Straight Pipe

[BlazerTurbo]

I have heard several theories about straight piping a 6.5 diesel. Is it bad for the engine w/ a straight pipe on these or is it better for the engine since it can breathe much much easier? I also have heard that if one runs an alternate fuel in these it is a good idea to have cat remove. Is this true? Thanks

[Mark Rinker]

Not bad for the engine. I liked the sound of my Jardine (Pinnacle) 4" exhaust sans cat or muffler. Didn't really add any power or economy, however...

Not sure on your other biodiesel/WVO question. Sounds reasonable - the cat would be first to plug if you had unburned particles in the exhaust.

[BlazerTurbo]

alright.maybe i'll see if i can remove it. thanks a lot

[97-6.5TD-F]

Ive had my straitpipe on for a year now, love it! Gained a bit of seat of the pants pull, and the tone is perfect! No resonance on the highway, yet a nice throaty roar on hard accel!

[AKMark]

I replaced the collector and muffler with a 4 ft section of 3" pipe. It's got a better note, the turbo spools up quicker and puts out a bit more boost than it did previously.

I got an increase in mileage, but my collector was plugged.

[maverick_935]

No power gain or economy??
What do you get for mileage and at what speed?

[maverick_935]

No power gain or economy??
What do you get for mileage and at what speed?
I just ordered a 4" from Pinnacle. I'm at least hoping for cooler temps when pulling my 5er. I'm not hot yet but summer here in Canada is just starting.

[AKMark]

I don't have great numbers to give but this is what I got.

I live 10 miles from where I work. The speed limit is anywhere from 15 to 50 mph with lots of steep hills, and altering limits. There are two 50 zones, the first one is about 2 miles and the second 3 miles. So yeah that's not great on the mpg game.

Before I took it off, I got around 15-16 doing this on a daily basis. Now I get around 18-20. I should note that I am running 3.42 gears and 285/75R16's, I kinda wish I had 265's and less lift, or 3.73's gears with my current setup.

Power, it feels a little better, but I don't have any good numbers. As far as engine temps go, it's about the same. The EGT's should be lower now that the exhaust flows better.

I do make the occasional excursion elsewhere but when I leave this place there's lots of cities and traffic lights. I hardly ever can just get up to speed and set the cruise. With fuel prices at $5.35 as Monday when I added a few gallons, I don't fill it up all the way very often and don't drive anywhere I don't have to. Which is a bummer, as I used to love loading up the fam and going for a cruise.