found an International
trailer hauler for sale and it was only 2 years old. Saw it parked in a pasture with a for sale sign. Hmmmmm
My neighbor bought it on the spot. They are on a cross country tour now and due to be home in Oct. He called the other day and is ecstatic at the performance and how well it handles the trailer.

I guess what I am trying to point out is dont expect too much from our wonderful little trucks as they were never meant to due some of the things we would like them to do no matter how much we wish they could.
They will do it but at a high cost and a trail littered with burnt and broken parts.

Best to ya
Robyn

[baddiesel]

the exaust upgrade will help i just did mine what an improvement for towing i went with a 3" downpie 4" exaust took kitty off from warpspeed for 318.00 delivered . it pulls alot better my temp stays at 180 before it would hit 240 i also put a k-n cone filter on it the stock air box is very restrictive . you can also do a manual converter lockup mod that will help for pulling hills

[KTM Mike]

Thanks for the replies everone. I have been away from the board for a bit, but have been reading reading reading as suggested. I also have now gotten in a wee bit of towing our trailer fully loaded.

When I first towed the trailer home from the dealer (empty) seemed OK...actually I was pleasantly suprised. Then finally on Friday I towed it a bit fully loaded - water tank with about 100 gallons in it, 3 bikes in the back of the toyhauler - all the typical bike stuff. Oh boy...seems we crossed some line loaded like that! Clearly, the motor was not up to the task. Temp would bump up to around 240, but if I then backed off (fortunately no realllly long hills around here, would quickly return to 190 ish. (air temps were mid to upper 70s). Had the poor beast floored up one particular hill! On our return trip, we had dumped the water - and it seemed to do much better with just 800 lbs or so less weight. A third tow, with no bikes, but water in (so actually about same weight as no water but with bikes), again seemed better. Again, temp soared briefly, but would quickly recover.

While I would love to go get a for real truck - it just aint gonna happen. So that leaves me making this one do. I have concluded (as you have all suggested!)

1) will do exhaust. Lowest cost seems to be the Jardine (Pinnacle?) on Ebay...what is this Warspeed one - any links to info on them? BTW - I dont want to go straight pipes etc. if i can avoid it - dont want the wife screaming at me all the time in the cab! Specific exhaust suggestions that are gonna be a tad quieter would be appreciated!

2) Will do air intake mods of some sort. I have looked at some pics of the rather restrictive intake, but dont seem to see that on my truck (ie pull cap/snorkle) off filter box - seems pretty open to me? Am I looking in the wrong place? Anyhow, I will do something here to!

3) Yep, I can see the need for gauges clearly now! As I saw my temp guage rising, i kept worrying about what is my EGT? Again...specific suggestions?

4) ECM - boy so many options! Are there any specifically trailering oriented. Is it Heath that makes the MAx-torque or what ever it is called? I want torque for towing, not low ETs on a drag strip. any specific links etc appreciated!

Also, with all this stuff done, what impact can I expect on fuel economy? From what I am reading on the ECMs seems they crank up fuel delivery rates - seems that woudl kill economy? On a recent (short) tow of about 135 miles, towing 1/2 fully loaded (estimated weight at 10,000 lbs), then 1/2 less loaded...call it 9100 or 9200 lbs. got about 9.2 mpg. Actually a hair better than i expected.

Oh, to the question about my tow rating. It is a K2500 According to owners manual, shows 8,000 lbs - I am running the 4.10 rear axle. Prior (original) owner had speced this truck out for towing a big 5th wheel so I am sure it was the higher rating. From what I can see, it is rated same as a 3500 tow rating (3500 has more cargo capacity rating however). I will take a look at the T-stat as well - maybe I have the higher capacity cooling system? that would be great.

thanks again everyone!

[JSteward]

2) Will do air intake mods of some sort. I have looked at some pics of the rather restrictive intake, but dont seem to see that on my truck (ie pull cap/snorkle) off filter box - seems pretty open to me? Am I looking in the wrong place? Anyhow, I will do something here to!

3) Yep, I can see the need for gauges clearly now! As I saw my temp guage rising, i kept worrying about what is my EGT? Again...specific suggestions?

4) ECM - boy so many options! Are there any specifically trailering oriented. Is it Heath that makes the MAx-torque or what ever it is called? I want torque for towing, not low ETs on a drag strip. any specific links etc appreciated!

Also, with all this stuff done, what impact can I expect on fuel economy? From what I am reading on the ECMs seems they crank up fuel delivery rates - seems that woudl kill economy? maybe I have the higher capacity cooling system? that would be great.

thanks again everyone!

These are some of the exact same questions I have. I'm pulling a 7500lb bumper pull 35ft RV (park model). My gas burning 1/2 ton '97 Chevy 350 pulled it no problem, but I wanted the stability of dualls and fuel economy of a diesel. I'll be pulling it about 700 miles in two weeks.

[KTM Mike]

These are some of the exact same questions I have. I'm pulling a 7500lb bumper pull 35ft RV (park model). My gas burning 1/2 ton '97 Chevy 350 pulled it no problem, but I wanted the stability of dualls and fuel economy of a diesel. I'll be pulling it about 700 miles in two weeks.

Sep - looks like we are in rather similar boats! You can see above pretty much what I have learned so far. Since then, I contacted some of the more popular vendors - and asked similar questions. One pointed out a topic i had not really thought of (though it was alluded to in this thread) They strongly suggested no ECM or other power mods beyond intake and exhaust until AFTER cooling system mods. Makes sense to me. (I respect the fact that vendor was basically talking me out of something I otherwise might have went right ahead and bought from him right then.

Have you towed your trailer with your 6.5 yet? I was rather disappointed with how mine did actually. I must say though, I was around 2000 lbs over its rated limit - but I guess I had a rather uniformed idea of "its a big bad diesel...it can tow anything...!!!" Well, yes, it can indeed tow a lot...but not 10,000 lbs. Maybe my expectations were out of line though, or maybe my truck is not currently even towing "up to" what it really should be able to (though there are no known "issues" with it mechanically - it runs well from what i can tell).

As I noted in my prior post - when I towed it empty (supposedly 7800 lbs), it seemed to do OK. But some where between that weight and fully loaded (estimated 10,000 lbs...maybe a tad less) it crosses a line it does not like! (one lesson - load lighter - I wont haul so much water when I can avoid it)


So - sometime in the next few weeks - I will order up the exhaust. A short while later guages. Just yesterday I did some of the air box mods. (look here: http://www.kennedydiesel.com/airboxmods.html no clue if they help an otherwise stock engine) I will do some towing with the exhaust and see how it goes. As I spent all my dough on the new trailer - the cooling system and ECM will have to wait a while.

[JohnC]

what impact can I expect on fuel economy? From what I am reading on the ECMs seems they crank up fuel delivery rates - seems that woudl kill economy?

This is not really much of an issue. Diesel engines are regulated by controlling fuel rate. Add more fuel and it goes faster. What the ECM upgrades do is raise te maximum fuel rate, and hopefully corresponding manifold pressure, but they don't force you to use it. Cruising along at 65 shouldn't be any different after the mods. Of course, if you can't keep your foot out of it, or if you use the new found power to crest the hill at 75 instead of 55, your mileage will suffer.

[moondoggie]

Good Day!

"This is not really much of an issue. Diesel engines are regulated by controlling fuel rate. Add more fuel and it goes faster. What the ECM upgrades do is raise te maximum fuel rate, and hopefully corresponding manifold pressure, but they don't force you to use it. Cruising along at 65 shouldn't be any different after the mods. Of course, if you can't keep your foot out of it, or if you use the new found power to crest the hill at 75 instead of 55, your mileage will suffer." Never stated better. When folks come from gassers to diesels, they're unaware of the significant differences. LOTS of diesel mods not only don't decrease mpg, but actually might increase it a little, AS LONG AS YOUR DRIVING STYLE IS UNCHANGED, which is in most cases unlikely; FEW gasser mods can make the same claim.

Blessings!
(signature in previous post)

[JSteward]

Have you towed your trailer with your 6.5 yet? I was rather disappointed with how mine did actually.


I haven't pulled it yet. I'll have to move again in about a week. Its sure different comming from a gas... my TD can't even catch a wheel in a gravel parking lot. I even put it in low gear and tried to drive in a circle to no avail; just wouldn't spin the tires. Felt like it may not have enough power.

[KTM Mike]

I haven't pulled it yet. I'll have to move again in about a week. Its sure different comming from a gas... my TD can't even catch a wheel in a gravel parking lot. I even put it in low gear and tried to drive in a circle to no avail; just wouldn't spin the tires. Felt like it may not have enough power.

Wow...now that is quite surprising. that is not the case with my truck at all. Only issue I could think of is perhaps the duallys offer soooo much traction...or else you have some engine issues? Does your truck have the 4:10 axle ratio? Maybe the turbo is not doing its thing? There are some basic checks you can do to verify that...not that I know them well enough to tell you what to do though!

[Chuck1]

I,ve noted that no one mentioned intercooler .I,m thinking thats the best up grade for towing .Any thoughts?

[JSteward]

Wow...now that is quite surprising. that is not the case with my truck at all. Only issue I could think of is perhaps the duallys offer soooo much traction...or else you have some engine issues? Does your truck have the 4:10 axle ratio? Maybe the turbo is not doing its thing? There are some basic checks you can do to verify that...not that I know them well enough to tell you what to do though!

It does have a 4:10 ratio. I'm ordering some guages... one of which is a boost guage. It is my understanding that the "boost" is talking about the amount of turbo boost.

I've used diesel trucks at work. I've never seen any diesel with any get-up-and-go similar to a gas burner. I bought my truck for better fuel mileage not for power. ...I don't know, maybe it should be more powerful? I'm relatively new to diesels.