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Discussion Starter · #1 ·
Hey had a quick question. I just put on a 4" turbo back exhaust straight pipe and was severely disappointed in the loss of low end power. It is extremely doggy when I take off but seems to have more response at higher RPM. I'm guessing this is because of backpressure? just wondering if anybody can shed any light on this. Love the lower egts but miss the low end power.

Mods.
AFE Stage 2 intake
DP tuner 20tow,30tow,80econo,140extreme
4" turbo back exhaust(muffler delete)
 

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Let's go B's!!!!
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6,020 Posts
I'll bump this up for ya, cause i'm not sure...
 

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John Wood Nut Swinger
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3,413 Posts
It is a 4" down pipe thing. It releases the pressure in the turbine too fast to keep the turbo spinning. It happens to some and it doesnt to others. You are one of the unlucky ones.

I went from a 4" DP to a 3.5" DP and the bottom end increased power.
 

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Let's go B's!!!!
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I was thinking about going to a 4" dp when I put my stack on. but after hearing this, i'll keep my stocker on there until I have an egt issue. :thumb:

later
 

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Powerstroke Junkie
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8,308 Posts
Strokin has it right above. I believe they all loose power with a 4" downpipe but only those that really know their trucks notice it. This is why I never recommend going to a larger downpipe, truth be known I don't even see the benefits of a 4" exhaust over a free flowing 3.5" suystem, but that's another story!!! Go back to your 3.5" downpipe and you will notice some of that low end come back.

NCH
 

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Discussion Starter · #8 · (Edited)
sorry for not posting this previously. but I cut the cat and the rest of the exhaust off at work before putting the 4" dp and this is when I lost power even with the 3.5" dp.
 
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