Hey all, just had the roush kit installed on my 07 Mark LT. Noticeable difference in power but not as much as i assumed. common sense tells me exhaust is the next step. thinking of going with 3" stainless y off the factory cats into a single 3" into a 40 series flowmaster dumped at the rear axle. is this the right thing to do and is it the most likely cause of my not feeling a bigger power change with the s/c?

 

Do you have a custom tune? If not I get would one ASAP. That should bring you to 30 hp/35 tq gain with the LTs. As far as exhaust goes, your wanting to put a new 3" Y pipe and single 3" piping into a muffler? That will be good if thats what you want. Flowmaster and dumping before the rear axle is a negative. Go with a straight through muffler and AT LEAST dump OVER the axle.

 

thank you. what do you recommend for the exhaust, is 3" single ok? what will get me the most power gain as i feel like the exhaust is REALLY restricting me right now? I dont want the truck to be really loud, just a good throaty, healthy sound. is the 3" single with a y and a 40 series good. its not necessarily what i want, i just said that because my buddy recommended it. i just trust the guys on here more than him!!! Thanks so much

 

The most power gains will be a true dual exhaust (eliminates the Y pipe). Either 2.25" or 2.5" pipe with a STRAIGHT through muffler (no baffles), not flowmaster. Single 3" exhaust is a good increase, but not as much as true duals (dual mufflers). All about how much $$$ you wanna spend.

 

sorry, but also, whats a "straight through"? do you recommend 4" tips or is that just a sound thing? new to this and really want the max potential outta the roush s/c

 

^^^ Read my last post. Straight through meaning no baffles. Flowmaster has baffles which restricts flow.

 

Hey Duckman.. Check out the thread I started..

Do I Have This Right?

This would be a great system for you.

 

I have the roush system on my truck and have been through 3 different set ups already. I just finished my 4th, performance and sound wise it is by far my favorite. Check out some vids and pics here:

https://www.f150online.com/forums/ex...pics-vids.html

 

that's the first x-piped exhaust sytem I've liked the sound of...

 

thanks

 

HA! I know your partial to H pipes, but that truck sounds good indeed!