Need to add a little more power?

[KenInCa]

Ok here's my situation, I have a 2003 4.6L 2WD and I use it to tow my 6,000 lbs travel trailer. I have the Edge Evo HT programer and K&N drop in filter with the Gotts mod. I get about 16 mpg with the driving I do.

I pull the trailer about 4-5 times a year and I dislike the fact when I hit a hill, I have to down shift to 1st gear and go 30 mph. If I shift to 2nd, I don't have enough muscle to keep it there as it slowly decreases in speed and have to downshift again.

I don't have any money to throw at it, but I could scrape up maybe $500-1,000. I'm not looking to drag race it up the hill, I would like to have enough power to keep it in 2nd, (going around 40 mph?) so what options do I have. I would like to do most of wrenching myself to keep the costs down, but if it means to open the engine up or change the gear ratio, I'll have to take it in.

Thanks for your help,
Ken

 

[GAINMOB]

exhaust and efans

 

[KenInCa]

exhaust and efans

When you say exhaust, I'm assuming cat back? not just the muffler, right?

Any good cheap efans out there for my truck?

Ken

 

[toms89]

With 2wd... I would recommend a gear swap. This will increase the torque your rear wheels see. Short of spending big $$ for supercharger, turbo, more displacement I think a gear swap would have the most dramatic effect on your towing capacity. Near 12,000 LB's is a lot to ask of the smaller 4.6 pulling up a long incline.

You will need to input the new gear ratio into your programmer to keep your speedo and shift schedule correct. You will trade off higher hwy rpms for the increase in torque.

 

[FordandPolaris]

I agree gears will be the most dramatic. My truck has a lot more go then my mom's expy with 3.55's. Now the torque with the 5.4L helps too but still the gears are paramount. And since it is 2wd, it shouldn't be super expensive to have them put in since you don't have to replace them in the front diff as well.

Also, talk to an exhaust shop on what they recommend for max torque. You can use their information and then install it yourself if you like.

 

[Goats]

exhaust will be a waste unless you get long tube headers. With a cat back theres only maybe a 5hp gain. Gears is the best bang for the buck.

 

[FordandPolaris]

exhaust will be a waste unless you get long tube headers. With a cat back theres only maybe a 5hp gain. Gears is the best bang for the buck.

I am no exhaust expert, but I thought that certain chamber mufflers were shown to improve torque? I agree that headers will help in the hp department, but that is more top end fast speed anyways. I think he is looking for the down low grunt.

If you can find a shop specifically dealing with exhaust, they will be able to tell you what will work best for your situation. I know when I was considering having custom pipe done, my shop tried to talk me into flowmasters since they would help with low end and fuel economy. I was more interested in the sound though so I just went with a cheap glasspack that I did myself.

 

[KenInCa]

With 2wd... I would recommend a gear swap. This will increase the torque your rear wheels see. Short of spending big $$ for supercharger, turbo, more displacement I think a gear swap would have the most dramatic effect on your towing capacity. Near 12,000 LB's is a lot to ask of the smaller 4.6 pulling up a long incline.

You will need to input the new gear ratio into your programmer to keep your speedo and shift schedule correct. You will trade off higher hwy rpms for the increase in torque.

This sounds reasonable, other than the fact that I would have to have a shop do this. Sounds out of my league.

So what gear ratio would you recommend? Currently I have 3.73 I believe.

Thanks,
Ken

 

[toms89]

This sounds reasonable, other than the fact that I would have to have a shop do this. Sounds out of my league.

So what gear ratio would you recommend? Currently I have 3.73 I believe.

Thanks,
Ken

The next ratio up would be 4.10's. This would give you a 10% increase in torque at the wheels vs 3.73's. This should be a noticeable improvement. It will also increase your rpms by 10% at hwy speeds.

Divide the ratio you are considering by 3.73 that you have and it will give you the difference in both available torque at the wheel and increase in rpms.

If your tires are stock size I would try 4.10's. 4.30's would be an additional 5% difference over 4.10's for a total of 15%. If you have non-stock tire size we would need to know what size before making a recommendation.

 

[toms89]

Here is a link to a chart for gear ratio vs rpm @ 65 mph (1:1 tranny ratio, 3rd gear with ours, not overdrive. ) Stock tire should be right around 30 inch diameter. If you read their description please note there is no slippage with our trannys as the torque converter is generally locked.

Differential Gear Ratio Chart - Tire Size to Gear Ratio

 

[jjbusa]

where can i buy some 4.11 i have 24s on a 4.6 and its kinda sluggish. gears may do the trick.

 

[toms89]

where can i buy some 4.11 i have 24s on a 4.6 and its kinda sluggish. gears may do the trick.

2wd ?

Need to know if its 8.8 or 9.75 rear.

9.75 = 12 bolt rear cover
8.8 = 10 bolt rear cover

 

[jjbusa]

2wd

 

[GAINMOB]

i forgot about gears...cat-back exhaust will increase mpg 2-3...did for me