jishead

I gotta say that the Magnaflow kit is quality stuff. Very impressive fit and finish. Bolted up nicely back when my suspension was OEM.

I have since lowered the GT with Eibach sportlines on all 4 corners. I hear knocking noises and suspeted the big fat Magnaflow pipes. Removed all other possibilities like spare tire rattling around etc. Inspected under the car and found areas where pipes can come in different degrees of contact with rear sway bar or fuel tank cover or etc. I remove the entire section of Magnaflow starting after the mufflers...the tubes and tips. Now there is silence going over the most brutal bumps (besides the awful resonation caused by not having the pipes). Anyway, this proved that the knocking and noises was 100% pipes and not springs, shocks etc.

Now I don't see much room for adjustments. Anybody have similar experience? Do I have to find those interference areas and beat my pipes into submission? That Magnaflow kit is beutiful and hate to hammer on it. I don't have any special tools so it will be primitive at best. I really be p1$$ed if I beat them to death, go through the pain of putting them back on, and still have problems!

mdvaldosta

larger exhaust piping usually hits around the upper control arm area

Obselite

Not to hijack...but do ALL exhaust parts bolt on? Headers, X/H pipe, and the end pipes?

By the way: I'm gonna be gettin some headers, and an X-pipe, i won't be running cats and my exhaust right now has Flowmaster American Thunder end pipes. Will the Thunders bolt right on to the X-pipe?

jishead

Is it common practice to put dents in them to accomodate suspension changes? I'm don't want to do anything that I will regret!

jishead

In general these parts bolt up. For example, the MAC pro-chamber went on without a hitch a bolts directly to the OEM hangers etc. It was a little bear to get to the upper O2's and bolts etc but it still bolts on and you don't need special tools or welder or anything. I put my MAC on before my catback so it was: Ford exhaust manifold -> MAC prochamber -> Ford cat-back and the fit was fine. Later, I put on the Magnaflow and it bolted up directly to the OEM hangers with no special tools again. It's a bit of a bear to get your car safely up in the air if you are doing a driveway / garage project. SAFETY FIRST!!! But you can do it. A little trial and error on the fit sometimes. My maganflow sounds it so deep and mellow. Doesn't sounds like a 4.6. Now if only I could solve my Magnaflow / Eibach fitment problems!

I'm sure that there are some parts from some vendors that don't fit as well. In general, if it was made specifically for your make/model/year it really should fit decent. I've read threads from folks complaining of fitment/ leakage/broken welds etc. Do your homework for sure or just by a MAC pro-chamber and MAGAFLOW and don't lower your car like I did!

JamesSocal

My Magnaflow catback hits the swaybar on large bumps. Seems to be a common problem on lowered and stock height cars.
From what I have found you just need to mess with the pipes until you get proper clearance between the swaybar and the gas tank. The key is to adjust the pipe in between the H pipe and the muffler along with the tailpipe. Its doable but a pain in the butt.
Aftermarket lower control arms tend to move the rear swaybar down about an inch. This may solve the problem too.

jishead

Man I need a lift don't I? Sounds like much trial and error. I think what bugs me most is that while the sway bar caused the most physical evidence of fitment problem (left nice scars on the tubes) the sounds that I was hearing sounded more like the tubes hitting the plastic fuel tank shell or maybe body pan or something. It's difficult to get those big fat tubes where they won't bang something on a lowered car. I'll have to get down there and do more inspecting. The real pain too is that when you jack the car up then the axle hangs with gravity and spring tention and you can't reall get a feel for where things want to rest like you could if the car weight is resting on the tires. Maybe dig the steel ramps out of the attic huh? I used to use ramps alot on my front wheel drive vehicles. Never have put the rear wheel drive lowered GT up on them.

JamesSocal

Yeah use the ramps thats how I found the problem. Its real easy to back up on the ramps. So don't worry about that.
Have someone push down on the car as hard as they can and see if you can find any contact.
Its a lot of trial and error like you said but it is fixable.

Djs94stang

The Mag system is fairly adjustable. I would try moving the pipes around to eliminate the interference. Go to the parts store and try to get a different rubber hanger either longer or shorter depending....you have to look at it first to see where you have the most room. Lowered or not...the system should not bump throughout the entire suspension range. Lowered just means you have less range but that actual bottom out should be the same. Keep looking...you can adjust them to eliminate the interference.

jishead

Looks like problems are solved. Put the tubes on and paid careful attention to where I believed most of the interference was at. Use the Muffer-to-tailpipe connection to adjust front-to-rear fitment resulting in different axle hump alignment. Drove over severly bumping roads that were previously causing nasty sounds. No bad sounds. Case closed. Glad that I didn't have to 'beat my tubes'.