06Cummins

I recently put in a 5 Inch downpipe back straight pipe. I read somewhere that people were either losing power with the bigger exhaust or it was making the turbo spool slower. I know the turbo creats the backpressure so i really wasnt hesitant putting it on, but now i am rethinking it after i read that. Also, I saw it mention that the 5 inch really didnt do anything until your running over 550rwhp. Is this true? Should I switch back to 4 inch on my stock truck, which will be getting intake and a chip soon...i just dont want to lose power or slow the spooling of the turbo. Any suggestions??

HP Upgrades

06cummins,
I would not change what you already paid for and installed. You will be ok with the 5" exhaust, although you are correct in thinking that the 5" will really benefit the performance at the 500hp or more level. Turbo spool up might react slower, but it should only be slightly less and will improve when you add more fuel to the engine.

Seeing that you are going to add an intake and chip that will get you going in the right direction. The Bully Dog Power Pup can help add lots of power and get you closer to the range that will give you the benefits of the 5" exhaust. On the extreme setting you should be able to add 130+ hp, which would be a kick in the pants....hahaha

Also consider which air intake you will install. AFE make a stage 1 or stage 2 that will help get lots of air to your motor and get it to breathing in the way it needs to. The Pro Guard 7 filter is constructed for the most demanding conditions, like dusty construction sites and so forth. If you only stay on the road you could install the 54 series air intake which has a good filter too but doesn't cost as much as the 75 series with the Pro Guard filter.

Dont give up on your 5" exhaust. In time you will be glad you installed it.

mr T

it doesnt matter what kind of exhaust u have...the only restrictive part on the exhaust is the cat (if u have one)...the exhaust is all about sounds and reducing egt's...it may "feel" like u have more power...there's guys running 3" straight pipes with 400hp no sweat

06Cummins

cat...what cat?? I didnt know these things had them...mine must have dissapeared when i was sleeping the night i brought the 5inch pipe home But the only reason i was going to start over is because i have the exhaust dumped under the bed...if i keep it i am going to have to custom fab the over the axel part with bends...im thinking it might be a pain but i dont want soot all over the underside of my truck when i start moding...

wap

What about a side pipe?