[Russellnyc]

No flames please, I am not complaining about this infinitessimal amount of lag, but just for those 335i owners who say it doesn't exist (largely because they haven't ever experienced bad turbo lag and so don't have a point of comparison), I can show it to you. This particular example probably only works in the 6MT.

Drive in 3rd gear around 20-25 mph. Floor it. The car responds with a little naturally aspirated thrust (i.e. what it would do without the turbos). Wait about 1.25 seconds with the pedal down and you will feel the surge of torque as the turbos spin up. In case you were wondering, that's turbo lag. That's the longest lag I could find anywhere in the range, even 5th and 6th spool up faster, probably because there's more load to apply.

3rd gear is especially long in BMWs (it's the driving-around-the-city gear), so the car drags more here than it does in other gears. I think this is clever engineering, since even under hard acceleration, you're beginning to lay off by 3rd gear as you pass 70+ mph after the 2-3 redline shift, and you completely miss this laggy rev range.

Obviously, this degree of lag has no bearing on mid-corner handling dynamics, since no aggressive driver is going to hit a hard corner in 3rd gear at 2k rpm. Note that even in cars with huge turbo lag, that lag is much less pronounced at high revs.

[S4to335]

Originally Posted by Russellnyc

No flames please, I am not complaining about this infinitessimal amount of lag, but just for those 335i owners who say it doesn't exist (largely because they haven't ever experienced bad turbo lag and so don't have a point of comparison), I can show it to you. This particular example probably only works in the 6MT.

Drive in 3rd gear around 20-25 mph. Floor it. The car responds with a little naturally aspirated thrust (i.e. what it would do without the turbos). Wait about 1.25 seconds with the pedal down and you will feel the surge of torque as the turbos spin up. In case you were wondering, that's turbo lag. That's the longest lag I could find anywhere in the range, even 5th and 6th spool up faster, probably because there's more load to apply.

3rd gear is especially long in BMWs (it's the driving-around-the-city gear), so the car drags more here than it does in other gears. I think this is clever engineering, since even under hard acceleration, you're beginning to lay off by 3rd gear as you pass 70+ mph after the 2-3 redline shift, and you completely miss this laggy rev range.

Obviously, this degree of lag has no bearing on mid-corner handling dynamics, since no aggressive driver is going to hit a hard corner in 3rd gear at 2k rpm. Note that even in cars with huge turbo lag, that lag is much less pronounced at high revs.

Try driving a 1979 Porsche Turbo...that has lag.

[2009BMW335]

doesn't every turbo have lag?????? this car has significantly less lag than turbo cars i've driven ( 3 ). not that i've driven a lot

[DocRoss]

Also, did you know:

1. Golf balls have dimples;
2. Cheetahs have spots;
3. Plants have cellulose as a function of their cell wall;
4. Purchasing a mattress is pure hell;
5. Yes, there is NO Santa;
6. AND ALL TURBOS HAVE LAG!

I believe posters say "no" in a relative sense. No lag compared to...

[Russellnyc]

You're preaching to the choir, my friend. There are people here who have argued vehemently (and angrily) that the 335i has no lag. My post is instructional, not naive.

[ironic]

^ true, but good info from the op none the less

[DocRoss]

Originally Posted by Russellnyc

You're preaching to the choir, my friend. There are people here who have argued vehemently (and angrily) that the 335i has no lag. My post is instructional, not naive.

Well, if that is indeed the case we have some turbo virgins running around in a delusional state believing they have "no" (absolute empirical sense, here) lag.

[canucklion]

that's a very interesting observation/hypothesis!

Originally Posted by Russellnyc

3rd gear is especially long in BMWs (it's the driving-around-the-city gear), so the car drags more here than it does in other gears. I think this is clever engineering, since even under hard acceleration, you're beginning to lay off by 3rd gear as you pass 70+ mph after the 2-3 redline shift, and you completely miss this laggy rev range.

[Russellnyc]

http://www.e90post.com/forums/showpo...0&postcount=18

Not to single out the poster from this thread, but this point of view does exist...

Iam being serious there is no lag what so ever.
Pure power ON DEMAND!! :rocks:

[ksfrogman]

I bet if it were called "turbo surge" instead of turbo lag, almost everyone would say "yes, it has it!"

It's the surge that makes a turbo car feel more impressive.

[CanadianTSi]

Turbo Lag is so blown out of proportion its not even funny. Boost is always a down-shift away and its not like you need to do full boost pulls when simply daily driving. Also when your at the dragstrip revs are never low enough to fall out of boost.

A car that doesn't hit full boost until 4000rpms is perfectly fine for daily driving and even helps with the MPG as you only get into boost if you want to.

[S4to335]

coming from turbocharged Audis...I think I can comment. It always takes a while for a turbo to spool up. Most stock cars, Audi A4/S4 and the 335i have slight lag...but its not that bad. Try some of the cars with BIG single turbo kits...some of those have scary lag.

[Russellnyc]

Yes, my Audi has much more lag, and chipping any car just makes the lag more noticeable. By the way, the S4 doesn't have lag, because it's normally aspirated...

[jmenge]

I believe he was referring to the B5 s4's which I'm sure you know are bi-turbo.

[schneid4323]

Ofcourse if your at about 1k it is gonna have lag, turbo or not all cars take a second to get up from that low of an RPM in 3rd gear, the turbos kick in about 1.4k but you're still in the wrong gear. By no turbo lag people are saying, with a proper launch, the turbos are constant throughout all gears. Obviously if you slam on it that low in third you're gonna have some difficulties.

[Russellnyc]

Originally Posted by jmenge

I believe he was referring to the B5 s4's which I'm sure you know are bi-turbo.

Oops, right.

[S4to335]

Originally Posted by jmenge

I believe he was referring to the B5 s4's which I'm sure you know are bi-turbo.

Yes, I was..since I had three of them.. :-)

[S4to335]

Originally Posted by Russellnyc

Yes, my Audi has much more lag, and chipping any car just makes the lag more noticeable. By the way, the S4 doesn't have lag, because it's normally aspirated...

BTW, the Audi that I felt the most lag in was a 225TT that I drove in Denver...I was actually very surprised.

[Russellnyc]

Originally Posted by schneid4323

Ofcourse if your at about 1k it is gonna have lag, turbo or not all cars take a second to get up from that low of an RPM in 3rd gear, the turbos kick in about 1.4k but you're still in the wrong gear. By no turbo lag people are saying, with a proper launch, the turbos are constant throughout all gears. Obviously if you slam on it that low in third you're gonna have some difficulties.

Agreed. Again, I wasn't saying that this was a problem, just that there was evidence of it. You know how in court, before you can argue that Professor Plum killed Colonel Mustard with the candlestick, you have to prove that a candlestick can be a lethal weapon, that both of them were in the room, that they were both alive prior to the time of the murder, etc. I'm just proving that, a priori, lag exists.

By the way, I LOVE this image from your site

[Russellnyc]

Originally Posted by S4to335

BTW, the Audi that I felt the most lag in was a 225TT that I drove in Denver...I was actually very surprised.

Yep, and my chipped 180 lags just as badly now. I think the surge of power is kind of fun, but it sucks to get caught in the wrong gear at the wrong time. Since I bought the BMW I basically hate driving my TT for this and other reasons.

[DocRoss]

Originally Posted by jmenge

I believe he was referring to the B5 s4's which I'm sure you know are bi-turbo.

B5 S4

[HyperM3]

I think for people who havent driven a turbo before might find that they personally feel there is no turbo lag. Those of us who have will be looking for it because we know what it feels like.

That being said, I think BMW did a superb job in creating a virtually lag-free and surge-free turbo system. Of course any car down low will be slow to get power but thats irrelevant. You never really feel the turbos on this car, you just feel a constant thrust of movement. Its very refined and smooth.

My a4 was like a one-legged sprinter it was so underpowered. Try merging with that car on a 90°+ day. After some mods it felt definitely more brisk but you get that turbo surge around 3500 that immediately presses you into the seat.

Yeah, theres lag, but very minimal. Thats what two small turbos can do for you. BTW, where is the intercooler and can it be upgraded?