Join Date: Jan 2009
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It will hurt it a little bit, but not really that much. You really don't need to run a 5inch exhaust until you are in the 500+ hp range. Yes you will actually lose a little performance, but honestly, its such a small amount it shouldn't be noticable, IMO. I have a couple friends that put them on unmoddified Common Rails, and actually lost about 1.5mpg in doing so. I'm not sure what you'd lose with a vp44 24v though.
2000 2500 reg. cab 4x4 auto 577hp
09 6.7L QC LB stick, 4x4.
TOTAL PERFORMANCE DIESEL 707-545-FUEL (3835)