Hey Tom and Ray,
I would like to upgrade my toyota tacoma exhaust system. If I use the flowmaster 50 series muffler, and an Eastern free flow catalytic converter, do you think I will get any better torque, and HP, or is all that just BS?
The results are car (make model and year) specific. Some will provide more torque and power, but likely it will be minimal.
Back when I was a kid in the 1960’s it made a big difference in almost any car. Today, the manufacturers figured all that out and found that making free flowing systems was a cheap way to get more power and maybe even a little better mileage.
There is little to gain with today’s cars.
If your goal is more noise, then that can be accomplished with that kind of work.
If your true goal is to be noticed, just remove the mufflers completely (like Harley riders do) and have an exhaust shop run 3" tailpipes with 4" chrome extensions out the back…Your stock converters will act as crude mufflers and keep the noise down to a dull roar…
Not likely to help much, if at all. They’re good for making noise, makes you feel faster. But that’s what many like. If you want HP, you need to spend $$$.
On that particular truck, don’t look for any real difference, the stock exhaust system is adequate for the small 4 cylinder and V6’s that come in the these trucks. The exhaust tone will change, if you have a 4 cylinder it’ll sound like a weedeater. If you have the V6, it’ll be louder, but it won’t have a throaty low rumble/burble that you get from a V8. Exhaust sound is subjective though.
Any perceived improvement will be only from a placebo effect. The engine is not designed for performance, and its restrictions to breathing fuel in and pushing exhaust out are in the intake, the manifold, the valvetrain, and the heads (ports).
Said simply, your stock exhaust is capable of allowing all the gas flow that the engine is capable of pushing out without undue restriction. Therefore, upgrading only your exhaust will have negligable if any benefit.
Which is also ILLEGAL…and won’t pass inspection in any state that has state inspections.
Something else important to note is that claimed horsepower gains on aftermarket parts are not linear.
In other words, if I get a new catalytic converter that claims a gain of 5 horsepower, and a muffler that claims a gain of 8 horsepower, I will not drive away with 13 more horsepower.
Also, it’s generally claimed “up to” however many horsepower. The number they give is probably assuming a lot of things, like “he also replaced the entire exhaust, the headers, and the intake, with higher performance parts.”
Yet another thing to note is that modern naturally aspirated engines are designed to work with a bit of back pressure. If you get rid of all or most of the back pressure by doing a free-flowing exhaust, you may actually lose horsepower.
All this is of course general theory, and not specific to your truck. I’d recommend finding a Toyota enthusiast board, reading it for awhile to be sure they know what they’re talking about, and then asking them.