danweasel

Hi there,

So I am the proud owner of a 1997 F-150 XL Supercab with the 4.6L. It's not all modded out, just electric fans, Gott's Mod and a Flowmaster 40 series. I am now obsessed with replacing the Flow with something more performance orientated. I know it wont be that much HP gained in the grand scheme of things but I still want to upgrade. I am not concerned too much with sound (quieter is better but it's not a priority) just what actually produces some gains. Also, I cannot hollow out my (4!) cats and go open pipe or anything like that. My truck may be from Alaska but I live in California now... In fact I have smog coming up in a few months I think.

So yeah, can anyone recommend to me a specific muffler that would do the trick? I like the idea of a Hooker Aero Chamber (cause I'm secretly still 14 years old) or a Boria (because I seem to read that they are good in searches here) but I'd really like if someone could point me toward a certain one that is known to be a good buy for the 4.6 so that I won't repeat my mistake from 10 years ago thinking the Flowmaster was a performance exhaust.

Thanks everybody!

Dan

rcairbear

DarrinT04

what makes you think the truck is from alaska?

danweasel

Cause I bought it there.

OhioLariat

I feel ya, RC.

OP: With a stock 4.6, no mainstream aftermarket muffler will provide a noticeable performance increase (or loss) over the 40 you have now. Just pick one that sounds good to you and put it in. If you want quiet with a mellow/deeper tone, I suggest a 24" Magnaflow. And not that it matters much, but the MF's straight-through design *does* flow better than the 40.

formerjeepguy

The truck is 22 years old and works fine. Is it really worth messing with? You are not going to get any performance benefits and if you make it louder all you will get is a headache on long trips and **** off everyone around you. Save your money for important stuff.

danweasel

Well Dammit. That's basically what I was thinking too. I was hoping for some kind of magic improvement that I didn't know about. Thanks guys.

Jbrew

Good, your thinking is pretty much right on. Yea, the 40 was a bad choice afas performance, you lost a little bit everywhere over the factory set-up with a chambered muffler on the end. This is due to more exhaust gases expiring in the pipes vs clearing. That's a ancient proven fact which still stands today. I recall a Mustang site performing a muffler shoot out of the brands. Dyno result comparisons were used since the difference isn't that much. However, this compounds in certain situations. In cold climates particularly with the amount of moisture that builds in the system that becomes even more difficult to clear. You can feel THAT slug affect in the butt dyno. Borla was the clear winner, Flowmaster was the only chambered in the mix so.... Keep in mind, Flowmaster seen the light and has straight through variations of their product which have been available for purchase for that last 5 years or so.

Back in 05 Troyer Performance performed a Dyno of their 3" cat back Magnaflow system with a 10th generation Expedition. They called it their SUV set-up back then. It showed a gain 14 hp over factory. Although this was true/documented, the power increase was far up into the powerband/rpms which is for the most part,- unusable horse power. Unless you were into dragging the family truckster on Sundays..yea, that market never happened. However, that system did show little gain down low (usable HP/Tq), perhaps by 2 whole numbers.

So it's just as everyone is posting and basically what you've learned thus far other than, - stay away from chambered. Not only because they are little less in comparison, it's ballpark petty. Main reason is, they are a lot less in high build moisture situations encountered in cooler climates.. Anything straight though will due, from factory to Borla, for a DD anyway.

Btw, the Expedition used was completely factory. A 4 catted Y. The 2.5" intermediate pipe was chopped right after the merge. It was replaced with a 3" intermediate pipe, plumed into a Magnaflow muffler. The tail pipe was 3" mandrel bent and smoothed/relaxed over the rear axle vs the factory radicalized loop over.