Gunpilot77 wrote:

An aquaintance of mine ran several dyno tests on older diesels with stock 3 inch and 4 inch exhausts. The 4 inch did not deliver any performance or egt benefits until the engines exceeded 400 HP. Your seat of the pants improvement is in your mind.

kemo 1 wrote:

I have been told by many that the K&N air filter is the worst thing for a diesel engine. Figure if they are free breathing air they must be free breathing unfiltered dust.
Ken

TxTiger wrote:

As a little background, I bought a 2000 F250 SD with a 7.3 diesel about 3 months ago specifically to use as a tow vehicle. Great condition and in completely stock form, and performance is what I would call gradual and "steady". The 7.3's are not known for speed, but for longevity. It's a standard trans and even driving without the trailer I felt that I was really holding up traffic until I got into third.

I wanted to free it up a little so towing would be easier. I know tuners are popular but I believe many of these types of devices, particularly used in the higher performance modes, put more stress on things and shorten engine life. So I went simple with a Summit Racing 4" turbo back exhaust and cold air intake kit. $530 delivered. This replaces a 3" down pipe into a 3 1/2" exhaust with a muffler about the size of a suitcase.

Everything went on relatively easy and I can definitely feel a difference in performance all the way through the power band. It's better off the line and revs much smoother/easier with less pedal. The muffler is a glass pack and I was worried about it being load, but I can't really tell any difference.

I think this is an upgrade really worth the money and highly recommend it for anyone who has an older diesel with stock exhaust. I've only towed my trailer twice but I can tell it's going to pull much better and I won't be such of a traffic jam until I get rolling.