OK, I'm trying to formulate a plane of attack. Now that I've got tires, my long term plan to improve performance centers around gears, a tuner, exhaust (including headers), and intake.

For gears, I'm presently plagued with 3.55 which is fair, but its not ideal for driving in hilly country or towing/hauling. There's a pretty big ratio jump between first and second gear which presents problems on steep hills when speed is limited to the 20-35 mph range. And, on the highway, I'm sitting around 1800 rpm at 70 mph, which is a little lower than I'd like. Even in tow/haul mode, I'm still only turning 1950 RPM at 70.

I'm looking at either 4.10 or 4.56 gears, but I'm not sure which I want yet. I will note that I'm running 265/70R-17 tires, which are basically 32 inches in diameter. 4.10 appears to give me 200-300 RPM more in top gear at 70. amd gives me a couple of hundred RPM at the lower speeds where I'm still in second gear (either version of second gear). 4.56 gives me more RPM in both situations. My only concern with the 4.56 is that it'll have me using more gas at highway (70-75 mph) speeds. It's probably a good tradeoff for the increased driveability around town. Most of my long trips will remain with my little Honda.

I'll add that I'm going to bet an Auburn LSD for the rear when I do the gear change.

Now, on to exhaust. Many options exist - various brands of headers and exhaust systems. I'm not as familiar here with all the options, but what I'm looking for is midrange torque and power. I don't want to lose torque at 2000 RPM to gain HP at 5500 RPM. 2000-3500 is a useful range and I want that strong, along with a little more peak HP.

I definately need to have Cats, though I don't think that they have to be in exactly the same locations as stock. We e-test here, but they only look to make sure that there are cats. OBD-II is the primary test. My thinking here, and I might be way off, is that I need medium or long-tube headers with cats, perhaps 1 5/8" primaries. Behind that, high-flow cats and the appropriate O2 sensors, then a nice exhaust, either a 3" single, or maybe 2 1/4" duals with some kind of crossover. Maybe Magnaflow, Borla, I don't know.

I don't know much about tuning exhausts, but I do know that I want to keep my midrange power.

For a tuner, I'm looking at the Superchips flashpaq 3865.

Intake, which I'll probably do last, would be a typical 3" CAI setup. There's plenty of options there. I'm not upset with the factory setup, but it might prove to be inadequate after the other mods are made.

 

This FAQ page HERE will certainly help you out

As for gears with 32" tires, I would go with 4.10s but you need to make sure you are not going to want to upgrade to a bigger size later.

I spin 2100 rpm at 70 mph with my 456s and Auburn LSD and 36" tires

I love my Auburn LSD btw. It has never given me any issues.

As for exh headers and needing cats, LTs are doable but some shops might not want to do them being they will have to be moved back. So mid tubed or shorties might be a better option. Anything is better than the stock manifolds

A good CAI is always a plus. That page I gave above will help you out there as well. A lot of guys like to make their own.

Superchips 3865 is certainly the way I would go as well as picking up a power wire or making your own.

Sounds like you have some good plans and solid ideas

 

Thanks - I'll dig into the FAQ pages a little deeper. The one thing that seems to be lacking out there are solid comparison tests with hard numbers. I know that people can't buy 3 or 4 different brands of headers and dyno them all along with 2 or 3 different exhaust systems, but I'm hoping to see some hard data for a few setups.

Seems like a lot of exhaust systems are single outlet instead of duals. I got spoiled with the duals on my old Mustang 5.0 - one of the best-sounding exhausts out there at the time. Anything that sounds like that is a plus for me.

I've seen quite a few CAI setups - do-it-yourself as well as packaged kits. I don't think that there's a lot of difference from one to another. Just opening up the intake a little with a larger-surface air cleaner ought to help, at least at higher RPM. I'd kind of like a ram-air setup, but I don't know if that's a reasonable type of thing or not.

I'll have to get to the store and pick up a couple of 4.7K ohm resistors and some connectors and put together a power wire. I watched your video the other day - good, easy-to-follow instructions. The power wire only effects things at wide-open throttle, right?

I had an Auburn on my Explorer and put around 70K on it without any issues. It worked well for me, which is why I want it on the Dodge as well.

I'll have to really think about future tire sizes before I pick the gears. Right now, with these 32's being new, I don't think I'll be swapping tires out any time soon and if I do, 33's are about the limit (I think) unless I go with a lift. I'm not looking at doing that. According to the chart I printed off, with 4.10's and my 265/70R17 tires, I would be turning 2100 at 72 mph in top gear, and 2100 at 64 mph in tow/haul mode. That's presumably with the torque converter locked up. 4.56 would put me at 65 mph at 2100 rpm in top gear, which would be OK for towing but I don't think I need that much RPM for normal highway cruising.

 

I towed my 28' 5th wheel with 3.90 gears in a 245HP '98 RAM 1500 (360ci).

I had no issues with torque or highway traveling. I don't see the point of more RPMs at highway speeds.

I have yet to tow with my new truck (bought 7/28/2010). It has 3.55 gears but I'm betting the 100HP gain I got really makes up the difference. By the by, the '98 was a 2WD and the '07 is a 4x4.

I personally wouldn't change the manifold to headers.unless you get long pipes.

Also, I'd do the CAI and Exhaust before the tuner. Make sure that truck can breath, before you modify stock computer settings.

 

No company I know of puts out proven numbers and compares against others. Anyone can claim number and I know what you want but as for any one person here on the board, I have not seen anyone add a mod and go out and get dyno-ed for one mod.

Ive for Pacesetter LTs with no cats, an x pipe, dual cutouts and dual Magnaflows and love it. It is a really nice sound and I did notice a slight power increase I think after I re-did my exhaust. The only problem there is my exh setup was not cheap at all.

Yes the Powerwire only affects WOT as that is the only time the PCM will ignore the O2 sensors and not correct itself like when not at WOT.

 

I'm seeing issues when NOT towing. The doggone thing wants to be in OD as much as possible and you really need to kick it to get it to drop down to the next gear for passing or pulling steep hills. It's not the end-of-the-world horrible, but I want to be able to utilize the engine's torque a little better without having it downshift as often. Lumbering along at 1800 RPM is well below the engine's torque peak. Not necessarily a problem when cruising along a flat pice of highway like I-71 south of Columbus, but quite an issue on many of the 2 and 4 lane roads here in eastern Tennessee.

I'm also seeing issues at lower speeds - there's quite a gap between first and second gear ratios on these things and the same issue applies on mountain roads - you slow down to 20 mph to go around a switchback and then push on the gas and it's lumbering along below 2000 RPM and not accelerating until you finally kick it down into first gear. then it takes off like a scalded dog. If there's loose dirt on along the side of the road, I lose traction. If there's bumps, I get wheel hop.

Getting the RPM up closer to the power curve would be helpful, not to mention the mechanical advantage that a 4.10:1 ratio has over a 3.55:1 ratio. Imagine moving all your transmission's gears down a half a gear so that second is like "first-and-a-half" and third is like "second-and-a-half". This factor alone improves acceleration and reduces the need to downshift.

It'll tow OK - the guy that had my truck before me towed quite a bit with it, without too much trouble. But it should be noted that the towing limit is 800 or 1000 pounds lower with the 3.55 compared to the 3.92 according to Dodge. I'm not saying that mine won't tow - I just want it to tow better!

I've heard a couple of people say that about the headers, but others say differently. Wish I could see some dyno results. I'm not convinced that an exhaust alone would do a great deal without the headers. Perhaps a bit more, but there's a lot more to tuning than just opening up the pipes. With equal-length header tubes, you've got your exhaust gasses from the various cylinders entering the exhaust system at somewhat equal intervals so that you don't have some cylinders breathing differently than others, and you don't have the restrictive effect of two cylinder's exhaust pulses trying to travel down the pipe at the same time.

Anyway, I'll look at the long-tube solution. I have to check a bit more deeply into our emissions testing. As far as I know, they just take a mirror and look to see if the cats exist, so longtubes with high-flow cats would do the trick as long as it's OK for the cats to be a little farther back.

I'm also a little skeptical of the CAI systems - again, no dyno results and quite a few folks are saying that it doesn't "seem" any faster but it sounds better. Is the stock intake really that restrictive? I opened up the stock air box on my Explorer back in 1999 or so, but it had a smaller-diameter intake "horn" on the front of the stock airbox that was less than 2 inches in diameter. It was obviously a restriction on that vehicle when everything else, intake and exhaust, was at least 2 1/2 inches in diameter. It was even named something that had to do with sound. Ford presumably put it on there so that people wouldn't sound like Dale Ernhardt Jr. when they were driving to the grocery store.

 

I got a little spoiled reading the Honda Civic Si forum. Those folks must live next door to the dyno shop because they're always posting slips. I guess with all the money that they're saving in gas, they can afford some time getting tuned.

They are a more race-oriented group though.

I've seen a couple of magazine articles that have thrown headers and exhaust on trucks and they will show the results. One of them disturbed me - they bumped up the HP and Torque by about 20 or so, but lost low-end torque below about 2500 RPM. That's not a good trade IMHO, since I don't drive at 5000+ RPM all day.