Novice Needs Guidance

[djljr]

Getting ready to start upgrading my '03 4.6L; nothing radical, just looking for a little more snap and mpgs. Starting with air intake/TB spacer and cat back system before moving on to UD pulleys and electric fan(s) and somewhere in there a chip.

I ride Harleys and build my engines so tools and mechanical skills are OK. My problem is evaluating the myriad of products for the above upgrades; which are quality and deliver? I think it foolish to go start buying stuff before checking in here. Most driving is in town, hit the highway for some short trips to the coast and tow a trailer with a Harley on occassion. Looking for torque first, horsepower second. Don't want loud exhaust, don't want a resonating hum in the cab.

Looking at air intakes, TBs and exhaust first and have narrowed air intakes down to K&N CAI 77-2514KP or AEM Brute Force with Jet Flow TB spacer and Flowmaster or Magnaflow cat back system.

Looking for recommendations for/against any of the above from people that have used them and know what they are talking about. Also would like input on the value of replacing the stock CAT with a free flowing unit.

 

[ELVATO]

Hmm, I have most of those things done on mine (an 03 4.6 Expy). Not real sure how much HP I've gained with my mods (listed in sig) since I've never put the Expy on the dyno.

I wouldn't get a TB spacer. The general consensus is that they don't work. The air intake made my engine louder, making it sound more like a V8. I'm not real sure how much I gained in mileage since I was always stomping the gas to hear the deep sound the engine made. With an intake, though, I think you lost a little low end torque, and gain in the high end HP. Not having to buy paper filters is a bonus.

Instead of a cat back exhaust system, I just swapped out my stock muffler for a Magnaflow universal one. That mod was more for sound than it was for performance. Although I'm sure they do add some power, I've always seen exhaust systems more as a sound mod than a performance mod. Ask exhaust shops around your area how much they would charge you to fab a custom system, just get the muffler(s) online. It's probably cheaper than getting a cat back setup. BTW, a bigger muffler makes for a quieter ride.

As far as high-flow cats, I think someone posted a dyno sheet on a car of what various cat setups did, and I think the gain was around 4 HP. They do make your exhaust considerably louder.

The fan, I'm not sure if I felt that much in the "seat of pants dyno." It did seem to improve the mid level power a little. You could, on a chilly night (less traffic at night), take a short ride. Then take off your stock fan (you can rent the tool for 20 bucks at Autozone or Advanced), and take a short ride. That should be about what it feels like to have an E-fan. Just make sure you don't idle too long in one spot. As long as you keep moving at around 30+ mph, you should be OK. Then put the fan back on, and take the ride again. See if you notice any difference.

I noticed a pretty good response with the U/D pulleys. Not sure how many HP I gained, but the motor felt "lighter," if that makes sense. It also seems that you can coast longer (good for city mileage, if you already coast to red lights.)

My "chip" (it's really called a programmer) is a custom tuned by forum member green03. It's a 93 octane tune. Though they add power, the real benefit of tuning is the improved "drivability." Shifts are firmer (you can vary how firm you want them) and the tranny doesn't hunt for gears.

That's all I can think of for now. If you have any questions, ask away.

EDIT: Forgot to talk about mileage. With the above mods, I usually got around high 14's-mid 15's with a highway/city combo on Shell/Chevron gas. Granted, I drive rather aggressively in city, and usually go around 70-80 on the highway. My best MPG was 16.9 on an all highway trip averaging 80+ mph.

This tank, I'm trying to take it easy, and see just how high I can go. I'm doing a lot more coasting, and keep the RPMs under 2000 when accelerating. On the highway, I went a constant 60-65 at night, and aired up my tires to 40. Let's see how I can get.

 

[djljr]

elvato,
Thanks for the response. I would have to question the cost/benefit relationship if 16.9 is the best I could get after making the previously discussed modifications. I am getting about 14mpg, all city driving now, mix in 1/3 highway and mileage goes to 15mpg (that's at 70-75) and I suspect I could get 16mpg on a road trip. I have to ask myself why invest the money and energy in UD pulleys, electric fans, air intakes and exhaust for another .9mpg?

I would agree on your comment about exhaust and a trip to a local muffler shop is a good idea. The programmer sounds like a worthwhile modification as well. I don't want to lose any low end; the 4.6 is a little light on the low end anyway. Maybe what I need is a little headwork, some torque cams and a re-mapped engine control module. Works real well on a Harley!

I don't know what I don't know but you now know what you didn't know before modifying your 4.6. Now that you know what you know; which modification had the most impact; which are toss ups and which are the mods you would surely do again on another vehicle?

Thanks again for the informative response.

 

[ELVATO]

If I remember correctly, I was getting around 13ish mpg.

I've really liked the mods I've done. I didn't really have mpg in mind when I was doing them. I was just trying to make the Expy a little more fun to drive.

Out of all of them, I probably felt the programmer and U/D pullies the most. How much gains they provided, I don't know, but they seemed to affect the butt dyno the most.

To me, at least, the intake and muffler swap were more sound mods, which made my driving "funner." The intake did seem to improve throttle response.

I really don't know how I feel about the e-fan. Most people who've done it on their F150's seem to think it was one of the most noticeable mods, but it didn't feel too different to me. Just try doing what I talked about in my previous post, and see if you notice something.

If I remember correctly, here's the prices off the top of my head: programmer ($300-400 from Sniper+$50 for custom tune from green03), intake ($200 from PDQ performance), muffler swap ($65 for muffler from performancepeddler.com + $70 to install), pulleys (170ish from summit racing), e-fan ($60 for Mark VIII from ebay + $130 for DC Control fan controller).

Hope this helps, and that other members with some of the above mentioned mods chime in.

 

[djljr]

elvato,
thanks again, all good information that I will archive for this winter when I get around to actually doing something. how do I contact green03 for the programming?

 

[ELVATO]

I'll see if I can get him to PM you since he's always having trouble with his inbox.

 

[green03]

I cleaned out my inbox... still no messages...
my number is 9.7.9.3.2.4.4.3.4.8
I put the periods in there for the spamers...
Programming makes a big difference on the 03 especially.

Matt R

 

[djljr]

elvato, thanks for facilitating.

green03, look for a PM.