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Pathetic Towing performance...

restoguy

restoguy

Active Member
Messages
380
Reaction score
40
Location
NW Kansas
Long story short...I pulled a trailer from Houston to Denver and was disappointed with the pickup the whole way. Any help from the crowd to get this corrected would be greatly appreciated!

To give you some info to work with, It's the '99 in my signature. I was fairly happy with the way it ran solo, but I hadn't had the chance to pull anything with it yet. I bought a trailer at auction in Houston so I went down there to get it. The trailer is a Pelsue FOST (you can check it out on their website). Mine is a 94 model so it's just a little different than the one they sell now, but almost the same. It's 7x12 double axle and around 7' tall plus an A/C on top. The tag says it weighs 4135 dry. It trailed nicely but pulled like an anchor! There's no way guys can pull 5er's with a 6.5 if they all pull like mine! On the flat I pulled it at 70mph, seeing 11-13lbs boots and 900F EGT (pre turbo). Any kind of a hill and the egt would climb to 1200 and I'd have to back out of it. Boost would peg my 15psi gauge. I had some wind in spots but not the whole way. I got 11-12mpg on the way back. Unloaded I usually see 16-17. One good hill in east CO I started up at 70 with 1050F egt and reached the top doing 43mph at 1100F egt. That's not much of a trailer for the thing to struggle so hard. WTF? Is it my tune or something else? Time to park the 1 ton and start using the 1/2 ton again?
 
Upon reading my sig, I should clarify a few things. I don't have the Fluidampr, HX40 adapter, Water injection, or HO injectors installed. They are all at home waiting on me to get time. I do not know the history before 289K miles or the age of the pump/injectors. It starts good down to 0F and doesn't smoke more than it should. Timing could be advanced a little but it's not way off.
 
1550F? That seems really hot to me. I thought 1200 was kind of the limit before you're worried about things starting to come apart inside. I forgot to mention that the ECT would rise a little but never broke 200-205. I have a Dmax fan on the original clutch and a set of brand new Delco 195 thermostats. The clutch definately seemed late-to-the-party. The temp would be back at 195 before you'd hear the fan fully on, but it was doing it's job before that enough to cool things down. I feel like if I had any bigger trailer and I wouldn't have made it up some of those hills!

I also think it shifts into OD too soon. About 52mph, and it drops the RPM to 1600 and just kills the power.
 
Reading your post assuming you had a better turbo I though you were letting EGT hold you back. On edit it's the factory turbo holding you back while towing. A HX40II or ATT turbo on your engine and wind it up on a grade and you'll sell the "gutless" 1/2ton. ;)

1550? Imagine what the cylinder temperature is before the 21:1 compression lets off. Yes, it scorched the turbo blanket on the ATT turbo. Yes the EGT was sustained and the engine is running still 4 years later. EGT limit on a 6.5 is a busted myth! I even crossed the imagined EGT limit with the factory turbo every weekday. This EGT myth causes nothing but heartburn.

After best effort tuning I was able to manage EGT of 1350. Again ECT with a aftermarket turbo is the real number to worry about and cooling system load is reduced with a better flowing turbo.
 
Hahaha, turbo, I got it! I have an ATT sitting at home but I need the turbo-intake coupler... And I think it might not be the best turbo for my usage. I'm leaning more toward an HX35/40 hybrid. I've had this pickup since 07 and this is the first time I've towed with it. That should say something. However I would have used it before now if it was always ready to go, which it wasn't for a while when the engine was down. I also have another turbo I want to test, but I need to make an exhaust adapter for it and I'm just too busy right now. I guess I didn't blame the turbo because I didn't see RPM's over 2600 or so. I thought the big drawback to the GM8 was that it dies at higher rpm, say 2800ish. My problems seemed to be lower than that, especially when it would shift into OD and drop down to 1600. I started manually shifting it into 3rd while going through town and keeping it there until it reached 2800, then popping it into OD. Pulled much better that way.
 
What about the guys that pull 5er's with these pickups. What do they see for mileage and performance? I have a friend that has a 36' toy hauler that probably weighs in the neighborhood of 12K and I've considered asking to borrow it for a weekend, but I can't imagine how I could pull it after the trip with this fiber trailer. He pulled it with his 2010 dodge and got 12pmg. I know it's not apples to apples, but I expected different with this little trailer. Maybe I expected too much?
 
WarWagon said:
A HX40II or ATT turbo on your engine and wind it up on a grade and you'll sell the "gutless" 1/2ton. ;)
Click to expand...

I just couldn't... That pickup is loved, just like my diesel. But I know what you're saying. It is, however, time to get the 334 into that Z71 and see what it will do! Where can I buy some time?
 
You have turbo to fix your problem (ATT) slap it on there! Will take 3 hour max. A tune will get the most from it, but just the turbo alone would have raised your MPGs, lowered EGTs and ECTs
Better fuel delivery will help too.
 
I know how you feel, I traded "ol blue" for the dually and the stock dually is a sick pig with less than half the load, can't wait to get the new motor done...
 
I remember reading about one of the Suburban drivers with a freshly installed ATT, good tune, and other mods got 10 - 11 pulling his ~30' Spartan. So if the '99 3500 has 4.10 rears, that mileage is pretty good considering the extra windage.

Like AK mentioned, drop it into direct (3'rd) if you are on anything other than a flat.

Regarding advancing the timing, am presuming the question is whether to do this by rotating the IP. Consider leaving the IP alone (or more specifically OE TDCO position of -0.75) and let the ECM control the advance like it should. There is a lot of passionate debate about advancing the timing where I remain unsold that it is worthwhile in an OBD-II system seeing as the computer is going to control it anyway. So, just get a tune with fuel and timing curves where you want them and leave the IP in the OE configuration.
 
Get that ATT on there! If your really worried about the lower end after the tune, you can have it all with a QSV. 2200 rpm is the gm"x" choke point not 2800.
 
I've pulled 1100 gallons of fertilizer (11lb/gal) in a nurse trailer with a bone stock 94 CCLB 6.5. Speeds were low due to the trailer having no brakes, but with that in mind, I thought my pickup with tune and exhaust would drag that little fiber trailer on its side and not sweat! I spent most of my trip back thinking I really made the wrong choice not to put a Dmax in this pickup when the motor went down a few years ago. I'll get the ATT on there and try again. Maybe I can find an HX40II (or HX35) to try with the adaptor I bought.
 
What is my Heath tune going to do with the ATT? Is it going to smoke real bad? (I HATE 'rolling coal'. Don't even get me started on that topic) My crossover pipe is heat wrapped so it shouldn't cool off as much as others. Maybe it'll help light that turbo sooner?

On the upside, I thought the engine braking feature Bill puts in his tunes worked pretty well. Better than I expected for just keeping the TCC locked up on de-cel. I just want it to stay locked longer, like down to 25-30mph instead of 42.
 
Just out of curiosity, what turbo do you have that you want to test. There are a few people that have different turbos besides the att & hx you see around here.
 
I think it's a TD06E (or maybe that's an H on the end). It's the turbo that came in the Banks 6.9/7.3 kit. There were two different ones, mine is the wastegated version. No one seemed to have an opinion on it before. I got it pretty cheap, so I figured it was worth a try.

I really think that an HX hybrid or an HX40 with a small exhaust housing it the ticket for the way I use the pickup. At least until someone makes an affordable HE351vgt controller that works with my 6.5!
 
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