I'm a virgin turbo owner who just got his first Audi. I've read exhaustively on the topic, but would like a straight answer. I bought a 2006 2.0T quattro MT and put an APR 91 octane chip in it. The turbo lags out of first gear in the first 1000-2000 rpm range. Can I combat that somehow? Am I driving like a loser? I'm still trying to get used to the clutch. Also, should I have a boost gauge? If so, what is the normal values for boost. All the info I could find seemed to be focused on the 1.8 motor. Thanks for any intel I can get.

 

I have an '06 2.0T quattro as well, but auto/tip trans. with APR91. There shouldn't be a lag in first gear, especially when you're manual trans. As for boost, stock is 14psi and with APR91 at 18psi with monster of a torque. If you don't have a boost gauge, I recommend getting one. The lag you're experiencing could be a leaky PCV. Do you see any oil residue on the oil cap?

 

+1 for the gauge (Audi should have installed one)

If you have the clutch fully engaged at 1000 rpm and stomp on the gas, that's lag. By the time you get to 2000 rpm the turbo is capable of full boost. From low revs (~1000) in addition to spinning the turbine/compressor up to speed (100,000 rpm range), the intake system also has to go from sub-atmospheric pressure to the plus side. The volume of the intake between the compressor and throttle body, including intercooler volume, has to be filled with twice as much air in order to maintain 14 psig. Air acts like a spring during the transient, the mass of the turbo has to speed up, but the engine isn't yet producing sufficient energy in the exhaust to meet the requirement, so it all results in lag. Once engine revs are above the 1800-2000 range, the turbine is spinning a bit faster (even without load on the engine) so there's less of a speed increase required before it starts pressurizing the manifold, and the exhaust has enough energy to dothe requiredwork. There are A/R ratios, different compressor wheels, turbine wheels, and scrolls that determine the behavior of the turbocharger, but our stock turbos provide good manifold pressure at low rpm because they are smallish. A larger turbo will provide more pressure,volume and horsepower, but it would exhibit more lag in the 1000-2000 rpm range than stock. Everything is a compromise, overall I think Audi did a good job of balancing performance, economy, and lag.

 

Thank you both gentlemen. That's exactly the type of intel I was looking for. My problem is the fully engaged clutch, but I'm working on that. Thank you very much. I guess my next purchase is a boost gauge.

 

TorsenTaxi is right.
The turbo kicks in at 2k rpm. If you step the gas pedal to 2k rpm before release any clutch, there won't be any lag from stop. I always drive my car no less than 2k rpm, so the turbo can kick in any time.

Hope that helps.

 

This is kind of a spin off of the original question but launching the manual consistantly and fast seems to be a bite of a mystery to me.

I have tried everythig it seems and haven't found and answer. I understand that the rpms need to be higher to be in the turbo range but how high.

Also I have played with the traction control, on or off to launch what do you guys think?

Thank you in advance b/c I am kind of tired of being a 2nd and 3rd gear rock star.

 

What were you driving before? I think you might be expecting too much acceleration off the line...even with a chip.

 

I was driving a POS mercury before thisso beleive me my expectations are not very high.

The car just flys in 2nd and 3rd. I realize that it may just be my clutch work but I was looking for some help. On launch it really feels over geared then starts to really wind up but it is the initial lag that I was trying to eliminate.

The car has a little upgrade with Stage 1 Revo but even before this upgrade I had the same issue.

I don't want this to sound like a diss to the A4 b/c I love it I just want to learn how to drive it better and was looking for some help.

Thanks again.

 

Hold it at 2k rpm, before release any clutch pedal. While relasing the clutch pedal, put in more gas. If you do it right, you will have a good launch.

 

Edkwok, I try not to use "kicks in" as it confuses some folks. When the revs are below 1500 with a load on the engine, the turbo is still spinning. It's just that there isn't sufficient exhaust energy to provide full pressure to the manifold, but as the exhaust energy increases at 2000, the turbine and compressor have enough energy to supply what the engine can use and more. It's more of a balance thing.

When launching with a manual transmission there are two approaches: One sane and the other not so much.
Sane;
Knowing that you need 2000 rpm to get full boost, keep the revs above 2k at all times. This will require a bit of foot coordination and practice, but it won't place the hellish loads that the alternate method produces on the drivetrain. Get revs above 2k and hold, now when you're ready to go ...nail the throttle while at the same time letting the clutch out. Don't just let the clutch out in one motion, because as soon as the car starts to move the engine begins to see increased load and the turbo will spool. So the clutch motion becomes two steps, find friction pointto spool the turbo, then the clutch is used to modulate the torque transfered between the engine and transmission. If the rate at which you engage the clutch is faster than the rate at which the engine can increase revs, it will bog, you'll fall below the minimum engine speed required to produce full boost and the whole launch falls on its a**. However, if the rate at which you engage the clutch is too slow, engine revs to the limiter, clutch is smoked due to the excessive speed difference between flywheel and transmission, you make a lot of noise and still don't come off the line any better than a Kia. When it works correctly it is a sweet feeling in the seat. The tach should just sweep smoothly to your shift point after you nail the throttle, hard to do but it places the least stress on drivetrain and yields the best hole shot. Note that the studder step with the clutch is fractions of a second, once the turbo accelerates into its powerband it will keep up with a pretty quick foot. You might feel a little slow in the first 2-3 feet, but getting the engine power up before you try put it all to the ground will more than make up for it in the next 10 feet. The beauty of quattro is that once you let the clutch out, you don't have to even think about spinning up a wheel with too much power like a two wheel drive.

Not so sane;
Floor the throttle, when the tach is flying past 4k . . . side step the clutch. Ouch, the torque spike that you just sent through the drivetrain will shortenits life significantly. This is not recommended, intended to make you smile.

There are other launch methods that use brakes to hold the car while the turbo spools up, but the clutch has to dissipate all the energy as heat with no movement. No huge torque spikes but the clutch plate would prefer a bit less heat.