Flex pipe install for MTX Dynomax system?

[ShoMe1More]

I searched the forum high and low but can't find a guide for how to modify the Dynomax MTX system to accept a flex pipe.

SHO Source said it could be done and I ordered the flex pipe, Magnaflow y-pipe and MTX Dynomax exhaust from them. My mechanic can't figure out how to get the intermediary pipe with the resonator installed, as the flex pipe makes it too long. Because there was just supposed to be a donut gasket for this MTX system and the flex pipe adds length where the gasket wouldn't have.

Any suggestions on how to do the proper flex pipe conversion for a MTX exhaust system?

Thanks

 

[K-Dawg]

You're going to have to chop a section of pipe out and weld in the flex pipe.

 

[LOUDSHO92]

You're going to have to chop a section of pipe out and weld in the flex pipe.

Yes correct.

 

[msteiny]

Funny thing with exhaust systems. They say "it goes right in", Then you read the small print that says "after using your imagination".

 

[ShoMe1More]

Chop a section of pipe from the intermediary pipe you mean? Which end of that pipe do you chop, the end with the resonator on it, or the opposite end?

I told the mechanic to chop the intermediary, and they said they might just hack off the resonator and weld it on a shorter pipe. I'd like to get this right, I don't want this annoying buzzing without that resonator.

If someone could give me more specific direction I'm sure it will finally make sense for the mechanic. Hopefully...

 

[K-Dawg]

Put the flex pipe where ever you want it to flex. I would put it right after the y-pipe. If your mechanic can't figure this out, maybe you should take the car somewhere else.

Unless you are having problems with leaks, I would probably just put it together without the flex pipe.

 

[LOUDSHO92]

Chop a section of pipe from the intermediary pipe you mean? Which end of that pipe do you chop, the end with the resonator on it, or the opposite end?

I told the mechanic to chop the intermediary, and they said they might just hack off the resonator and weld it on a shorter pipe. I'd like to get this right, I don't want this annoying buzzing without that resonator.

If someone could give me more specific direction I'm sure it will finally make sense for the mechanic. Hopefully...

If you cut off the section with the bell mouth you will eliminate the need for a donut gasket and can go to a flat gasket. The flex pipe will now provide the flex that the donut gasket was allowing.

If the mechanic can't figure this out it may be time to take it elsewhere.

 

[ShoMe1More]

Thanks for the responses, I think they can install it correctly now. Tomorrow will be the verdict!

I am going to post the email, with info and pics from shosource.com and rcmautomotive.com, that I sent the mechanic explaining modifying the MTX dynomax exhaust system to accept a flex pipe instead of the OEM donut gasket. The intermediary pipe for the MTX system has a bend in it in case you ever want to convert the clutch cable shifter system to a rod based shifter. For anyone else that might have trouble installing this:

"If you cut off the section [of the intermediary pipe] with the bell mouth you will eliminate the need for a donut gasket and can go to a flat gasket. The flex pipe will now provide the flex that the donut gasket was allowing."

-LOUDSHO92


Here is a diagram and picture of the dynomax MTX exhaust system:

SHO 3.0L MTX Dynomax Exhaust System
Mandrel-bent, aluminized steel pipes
2.5" intermediate pipe into split 2.25" tailpipes
2.5" stainless-steel tips
Aluminized Super Turbo mufflers
Cat-back system (no front y-pipe or converters included)
Retains original mounting/hanger locations
Resonator pipe section has clearance for "Rod" shifter
Includes clamps and hardware
1992-95 SHO 3.0L MTX
Made in USA
(Can also be used on 1989-91 SHO 3.0L MTX w/rear hanger adjustments.)


Here are pictures of the difference between the Manual and Automatic resonator pipes:

1989-95 SHO MTX Dynomax Resonator Pipe
Aluminized, high-flow replacement resonator pipe!
Has clearance for "rod" shifter setup.
Designed as part of the Dynomax cat-back system, but can also be installed with stock system with minor modification.
Made in USA

1993-95 SHO ATX Dynomax Resonator Pipe
Aluminized, high-flow replacement resonator pipe!

 

[zak]

On pics 1 and 3, on the far left is the "bellmouth" that slides on the donut gasket that is afixed to the Y pipe. The donut gaskets are always a weak point, but that approach does allow for smoother gas flow than most (not all) commerical flex pipe inserts you can buy.

So, the flex needs to go there on the far left. Many end up doing this when the bellmouths rot away on their original exhausts.

It might be cheaper to just replace the donut gasket and spring bolts.

 

[ShoMe1More]

They wound up cutting the resonator off the intermediary and welding to a straight pipe into the rest of the exhaust. Then they connected the resonator directly off the flex pipe. It looks more like the ATX intermediary. Works fine.

I think maybe there is something to 89-91 not supporting the bend and length in that intermediary even with the donut gasket.

Anyway, alls well that ends well.

 

[platoribs]

Flex pipes will start to leak after maybe a year or two...

Cheap ones, right away...