dynatech exhaust cones

[Joe 1320]

I remember the "cone of silence" in the LT1 SS, I was thinking of getting one of these to see if I can cut some of the resonance from the 4" mufflex. Anyone had any experience with these?



The idea looks interesting, wonder how well it works without being a cork in the system.

http://www.jegs.com/webapp/wcs/store...tegoryId=19855

"The Vortex Insert Cone, installed near the exit of the header collector or muffler outlet, provides a large friction area to reflect and dissipate sound energy, thus reducing the dB level. Because no significant backpressure has been introduced, the engine is still able to use the scavenge ability of a good header to create horsepower and torque. Dyno and track testing show significant noise reduction with little or no power loss. Sold individually."

[Kevin - Blown 95 TA]

Hi Joe. I have one of those on the other side of the muffler on a borla system. It is essentially in series with the muffler and it is placed in the tailpipe coming out of the muffler to make it more quiet. Because of where I have it placed, it didn't seem to help the noise much. I also don't think it corked up the exhaust either. Maybe when the new engine is built, I'll try taking it out and see if it really makes much difference or not. It is also too expensive for what it does.

[Injuneer]

I bought a pair of them in 3" turndowns, but never added them to my system. I was going to dyno them, but we ran into some problems with the nitrous system, and I had to leave the car in the shop for them to finish the testing. They never ran the tests on the cones.

Last time I tried to take the "open" turndowns off my exhuast to at least measure the noise reduction with my Radio Shack noise meter, they were rusted to the pipes and I couldn't get them off without damaging them.

Someday, I'll try them.

The theory is that the open area in the elongated cones is greater than the open area of the pipe cross-section.

Seems like my car is all but forgotten...... maybe in the Spring

[Joe 1320]

Thanks for the responses guys. I'm not sold on spending that kind of dough on a whim. I was thinking of putting it way up at the end of the dual cat Y pipe, essentially at the very beginning of the 4" catback just to try and cut some 2-2.5K rpm resonance. If you guys haven't noticed anything than I'll just look into perhaps some dynamat sound insulation. It will add a few pounds, but would likely be worth it to me in it's sound deadening properties. The exhaust at wot sounds good so I don't want to mess with that either.

Something tells me those things are going to cause a bit of heat retention at the point of installation. Not sure if that would be good or bad. hmmm.....

[casey02ws6]

Joe -

The common fix for your problem around here is to put a bullet muffler in the I-pipe like the borla XR1. I have kicked it around because I have the same problem - except mine is better described as "rasp" - but just around the 2000-2500 RPMs.

[Injuneer]

When I ran the 4" Mufflex (the one Joe has in his car now) I had 3" Borla XR-1 shorties in each branch of the Y-pipe. It still had the chest rattling resonance in the 2,000-2,500rpm range. The LT1 has that sort of low end resonance, which the LS1 seems to lack.

[Joe 1320]

When I ran the 4" Mufflex (the one Joe has in his car now) I had 3" Borla XR-1 shorties in each branch of the Y-pipe. It still had the chest rattling resonance in the 2,000-2,500rpm range. The LT1 has that sort of low end resonance, which the LS1 seems to lack.

That about describes it. chest rattling. Oh well. The price you pay for performance.