Which Muffler? Dynomax, Magnaflow, M&K - Dyno Charts

[RarlyL8]

We designed a couple high flow mufflers for the big bore and race engines that will accommodate different inlet types and tailpipe configurations. This solves the problem for those shoehorning larger engines in earlier chassis. The inlets, outlets and internal flow paths are sized for the engines output. This one uses 2.5" secondaries terminating in conventional 2-bolt flanges sized to match. Internals and tailpipes are also 2.5". Others use slip joints or v-bands. None are baffled as that disturbs flow.

[Bill Verburg]

Originally Posted by jj911c2

Bill - That setup looks nice. What model flowmaster muffler are you using?

I can't really can't remember it's been in there so long, probably definitely Flowmaster probably a 44 series

loud but livable for me, wouldn't be allowed at most tracks around here


This thread is timely as it just blew out over the weekend, Installed 2/12/2001, guess I got my money' worth

[Mr. Merk]

Got my Borla muffler installed. It's quite a bit larger, but lighter than the B&B. I have less real estate since I still have heat, so the muffler hangs down quite a bit under the valance.

Right away I noticed it has zero drone. Thank God. It's definitely not as loud, and does not have the same parking lot presence at idle or low rpm. It sounds pretty good under power at higher rpm. It's breaking in and getting better with more miles. Starting to hear a little off throttle burble, which I'm addicted to. It pulls good all the way up the tach. Not mad about it, especially knowing it'll get louder with time.

[JonT]

Originally Posted by RarlyL8

We designed a couple high flow mufflers for the big bore and race engines that will accommodate different inlet types and tailpipe configurations. This solves the problem for those shoehorning larger engines in earlier chassis. The inlets, outlets and internal flow paths are sized for the engines output. This one uses 2.5" secondaries terminating in conventional 2-bolt flanges sized to match. Internals and tailpipes are also 2.5". Others use slip joints or v-bands. None are baffled as that disturbs flow.

Hi Brian was this for a 3.6 by chance ? I'm looking for something like that for my 964 3.6 in my 80SC. How does that setup sound? Thanks

[Redliner911]

Maybe a dumb idea, but I wonder if it would be possible to do a single center outlet (to avoid the dual outlet drone) and then attach GT3 style tips to that single outlet so that it looks like a dual outlet GT3 style?

[Mr. Merk]

Originally Posted by Mr. Merk

Got my Borla muffler installed. It's quite a bit larger, but lighter than the B&B. I have less real estate since I still have heat, so the muffler hangs down quite a bit under the valance.

Right away I noticed it has zero drone. Thank God. It's definitely not as loud, and does not have the same parking lot presence at idle or low rpm. It sounds pretty good under power at higher rpm. It's breaking in and getting better with more miles. Starting to hear a little off throttle burble, which I'm addicted to. It pulls good all the way up the tach. Not mad about it, especially knowing it'll get louder with time.

It's definitely been getting louder. Still has more of a GT3 tone than an RSR growl.

I haven't noticed any drone UNTIL I removed the heavy sound deadening mat from the backseat/speaker shelf. It's still not as bad as the B&B, but enough that I'd like to try and remedy it with a light(er) weight sound deadening.

[jrwilson]

So it seems like there's two options for street use - the dual Vibrant Ultra Quiet Resonators in 2.25” and now the Borla? But the Borla looks like it needs a ton of fab to install?

I'll be running the Rarly8 headers with heat and I'm interested in max low-end torque and no drone at all as it's a purely touring car I'll be doing a ton of highway miles in, with a rebuild 3.0 CIS engine with 9.3 pistons but otherwise stock. So what's my best option?

[AlKidd]

Not sure where you saw the info on vibrant resonators. Ive seen info on vibrant mufflers but they are the same amount of work to use as the Borla.

Originally Posted by jrwilson

So it seems like there's two options for street use - the dual Vibrant Ultra Quiet Resonators in 2.25” and now the Borla? But the Borla looks like it needs a ton of fab to install?

I'll be running the Rarly8 headers with heat and I'm interested in max low-end torque and no drone at all as it's a purely touring car I'll be doing a ton of highway miles in, with a rebuild 3.0 CIS engine with 9.3 pistons but otherwise stock. So what's my best option?

[jrwilson]

Originally Posted by AlKidd

Not sure where you saw the info on vibrant resonators. Ive seen info on vibrant mufflers but they are the same amount of work to use as the Borla.

This setup looks a lot simpler to plumb than the Borla one.

[mikedsilva]

Originally Posted by jrwilson

This setup looks a lot simpler to plumb than the Borla one.

Yep, that was one of mine.. I started this thread in my quest for the penultimate muffler!
Turns out, there is no such thing.

The Vibrant Ultra Quiet system was almost too quiet when I first had it made.
But after a short while it burned through the packing and became much louder. At idle and cruise it was fine.. but when you planted the foot and the rpm were over 4000 it was mental. I will say though, that it worked.

I had previously tried a well known, off-the-shelf aftermarket muffler that ended up robbing me of power and torque. The custom muffler and also the GT3 that I ended up with, worked the best in my case.

[jrwilson]

So the Vibrant setup worked well and didn't rob power? It sounded good on the videos? It also has the added advantage of being one of the cheapest!

[Mr. Merk]

Originally Posted by jrwilson

the Borla looks like it needs a ton of fab to install?

I'll be running the Rarly8 headers with heat. So what's my best option?

They just cut out my B&B muffler and welded the Borla in. Simple muffler shop stuff.

If you have Rarly8 headers, I'd utilize their bolt-on muffler

[jrwilson]

They told me no mufflers in the foreseeable future so I'm looking for alternatives.

[RarlyL8]

We are building our standard 911 sport mufflers (that use the OE 2-bolt flanges) right now. Lead time depends on which model (tailpipe configuration) you prefer.

High Flow mufflers are build to order and match the tuned headers per application. The GT3 and S tailpipe options integrate into the muffler body; the R and Dual Out options exit the end caps. The exhaust flow from each bank is straight through and isolated in the R and DO configuration. Both have larger inlets to match the header secondaries, which depend on the application. We also use 2.25" inlets on the 2-bolt OE style flanges for engines requiring that size. Larger displacement or output bump up to 2.5" v-bands. The latter is what we would use for 3.6L stock engines. We recently finished up a system for a 400hp 4.0L engine early chassis transplant.

[AlKidd]

Other than where the sound deadening failed. You will want to shoot yourself if your stuck in a car at highway speeds with a drone or overly loud exhaust.

Originally Posted by jrwilson

So the Vibrant setup worked well and didn't rob power? It sounded good on the videos? It also has the added advantage of being one of the cheapest!

[mikedsilva]

Originally Posted by AlKidd

Other than where the sound deadening failed. You will want to shoot yourself if your stuck in a car at highway speeds with a drone or overly loud exhaust.

The Vibrant version produced the same amount of power as the 997 GT3 muffler that I ended up using. No discernible difference. The 997 GT3 seems to have a good reputation for decent power production.

Although the packing on my Vibrants seemed to 'burn out', it was only loud when you were hard on the throttle. Light cruising and acceleration were no problem at all. There was still zero drone in my situation.
It really surprised me, since when I first had it put together, I was completely disappointed as it was just so quiet at all rpm. Clearly, I asked too much of it!

[Focker]

I'm strongly leaning towards the 2.5" vibrant resonator route or the big borla muffler. I have a magnaflow installed now as a temporary measure as I'll need to have the car inspected to get it on the road.

[mikedsilva]

Originally Posted by Focker

I'm strongly leaning towards the 2.5" vibrant resonator route or the big borla muffler. I have a magnaflow installed now as a temporary measure as I'll need to have the car inspected to get it on the road.

I'd like to try that Borla... we don't have it here in Aus, but to order from usa with freight is drug money expensive with the exchange rates...

[AlKidd]

Getting it in Canada isnt much better. Cheaper shipping but exchange + Vat of 13% starts to add up real quick

Originally Posted by mikedsilva

I'd like to try that Borla... we don't have it here in Aus, but to order from usa with freight is drug money expensive with the exchange rates...

[3literpwr]

+1 for the Borla, it's pretty nice.