When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I finally got to drive mine further than around the block. All the work I've done the last few weeks was totally worth it. The car is quieter, it shifts smoother, it smells better, and I can actually hear the stereo now.
Also, I bypassed the N249 valve so that the diverter valves are operated with a direct vacuum line to the intake manifold. It seems to help with low speed driveability and smoothness (which is the reason this a common mod on Audi's with the 2.7T engine).
I finally got to drive mine further than around the block. All the work I've done the last few weeks was totally worth it. The car is quieter, it shifts smoother, it smells better, and I can actually hear the stereo now.
Also, I bypassed the N249 valve so that the diverter valves are operated with a direct vacuum line to the intake manifold. It seems to help with low speed driveability and smoothness (which is the reason this a common mod on Audi's with the 2.7T engine).
So the valves stay shut until the car boosts enough or spikes enough to open them?
So the valves stay shut until the car boosts enough or spikes enough to open them?
Other way around, they stay closed until you let off the gas. These are the diverter valves I'm talking about, not the wastegates (those are controlled by the N75 valve).
Originally Posted by Dock
What low speed driveability issues have you had?
Not driveability issues, but it makes it a little smoother at lower speeds. It also allows the diverter valves to open faster because they are directly controlled by intake manifold vacuum.
It was mostly done as an experiment since this is a very common modification on 2.7T Audis. However, since I'm on a mafless tune I've already eliminated one of the safeguards for the engine, so I'll probably put it back to the original configuration since the computer will sometimes open the diverter valves to bleed off extra boost pressure if needed. Either that, or maybe a hybrid setup where one is actuated directly from the manifold and he other one is connected to the N249 still which would get me the best of both worlds.
(I asked about what driveability issues you were having because you said your mod helped with low speed driveability and smoothness.)
funny you mention that, as i also wondered what driveability "issues" or lack of smoothness was meant also. i've always felt my car was super smooth at low speed. so smooth in fact for a relatively high powered sports car that the low speed "driveability" was really the only thing about the car that reminded me of a volkswagen.
I don't have any issues either, but I did it to see if I had any I didn't realize I had. The car drives the same. I think part of the reason this is popular with the 2.7T is because the K03 turbos on them spool really quickly so even at low speeds you can get a little bit of jerkiness during part throttle driving (it made a noticeable difference on my old S4). My K24s don't spool nearly as quickly as those little guys, so it's a non-issue on these cars.
04-26-2020, 02:39 PM
