There are many that are considering buying an aftermarket muffler for their vehicle. There is a lot to choose from out there, all with their unique benefits and sound. I purchased the Flowmaster Super 40 Series Muffler. Flowmaster claims it to be one of their loudest, high flow mufflers. According to Flowmastermufflers.com “The Super 40 has that “deep powerful” sound of the original 40 series but with all the benefits of performance and low interior resonance from the “Delta Flow technology.” I have to say that I agree with the fact that it has a deep powerful sound, however, the interior resonance is significant. I have not heard the interior resonance of a delta flow, but the Super 40 Series still has quite a bit of interior resonance.
I put this muffler on a 2001 Toyota Tundra 4.7 Liter V8. I ordered the muffler online, and when it came I took it and the truck to a local muffler shop and had it installed. The shop simply cut out the stock muffler and installed the new one. The resonator was left alone. I also added a stainless steel tip. From day 1, I have been very impressed with the sound of it.
Between.5 & 2 RPM’s the sound is very throaty and deep, especially when I an really on it, however as my RPM’s increase above 2.5, the sound from the cab get a little quieter and the rev of the engine takes over the sound from the tail pipe. It still sounds really great in my opinion, it’s just not quite what I expected.
As far as performance is concerned, I feel that I have lost a little low end power. With high flow mufflers like this one, this can be common. The horsepower gains that are claimed are true, however, the increased horsepower is found at the higher RPMs. The loss in low end power is enough for me to notice, but not enough to make much of a difference. (I’m picky)
I have not noticed an increase in MPGs. I was hoping that I would, but it remained unchanged. (even with a K&N drop in air filter). I continue to get between 16 and 18 MPG.
* Deep throaty sound in the cab and out.
* Great price.
* Increased power (high RPMs).
* Not a stainless steel construction, instead it is painted. After several months of use, the lovely black paint has almost all burnt off.
* Around 65 – 70 mph, there is interior resonance that I just don’t like. It goes away at about 72 mph, so not a big deal. I liked it at first, but gets annoying after a while.
Overall, the Flowmaster Super 40 is a great product. I really like the sound of this muffler. It is deep, and smooth. It’s not raspy and “rackety”. It produces a powerful sound and really lets you hear the beast that the 4.7 Liter i-force is. It’s one of the best Toyota aftermarket parts I’ve purchased.