Dynomax Bullet Noise Reduction
 

How much noise reduction does a Dynomax bullet provide? Thanks.

What is it?

your exhaust is pretty damn quiet allready man.. why do you need quieter?

I somewhat disagree, but if/when the cat goes I'll need to quiet it down a bit.

The Dynomax bullet is pretty much as 1987RX7guy suggests. It seems to be specifically designed designed for race applications and is considered good for some very high temps.

Dynomax is quality stuff, at least their stuff I have used on previous vehicles. Dynomax has never let me down on sound quality.

Is this 'bullet' model SS or just regular steel?

I think they may just be aluminized.

I have this muffler on my Subaru impreza. I got the 3in in and out and 18" long one. This is the only muffler I have on there and it doesn't seem to make it any quieter than when I had it 3in straight piped. it does give it a even more lower grunt without the high pitch noise. Basically it is what it is said to be a race muffler. Also one note, if you get one, paint it with some high temp paint as it will rust. Mine started rusting about a week after I got it, a little bit of high temp flat black and no more rust issues. I have attached a picture of mine.

It's a race muffler - read, it doesn't do jack about killing the noise.


-Ted

Thanks for the testimonial. That's about what I expected. I guess if you can't tell the difference between wide open you can't say much. Do you have any experience with other race mufflers that are worth commenting on?

haha, sorta kinda...

Nope, all race mufflers I've ran into didn't do jack.
You might get away with proper placement, as this seems to work sometimes, but only in certain RPM ranges.

If you place a muffler (any muffler) where the stock cat is, this kills some of the noise under 3kRPM.&nbsp Place it a little forward from that position, and it shifts it a little higher.&nbsp I don't think you can suppress all the exhaust noise across the entire RPM band with a single muffler in one position, except with something not very free flowing.&nbsp There are mufflers (more like cat-back) systems that kinda "cheat" and run their perforated pipe at an angle - this applies to the Racing Beat 3" (old - I dunno about the new system), and the GReddy PE stuff; this keeps the "straight through" design, but due to the angle, it allows the exhaust gases to get absorbed more.


-Ted

Well then I'll ask the question I'm really trying to answer. Essentially I'm looking to emulate the racingbeat philosophy, performance without raising the volume level too much above OEM. While we're at it I'm thinking of replacing the muffler at the back too. I know what I've written risks getting the post discounted as shit, but this stuff isn't covered anywhere! Real numbers/comparisons would be appreciated.

Find a muffler that has a straight-through perforated tube, but is angled and it'll get the sound suppression.


-Ted

Something like this, right?

http://www.dynomax.com/images/UltraFloSS_cutaway.gif

Fiberglass? I give it 15 minutes to survive.

Yeah, that'll work.&nbsp With the muffler in the rear of the vehicle, the EGT's should be pretty tame by then...under 1000F.&nbsp It should be alright.


-Ted

What would be the EGTs on the main cat?

I was wondering if I could use one of this as a replacement of the main cat...for those track days :o:

The center of the car should easily see temps in the 1000F to 1200F.


-Ted