Opionins on Mach I exhaust project.

Need some help making decisions on my spring project. I plan to replace the crusted pipes and rotted out mufflers with fresh metal. I have ideas but decided to run past the experts.

Currently, I have a 351 Cleveland, Toploader 4sMT, and a crusty set of what the previous owner claims are Hooker long tube headers. The existing setup is rusty and the Thrush mufflers are both blown out. (BTW, dual exhaust, straight back, no X-pipe)
I'm not looking for strip performance, just a nice note, kind of what I have now; I still want to make small-engined ricers pee themselves when I blip the mighty Cleveland.
It's the only loud noise my kids like, so I don't want it shut it up completely. Last, I want it to stay in line with the rest of the car's mods, done over 20 years ago, so no Flowmaster stuff.

Three items for discussion:
*- Size of pipe to use. The collector is 3". Don't think I want that, I was thinking of 2-1/2. I've read where there's a point that pipe size becomes counterproductive. What are your experiences?
*- Muffler brand. I say Cherry Bomb Vortex. Not interested in a straight-through glasspack. Any other recommended brands/models?
*- Mach I Exhaust Tips This one drives me nuts. I got larger-than-stock pipes installed, but they're capped with reducers to shove the gasses through the original Mach I tips. :eek: Doesn't this defeat the whole point of the larger pipes:shrug: ? That said, I'd like to keep the tips, or a reasonable facimile that will fit the cutout under the bumper. Where can I find a set of tips, or can I somehow use the originals?

-EDIT- Last question>> Is an X-pipe worth it?

Thanks in advance for all of your 2¢.

Scott
long time dreamer
first year owner
 
  • Sponsors (?)


Size of pipe to use.
I say stick with 2.5" unless you are somewhere in the neighborhood of 425hp+ If you are starting to get close to the mid 400s then step it up to 3".

Muffler brand:
Magnaflows. Unless you want to only have glasspacks and not actual mufflers I'd say Magnaflows are the way to go.

Mach I Exhaust Tips:
I'm not sure about reproduction tips/tips that are close to stock style but bigger. What I do know is that the further the tip is away from the exhaust port on the heads, the less it matters if its 1/2" smaller then the pipe. It is never a good thing but it can come to a point where you aren't going to be hurting all that badly. What you may be able to do is cut into the tips and have the pipe enter the tips further in where the tip is wider. Depends on the tips, this may look ugly as hell or no one may be able to tell without geting under and looking at the tips. Post some pics of the tips you got on there now.

Is an X-pipe worth it:
An x-pipe makes about the same HP/Torque as an H-pipe if both are done properly. An H-pipe will sound more agressive where as an x-pipe will tend to be more mellow. I think straight through pipes like you have now will sound even more agressive then an H but I'm not sure.
 
MagnaFlow- those Cherry Bomb things are made in China now- I would rather not put Chinese parts on my Mustang-

I picked up over 9rwhp and 11rwtq going from an H pipe to an X pipe-

2.5" pipe definitely- I personally wouldnt even think about 3" unless I was over 500hp-

tips- thats a hard one- I went with a nice 2.5" tip on the back of my Shelby and it looks great- not stock- but nice, with out being too big
 
I have an idea for the exhaust tips. Use the stock tips and run your 2 1/2" exhaust all the way back. At the junction where you would change to 2" tips put in exhaust turn down tips. Weld the original tips to the turndowns but drill a hole in the turndown so that the exhaust can go out the back or down. Keeps an original look without sacrificing performance.
 
Magnaflow magnapacks. I've had them on me Bullitt, as well as my 03 cobra, and I love them. The packs are much louder, and louder at idle then the magnaflows. I currently have flowmasters on my 65, but the are getting cut out, and some dumps are going to be run.