High Flow Cats

[the.beast.2008]

I have a 2008 expy and I want to do high flow cats but i've heard from too many people different answers. i'm curious for others with 3rd gen expeditions who have done high flow cats, does it make it louder and what brand did you go with. currently I have true dual with an x pipe and no muffler out the back. Its honestly not that loud for a straight piped v8 which is why I would like to make it louder and longitude headers aren't available for expeditions. so hopefully high flow cats will be the answer to truly wake up this engine. please let me know!

 

[jeff kushner]

I completely understand that you appreciate the "Beast"(unstoppable) nature of our trucks but since there is no return other than 3-4HP and noise, would it make more since to just swap out the muffler instead of the entire exhaust? From what I learned about the 5.4 in the two previous Expys is the power is limited by the valves....not much you are going to do it to get more power.....

jeff

 

[07xln]

High flow cats will do nothing for you. The sound gain will be minimal and the hp gain won’t be anything you’ll notice.

Removal of the cats all together should gain you more sound but again not enough hp to be felt.

Bout the only way you’re gonna make power with a 5.4 is to put a blower on it

 

[the.beast.2008]

Gotcha. I’m not exactly looking for hp just sound. And there’s currently no muffler on it so I was curious if high flow cats would make it louder

 

[the.beast.2008]

I completely understand that you appreciate the "Beast"(unstoppable) nature of our trucks but since there is no return other than 3-4HP and noise, would it make more since to just swap out the muffler instead of the entire exhaust? From what I learned about the 5.4 in the two previous Expys is the power is limited by the valves....not much you are going to do it to get more power.....

jeff

When you say noise are you saying that it will get louder? Because that’s all I’m really trying to achieve by making it louder

 

[07xln]

When you say noise are you saying that it will get louder? Because that’s all I’m really trying to achieve by making it louder

Yes that's what he means

 

[the.beast.2008]

Gotcha because I’ve been hearing some people say that high flow cats don’t do anything to make it louder

 

[JExpedition07]

High flow cats won’t “wake up” the 5.4L. To wake up the 5.4L you do an intake and tune. Fords biggest drawback is that their drive by wire control is pretty lazy (when you punch it and the truck sits there and thinks before it gives the go ahead WOT signal). Intake and Retuning new software will take care of the drive by wire delay as well as adding a few horses. If you just want noise yes I’m sure high flow cats can accomplish that, but not much else.

 

[jeff kushner]

I know that they are completely different engines but one of the SLK guys in that forum and I did a LOT or "HP research" into the stock SLK230 supercharged engine. When Steve installed the cat, he hated it....the dyno showed 1-3HP out of a 2.3 engine and he didn't like the QUALITY of the sound. He specifically told me that it wasn't that it was too loud but that it sounded horrible, like a "ricer". Of course it would...it's a 4IL engine, just like half of Japan. Your big V8 will be much different but there might just be less expensive routes. Do you have Emissions testing in Georgia? Will it matter?

There is no muffler on it now, right? Bet it sounds badass as hell!


LMAO

jeff

 

[the.beast.2008]

sadly I do have emissions where I live which is why I cant just straight up cut them out (I would if I could) and im probably gonna try it out at somepoint and when I do I plan on making a video to explain it and really see what difference it makes to help others out which I will be posting on youtube. and I have a K&N intake and im planning on getting it tuned to fix the heaviness of the way that it drives now