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Topic: Exhaust Notes / Backpressure (Read 1345 times) previous topic - next topic

Exhaust Notes / Backpressure

Re-worked the exhaust again on my show car cat.

Swithched out the old X pipe to  a Pace Setter off road H Pipe, Pace Setter Intermediates, Magnaflow "Glasspack Style" lers, and turn downs right before the rear axle.  It's a true dual setup with all mandrel bent 2.5" tubing.

A set of 5.0 Headers from a 93 Cobra start things out.

The engine is a Cobra/GT40 Crate Engine fully balanced/ blue printed, and tested at approx 400 HP at the flywheel.


May be I'm just being overly critical, but for some reason I think that my overall exhaust note has too high of a tone.  It's not overly high to be annoying, but to me it would sound better at a little lower tone.

Any idea's on how to lower the tone of the exhaust note, preferably without un-doing much of what I just changed?


Also, I'm a little concerned about the backpressure in this system.  Previously, I was using Flowmaster 40's and really didn't have much of an issue.  Now with a little more of a "flow through" style ler, I suspect I may need to some how add a small amount of backpressure to maintain my low end torque.

Granted, I've got enough power there where it's not a big issue, however, it sounds and feels like I need at least a little more backpressure.

Any idea's on this as well?
To laugh often and much; To win the respect of intelligent people and the affection of children; To earn the appreciation of honest critics and endure the betrayal of false friends; To appreciate beauty, to find the best in others; To leave the world a bit better, whether by a healthy child, a garden patch, or a redeemed social condition; To know that even one life has breathed easier because you have lived. This is to have succeeded.

]Ralph Waldo Emerson

Re: Exhaust Notes / Backpressure

Reply #1 –
put tail pipes on it, more pipe will deepen the tone
It's Gumby's fault.

Re: Exhaust Notes / Backpressure

Reply #2 –
Quote from: Tbird232ci
put tail pipes on it, more pipe will deepen the tone


plus increase torque. ^_^
2005 Subaru WRX STi|daily driver

Re: Exhaust Notes / Backpressure

Reply #3 –
I think if you ditched the Ford headers in favor of one with larger primary tubes you'd lower the tone. In general, the larger the diameter of any tube sound moves through, the deeper the tone. Compare a flute to a tuba...
  Also, a 400hp engine should really have headers with 1 5/8" primary tubes to properly exit the exhaust gas. Adding tail pipes may help the sound of the axhaust also. I doubt it will actually lower the pitch, but the sound will change as it echos through the bends in the pipe. From what I've seen, the sharper the bends, the sharper the cackle.

Re: Exhaust Notes / Backpressure

Reply #4 –
I purchased a pacesetter offroad Hpipe for my Cougar. Did you have any problems getting yours to fit? What did you have to modify? Were you able to get the hangers in the horns under the transmission?
Thanks

Re: Exhaust Notes / Backpressure

Reply #5 –
Quote from: whitebeastxr7
I purchased a pacesetter offroad Hpipe for my Cougar. Did you have any problems getting yours to fit? What did you have to modify? Were you able to get the hangers in the horns under the transmission?
Thanks


Everything fit fairly well with only minimal annoyances.

I even retain the column shift with no issues.

The main area of problem was that you have to install everything at once in order for things to line up right.    Doing this on your back while lifting that weight through the column shift linkage, and past the starter mount, as well as the tranny mounts, was flat out a pain in the ass.

A little creative moving of the s and they should bolt up without interfering with the linkage, motor mounts, or anything.

The only modification I had to make was chopping off one of the brackets that slide into the tranny hangers.  I spent the better part of an evening messing with the darn thing but they would both not line up no matter anything I tried.

It just took me a little thinking and time to get the H-Pipe on the car.  Likely it would have bolted up to a Mustang easily in half the time, well you get the idea.

Point is, after being told by many that it isn't possible;  I now run headers and an h-pipe with a column shift, and have no interferance issues.  :)
To laugh often and much; To win the respect of intelligent people and the affection of children; To earn the appreciation of honest critics and endure the betrayal of false friends; To appreciate beauty, to find the best in others; To leave the world a bit better, whether by a healthy child, a garden patch, or a redeemed social condition; To know that even one life has breathed easier because you have lived. This is to have succeeded.

]Ralph Waldo Emerson

Re: Exhaust Notes / Backpressure

Reply #6 –
thank you. I will give it another try