[CROCIE JR]

I have run multiple 2.5" systems at 425-450HP at the wheels. Engine dyno 2.5" at the 540-560hp range. Flowmasters in most cases. I like the Flowmaster crossflow system. Sound is very unique for a Flowmaster. I would do 2.5" sys. with cutouts. Never put smaller tailpipes on a system.

[78w72]

Originally Posted by CROCIE JR

I have run multiple 2.5" systems at 425-450HP at the wheels. Engine dyno 2.5" at the 540-560hp range. Flowmasters in most cases. I like the Flowmaster crossflow system. Sound is very unique for a Flowmaster. I would do 2.5" sys. with cutouts. Never put smaller tailpipes on a system.

interesting & good to know. can you comment on what you think your 450 rwhp would have done if it had 3" exhaust? thats my main concern here, will 2.5" hinder or limit the engine? even though its mostly a street car i do not want to choke this thing out, especially with possible future power increases. if i'm at ~520hp now with no tuning or possible upgrades, what happens when i hit 550-575? do i get to replace the $500 system with another $500 system? just trying to avoid that & get a system that will not hinder what i have currently & be able to support possible future increases.

as for the smaller tailpipes, what about the fact that the exhaust gases have cooled dramatically by the time they get to the tails & dont need as much diameter to flow adequetly. it's been commented on many times & even tested & proven at the track by jim hand.

my dilema is based on everything i read on this forum & others sources. if bigger exhaust is not required for higher hp, why does everyone say you need 3" at about 500hp & above. quite a few guys on this thread alone are running 3.5" off the headers into 3" mufflers & tails.

i'm curious why you say 2.5" is ok for 500+ & to "never put smaller tailpipes on a system" can you elaborate on that?

[twov8sandat4]

Originally Posted by CROCIE JR

I have run multiple 2.5" systems at 425-450HP at the wheels. Engine dyno 2.5" at the 540-560hp range. Flowmasters in most cases. I like the Flowmaster crossflow system. Sound is very unique for a Flowmaster. I would do 2.5" sys. with cutouts. Never put smaller tailpipes on a system.

I had that 2.5" crossflow system on my car. Did the drone when cruising bother you? My Pypes 3" is actually much quieter than the Flowmaster

[ta man]

How about posting track data with exhaust...my car mph's in the 118's with 3 inch PYPES X ,2.5 Ultraflows and 2.5 inch tailpipes.

[Silver Judge]

If you have a really healthy exhaust system budget, you could get a system that uses oval shaped exhaust tubing. Spendy but very nice & helps keep a boatload of ground clearance

[mnfatcat]

Built a stainless 3" system out of mandrel bends from Columbus River. Used 3" Ultra Flows w/o a crossover. Have had many compliments on the sound, will never have another car w/o a 3" system. Worth every penny and the extra effort.