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  #1  
Old 12-17-2011, 12:47 PM
a3carlo's Avatar
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Default turbo - newbie

hello,

just picked up a 2006 a3. this is really a sweet car. perfect form factor for the city.

this is my first experience with a turbo engine. i have heard about turbo lag, and think i'm experiencing it, but just want to see if this is an issue or not.

when i want to match speed for merging into traffic from a slow/standing start, the revs go way up for a second or two without moving the car faster. from what i hear, this is classic turbo lag, but am still a little unclear how the turbo works and why the lag is there in the first place.

also, even when making sudden, minor increases in speed, there seems to be a lag there, too. this is a little surprising. i have done this a few times where on the highway, i just need to get around a car, and there is a gap next to me, but the cars are moving +8 or +10 mph faster. pushing the accelerator a bit to match speeds, and it seems to not kick in immediately.

thank you for any replies, and i just really love this a3. will post photos soon!
 
  #2  
Old 12-17-2011, 01:03 PM
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I'm guessing you also have an automatic transmission v a manual trans?

If so this would account for some of this lag you are feeling. The ko3/04 turbos aren't beastly turbos so no huge power. But because they are small the actually respond fairly fast. If your having a lag I'm going to say it's not your turbo but something else causing this issue weather it is the trans needing to downshift or something else
 
  #3  
Old 12-17-2011, 01:40 PM
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I would agree. It sounds more like you're experiencing more of a lag in the transmission, with a possible mix of turbo lag. An auto trans is probably cruising at highway speeds at an RPM below the turbo's effective power range, so when you press down on the accelerator trying to speed up quickly, the trans needs to downshift (as with most auto trans) and then the engine RPMs need to increase, then the turbo starts pushing more air, then you actually feel the acceleration

The principle behind the turbo is the exhaust fumes coming out of the exhaust manifold spin a turbine (like a fan) as the exit. On the other side of the center shaft is another turbine that sucks in air and forces it into the intake, and into the engine. Every turbo has an optimal effective range. In order for the turbo to spin, you need exhaust gases. Below a certain RPM, there isn't enough exhaust to spin the turbo fully and force enough air into the engine. This is what turbo lag is.
 
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Old 12-17-2011, 03:51 PM
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Way to get all technical and ****
 
  #5  
Old 12-17-2011, 04:13 PM
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Originally Posted by bradtyler02
... so when you press down on the accelerator trying to speed up quickly, the trans needs to downshift (as with most auto trans) and then the engine RPMs need to increase, then the turbo starts pushing more air, then you actually feel the acceleration
got it ... i think ...
yes, it's auto-6sp, so i will have a look to see if it's changing gears, too.
probably is, cuz the rpms go waaay up, how else to do that and maintain the same speed?

thanks!
 
  #6  
Old 12-17-2011, 04:27 PM
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IIRC, you can only get an A3 in FWD, so you probably have a CVT auto trans, which I believe will exaggerate the "lag" even more. If you have a "shiftable automatic" try to manual downshift it to get the revs up, then give the accelerator a good push and see if that "fixes" the "problem."
 
  #7  
Old 12-17-2011, 09:33 PM
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ouch. i don't think it's cvt : 6 spd auto with tiptronic..
will experiment a little with it.
friend of mine just told me in a month, i'll just get used to it.
 

Last edited by a3carlo; 12-17-2011 at 09:51 PM.
  #8  
Old 12-17-2011, 10:01 PM
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Get a tip chip or regear it. Manual swap?
 
  #9  
Old 12-19-2011, 02:02 PM
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i'm prolly not gonna chip it soon. want to test out the base before going any distance. and no manual convert: wifey-poo can't deal, and in nyc we can only manage a single car at the moment..
 
  #10  
Old 12-19-2011, 06:29 PM
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Tip chip allows the manual shifting to be faster
 


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