Ford 7.3 turbo: exhaust too loud
Purchased (new to me) Ford 250, 7.3 ltr turbo, 126000 miles. Exhaust has been modified and has big tip. Wife says too loud. (I have to agree) Saw 4.5 inch tip silencer that attaches to tip of exhaust...
Forum Discussion
Wes Tausend wrote:
...
Just reasoned speculation on my part, but it seems if one has 4 inch exhaust all the way back, that just about all significant restriction would already be removed by the 4 inch forward pipe, even if a quiet stock muffler were retained.
The increased 4 inch pipe volume ahead of the muffler should be fairly sufficient to absorb the added hot exhaust expansion, especially at the low 100-200 hp boost levels usually attained by street trucks. By the time the muffler is reached, the exhaust is cooled and already contracted quite a bit. Once the exhaust gas is cooled, it no longer needs the volume it did while hot and, of course, the turbo power has already been extracted.
I'll bet there is very little dyno difference in 4 inch all the way back as opposed to half-back. Of course, if I were a truck accessory company, I wouldn't want to lose lucrative "plumbing" sales. As usual, there is more money in selling overkill.
So if the OP has an exhaust temp gauge, it would be interesting to see if downpipe temps don't remain about the same with no other changes except the muffler.
Wes
...
I have an egt gage and I assure you temps from stock to a 4" is a 200 degree difference. A muffler is all he needs. You don't want to go from a 4" down pipe to a 3" half way back. It's like an hour class, sand will flow fast at first then slow down as the opening gets smaller.
