Topic: back presure

[motoracer]

  my truck pulls good on flat ground but bogs uphill. i have a short exhaust. headers and straght pipe with a cat. it ends right behind the cab its only 4 foot long from end of header to exhauxt tip. i was woundering if i need more back presure. do i need to make it longer and take it out the back of the truck?

[Snowtoy]

A 45* bend on the end of the exhaust tube or a narrower type might help some.  I had the same issue on my '91, no header, but ran 2" straight pipe from a turbo muffler all the way back.  I put a 45* bend in section and welded it on the end and it seemed to help a quite a bit w/low end power. 

I am not sure how well a narrowing type would would work, it is what a custom muffler shop recommended doing, the owner said it is what they run on race cars to help out with the lower rpm range.

[79coyotefrg]

thats all a gimmick.   all it really accomplishes is moving the end of the pipe further away from your ears.

I'm gonna guess it bogs on hills when your in 5th or your rpm is below 3000 rpm. 
these engines NEED to run in their sweet spot.