Hey guys. Got a 98 f150 4.6. Was wondering if there's a trick to getting my exhaust sounding good. I plan on getting rid of the 4 cat system and going with 2 hi flo's. But I thought by putting a si/so flowmaster on it would be enough. wrong. at idle it's ok at best. when I get on it, all i hear is the engine. and it doesn't sound all that great. sounds like a lot of noise/air...like wind/ and when it gets in high rpm a rattle? What's that all about?? 145,000 miles on truck. Could it be the cats are partially plugged giving it too much back pressure causing the wind noise? I just want to be sure it's worth getting rid of the cats and installing 2 hi flo's. I hope the sound comes with it. :o

 

That's odd, but yeah hi flows will really wake it up, volume wise.

 

Firstly i'm going to recommend you verify that your muffler was installed properly. The way you explain your sound is very much like the affect when these mufflers are installed backwards. Flowmaster is a chambered muffler so there is only one way to install them, the proper way with the Inlet first. Some exhaust installers are idiots and just put it on since they are used to straight through designs which are 100% reverseable. If it is installed properly with the Inlet end installed at the inlet, then assume its fine and move onto the cats.

Hi-flow converters would really be worth the investment. You will gain a little gas mileage due to the much healthier flow, a little torque too, and ofcoarse sound. Magnaflow cat part #s 94306, 94006, and 94106 will work properly for your truck.

 

what series flowmaster did you get???
where are your tips at?

if you got a 50 series, many people claim the 50 series is too quiet but once again I agree with Darrin when he suggested you take it to another shop to verify it was installed correctly

 

75 mile radius here, One of 7 shops exhaust wise, know what they are doing

I can't wait to get my Hi flows. Damn,

 

Thanks for the input. Yes the inlet is facing the inlet side (front of truck). The muffler is a flowmaster 40 series delta flow. It exits at the stock location. I haven't put a tip on it as of yet. Which leads me to my next question..does that improve the sound any or is it just for looks? Also Darrin, of the part numbers you mentioned for the cats is there one that is preferred the most? Again it's a 98 f-150 4.6 4x4. Thanks again for your help.

 

Tips do make a bit of a difference, it gives a nice open/hollow like sound with a metallic note, and it megaphones the sound further away.

94106 Magnaflow cats really let these Ford modulars get their message out.

 

I have a SI/DO Flowmaster 40 on my truck exiting out the rear. Whenever I floor it the exhaust is very loud. You might want to switch your exhaust setup to get the sound you want.

 

I have side lightnig style exits and it's not to loud in the cab

 

Update:

I got my manganflow Hi-flo converters on order (#94106). I'll let you know how they sound when they come in/installed!!

 

Sweet man, it's going to sound mean.

 

What muffler are you going with? a magnaflow to match hi flows.

 

I'm running a flowmaster 40 series right now. I think I'll stick with that for now and see how it sounds with the new hi flows.

 

Here's a question for all ya. Since I'm getting some exhaust work done soon I decided to play around with my exhaust a little the other day. What I did was I took my tail pipe off and the extension pipe that goes from the muffler to the tail pipe. So basically there's nothing after the muffler. Wow! Does it sound mean! I like it alot. It's way louder than with the tail pipe on it. But then as soon as I put the extension pipe back on it (the one that connects from the muffler to the tailpipe) it turns the volume of the exhaust Waaaaay down. And then even more when I attach the tailpipe. What I want is the sound I get with no pipe coming out of the muffler but a little more refined. But I want the tailpipe to be on. Thoughts?? Oh I don't have a tip on the tailpipe as of yet. Will that help bring all that loudness back? Thanks guys!

 

good choice since youre wantin it louder stay with the flows. if its still not loud enough and you want more, i highly reccomend the 10 series flowmaster. 6.25 inches long and 1 chamber. it will be noticeably louder.