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Re: Straight through mufflers

Posted: Fri Jun 26, 2020 6:20 pm
by gmrocket
SpeierRacingHeads wrote:
Fri Jun 26, 2020 10:04 am
17225 Dynomax straight through. Not sure I like it.

Ya, I don’t like it either

Re: Straight through mufflers

Posted: Fri Jun 26, 2020 6:42 pm
by GARY C
In car is probably very different then laying in the driveway behind it?

Re: Straight through mufflers

Posted: Sat Jun 27, 2020 11:09 am
by SpeierRacingHeads
It's totally different in the car and in person. The Flowmaster Ultra was louder in the car. I'm having a round aluminum muffler made for it.

Being a 4" system, the muffler selection is thin.

Re: Straight through mufflers

Posted: Sat Jun 27, 2020 9:59 pm
by MadBill
SpeierRacingHeads wrote:
Sat Jun 27, 2020 11:09 am
...I'm having a round aluminum muffler made for it...
You wouldn't want to run Bonneville with one. Aluminum melts at ~ 1250° F. and loses half its strength by 600°.
Decades ago, I used a relatively giant 2" aluminum tailpipe on an 850 cc Morris Mini road race car. After one track session, it had sagged between the hangers like a power line in summer. Second time out the front three feet fell apart. :oops:
1962 Pontiac Catalina 421 Super Duty street legal drag cars were optionally available with aluminum exhaust manifolds. Owners were cautioned not to use full throttle for more than 15 seconds...

Re: Straight through mufflers

Posted: Sun Jun 28, 2020 5:44 am
by ptuomov
Aluminum case with sound absorbing material should work as long as the perforated pipe going thru is stainless steel, no? Motorcycle mufflers appear to be mostly aluminum and plastic and hold up fine, because the pipe itself inside is by my understanding steel.

Re: Straight through mufflers

Posted: Sun Jun 28, 2020 5:30 pm
by tjs44
Has anyone ever tried 2 diff mufflers to break the resonance of the drone?Im thinking of just putting one of my Hushpowers on to see if it makes any diff.If no change than I just need to decide which one I want to change afterward.Tom

Re: Straight through mufflers

Posted: Sun Jun 28, 2020 5:42 pm
by ptuomov
tjs44 wrote:
Sun Jun 28, 2020 5:30 pm
Has anyone ever tried 2 diff mufflers to break the resonance of the drone?Im thinking of just putting one of my Hushpowers on to see if it makes any diff.If no change than I just need to decide which one I want to change afterward.Tom
You mean like this?

viewtopic.php?f=1&t=61506&start=45#p868322

Re: Straight through mufflers

Posted: Sun Jun 28, 2020 11:51 pm
by lefty o
a smaller muffler after the standard muffler used to be called a resonator, well it still is by the ricers.

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 8:56 am
by autogear
lefty o wrote:
Sun Jun 28, 2020 11:51 pm
a smaller muffler after the standard muffler used to be called a resonator, well it still is by the ricers.
My parents brand new charger has cats, at least 1 muffler and resonators. The resonators are BIG.
The guy that makes Classic Chambered exhaust, does a combo of the chambered 'muffler' and a glasspack-style resonator, as a 1 piece deal, about 30" long total (I think).

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 10:49 am
by SpeierRacingHeads
I put 100 miles on it this weekend and it's not loud in the car at all. I could carry a conversation with no problem.

It's sounding a little different now that when it was new. It's not bad, keep it on for awhile.

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 11:53 am
by CGT
ptuomov wrote:
Thu Jun 25, 2020 8:26 am
travis wrote:
Thu Jun 25, 2020 3:28 am
“A” would be correct, but for now it’s just a temporary exhaust system. I’m going to add a crossover of some sort, probably an X pipe
My car went from true separate duals with a single straight thru muffler on both sides to this, also with straight thru mufflers, and the sound improved dramatically despite the pipes being upsized from dual 3" to dual 3.5":

Image

Image

Functionally, it has a Y-pipe that divorces into two legs again, which have (Borla) straight thru mufflers. After the straight-thru mufflers, the divorced pipes are unequal length before they merge again into a (custom) tail pipe-muffler. So the system has two cross-overs and unequal length path between the two, which I am guessing is important for the success.

I think that a "two-crossover" system with an X-pipe, two straight-thru mufflers, unequal pipe lengths routed to one side, and a single tail-pipe muffler merging both pipes is a recipe that might work more generally for any car where it's aesthetically acceptable to have a single tailpipe exiting from one side (looks IMO good on for example pickup trucks). One would have to basically win the lottery to by chance get it fabricated with enough equal length segments for it to drone at any rpm. It will also usually use a lot of the available volume for mufflers which is key to noise suppression.
That exhaust system is extremely, nicely fabricated. Are you the fabricator of that? Really cool.

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 12:26 pm
by ptuomov
CGT wrote:
Mon Jun 29, 2020 11:53 am
ptuomov wrote:
Thu Jun 25, 2020 8:26 am
travis wrote:
Thu Jun 25, 2020 3:28 am
“A” would be correct, but for now it’s just a temporary exhaust system. I’m going to add a crossover of some sort, probably an X pipe
My car went from true separate duals with a single straight thru muffler on both sides to this, also with straight thru mufflers, and the sound improved dramatically despite the pipes being upsized from dual 3" to dual 3.5":

Image

Image

Functionally, it has a Y-pipe that divorces into two legs again, which have (Borla) straight thru mufflers. After the straight-thru mufflers, the divorced pipes are unequal length before they merge again into a (custom) tail pipe-muffler. So the system has two cross-overs and unequal length path between the two, which I am guessing is important for the success.

I think that a "two-crossover" system with an X-pipe, two straight-thru mufflers, unequal pipe lengths routed to one side, and a single tail-pipe muffler merging both pipes is a recipe that might work more generally for any car where it's aesthetically acceptable to have a single tailpipe exiting from one side (looks IMO good on for example pickup trucks). One would have to basically win the lottery to by chance get it fabricated with enough equal length segments for it to drone at any rpm. It will also usually use a lot of the available volume for mufflers which is key to noise suppression.
That exhaust system is extremely, nicely fabricated. Are you the fabricator of that? Really cool.
Nope, I did no fabrication on it. It was all John Kuhn Of Kygn a Performance Technologies. I did participate in the design effort, including estimating the exhaust gas temperature losses and density gains, researching the supersonic blast waves, and simulating the exhaust sound frequencies with Vannik’s software. But is did no fabrication (which is more than coincidentally related to the exhaust looking so good).

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 12:38 pm
by Belgian1979
tjs44 wrote:
Sun Jun 28, 2020 5:30 pm
Has anyone ever tried 2 diff mufflers to break the resonance of the drone?Im thinking of just putting one of my Hushpowers on to see if it makes any diff.If no change than I just need to decide which one I want to change afterward.Tom
Yes, bullet style under seats and magna flows in the back. All straigth thru. No backpressure, great sound, but a little loud to cruise imo. Was looking at a bit more muffler under the floor pan.

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 3:00 pm
by tjs44
im talking about putting a ST on one side and a Hushpower on the other side.No room to put 2 in a row under my bird.Tom

Re: Straight through mufflers

Posted: Mon Jun 29, 2020 3:03 pm
by tjs44
I dont care if i loose 50 HP if I can kill the drone.Car operates 99.9% of the time from off idle to 2500 max.Cruise either in 4th on the street of 5th on the freeway is at 2000.Tom