Hi, there.

Maybe its wanting to have your cake and eat it too, but I'd really like to know if anyone has any actual before and after dyno's? If you've done -anything- and have a before and after dyno, I'd really appreciate hearing what you have to say.

I'm not talking about box claim gain here, supposedly my K&N Air Filter game me 10hp but I don't -quite- think so. Thanks.

1999 F-150XL,RC,LB
4.6V8 5sp
Sony Mobile ES HU
Memphis Coax 5x7
Xtant Sub 12"
XPLOD 125x4W Amp
Double-Spray liner
K&N AF
CRIMESTOPPER 2001

 

IMHO most claims are unsubstantiated. Some mods will probably get you some horsepower . . like a superchip. And maybe some exhaust system mods will give you some horsepower. But depending what you do and how you implement it, you can wind up with issues like reduced low end torque that perhaps offsets top-end horsepower gains. I think this may be true of some exhaust system mods. As for the K&N, I personally don't believe that it buys you a darn thing.

 

thanks, all opinions welcome of course. gotta love the 1st ammendment.

I feel pretty good about the filter. I've had no problems with it, and its a good bit tougher than a reg. filter. Was $4 more at the store I got it at (autozone?, dunna remember).

I've got the little 3.10 gears in the rear (3.10, 3.08? one of those). Its not all that for low-end anyhow and I DONT want to lose anything there. What it does that I really like is run right at 1750 or so at highway speed. And if I downshift, it doesn't rev -too- high and does seem to have PLENTY of power (though this is the first V8 I've ever owned) for that.

I could care less what my truck sounds like to others. I don't want people gawking at me anyhow. I've got my stereo if I want sound.

I guess what I want is more mileage if possible, and more low-end. I'd trade low-end for milage if I had to.

1999 F-150XL,RC,LB
4.6V8 5sp
Sony Mobile ES HU
Memphis Coax 5x7
Xtant Sub 12"
XPLOD 125x4W Amp
Double-Spray liner
K&N AF
CRIMESTOPPER 2001

 

If you want to retain low end and midrange power that is where you need to be very careful on intake and exhaust mods. The intake systems sold aftermarket along with some of the mods posted on this website will help topend type power but will likely actualy hurt low and midrange torque in some portions of the power band. All engines have intake resonance frequencies that have to be accounted for when tuning. When you remove the carefully designed resonance chambers of the stock system and simply replace with a straight pipe, you loose power at those RPM's. I've seen dyno plots on 4 cyl engines where they lost up to 10% of their torque at certain points in the RPM range. They gained more on the very top but unless your racing, what good will that do you. Have you actually seen a detailed dyno plot of stock versus one of those FIPK'S over the entire RPM range. NO, they only post peak power gains, they don't talk about the power loss where you do most of your driving. That is also why it's important to have some amount of backpressure in the exhaust, to maintain low and midrange power. It would be nice to have a dyno for a day and prove/disprove a lot of what is posted and tried on this site. That's one of the tools I don't have in my shop right now though.

This isn't just my opinion, these are common known facts on engine tuning on how the length of the intake and exhaust headers shift the power band around. But hey, anyone can do anything they want to their vehicle, free country and all.

 

Thanks for the info. I've been putzin around with motors forever, but by far the best examples I have was with model engines (for RC).

The principles are the same. More open exhaust was RARELY the answer, and I can't tell you how many pipes I've had to tune.

I guess maybe things like Ignition, Superchips, underdrive pulleys, electric fan? What else?

 

I seem to have hit on a combo that really works. I have a Superchip,K&N fipk,and a custom true dual exhaust. The exhaust being the only thing not pre-made,I believe it's helping rather than hurting low end torque. It starts
about a foot behind the cats,turns and goes side by side for about two feet.
At that location,the tech put in an H pipe. It then continues on as far back as possible(to reduce cab noise)where I used 24" glasspacks. Yes,I know they are not high tech modernistic flow monsters but they work for my truck.
Then the pipes exit under the rear bumper with Gibson rectangular tips(their side exit tips) The low end is still there,as it wants to fry the tires half the time if you give it too much gas. At highway speeds it seems to flow well and has plenty of passing power. The key to good exhaust system is to not go too large on the pipes,that's when you start to lose low end. True duals/stay down around 2 1/4 inches(what I did),,and for a single/you can go up to 3",depending on engine size. It's like the carb. thing,some inexperienced guys will build up a mild small block,and dump a 1200 cfm unit on top of it
These are just my opinions,and no one elses,so don't rail on me too much
if you disagree. Sorry for the book I just wrote here,,,,,,98

One more thing,DO NOT consider adding a poweraid TB spacer,some people have lost HP with them(They claim a 12 or 14 HP increase)........