Well at first I do it for the horse power increase, but after that I begin to realize that the miles per tank increase in like 12%. Before the mod it gets 290 to 300 miles per tank on average and now it have increase to 340 to 350 miles per tank. I did not believe it at first so I did not post for like 4 full gas fill up.

Here it is, not the most beautiful but it does the job.

The last picture is the only other performance mod that my Cayenne have.

 

Are you telling us the by-passing the secondary cats and and IPD Plenum are all of your mods?

 

Is that the mod?

 

Yep that's all, but I see the increase in MPG after the cats delete.

 

Yes, the mod is cat deletes by muffler shop not so good looking like others but it works.

 

Did any sensors go off?

 

There's some sweet welds in those pics

 

Ok so this brings up a really good topic actually....and no I'm not going down that "Does IPD Plenum really help" road again as that horse has been beaten here.

Rather a question I haven't seen addressed on the board...I don't think.

What's the difference with say Fabspeed catbypass and having your local muffler shop mold some pipes and remove the two cats? Sure, not polished but it's gotta be a good $400+ less.

Just a thought, and not picking on Fabspeed just the first that come to mind for catbypass.

 

The Fabspeed pipes have research and engineering behind them. I'm sure you'll benefit more from them over a shop that spent 30 minutes making their first ever Cayenne bypass pipes.

 

simple...the price is market driven. fabspeed and others will continue to get 500+ for the pipes as long as we keep paying!!! i guess those that spend money for a cayenne purchase are easy to talk into parting with 5 bens!!! lol

incidentally, my stainless exhaust for my 66 mustang was just a bit more than 500 at the local muffler shop which as it turns out is a work of art!!!

 

Point taken and I'd put my money on Fabspeed any day. I'm almost positive I'm going with the Fabspeed mods regardless of what this thread says or proves...I'm just bringing up a topic I haven't seen yet.

Let's get some more input on how much more HP you really think you'd get out of a few extra minimal curves from your typical catbypass.

I know I'm stiring up some controversy here but that's what this forum is for right? :-p

 

As long as it's not done inside of the politics subforum with pro-Democrat connotations

 

Either way, notice the 3rd pic in RXporsche post above, welding the steel arms onto to the bypass pipes prevents rattling of the pipes when you slow down. Even using Fabspeed this s highly recommended to avoid rattle. Great Job! I went back and had steel rods welded to eliminate the rattle. Annoying...

 

I am getting around 420-450 to a full tank of gas with these mods, driven VERY hard......

GIAC ECU Flash
IPD Plenum
EVOMS Intakes
Hyperboost DV's
OEM Turbo S Intercoolers
Fabspeed Cat-Bypass/Cat-Back Exhaust

 

downhill?