Hi everyone, I will be getting real active on this forum here this winter (big big plans for the truck i.e lift, supercharger, coilover conversion etc..) and am still in the planning stages.

My question for now....Does the FX4 LVL II from 04 have an louder exhaust? My sister has a 05 B4000 with the same SOHC 4.0 and exhaust, and it sounds like a stock vehicle, but mine definitely has a louder meaner tone. I assumed it had aftermarket mufflers on it when I bought it. After getting underneath, the cats are there, there is no evidence of cutting or welding that I could see, and the muffler had the same oval tube shape (couldn't find any aftermarket markings) as my sister 4.0. I will have to check again when it stops raining, but for now I thought I would pose the question to you guys.

I need a definitive answer, because installing the moddbox supercharger assumes you have stock engine. I worry that I may have some sort of mod to the engine that is making it sound "throatier", since the exhaust appears to be stock.

 

I just got under the truck again and still cannot see any signs of of exhaust alteration. Both cats are there, single old rusty pipe running to a passengers side oval rusty tube on rusty hangers, exiting through a stock 90 degree bend out the passengers side.

A little history on the truck. I bought it in June of this year down in Vegas. It is a bright red 2004 FX4 LVL II Manual. It had 109,000 miles at purchase. Stock everything except a crappy radio, and the original Bilsteins were replaced with stock 4.0 shocks. Stock wheels, tires, interior etc... I didn't bother looking at the VIN to verify if it was a true FX4 LVL 2, or if that is possible to tell via the VIN, because it had everything (skid plates, Torsen, 8.8 31 spline, Alcoas and Bfgs, black interior, chrome shifter etc..) I did do a carfax, and it was most likely owned by a military member because it was in North Carolina, then Hawaii, then Vegas. My guess is an older guy, because who the heck replaces Bilsteins with stock shocks???? Also, there was no off-road damage. The skid plates were immaculate, along with all other metal underneath, just some surface rust from being in salty environments.

My last truck was a 98 Ranger 3.0 Manual. It had Flowmasters on it, and so does just about every other car or truck in the family, so I am familiar with exhaust tones. Especially since My sister has an identical engine and exhaust parked next to mine, and they sound different. Her's is quiet and dull, not loud, not deep at all. Mine sounds like a toned down version of the flowmasters on my old 3.0. It has tone, sounds "throatier" and has a drone that reaches the cab at any speed. It isn't as loud as my old 3.0 flowmasters, but it is certainly louder than my sisters exhaust.

So, what kind of mods could account for an increase in exhaust tone? A tune? I need to debunk this, so I can pull the trigger on my moddbox kit!

 

58 views and not a single thought? C'mon guys help me out!!! I really have the bug to get this baby supercharged.

 

There shouldn't be any difference engine/exhaust wise between a Level II and any other models with a 4.0.

 

Exactly. But there definitely is in my truck. Perhaps I will make a video and link it.

 

Did you check the exhaust manifold for any leaks?

Did you check the entire length of the exhaust for any holes or loose connections (at the cats and muffler)?

 

pictures, videos something. You 100% sure its stock?

 

Any possibility your muffler or pipe has some rust that could cause it to be louder? The exhaust on those 2 trucks should be identical.

 

My 02 FX4 sounded OK at idle and part throttle with the stock exhaust but had a terrible whoosh (almost hiss) sound at WOT. I could not stand it and installed a Gibson cat back system with less than 1,000 miles on the truck. I have a feeling someone installed a cat back system on your 04 if it has a decent sound to it.

 

So... I got around to inspecting it again, and even made a comparison video between my truck and my sisters........I found the problem! Upon an extremely thorough inspection from the headers all the way to the tailpipe, I found an actually quite large hole, directly on top of the muffler, where it is out of sight. What is interesting, is that because of where it is, if resonates directly off the truck bed and makes it sound not half bad, and also tricked me into thinking it was coming directly from the tailpipe. I also believe it to be the culprit of premature rusting of the bed underside, as there is a small hole in the area that should not be there. I will have to patch it with my new welder while I have the bed off installing the fuel pump and new leaves and painting the frame etc...

Moral of the story, stock mufflers are made of shitty metal. Double check it all. I have since ordered my Moddbox kit, and am in the process of rebuilding my m90! They had 10% off everything, and free shipping on Magnaflow exhausts, so I got Magnaflow's turndown system for the truck. It is gonna be sweet!