Don Terrill’s Speed-Talk

SpeierRacingHeads wrote: ↑Fri Jun 26, 2020 10:04 am 17225 Dynomax straight through. Not sure I like it.

SpeierRacingHeads wrote: ↑Sat Jun 27, 2020 11:09 am...I'm having a round aluminum muffler made for it...

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

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.

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":





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.

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":





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.

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