Hi my name is Casey, im new to the forum world and i have run out of people to ask about problems and performance on my trucks. I figured some people on here could help me alot more than most of my idiot friends with their chevys. I have a question about throttle body spacers, I just bought a K&N cold air intake for my 99 F-150 5.4 with 113,000 on it and i love it. One of my friends suggested i buy a throttle body spacer to go with it. It was only about 70 bucks so i bought one and i haven't noticed any difference besides a funky whistling sound that wasn't there before. Should i just take it off or leave it or what?

Also i was wondering what to do about my exhaust, I have flowmaster 40 series single in, dual out dumped, but I have been told by a few people to to get rid of the cats and put a full performance exhaust on it. Any suggestions?

 

Casey, glad you posted. I am no gearhead, but wonder what a throttle body spacer does. I don't have a CAI, but may consider it down the road. Will wait to hear from all the gearheads with the expert advice.

 

On a MPFI engine, a throttle body spacer is useless. This is old technology from the carburetor days. They used carb spacers to lower the temp of the carb resulting in denser fuel. There is no fuel in a MPFI throttle body so a spacer is a useless mod to perform.

 

I still have a 30 day money back guarantee on it so should I take off and get my money back?

 

If the retailer will take it back even though you installed it, then yes, get a refund. Take that $$$ and use it toward other mod's that will yield performance gains. As for a new exhaust system, the question is how much $$$ are you willing to spend? You have a lot of options for the F150...

 

Well I figured around 4 or 5 hundred? I would like the most bang for my buck.

 

Let me do some research and I'll get back with you... Edit: What is more important to you... additional performance or better sound/appearance?

 

Im not really concerned with appearance, dont get me wrong i dont want something that looks afro-engineered but performance and sound is my primary concern.

 

IMO, you would yield the greatest performance gains by installing headers and high-flow cats. You already have the FM 40 muffler so let's build on that. I've been looking at the OBX headers for over a year now and believe that they make a quality header at a very competitive price. Because we are working with a limited budget, I recommend the SS short-tube headers. They are $325.00 plus $32.00 shipping on eBay (see link below). If the $400-$500 budget includes parts & labor, then you'll have to stop here. If the $400-$500 budget includes just parts, then you can replace the OEM cats, which are probably ready to be replaced anyway. I don't know if your F150 has 2 or 4 cats... contact Bear River Converters (FTE sponsor, link below) and ask what high-flow cats could be installed on your F150. I'm guessing that will be another $150-$300 depending on the number of cats required. You probably can install the headers yourself to save some $$$. Then just take your F150 to a muffler shop and have them cut out the old cats and install the new cats.

eBay Motors: OBX Racing Exhaust Headers 97-03 Ford F150 F250 5.4L V8 (item 350170466230 end time Mar-25-09 23:14:55 PDT)

http://www.bearriverconverters.com/index.aspx



Hopefully other FTE members will chime in and offer recommendations as well.

 

Headers and a cat back are good upgrades on these motors, combine it with a tuner to raise shift points and you'll see significant power increases.

 

Thanks guys, i really appreciate all the tips.

 

Let us know what mod's you decide to install and how you feel about them!