Solution: get bigger turbos and get rid of drone. mufflers are for girls

 

Wow, that's a terrific looking exhaust. I really love the slash cut tips too. I'm considering a similar system, but it also has 2 resonators installed to take the edge off the drone. Since I also currently run an OEM exhaust without cats I suspect I'm in for a pretty harsh reality myself. Good luck getting the system to meet your needs!

 

On a serious note, I guess that does make sense. How large do turbos have to be on this application before you get into the realm of 'no drone' at cruising speeds?

 

thats actually an interesting point. my exhaust has much less drone and cabin noise then m3ntal's car that has the 4" slash cut tips. out systems are very similar and were made by the same person. i have no mufflers and he has two tiny ones.

 

I talked to Chris last night and he's got a really unique way to get rid of the drone without losing the glorious exterior tone. And once he nails it down with this exhaust it'll apply to any others. Crossing my fingers it works out. I'll keep you guys posted.

 

I'll try this argument with the wife

 

Subbed to see if/how the drone is resolved. System looks amazing! I'm just like you and scared of the drone as i drive my car constantly and sometimes a nice quiet freeway ride is a good thing on the way home.

 

There are "two" easy ways to solve drone that I have been waiting on a opportunity to play with for the exhaust we make. I did some research with University's physics department search engine, the easiest way is to make the piping thicker. The thicker the piping absorbs the lower frequenzy waves get cancelled out more. The thinner piping the more "resonating/drone". I'm sure you can think of the pros and cons of thinner and thicker metals. Method number 2, there is a patent on it. It basically a metal mesh weave that goes inside the piping. It is layed criss-crossing with each other, with 98% flow rate of without the mesh. It eliminates all drone. I want to try this but obviously patent in-friction.

 

There is a 3rd way that uses math. I've tried it on my camaro and it works exactly as promised. We shall see if we can get this one sorted the same way.

 

helmholtz resonator theory... yea I know all about it. Not enough room with a proper X pipe design exhaust to eliminate those drone wavelengths. Good luck.

 

Is the technique similar to APR's "RSC" exhausts?

 

Just use some decent mufflers it really will help... the bigger OD on the piping the louder- you know that... the smaller , shorter muffler( not resonators) the louder it will be... OEM tips make it quieter because the piping drop s to a little over 2"... etc... this is why I refuse to make them with only 2 mufflers.. in my opinion is is still to loud for 90% of the clients...
Burns stainlkess has nice ones but $250 a crack...

 

My thoughts are that there is alot of drone on a 3'' X- pipe type because of the large OD of all that piping,volume, which at low RPMs the velocity is not there in the exhaust gases to keep it from flowing fast enough in the piping??..Just my thoughts..

 

I understand you . The exhaust i sell is a race /track exhaust and it is advertised as that. I rather stay put than try to cater to everyone and still have those complain. you know what i mean. I like my exhaust for the sound it makes and Im happy.



Perhaps. Our Audi RS4 2.75" exhaust does not drone much at all, if any. Perhaps doing one for the Porsche's but I rather not at this time. I'm happy with my 3" I rather keep spending time in development into my aero parts.

Btw John. My exhaust showed 25awhp and 19awtq gain over a milltec exhaust with 100 cell cats while my exhaust had 200 cell cats.

 

Perhaps. Our Audi RS4 2.75" exhaust does not drone much at all, if any. Perhaps doing one for the Porsche's but I rather not at this time. I'm happy with my 3" I rather keep spending time in development into my aero parts.

Btw John. My exhaust showed 25awhp and 19awtq gain over a milltec exhaust with 100 cell cats while my exhaust had 200 cell cats.[/QUOTE]

At what power level were you at? But I could believe that..
I still do like your X- pipe merge design the best.. I just dont want something that loud and that drone .... But IF I go to 3071 turbos ,I will need it to get a bigger exhaust..

Also I wonder how a stepped pipe would work for keeping the drone down because that would be great for velocity while still being somewhat less restrictive....Perhaps a 2.5 to 2.75 to 3'' for drone concerns..