View Single Post
  #2  
Old Tue, September 22nd, 2009, 10:28 AM
Jackpine's Avatar
Jackpine Jackpine is offline
PHP Groupie
 
Join Date: Nov 2008
Location: Among Elk, Deer and Javalinas on the Mogollon Rim in Aridzona
Posts: 4,328
Jackpine is a name known to allJackpine is a name known to allJackpine is a name known to allJackpine is a name known to allJackpine is a name known to allJackpine is a name known to all
Default

Quote:
Originally Posted by RobbyMartin View Post
On another message board I raised the question of whether the 2.5" exhaust tube is better for my '02 4.6L over the 3" tube. Opinions were about 60/40 in favor of 3". One guy suggested that the 2.5" provided the proper back pressure and scavenging affect, while others suggesting 3" failed to mention back pressure or scavenging in their opinion.
Now this question becomes even more valueable because I am intending to buy the Gryphon and I'm trying to gather all the info possible in order to have Bill write a tune that is best for my truck. I have a 3" tube installed after the "Y" on my truck, but it was done by an accessory shop, not by an exhaust specialist. Should I have 2.5" put in place of the 3" or should I leave it?
If anyone chiming can also give me opinions on these mods I would appreciate it: I own these already.
Airaid CAI or Gotts mods (I live in So Calif - hot climate)?
Stock or BBK 75mm TB?
U-Drive Pulleys?

I'm more of a daily driver with a heavy foot.
I think Lars and Bill are more expert on this than me, but I'm going out on a limb here and saying it probably doesn't matter if the modification is downstream of the cats. The reason I say this is your exhaust is already seeing the "stock" restrictions from the cats forward and what you do beyond them isn't going to do much (to engine performance that is).

But the bigger tubes look different and they probably effect the exhaust sound.

- Jack
__________________

2014 F150 Platinum SCrew 3.5L EcoBoost 4x4 with SCT programmer
Reply With Quote