This might have been asked before but I'm new to these boards and didn't see it... I have a 99xlt extended cab with the 4.6 auto, and I pull a 3100# race car on a car hauler trailer (not sure about the weight). The truck pulls it pretty good on non-highway speeds. Once I get it up to about 70 mph it does ok but struggles a little when I'm going up a hill and I have to wind it up pretty good. Will a performance muffler and a better intake help any or make it worse? If not, then what are some solutions other than gearing. And I don't haul enough to justify spending a lot of money on it. Thanks
-Casey

 

There's not a whole lot. Usually a performance exhaust hurts the low end torque #'s and hurts towing. You can get a chip that tunes for pulling that would help a little. I think those are $300 or so. Overall I don't think there's a whole lot that can be done on the cheap.

 

That seems pretty typical for a 4.6 with that much weight. I don't know what else to tell you except to upgrade your truck. Good luck.

 

You probably only have a #5000 max load there, so what you are experiencing is what I would call "normal" for your setup.... You ain't ever going to be able to keep from downshifting on the hills.....

Towing at 70, I assume you are in OD? That's fine, but it won't hold it long once you need to put some pedal into it. So you will find yourself in 3rd... Still, not a big deal. If you want to maintain 70, then expect some high rpms... That's all there is to it.

Slow down and the rpms drop. Going up the hills, you'll probably downshift into 2nd. Again, that's fine. That's what the gears are for. If you still want to maintain 70 going up the hills, then you need a diesel....

You can bolt on all the 'easy stuff', but it still won't keep you from downshifting.... The 4.6 needs to rev to get to it's peak numbers. It'll do fine towing at 2500 rpms all day long. It'll do fine at 3500 going up the hills. Just don't expect the same performance you do when you are running empty, or don't expect to keep up with the Power Strokes', Cummins' and (ugh) even the Duramaxs'.....

Good luck!

Mitch

 

But do you think adding bolt ons will hurt my towing? Thats all i'm really worried about

 

Just like every 97-03, intake, exhaust, chip, e-fans, and if all else fails, supercharge!

Might also want to look into an auxiliary transmission cooler if you don't have the towing package. It won't help it perform any better, but it will help it run cooler and extend the life of the trans.

-Joe

 

IMO, if you get bolt ons that are only good for high rpm increases, then yes, that will hurt towing performance....

Stay away from the big dual exhaust setups. Stay away from larger MAF's, TB's and the like. (if you don't want to hurt low end power)

The only thing I've done to my truck is add a drop in K&N filter and a 3" cat back single exhaust.... I've even added taller tires and that's really the biggest killer in towing performance, but for me and what I can tell in the good ol' 'seat of the pants' meter, my truck is performing better then it did when it was stock and running little whimpy 235/70/16 tires!

I can't remember the exact time line of my tire size changes and the mods, but the combo I am running now with over 152,000 miles on the truck IS better then what it was stock and running the little tires....

The biggest difference was the muffler.... I had a Gibson Swept Side setup and running the same tire size and K&N I started towing a #5000 travel trailer. I did OK, but it did down shift a lot, even on the small grades. The Gibson developed a nice little rattle to it (broke a baffle inside) so I had it replaced with a Pro-Flo brand muffler... Basically a straight thru oval design (no baffles!) and it was only slightly 'louder' then the Gibson.. Well, I could tell right away that I had some additional low end grunt, because the hills that I used to downshift on, I was not downshifting any longer... Yes, the bigger grades I still have to downshift, but it's the smaller 'hills' that used to cause a downshift and now the same 'hills' don't...

Yes, I do have the 5.4, so that's gonna get me some more low end then your 4.6, so I can't say what the same mods would do for you, but I just kept it simple, I don't expect to tow like an F350 and I realize I have a 2 1/2 ton brick hitched to my rear end, so as long as I'm not crawling up a hill in first gear, going 20 mph then all is good!

Mitch

 

ok thanks for the help

 

The best thing you can do for towing is put 4.10 gears in it. It will feel like you stuffed alot of pack mules under the hood.

I say that if you have 3.55s. If you have 3.08s or 3.31 you could go to 3.73s and get the performance you want.

I just ordered 4.10s and I have a 5.4. My brother went from a 3.08 to a 3.73 on his ranger, and my dad went from 3.08s to 3.55 on an 93 F150. To me gears are the best bang for the buck for towing. Both of those trucks pulled so much better after the change.

 

Probably the best advice on this thread.

Breathing mods that increase top end power don't necesarily decrease low end power. There are compromises to designs like headers, cams, and intake manifold parts, but putting a 3" exhaust and an intake on there isn't going to make the truck tow worse.

To build the most amount of towing power, you want to increase exhaust velocity (which improves low end breathing). Running a 5" exhaust or dual 3" will reduce exhaust velocity and torque. Mitch's example of muffler change is a perfect example. While his baffled muffler had more "backpressure", it reduced exhaust velocity and torque along with it. When he switched to a straight through, the situation improved.

My suggestion? The number one problem with towing is fuel economy. Since your truck it camping out in the lower gears more, do things to make it more efficient there. I would throw an intake, exhaust and gears on it. Maybe not something as short as 4.10s, but 3.73s would work well. The 3.73s would be like adding 5% more torque to your truck. Make sure to add some sort of transmission cooler, since your truck is probably unlocking the torque converter pretty often, you want something to help combat the heat. You also want to add a guage and make sure you aren't nuking your transmission.

 

He heh, I did that once, but it was an 11% grade that started within 400ft of being at a dead stop.

:santa:

 

As long as you're still moving, everything is ok