First off, great forum, very informative. I have read many post where people have installed dual exhaust and lost low end power. I have a 97 F-150 with a 4.6 I want dual exhaust but don't want to lose any power. If I were to cut out the y and put in seperate pipes with an h or an x pipe, then back to two mufflers and tails, would that still loose low end? I plan to use
Flowmaster mufflers(40's or 50's, haven't decided yet) and have a local shop bend the pipes and install everything. Any thoughts or suggestions would be appreciated. Thanks.

 

I think any way you go, you will loose a little low end, unless mabee you went with the 70 series flowmaster, bassani, or magnaflow. I'm just guessen, mabee some other people have further insite. With my 50 series SI/DO, I dont recall knoticing any low end power. ( I did add the FIPK at almost the same time though)
You will love the sound of the Flowmaster though.

 

Prolly if you stay with your stock pipe size you'll be ok.

 

I would run 2.25" duals, unless you plan on building out to 300+HP. Replacing the Y-pipe will definitely open up the restriction on the driver's side down pipe and with a free-flow muffler...you shouldn't be oversized to impact low end performance.

 

Thanks for your replies fellas. Area 51, that is just the set up I was thinking of, I just needed to hear from someone with the same train of thought. Now to scratch up a little dough.
Thanks

 

CAF,

Look at the following thread by Flats Man...you might even contemplate 2" duals:

https://www.f150online.com/forums/sh...ghlight=MARTIN

With his supercharger 5.4L, he was making good runs with 1.75" I.D. inserts in his exhaust...but remember he is supercharged so he's probably got a higher exhaust pressure than a naturally aspirated 5.4L engine.

If you want to compare the area of the different size pipes, multiply the square of the pipe inside radius times PI (3.1416).

 

I note several comments about loss of low end power when an aftermarket exhaust system is added.

Granted, it's all subjective for the most part, but most dyno curves I have seen the low end power band doesn't seem to change much if at all.

Speaking subjectively, my 02 5.4L automatic 3.55 diff SuperCrew seems to have more power in the mid-range.
Probably true on the top end as well, but I don't wind the engine over 4500 rpm for the most part.

Fwiw - exhaust is a true dual setup with dual 3 chamber Flowmasters, 2 1/2" in and 2 1/2" out on both tailpipes that exit in the same place the stocker did.
No X or balance pipe.

For those with a noise question, after doing the 3 chamber bit on this truck, the only reason I'd buy the 2 chambers is if nothing else would fit.

Exhaust note is somewhat unlike the typical Flowmaster sound, a bit more of a hot rod glasspack sound on startup and pulling away from a stop, although an attenuated throttle keeps the noise down to the same level as stock.

In fact - subjective opinion for sure - this is the best sounding dual setup on a pickup I've heard for some time.

C9