Turbo Lag and Reviewers...

[CanAutM3]

Originally Posted by Falafel Combo

It's interesting that you say that, because I almost never drive my car in sport+ (love the rev match). Could that be the lag i'm feeling? The comfort/sport settings?

Thanks for sharing this.

The anti-lag is definitely more aggressive in Sport+. Ultimately there is still lag present in Sport+ when going WOT from a constant speed. But even in aggressive transitions such as driving on a track, I don't feel much lag at all, and that is where is counts. The engine feels quite responsive. However, it needs to be said that the throttle response is not as sharp as it was on my previous ///Ms (E46 and E92) and the F8X responds a little less to throttle steer.

[CanAutM3]

Originally Posted by Hazey82

Shame the anti lag feature is only present in sport + and not sport as well. Id be wanting anti lag but without losing the rev match feature.

The anti-lag is also present in Sport, not just in Sport+. It is more aggressive in Sport+ though.

I think the "engine" settings are just right, I wouldn't want Sport and Sport+ to be calibrated the same, it would defeat the purpose. IMO, the problem resides in not having a separate control for rev matching.

[CanAutM3]

Originally Posted by jordon335

I have laughed so hard at the posts on here. One way to test your turbo lag theory is to get a JB4. Stick it in can map (stock map but with can options ie. Boost guage on fuel) touch the throttle and watch your guage hit full boost within a split second of touching it.

The "lag" you are feeling is the rise in RPM not turbo lag.

Your post is full of ignorance. There are quite a few experienced drivers posting here. Most understand the difference between boost threshold and lag. There is lag, there is no denying it. But does it hamper the driving experience? No.

[CanAutM3]

Originally Posted by AlterZgo

The M3 has about as little lag as can be expected for a turbocharged car. It just doesn't have the immediate, throttle wired directly to the throttle body feel that a responsive NA engine has. To me, all turbocharged cars have sort of a soft pedal feel... Almost like there's a pillow btw the foot and accelerator pedal so that when you push on it, it's not so much lag but more like a soft initial throttle tip in response. On good, high revving NA cars, the throttle body seems to be wired directly to your foot.

I think you are describing two different phenomenon of turbocharging: lag and slower throttle response.

Because of the longer intake piping, restriction caused by the turbo and (usually) lower compression ratio , the throttle response is less sharp on a turbocharged engine. That is what causes the soft pedal you describe. On previous M engines, with the individual throttle bodies just a few inches from the intake valves, that response is immediate.

Lag is the additional delay needed to build full boost and generate the full power.

[8600RPM]

Originally Posted by CanAutM3

I think you are describing two different phenomenon of turbocharging: lag and slower throttle response.

Because of the longer intake piping, restriction caused by the turbo and (usually) lower compression ratio , the throttle response is less sharp on a turbocharged engine. That is what causes the soft pedal you describe. On previous M engines, with the individual throttle bodies just a few inches from the intake valves, that response is immediate.

Lag is the additional delay needed to build full boost and generate the full power.

Technically valvetronic should make throttle sharper as it mitigates long intake piping by controlling air from the valve. In reality even on NA cars,with it, I never felt it was as sharp as the itb m cars so go figure

[solstice]

Originally Posted by AlterZgo

The M3 has about as little lag as can be expected for a turbocharged car. It just doesn't have the immediate, throttle wired directly to the throttle body feel that a responsive NA engine has. To me, all turbocharged cars have sort of a soft pedal feel... Almost like there's a pillow btw the foot and accelerator pedal so that when you push on it, it's not so much lag but more like a soft initial throttle tip in response. On good, high revving NA cars, the throttle body seems to be wired directly to your foot.

Very good description and exactly how I feel. However the S55 has just a tiny pillow enough to immediately identify it as an FI engine but not really an issue in most situations. However you can provoke huge turbo kicks if you want but the right foot is amazing at adapting to throttles ( and brakes and clutches ). It learns how to work in the engines pace and in case of the S55 make for a pretty much lag free experience.

[CanAutM3]

Originally Posted by 8600RPM

Technically valvetronic should make throttle sharper as it mitigates long intake piping by controlling air from the valve. In reality even on NA cars,with it, I never felt it was as sharp as the itb m cars so go figure

I was wondering the same thing when Valvetronic was introduced. It seems that the mechanicals of the Valvetronic system are still a little slow to respond on NA application. I remember reading that on the S85/S65 generation of engines, ///M figured that the Valvetronic technology was not yet ready to supply the prompt throttle response they were looking for on an ///M engine.

Further, the length and size of the intake tract upstream of the throttle body also has an impact on throttle response. How much and by how much the total mass of air in the intake tract needs to accelerate has an impact on the response.

As tidbit, the day that we will have perfectly responsive valve control systems will also signify the end of electrical starters .

[solstice]

If the next M3 will be a hybrid there is so much more options ( and complexity ) to work with the reduce lag, the electric engine used well could mean power unit response never seen before. it's going to be an exciting time, if we thought the F8X is a huge change for M , it's nothing compared to what could be coming in the next generations.

[Brindle101]

Originally Posted by Accel Junky

I LOVE my F80 M3. It combines some great things about most of the 35+ vehicles I have owned. But, I just have to get this off my chest.

I read just about every review from the press and from individuals and watched every video I could. The majority of these outright proclaimed turbo lag was either eliminated or virtually eliminated or greatly reduced or barely present.

I've owned a lot of turbo cars. Some factory, some aftermarket, some small turbos, some big turbos, some singles, some twins, some sequential, some non-sequential.

I can absolutely detect the turbo lag in this car. It is plain as day to me. I do not think there is anything remarkable about the lag reduction. That's OK. I bought a turbo car...I knew that going in. But let's not kid ourselves...

Not sure I agree with you. I have m4 with DCT. In sports plus I really can't detect turbo lag, almost imperceptible. In comfort mode, yes some turbo lag. For what it's worth, the m4 has much less lag than my m6.

[///F80M3]

Originally Posted by solstice

If the next M3 will be a hybrid there is so much more options ( and complexity ) to work with the reduce lag, the electric engine used well could mean power unit response never seen before. it's going to be an exciting time, if we thought the F8X is a huge change for M , it's nothing compared to what could be coming in the next generations.

Electric torque is no joke.

[parky1215]

I am hoping that higher flow intake with bigger diameter/smooth bent charge pipes will reduce turbo lag.
Still waiting for ER to release one...

[Jtjjen]

Originally Posted by jordon335

I have laughed so hard at the posts on here. One way to test your turbo lag theory is to get a JB4. Stick it in can map (stock map but with can options ie. Boost guage on fuel) touch the throttle and watch your guage hit full boost within a split second of touching it.

The "lag" you are feeling is the rise in RPM not turbo lag.

I admit I am a novice when it comes to turbos. However, the above sounded reasonable to me. It seems a lot of other people disagree.

To my thinking "turbo lag" is a lag in acceleration due to build up of boost in the turbo. If you actually are monitoring the boost while pushing the accelerator pedal, measuring the time to see the boost and it turns out to be "minimal" (whatever that means, of course) then be definition isn't any lag in acceleration not dur to "turbo lag"?

What am I not understanding here?

[CanAutM3]

Originally Posted by Jtjjen

I admit I am a novice when it comes to turbos. However, the above sounded reasonable to me. It seems a lot of other people disagree.

To my thinking "turbo lag" is a lag in acceleration due to build up of boost in the turbo. If you actually are monitoring the boost while pushing the accelerator pedal, measuring the time to see the boost and it turns out to be "minimal" (whatever that means, of course) then be definition isn't any lag in acceleration not dur to "turbo lag"?

What am I not understanding here?

The definition of Turbo Lag according to Garrett (I believe they know a thing or two about turbos ):

Turbo lag is the time delay of boost response after the throttle is opened when operating above the boost threshold engine speed. Turbo lag is determined by many factors, including turbo size relative to engine size, the state of tuning of the engine, the inertia of the turbo's rotating group, turbine efficiency, intake plumbing losses, exhaust backpressure, etc.

[GazM4]

Im an ex 335 owner and I owned it stock and cobb stage 1 and have now moved to an M4. With the M4 there is a lag to full power coming on even in comparison to my 335, I actually wouldn't describe it as a lag more as a deliberate electronic delay of power as its a consistent delay regardless of rpm. Having owned the m4 for 3 months I have a hypothesis on this lag/delay of full power coming on.

Firstly in my opinion it's not turbo lag. It has a fixed time length about 1 second, secondly it happens at all rpms and in all modes even sport plus where I believe turbos are significantly pre spooled. Furthermore being a 335 owner this lag wasn't there that means technically if they wanted they could eliminate it in the m4. In my experience it's like a two stage power delivery and I think it's there to smooth out the power delivery and make the power behave more linearly instead of giving it one huge boost which will make the car lose traction and give it a non linear feel. Before I bought the m4 I even test drove the m6 and felt the same. When I test drove m4 and m6s initially I felt they were slower than my cob'd 335. But then I realised that the 335 was giving me 390ish horses at once resulting in huge g force and the M's do it in a more linear fashion. I love my new m4 but I tell you I miss that push back the 335 would give when floored. All the girls would squeal! Although the m4 is going faster the initial pushback and g force isn't as good as the cob'd (tuned) 335. That's my two cents worth boys.

Personally I feel this forced linearity on the M4 also helps it control drifts better

[Super Spartan]

Originally Posted by Accel Junky

I LOVE my F80 M3. It combines some great things about most of the 35+ vehicles I have owned. But, I just have to get this off my chest.

I read just about every review from the press and from individuals and watched every video I could. The majority of these outright proclaimed turbo lag was either eliminated or virtually eliminated or greatly reduced or barely present.

I've owned a lot of turbo cars. Some factory, some aftermarket, some small turbos, some big turbos, some singles, some twins, some sequential, some non-sequential.

I can absolutely detect the turbo lag in this car. It is plain as day to me. I do not think there is anything remarkable about the lag reduction. That's OK. I bought a turbo car...I knew that going in. But let's not kid ourselves...

when I floor my M4, there is like a 2 second lag before the thing starts going super fast so yes it is there. I don't get it how reviewers always say there is no Turbo lag. Very annoying but it is what it is I guess.

[Ian1973]

Originally Posted by GazM4

Im an ex 335 owner and I owned it stock and cobb stage 1 and have now moved to an M4. With the M4 there is a lag to full power coming on even in comparison to my 335, I actually wouldn't describe it as a lag more as a deliberate electronic delay of power as its a consistent delay regardless of rpm. Having owned the m4 for 3 months I have a hypothesis on this lag/delay of full power coming on.

Firstly in my opinion it's not turbo lag. It has a fixed time length about 1 second, secondly it happens at all rpms and in all modes even sport plus where I believe turbos are significantly pre spooled. Furthermore being a 335 owner this lag wasn't there that means technically if they wanted they could eliminate it in the m4. In my experience it's like a two stage power delivery and I think it's there to smooth out the power delivery and make the power behave more linearly instead of giving it one huge boost which will make the car lose traction and give it a non linear feel. Before I bought the m4 I even test drove the m6 and felt the same. When I test drove m4 and m6s initially I felt they were slower than my cob'd 335. But then I realised that the 335 was giving me 390ish horses at once resulting in huge g force and the M's do it in a more linear fashion. I love my new m4 but I tell you I miss that push back the 335 would give when floored. All the girls would squeal! Although the m4 is going faster the initial pushback and g force isn't as good as the cob'd (tuned) 335. That's my two cents worth boys.

Personally I feel this forced linearity on the M4 also helps it control drifts better

I also came from a 335(N54) to an M3. There is most certainly lag in any turbo car, it's just the nature of design. It can obviously be nearly dialed out (and felt pretty good in the 335), but not in every situation, being different throttle openings in different rpm positions, etc. Once you tune the N54 it got worse, where I have noticed my Dinan tune on my M3 has not added any perceivable lag over stock, it has the same delivery just a bit more at any given throttle position/rpm.

[Nicky_do_it]

[QUOTE=Snappy Phoenix;21388589]when I floor my M4, there is like a 2 second lag before the thing starts going super fast so yes it is there. I don't get it how reviewers always say there is no Turbo lag. Very annoying but it is what it is I guess.[/

Is your car a manual or DCT? Also, is the lag experience in all throttle settings? I have a manual and don't feel it much at all.

[SD ///M4]

Originally Posted by ASAP

I am gonna guess people here havent driven an evo.

Or a Porsche 944 Turbo. Mash accelerator, wait for it, one thousand one, one thousand two, one thousand three, oh, there's that turbo!

[Super Spartan]

[QUOTE=Nicky_do_it;21392915]

Originally Posted by Snappy Phoenix

when I floor my M4, there is like a 2 second lag before the thing starts going super fast so yes it is there. I don't get it how reviewers always say there is no Turbo lag. Very annoying but it is what it is I guess.[/

Is your car a manual or DCT? Also, is the lag experience in all throttle settings? I have a manual and don't feel it much at all.

DCT

The lag is less in Sports and Sports+ but it's there. As in, the acceleration is not instant like it is with naturally aspirated engines. In comfort mode, it's horrible I can't imagine driving it in Comfort mode other than for shopping for groceries or having the baby in the back seat.

[Nicky_do_it]

[QUOTE=Snappy Phoenix;21393988]

Originally Posted by Nicky_do_it

DCT

The lag is less in Sports and Sports+ but it's there. As in, the acceleration is not instant like it is with naturally aspirated engines. In comfort mode, it's horrible I can't imagine driving it in Comfort mode other than for shopping for groceries or having the baby in the back seat.

I wonder if the lag is exacerbated by the DCT. Not from a stop but I felt a lag/hesitation when test driving the DCT. I also had the same feeling in my old B8s4.

[dkhm3]

[QUOTE=Nicky_do_it;21397290]

Originally Posted by Snappy Phoenix

I wonder if the lag is exacerbated by the DCT. Not from a stop but I felt a lag/hesitation when test driving the DCT. I also had the same feeling in my old B8s4.

I am not sure I understand, is this lag coming from flooring it from a constant speed? also, is the dct in D1?

The proper way to drive any car is the downshift the gear to where the rpms are at the sweet spot- around 4k in this car and THEN floor it. There should be little lag.

The only real lag I have experienced driving this car is when you bounce between gears. say you are on the highway at 50 mph in 6th gear, then you drop 3 gears to 3rd anticipating a pass. The is no room so you upshift 2 gears to 5th. If i then drop it back down to 3rd, the car is momentarily laggy, even in 3rd. and wot takes an extra second to kick in.

[Nicky_do_it]

[QUOTE=dkhm3;21397644]

Originally Posted by Nicky_do_it

I am not sure I understand, is this lag coming from flooring it from a constant speed? also, is the dct in D1?

The proper way to drive any car is the downshift the gear to where the rpms are at the sweet spot- around 4k in this car and THEN floor it. There should be little lag.

The only real lag I have experienced driving this car is when you bounce between gears. say you are on the highway at 50 mph in 6th gear, then you drop 3 gears to 3rd anticipating a pass. The is no room so you upshift 2 gears to 5th. If i then drop it back down to 3rd, the car is momentarily laggy, even in 3rd. and wot takes an extra second to kick in.

When off the throttle, then back on but not in manual mode and not floored. I actually don't think there is much "turbo" lag. Per my comments in an earlier post, I don't feel turbo lag in my mt m3. I was wondering if somehow the lag experienced by others is related to a slight hestitation in the trans. I don't have a much experience in DCT M3 but thought I felt a slight hesitation during a test drive.