Im getting some real bad resinance around 2000 rpm, the whole car shakes. I figured it was my exhaust touching in a few places, i fixed that and i still have this awefull resinance, any ideas on what it is or how to fix it?

 

I hate that sticky stuff too. Good Luck.

 

mine has verry litlle resonance but I have headers

 

Yea, mine from 1500-2000 is overwhelming sometimes. I have manifolds (for now), no cats and Magnaflow.

 

i never noticed it before, could have been due to the exhaust leak i had. but i have hooker shorties mf high flow cats and the full catback with xpipe

 

I just turn up the stereo...

 

If only people had posted on this before.....

 

can you say search

 

Yeah, mine drones like that too - and the funny thing is, it was the same with no mufflers at all. FWIW, I just took a short drive in mine with the top off (first time I've done that) and no resonance problem with the top off.

Time for 3.31 or 3.45 gears to get past that RPM range?

 

so there is no real fix for this, or is it in one of these other threads you are telling me to search for?

 

You can put the stock system back on including the resonator if it was removed. The LT1 system is a good one.

 

There is a solution (kind of) to your problem, but it's probably not the quick/cheap fix that you're hoping for...

The bad news is, you're pretty much stuck with that resonance because you chose to go with a Magnaflow exhaust. They sound great, yes, but the problem with Magnaflow, (like every other aftermarket exhaust for the C4) - is that it creates resonance or "drone" inside the cabin. Some people don't mind it. Others get used to it. Some hate it and try desperately to get rid of it.

Only time will tell which of those groups you'll fall into...

Unfortunately, there's just no quick fix for this problem. It's your mufflers "design" that's causing the resonance and short of ditching the mufflers for something else, you're going to have to learn to live with it

If it's really THAT big a deal for you, you should seriously consider purchasing a Corsa exhaust system. You can always put your Magnaflow set-up for sale and get a pretty good price for it. Put that money towards getting the Corsa and Presto! Problem solved.

I know it sucks to have to go out and buy another exhaust system, but it's really the only way to solve the issue you're having.

I hate to sound like an infomercial, but there's a reason why Corsa costs more than other brands. It's the only performance exhaust designed specifically to eliminate interior resonance. No other exhaust cancels out the drone like a Corsa and that's why it's so popular among C4 owners. You get what you pay for.

There are always those that will complain about the cost of a Corsa and claim it's "over-priced" and "not worth it" etc, etc. They go out and buy another brand to save some cash and 3/4 of the time you end up reading a post a month later by these same people asking what they can do, to eliminate the "drone" problems they got after installing "brand - x" exhaust.

I've read hundreds of of posts very similar to yours, with people trying all sorts of stuff like, buying different cross-over pipes, changing cats, adding additional resonators, stuffing steel wool into their mufflers ( ) and/or adding 50lbs worth of Dynamat to their interior etc. etc. - all this, because they didn't want to save up the extra bucks and get a system designed to eliminate drone to begin with...

Some people are stubborn and like to learn things the hard way. (Not saying you're one of them)

Personally, I'd drive the car for a little while longer, and see whether or not you can live with the resonance. If you don't mind it, keep the Magnaflows and enjoy. It's a really nice sounding system and the tips look awesome!

If you can't live with the drone and it bothers you that much, save up some money and buy a Corsa.

Whatever you do, DO NOT waste money on useless crap to try and eliminate the muffler drone because it's the mufflers themselves, that are causing it. Keep them or ditch them. Those are your options.

Sorry for the long post

 

The fix options are subjective. I don't think it's the brand Magnaflow, it's the choice of components and their ability to "muffle". Some tuning is envolved as far as the pitch of your exhaust but I think that's more attributable to pipe size.

I can tell you haven't tried a search by your statement above. Why don't you look at the variety of suggestions to see what people have chosen. I will say there is NO right answer. The poster above says Corsa's are the key. SlickFX3 recently said they suck and pulled them off.

Unless your exhaust terminates before the rear of the car, you'll need to add/replace pieces to "cure" your problem. There is a faily recent thread -- plus TONS more on this topic.

You can sit around and wait for opinions or read, read, read.

BTW...If you do a search, look for resonance NOT resinance.

 

If you plug one pipe in each muffler, the resonance will go away.
The reason is that you have two colliding sound waves inside the muffler. when the pulses slide down your tail pipes from your engine, they have a speed and concussion pressure.
WHen they meet inside the muffler because they are bouncing around inside trying to get out, they collide, and the collision is the resonance.
The reason factory mufflers do not resonate is because they have a chamber inside that the pulses go into. The pulse goes in, and then hits a dead end, and bounces off the wall in the muffler. The pulse then heads back out to the "door" it came in, and hits another pulse head on instead of colliding with it moving in the same direction. The two pulses hitting head on cancel each other's sound waves, and the resonance is gone. These mufflers are termed "restrictive" and do not produce as much power.
The chamber place that the pulse goes back out the door is called a heimholz chamber. It was discovered about 1917 by a german scientist.
Those chambers cancel pretty good. I have 1990 convertible mufflers. They are big, and are the least restrictive of the stock mufflers, and they are quiet. They look like big cans with pipes.

 

Hey look Gregg, another local guy. Parkville's only an inch away on the map.

I don't think it's the brand. I've had Magnaflow on two cars and they sound great IMO. There are alot of factors at work here that can cause this. My set up doesn't resonate, at least not yet. I am currently running a Magnaflow dual in/dual out in place of the stock resonator with no mufflers. The rest of the system is stock (pipes, manifolds, and cats) with stock LT1 tips.

When I first removed the mufflers, I experienced terrible resonance right in the rpm range you mentioned. I almost put the mufflers back on. But, while shopping for aftermarkets, I found the dual in/out. It has a built in x-pipe and sound absorbing material. Paid less than $100 for it from Summit BTW. This took all the resonance away. But there is another thing I noticed, and may have alot to do with resonance complaints on these aftermarket systems. I noticed that the tips were extended about a 1/4" beyond the bumper and aimed slightly downward. IIRC, they tips were flush with the bumper before the Magnaflow install. I can see where this tiny little detail could make a huge difference when comes to sound inside the car.

 

LT1 c4 imo said all you need to know reread is post

 

I have a cross over type Y pipe where the Magna Flows mount I have very little resinance around 2000 rpm.

I have Magna Flows with LT-1 Tips.

I was worried when I put the Magna Flows on my car I had a set on my Full size Dodge PU I hated them I end up going back to a stock system.

 

Hey, where did you find this item? I tried to find but didn't have much luck.

 

Exactly!!! I tried 3 different exhaust systems before finally getting the Corsa's. There are a lot of Corsa Haters out there for whatever reason but, Corsa is the Only muffler that Eliminates exhaust Resonance.

 

Corsa or stock your only 2 real choices