3vs3.5 downpipe?

[ytsglock]

When is it feasible to go to the 3.5 downpipe over the 3?

 

[fastblackracing]

There is a lot of debate on this issue, IMO once you make enough power to go 132+mph in the 1/4
the 3 1/2" pipe starts to have an advantage....and obviously a 145 mph car will benefit more than a 132 mph car will.

The brand of 3" pipe has an impact on this as well...some are made better than others and the rest of your exhaust
system has to be up to flowing an ample enough quanity of air for either size pipe to work to its full potential.
This includes the dump pipe, i have seen some that were a mess.

Lots of guys have deep in the nines on a 3" pipe.

 

[GNWANTED]

I have been debating going to a bigger down pipe. Kinda expensive if you wont see much in return. I have been 137mph so far. Wonder what a bigger down pipe would do?

 

[Mr.Spool]

The brand of 3" pipe has an impact on this as well...some are made better than others

I have seen this as well,the turn coming right off the turbo seems to be where the gain or loss is.

 

[Mr.Spool]

Wonder what a bigger down pipe would do?

if the downpipe isn't obstructing the exhaust wheel and the turn is good on the 3 inch you might see no gain.

 

[V6sleeper]

I would like to see a back pressure test with a 64 or 67mm turbo on a 3" then a 3.5 in dp back to back and compare the readings.