PLRX

I lost another battle with Magnaflow, and this one is the last one. It is my duty to inform
all C4 owners of my experience with the Magnaflow Cat-Back System and SS Mufflers.

Last Year I had a misfortune with the SS mufflers in my 95. I was way away from home
when the brackets failed, and cost me $100+ to put a band aid on it.

More details HERE


I bought the CatBack system for the 96, shortly after I bought it the right muffler's bracket
broke off. The magnaflow dealer/muffler shop welded it back for me at no cost. Shortly after
that the resonator tangled with a rock, and it was removed. There was some weird stuff
inside (it was a Y pipe), and I decided not to fix it, and it was removed and replaced with two straight pipes.

The Magnaflow resonator is bigger than the OEM resonator. This is how it looks. Another design flaw, it
is too big for the tunnel and too low that passes the floor level.



Back in June for the Hot Rod Power Tour I drove from California to Detroit. I met with Mike and Greg. The
day of the registration I noticed the passenger side Magnaflow muffler was hanging. Evidently, the bracket broke off again.



2,500+ miles awy from home, and I had a muffler hanging. I remembered the NAPA by my
house sells a long clamp. I found a NAPA, and bought two clamps. Once I got to the hotel it
was raining. Got my back soaked and wet, but the clamp did the trick, and held the muffler on
place all the way back to California.




We finally made it to Texas, and had a conversation with one of the Magnaflow reps there.
I explained to them everything. I told him that the only thing I would need is to replace the muffler.

http://forums.corvetteforum.com/c4-g...post1581095500

Few weeks ago, they finally got back with me. Now hear this due to the fact the resonator
was replaced, and it was tossed away because it looked all bulged up Magnaflow will not
replace the mufflers. They state they can not replace only a muffler, they HAVE TO replace
the whole system. I told Magnaflow that I only need the mufflers, the whole cat-back piping
is in OK condition and it doesn't need to be replaced. Bottom line is Magnaflow will not
replace the mufflers because their oversized resonator was tossed away two years ago.

Is the C4 too low, or the resonator too big?

You be the judge

<---Evidence--->

kimmer

I had magnaflows when I had mufflers and the hanger brackets on both of them ripped right off the mufflers. Had them welded and a short time later one broke again. Gave up on them and gave them away. My vote is your car is not too low.

RollaMo-LT4

Dang Pete, that sucks.

Eakster

Bummer.. yes the resonator looks like a bad fit for the vehicle. Maybe the sweet jumps are too high? Also something looks not right with the fellows heads in your meet pic..

I get the impression from my own searches that sourcing just a resonator alone is almost impossible. Personally I like my deletes so not had the muffler issue

383vett

Bummer of a deal, Pete. Hey, where can I order the neat bumpers with the bowtie license plate indent? (I know, just kidding) Willie

mike100

I cut the magnaflow x-pipe off that oversized resonator and had my muffler guy custom fit some pipes to it. I chose to run oem mufflers to make up for the lack of a resonator and it sounds nice.

as a matter of fact I actually wanted to use that resonator, but my muffler guy chopped it off saying that it would just get smashed in no time at all. I never knew it merged into a single 3" pipe until after it was cut off and could easily see it.

I guess they are telling you to F off- no more free mufflers (especially not after publicly posting here I'm sure). go ahead and throw something else on there. Some guys over at ZR-1 registry have been using dual mode exh outlets from C6's and putting them on some high flow 3" in/dual out mufflers from summit. Just go custom. Forget the bling.

ch@0s

Sorry to hear that Dude.. one more company on the sucky CS list.

-=Jeff=-

I think it is a poorly thought out system.. who in their right mind would expect the sheetmetal body of a muffler to support the weight of itself.. I mean cmon, I am not a mechanical engineer but even I know that was a poor design..

Sorry for your luck but I think it is time to find another system, or use the tubing and pick your own mufflers.

1993C4LT1

My vote goes to the resonator being too low.

Cliff Harris

I have Walker DynoMax mufflers on my car (very similar to the stock mufflers except both pipes are open and the tips are stainless steel) and on one of them the bracket came off the muffler. The bracket is spot welded to the rear wall of the muffler and when it came off it ripped a hole in the rear wall. My muffler guy welded on a heavy brace to the top and bottom rolled seams and it will never fail again.

96GS#007

cv67

Thats the problem any weld on a muffler most times wil corrode or fatigue then fail. I only use bolt in type hangers these days that clamp on the pipe

gerardvg

I have just the standard setup on my 85 but have never scraped the exhaust I have even done what some 4x4 drivers would consider off road without incident. Obviously it is a poorly designed resonator, the factory brackets are damn tough. But anything hanging down low enough is asking for trouble, it should then be designed to stop being damaged by some guarding or stronger brackets.

The pics (dated 2011) of your exhaust shows the cat and mufflers sitting a lot lower than standard maybe a good 2 inches, for a sports car it should fit snugly up underneath.
The standard mounts have not been used and the rubber hangers are obviously not up to the weight of the exhaust or for durability.

The way they welded a bracket on top of the muffler is just damn stupid, there is no strength there flexing will cause a crack. They should have put the correct tabs on the ends of the mufflers (as standard) to bolt up to the standard corvette exhaust brackets.

I shake my head in disbelief that some who should know better would do that.

-=Jeff=-

While I agree, every set of mufflers I ever had with the mount on the end of the body, I have never had a issue.

I also think the resonator is a bit low in the pic, but I still think the system in question is of poor design

H P Bushrod

The C4 is fine...The aftermarket exhaust manufacturer dropped the ball.

LongBeachC4

My 85 looks just like that, seems to be low to me. I did find the bracket on the chassie had loosened up a bit and it was moving around but I don't see any cracks around the support arm.

shakedown067

Makes me VERY glad I built my own magnaflow system. 3" from the manifolds back. I never did like the layout of their system...and I didn't even know the resonator was too big. Plus, I didn't like it all being so shiny!

And no, your car is NOT too low!

Klondike

Thanks for all that info. I had been thinking about one of those systems, but after hearing more than one story about the "easy rip" muffler hangers and the poorly fitting resonator, I think I'll steer around that one like a speed bump.
If you make a customer happy, they'll tell there friends.
If you ****-off a customer, they'll tell everybody!

Paul Workman

I bought that same MF system for my ZR-1. It was touted as a "3" system. However, upon investigation there were several choke points where the 3" was necked (abruptly) to 2-1/2 OR LESS, back up to 3" and then back down again.

Then as Mike pointed out, after it necks down to 2-1/2" for their "X" pipe, it goes into the resonator that is a single 3" diameter tube. I mean, WTF?? AND...then there was the bracket welded to the skin of the muffler that tore the skin in a short while...stupid design. And the resonator was HUGE - a certainty it was going to grab a speed bump and be ripped from under the car, taking whatever it could with it! (I sold everything but the mufflers, but soon to have those replaced too!)

However.... All that said, I will admit others in my ZR-1 (FBI) family used them for a while and they sounded great. And, with some porting, headers, sans cats, and tuning, one LT5 dyno'ed 400 RWHP with the stock (3") MF setup. (It started robbing big time above 400 hp (with head porting and more tuning), so a hybrid system was used to replace it.)

Over all...I was quite dissappointed with the system - primarily because they advertised a 3" system that was "full" of choke points along the way!

P.

PLRX

With anoyther $200 I would had bought a Corsa or OBX for less money and I would be happy with it.


Paul, you are correct, and I've never posted that issue on it. All weld points are reduced, the X, the resonator, and mufflers.

I think it would wise for all members asking for a great cat back system no to with this one. Let's say you are not mechanically inclined, you don't DIY, and you don't have large pockets. This system will ruin you.