Exhaust down pipe size 3.5" or 4"

[LHMissions]

I am buying an aluminized steel turbo back, kitty delete, 4" exhaust. I have an option of 2 systems.

Both are nearly identical with exception to the turbo down pipe and manufacturer but both manufacturers are well known. One is MBRP the other is Diamond Eye. One has a 3.5" downpipe - the other a 4" down pipe. The 4" pipe is actually less in price then the exhaust with the 3.5" down pipe.

Will I benefit with the 4" down pipe over the 3.5" down pipe?

[Slowrx]

That 4inch dp is probably going to require a little "massaging" to get it in there and clearing everything. Won't really be a difference in performance gain. Go with whichever you prefer however I am a far of the fit, finish and quality of mbrp.

[MoyockPowerstroke]

I have the 4" DP...go with the 3.5" better clearance from Trans lines and Uppipe and less loss of low end torque/mid range power.