bascho

Drone city [:@] and loud as hell. Good loud from the rear of the car but bad loud inside the car.

I have the GTA mufflers and before the o/r h-pipe I had no drone at all. Now with the h-pipe I have drone in the 1000-1800rpm band and in the 3000-3500 band. I also have some wicked vibration in the trans tunnel.

I know I have to bend the mounting rods a little because once bolted to the engine they are really tight up against the bushings.

I am not happy at all. What can I do about the drone?

TacoBill

Put your factory catted H back on. Or, get some ear muffs.

The O/H isn't for everyone... that's a fact. I for one, love it. [sm=smiley20.gif]

bascho

So your's drones also? I was hoping that different mufflers might help. I love the sound outside the car......but since I have to drive it from inside, I would like less drone. There is no going back to the stock catted h-pipe, I had to cut it off to get to thenuts on the passenger side manifold.

I'm sure some of the vibration is just the mount and that makes the droning worse inside the car. Also, because that mount is so tight it's possible I'm getting a small leak at the manifold. I put my hand up there after the install to check......didn't feel anything. But it sounds like a manifold leak from the inside of the car when you start revving.

TacoBill

I had the FRPP Stingers on prior to installing the O/R-H. There was already some moderate drone coming from the Stingers. After installing the O/R-H, it did amplify the droning. And yes, around 1800-1950 rpm's, the drone is almost deafening.

I had no install issues at all. I'm guessing you didn't spray any penetrant oil onto those manifold nuts before attempting to crack them loose?

I did not have to bend or modify either of the hanger rods, mine fit perfectly.

Also, I hope you put some anti-sieze lube on those manifold nuts before re-installing them. It'll make for easy removal if need be.

I have a write-up for the O/R-H, I should post it up here to help others considering this mod.

bascho

For the drone issue I am going to follow Crazy Al's recommendation to use resonators.

The nuts came off just fine......it was getting to them that was the pain in the a$$. I don't have to modify the hangers much.....just bend them back a little so that it's not so tight. With the manifold nuts tightened down, the hangers are literally pushing the bushing forward in it's bracket rather than just resting in it. I want to bend the hanger so that I have about 1/2-3/4 of an inch between the back of the bushing and the bend of the hanger rod.

MIKE562

+1 The o/r h-pipe is not for the faint-hearted!!!! I love it tooo

bascho

The issue isn't me not liking an o/r h-pipe. I had a 1966 with headers that dumped into 2-chamber Flowmasters.......no drone at all. Had a 1993 Cobra with o/r h-pipe and didn't have anywhere near this much drone. I'm no stranger to muscle cars and loud exhaust......but there is good loud and drone loud. Like I said, from the back the car sounds amazing......but inside the car sounds like I have a 72Novawith a rusted out hole in the muffler..

TacoBill

It's one of the pitfalls of having over-axle mufflers.

I've heard clips ofO/R-H's with resonators and from what they said, it did eliminate some of the drone, but also quieted the exhaust. Finding the perfect combination of loud with no drone or trumpeting will take a lot of experimenting and $$$.

bascho

I just checked out your write-up on your H-pipe install and I noticed something very interesting. Your hangers are a perfect 90deg bend and are welded nearly perpendicular to the pipe. Mine are more of a 110deg bend and are welded to the pipe at a forward slant. Strange since we both have Pypes.

I should have rebent those damn hangers last night [:@] I'll bet even though the nuts tightened up at the manifoldthat I have a small leak because of how tight those hangers are to the bushing. Not to mention I probably have more then the intended amount of vibration because the bushing is being pushed through it's bracket (hense the bend of the hanger is tight against the bracket around the bushing).

I'll get back under there this weekend and see ifI can't fix a few concerns.

Thanks for the help.

SonicBlue05GT

you could always put the stock mufflers back on with the O/R H. I tried that and it sounds pretty good. No drone at all and only loud when you stomp on it.