SteveKen
February 18th, 2011, 06:16
I spent the warm evening wrenching and finding the source of my overboost.
Here's my 3rd gear log from when I recently had my car on the dyno.
http://www.kendrish.com/galleries/RS6/misc/feb_09_2011_dyno_boost.JPG
I verified the N75 was in proper order and then basically gave the car a little 'mouth to mouth' by blowing into the wastegate hose off the N75. I didn't get any resistance. Root cause was the area on driver's side wastegate line where the flex hose is crimped onto a hard line. I barely pulled on the blue WG hose and it separated form the hard line. Note the blue area in the pic along with the new vac hose attached to the WG.
http://www.kendrish.com/galleries/RS6/misc/wg_hose.JPG
I snaked a dremel up there with a cut off wheel and cut the crimped portion off to where I just had the hard line. Slid the new hose on and clamped it. 2.5 hrs start to finish and I ran a quick log to see if that did the trick.
http://www.kendrish.com/galleries/RS6/misc/boost2.JPG
It appears that fixing this gets rid of the hesitation I was having in normal mode at/around 3500 rpm as well. Therefore I'm confident my trans in in proper working order.
Here's my 3rd gear log from when I recently had my car on the dyno.
http://www.kendrish.com/galleries/RS6/misc/feb_09_2011_dyno_boost.JPG
I verified the N75 was in proper order and then basically gave the car a little 'mouth to mouth' by blowing into the wastegate hose off the N75. I didn't get any resistance. Root cause was the area on driver's side wastegate line where the flex hose is crimped onto a hard line. I barely pulled on the blue WG hose and it separated form the hard line. Note the blue area in the pic along with the new vac hose attached to the WG.
http://www.kendrish.com/galleries/RS6/misc/wg_hose.JPG
I snaked a dremel up there with a cut off wheel and cut the crimped portion off to where I just had the hard line. Slid the new hose on and clamped it. 2.5 hrs start to finish and I ran a quick log to see if that did the trick.
http://www.kendrish.com/galleries/RS6/misc/boost2.JPG
It appears that fixing this gets rid of the hesitation I was having in normal mode at/around 3500 rpm as well. Therefore I'm confident my trans in in proper working order.