[Tomo]

Finally got rid of the annoying exhaust drone on my 64 462 GTO. The car has no name tri-y headers and 3" mandrel bent exhaust, with 3 chamber flowmasters as well as a 3" crossover
pipe. These pipes exit behind the back tires. I installed 3" Car Chemistry exhaust inserts into the header collectors and viola... no more drone. I can actually listen to the radio now!!!

tom

[Tomo]

Finally got rid of the annoying exhaust drone on my 64 462 GTO. The car has no name tri-y headers and 3" mandrel bent exhaust, with 3 chamber flowmasters as well as a 3" crossover
pipe. These pipes exit behind the back tires. I installed 3" Car Chemistry exhaust inserts into the header collectors and viola... no more drone. I can actually listen to the radio now!!!

tom

[Black 65 GTO]

Tomo,

Did you use the two or three disc version? I have a nasty resonance with my 2 1/2" 2 chamber Flowmaster system, at about 1900-2000 rpm, maybe this is the answer.

[Black 65 GTO]

Tomo,

Did you use the two or three disc inserts? I have this nasty resonance at about 1900-2000 rpm with my 2 1/2" 2 chamber Flowmaster setup. Maybe this is the answer!

[Will]

Tom,

Where'd you get the mandrel bent 3" exhaust?

What are those inserts like? I'd be afraid they'd cause some restriction... How do they work?

You can often cure drone by extending the tailpipes all the way out the back, so they exit under the rear bumper. From all the people I've talked to, and my own experience, I'd say pipes that exit right behind the rear tires aimed at the ground produce a fair amount of interior droning and increase noise levels both inside & outside the car. By extending the pipes so they both exit out the back under the bumper, interior noise levels are greatly reduced and exterior noise levels are reduced everywhere except directly behind the car.

[Will]

Dang, what is up with this board? When I wrote the above post, I couldn't see ANY of the replies. Once my reply was added, everything appeared.

[Tomo]

First I used the 3 disc setup from Car Chemistry. I got the exhaust from a place in Arizona ... bit Torque Tach in Valdosa, Ga sells the same thing. The 64 GTO has the exhaust exiting behind the tires... thats why I ordered the kit that way. As far a restrictions to the exhaust with these in the collectors... I seriously doubt it. These things consist of a metal tube with holes in it with 2 or 3 disc around this. It uses some time of noise cancellation technique . They have a WEB site WWW.Car Chemistry.com.
tom

[Black 65 GTO]

Sorry about the fifty million extra post's, for some reason my post's did not show up until today!

I'm using the Torque Tech 2 1/2" mandrel system with 2 chamber flowmasters. The pipes exit right behind the rear bumper and are of the turn down style. I'm pretty satisfied with the sound quality, but the resonance is pretty loud at about 2000 rpm.

[Joel Koontz]

It appears that you used two of them. Did you happen to try it with just one? I wonder how that might work. I also have headers(4 tube) 3" pipes and X-over. I'm very happy with the higher RPM sound but I also have some droning/resonance up to around 2000 RPM.

Has anyone else tried these?

Thanks, Joel

[Tomo]

Yes, I used one per collector. Hit them with a grinding wheel, cut them as short as is allowed in the instructions and hammered them right in. No problem at all.
tom

[Skip Fix]

Every Flowmaster I've had on my 78 TA has had a drone/resonance problem.