Acceleration in 2.T
Thread Starter
AudiWorld Member
Joined: Aug 2000
Posts: 78
Likes: 0
From: Colorado
Acceleration in 2.T
This may be a stupid question, but when I accelerate (not stomping, but fairly briskly) in my tip, the main "ooph" seems to be from downshifting. I was told that the turbos kick in at 2500 by the salesman, and I've been studying the feel of the engine and the RPM gauge, but I don't perceive a definable "boost point" like you do with more traditional single turbo setups. Maybe that's the whole idea with the twin turbos. I seem to remember people on this board waxing poetic about hearing the waste gates open in a big "whoosh", but I don't. Am I missing something? Do the turbos just make my 6 "feel like an 8" smoothly?<p>Andy Sonin
asonin@americanradiology.com
asonin@americanradiology.com
New Member
Joined: Mar 2000
Posts: 173
Likes: 0
Turbos are always "kicked in". Max torque is between 1850 and 3k ish (can't remember)
The turbos are small and spool up quickly becuase of their low rotational inertia - more quickly than a single "large" turbo-supercharger. I think a "kick in" would be annoying and the lack of it is what makes the 2.7T such a nice engine in my opinion. Max torque is between 1850 and 3 thousand something rpm. So in this range you'll get the greatest change in horsepower and thus acceleration. An upward change in horsepower gives you greater dr/dt (rev/time) and that's what gives that nice acceleration.
Elder Member
Joined: Mar 2000
Posts: 39,901
Likes: 1
yep, turbos always on
The reason you don't feel a kick is because they are low pressure turbos, not high pressure turbos. They are on all the time, but the impellers don't work well at very low flow rates. So they kind of "come on" between 1000-1500 RPM. The car is at max torque (according to Audi) at 1850RPM and stays there until 3600 or something like that. In actuality, Audi is lying and the torque continues to build and hits a peak at 3000 or something. The car is producing 258 ft-lbs (Audi's stated max) from 1850 to 4000 or something, but the actual peak is above 270ft-lbs and isn't so wide.
The waste gates begin to open at 2400RPM or something, dumping excess pressure (and torque). So they don't signal the beginning of the power, just that you are developing full power.
The waste gates begin to open at 2400RPM or something, dumping excess pressure (and torque). So they don't signal the beginning of the power, just that you are developing full power.
Thread
Thread Starter
Forum
Replies
Last Post
NogaroS4 in NJ
S4 / RS4 (B5 Platform) Discussion
74
Aug 5, 2004 12:28 PM
Geoff M
S4 / RS4 (B5 Platform) Discussion
4
Feb 10, 2002 07:47 PM
