Cayenne CTT exhaust
#31
After lurcking and posting here for a while, I've come to the conclusion that 2nd cat by-pass would be the way to go. I want a little more sound but not intrusively so. I still want the quiet refined lack of sound for relaxed daily driving.
How much improvement in mpg might there be?
I changed from Chevron to Shell nitrogen because it gave me a 1-2 mpg increase. Besides, I'm leery of techron additive effects on my oil/engine.
I'm assuming there would a reduction in weight.
How much improvement in mpg might there be?
I changed from Chevron to Shell nitrogen because it gave me a 1-2 mpg increase. Besides, I'm leery of techron additive effects on my oil/engine.
I'm assuming there would a reduction in weight.
#32
After lurcking and posting here for a while, I've come to the conclusion that 2nd cat by-pass would be the way to go. I want a little more sound but not intrusively so. I still want the quiet refined lack of sound for relaxed daily driving.
How much improvement in mpg might there be?
I changed from Chevron to Shell nitrogen because it gave me a 1-2 mpg increase. Besides, I'm leery of techron additive effects on my oil/engine.
I'm assuming there would a reduction in weight.
How much improvement in mpg might there be?
I changed from Chevron to Shell nitrogen because it gave me a 1-2 mpg increase. Besides, I'm leery of techron additive effects on my oil/engine.
I'm assuming there would a reduction in weight.
I don't know about your quality of gas, Chevron gas isn't available here in Alberta, but I run it every chance I get when I go out of province. I don't use Shell gas, never had good luck with it personally. I use Husky/Mohawk as the octane rating is higher on all grades, and I get fairly good returns in mileage.
I can't say about the secondary cat deletes, mine were changed just prior to me buying my CTT, but the previous owner said there has been a positive improvement (mainly power and sound). Extremely quiet inside, never intrusive noise in the cabin.
As far as weight savings, I don't think it's enough to really get carried away over (probably 15-20lbs removed), but everything adds up and it all affects mileage somewhat.
Can't speculate on mpg increase, I would venture to say it would be a marginal gain (less backpressure, easier spooling, etc) I'm always stepping on it a little too often to hear the sound it makes...
#33
With my driving habits and my fuel bills, I'm figuring the mod will pay for itself--eventually. Besides, it'll be more fun. I plan upon making this a half a million mile SUV. Passed 86,000 recently and darned beast saved me twice in one week towards the end of October. Can't put a price on safety.
I just ordered and got a bunch of spare parts. I figured the prices aren't going down anytime soon--especially for platinum plugs.
I just ordered and got a bunch of spare parts. I figured the prices aren't going down anytime soon--especially for platinum plugs.
#34
I just did this mod over the weekend with a 1" pipe due to the ease of installation - one weekend afternoon, cost- which was $10 (already had everything else) and the fact that I didn't have to drill into my muffler tips.
I wish I did a before and after, but I can tell you that inside the car I was initially disappointed and didn't hear any discernible sound difference (with secondary cat bypass and a tune).
Then I had my wife take it around the block and romp on it - and it is loud!
My expression from my driveway was
The sound was loud in a good way to me..similar to a mustang with Flowmasters on it upon WOT. When you are off of it, it is as quite as factory
I definitely will not be shopping around for a new "sport sound" muffler for close to $1K.
Can't wait to see the surprised faces around my area.
Thanks FastHackem for posting this cheap mod.
I wish I did a before and after, but I can tell you that inside the car I was initially disappointed and didn't hear any discernible sound difference (with secondary cat bypass and a tune).
Then I had my wife take it around the block and romp on it - and it is loud!
My expression from my driveway was
The sound was loud in a good way to me..similar to a mustang with Flowmasters on it upon WOT. When you are off of it, it is as quite as factory
I definitely will not be shopping around for a new "sport sound" muffler for close to $1K.
Can't wait to see the surprised faces around my area.
Thanks FastHackem for posting this cheap mod.
#39
I've got one of each set left:
The 2011 TT:
http://www.sharkwerks.com/products.php?pid=301
And the 2004-2008 TT:
http://www.sharkwerks.com/products.php?pid=310
The 2011 TT:
http://www.sharkwerks.com/products.php?pid=301
And the 2004-2008 TT:
http://www.sharkwerks.com/products.php?pid=310
#40
CEL issues wont be an issue since the o2 sensors are located way way way up stream from this mod.
Ergo, passing emissions wont be an issue since a CEL is not thrown.
Ergo, passing emissions wont be an issue since a CEL is not thrown.
#42
#43
So this may be a dumb question - but does everyone do these cat bypasses and homemade weld jobs just for the sound factor, and there happens to be a performance boost? Or is it the other way around?
#44
performance and sound. Removing the secondary cats will make it noticably louder but you will get a nice performance gain as well due to removing the restriction in the exhaust. Turbo cars like as little back flow as possible that is why I removed both the secondary cats and the rear muffler and just did all straight piping. The turbos actually noticibly spool up quicker and the torque curve feels a lot flatter all the way through the rpm band now as well as a noticible gain in hp at higher rpm's