I'm looking to increasing mpg and after installing a K&N and flowmaster, I only see about 1 mpg difference. What kind of gains might I expect by installing a throttle body spacer on my 4.6l F150? Any HP increase?

 

nope

 

about the same you got out of the other 200 dollar mods

 

Bolt on crap is about 95% hype and 5% go the only thing that really works is a chip for power and a supercharger..As far as gas mileage. nada get a smaller rig..He He

 

I guess I'll pass on the spacer. The other $300 I spent on mods was not a waste of money, I got a noticeable improvement in throttle response and performance.

 

THe spacer is junk, sorry to say it man. I agree totally with 99f350sd. Most of these bolt on guys rip us guys off. They tell us things like we can receive "UP TO" 7HP with a throttle body spacer. These companies really trick us into to spending our hard earned dollars into their nonsense.
I mean yeah, I felt my Flowmaster muffler and cold air but if you put it to the test the Dyno will leave you disappointed.
In my opinion, buy a programmer from Diablo, its the best bang for your buck.

Chris

 

I got a TBS off of eBay a while ago, made by Helix (I think). Can't really say I noticed a whole lot. It does make a cool whistling sound tho that makes heads turn.
SInce I didn't pay top dollar for one, I'm pretty happy with it.

 

I'll bet you made a few hp with the Flowmaster setup, but the K&N is nothing but hype and great marketing. A good Dyno test will prove this to be true even though it's hard to admit after spending a couple hundred $'s. The TBS is another marketing game that makes money for someone out there. If there was a way for Ford to get a few more miles per gallon on any of there trucks and still meet the EPA limits and the horsepower that you now have ---- they would do it in a minute. They are spending millions trying to get more mileage and if it was as easy as changing an air filter it would be done. Can you imagine the sales increase of Ford over Chev if Ford could get 25 to 30 MPG out of a 300 HP gas engine? Let's all remember that an engine is only a device designed to change gasoline into HP ---- the more gas/air-- the more HP. If you lean the mix down to 16 to 1 the motor won't run well and you will probably burn the valves --- if you run at 11 to 1 you are wasting fuel. One thing about our computer driven engines -- they adjust the proper mix to the load and that is a big help over the carb of yesteryear. Also remember, the automakers can't sell anything that won't meet the EPA spec's.

 

Allegretto, I didn't spend a couple hundred bucks on the K&N filter. It was the cone type that fits in the stock box ($45). The stock filter was caked with dirt and needed to be replaced anyway.

 

K&N filters are better and they last longer than your truck will. They are much better than the paper filters that these trucks come with.
Another thing, Ford has to develop engines under goverment emissions standards so not everything they do will be the best for your truck. I'm pretty sure if we didn't have these emmisions standards then Ford could create much more horsepower right out of the factory. Thats why they sell aftermarket parts. It's the buyers choice to tamper with their car and their responsibility.
But I still beleive most of the stuff they sell does't work nearly as well as they say but it can help a little if all these bolt on products are installed together all at once.

Chris

 

CPerry, -- I'm glad that you didn't pay the long dollar for the K&N. Some of the guys are buying the air horn and the filter and paying around $200 and I think it's a waste. I've used K&N's on high performance motors (race bikes & etc.) for years and there big advantage is that they can be cleaned and reused. I personally feel the stock Ford filter will pass all the air that these little motors can swallow, but if I am replacing a filter element I would consider a K&N because I can clean it and use it again.
Question for NASCARTRUCKDUDE --- sounds like you have removed your cat converter when you installed your muffler package -- did you notice a performance increase and/or a mileage increase? I would think that you would get both!! I have considered doing the same to my 5.4 and just haven't got around to it yet. The exhaust manifolds are really small and a nice set of headers would help these engines greatly, but I don't think I'm ready to go that far. The new Harley trucks have got my attention, but I'm not ready to drop 3 MPG and then have to run premium fuel. My days of stoplight burnouts have passed some with time -- although I still do it once in a while when my wife isn't with me. She just doesn't see the fun in it!!

 

Yeah, I still haven't matured pat that stage YET, but I'm pretty sure I will when I get busted. Anyways, cutting my converters off made a pretty good difference in my trucks performance.
Gas mileage got got better, especially on the highway, probably due to the fact that the engine doesn't have to deal with so much back-pressure from the cats.
Sound wise, WOW. I couldn't beleive how good these trucks sound without converters. The 5.4 probably sounds a little different than my 4.6L but basically they both probably sound very similar. Your engine will sound like a beast, especially if you do bolt on a set of performance headers.
Performance wise, I hate to say it but there is a drawback to cutting off the converters. I did lose some low end torque, enough to feel when you floor it or your towing. But when the truck reaches high speeds and higher RPMs it's all good from there. What the truck loses in low end torque it more than makes up for in the higher RPM range.
All in all I say it's a good idea and go ahead and cut those things off. Just make sure you buy a pair of MIL Eliminators and oh yeah, be sure you know a guy that will pass your truck in the emmisions test or you may be regreting your decision.

Chris

 

My engine light is on most of the time anyway -- I run a 160 stat and the light won't go off unless it gets real hot outside. Did you make your cat replacement pipes or is there someone that sells truck off road replacement pipes? I live in Michigan and they haven't ever checked us for emmisions.

 

The guy at the muffler shop just cut the cats off and welded piping in their places, cost me about $150. Pretty simple job but they had to bend the pipes just perfectly so that they fit in the place of the cats.

 

Sorta risky for the guy at the muffler shop -- I think it's a $10,000 fine for letting a car/truck out without the Cat. I'll probably have to make my own pipes. Thanks