Was THAT "turbo lag"? (more)
02-14-2000, 07:24 PM
#11
Guest
Posts: n/a
I've never noticed it before when accelerating hard while already in motion....(more)
...I guess the fact that I accelerated VERY hard on a takeoff in first gear, for the first time since I got my TT, is the reason the resulting "lag" was such a surprise to me. I'm constantly amazed by the fast pick-up my 180Q has when accelerating while driving, say, highway speeds already...particularly when I'm in 5th gear! Sometimes I prepare myself to downshift and then happily don't even need to.
Janet
'00 180Q
Janet
'00 180Q
02-14-2000, 08:33 PM
#12
Guest
Posts: n/a
Difference between accelerating from idle and at speed
The 'lag' is not there when accelerating at highway speeds as the turbo is already spooled up and ready to go....lots of exhaust gas passing through it and blades spinning nice and fast, lots of torque available when required and downshifting often is not required.
However, from idle there are minimal gases passing through the exhaust, and consequently the turbo blades are not spinning fast, hence no boost.
It takes time for the blades to start spinning fast ( albeit it a lot less time than in other turbo cars ) before the boost is produced. Up until that point the engine is like a normally aspirated 1.8 litre engine, the kick you noticed is the transition to the turbo induced engine. When you normally drive off from idle without gunning it, the transition is much more subtle, so subtle you probably dont notice it. But when the pedal is to the metal, it is very noticable indeed
)
However, from idle there are minimal gases passing through the exhaust, and consequently the turbo blades are not spinning fast, hence no boost.
It takes time for the blades to start spinning fast ( albeit it a lot less time than in other turbo cars ) before the boost is produced. Up until that point the engine is like a normally aspirated 1.8 litre engine, the kick you noticed is the transition to the turbo induced engine. When you normally drive off from idle without gunning it, the transition is much more subtle, so subtle you probably dont notice it. But when the pedal is to the metal, it is very noticable indeed
)
02-15-2000, 04:10 AM
#16
Guest
Posts: n/a
Yes...
Hi Janet,
That was indeed turbo lag. It's usually more noticeable in first or second gear when you suddenly floor the accelerator from low rpms. While it can be very noticeable in first gear, I've found that you can minimize it by keeping the revs above at least 2000rpm. In that regard, Audi has done a credible job engineering the car for as little lag as possible. Situations such as the one you describe are usually the only ones in which I've noticed more than a split second of lag in my car.
That was indeed turbo lag. It's usually more noticeable in first or second gear when you suddenly floor the accelerator from low rpms. While it can be very noticeable in first gear, I've found that you can minimize it by keeping the revs above at least 2000rpm. In that regard, Audi has done a credible job engineering the car for as little lag as possible. Situations such as the one you describe are usually the only ones in which I've noticed more than a split second of lag in my car.
02-15-2000, 08:55 AM
#18
Guest
Posts: n/a
Work with me here -- more air allows you to burn more fuel
Hence a larger turbo allows you to "cram more fuel into the same size engine".
Alternatively, we can always move this thread to rec.arts.nitpicking_simplified_posts_from_people_w ho_actually_sign_their_name