50i a bit laggy?

[bimmer_buachaill]

anzer, one thing I should point out - it's one thing to say there is a little lag off the line. Even with the minimal lag I experienced (whatever the reason), I would certainly not describe the 50i as "laggy" which implies that lag is an issue with the car which it certainly isn't. Whether or not there is lag, it is nothing to be concerned about.

BTW, the only other mention to lag I've seen was from a X6 50i owner in response to my test drive post:
http://www.xoutpost.com/739989-post4.html

[Fraser]

Originally Posted by LeMansX5

laggy in comparison to what?

Exactly!

The 50i has close to 20 percent more power and torque at 1000 rpm than the 48i and the power/torque differential between the two increases rapidly from there.

[MrBlonde]

Turbo Lag is the leg warmers of the 201xs, stop being ignorant! All my vehicles are turbocharged.

[Fraser]

Originally Posted by MrBlonde

Turbo Lag is the leg warmers of the 201xs, stop being ignorant! All my vehicles are turbocharged.

I'm not getting your drift?

[MrBlonde]

Fraser, what I mean is that people use the term "turbo lag" a lot but usually with very little real world knowledge. If you're driving a 1970s Porsche 930 then yes, you're going to experience turbo lag. With old school technology turbochargers, 6:1 compression etc the experience in transitioning onto boost will be radical. The "light switch" transition that people fear.

However in 2010 with a BMW OEM turbo system on a large capacity V8 multivalve engine with latest technology turbochargers .. really you're not going to experience the same issues. The turbochargers are ball bearing and they spin up so much faster, the exhaust gas volume generated by a large capacity multivalve V8 with variable valve timing is a different world to an old school flat 6 plus the ECUs now are vasstly superior.

I don't believe tubo lag is an issue on this vehicle. :-)

[Fraser]

Originally Posted by MrBlonde

I don't believe tubo lag is an issue on this vehicle. :-)

Nor do I. Nor on the 35i. These are both seamlessly tractive engines that are a driving delight. Perhaps not so good at the bowser if you've put your boot in, especially with the 50i and in heavy vehicle like the X. 335i is sublime and a great poor-man's M3.

[anzer]

For me the lag I'm really talking about is when you are cruising at about 30km/h down suburban street, slow for a speed bump at about 20 ..then try to accelerate briskly on the other side of the bump ...but ... catch the turbo sleeping and it takes too long to spool .... have also had the same problem cruising up to give way signs (for example) then flooring to get across traffic and slight delay (enough to be dangerous at times) ....

I suspect some of this has to do with the 4WD getting its act together? anyway ..there's flat spots that shit me ...especially when the 35d is suppose to have most of it torque spent by 2000 rpm ... but when you sit there waiting it certainly doesnt feel like that ... I drive in DS now to keep revs a little higher ..that seems to help a fair bit .....

In terms of 50i I read a motoring review that mentioned a little lag ..but once again this could be more about the '2nd gear start' that some are referring to on the new 8 speed box ?

When the 50i, 40d and 35i arrive I'll go and drive then using these sort of real-world driving scenarios - I'm sure I won't be disappointed ...but everyone has different expectations so no right or wrong answer I suppose ...just personal preferences ... good discussion though ..thanks for inputs

Fraser - went for 200km drive today (resetting BC) and avg was at 10.2 !! that's more like it (and I was pushing it here and there in the 110km zones) ... took your advice and headed for some hills to mix up the run-in terrain a little ... no doubt when school runs start again tomorrow I'll be heading back to 16 ;(

[MrBlonde]

Originally Posted by anzer

For me the lag I'm really talking about is when you are cruising at about 30km/h down suburban street, slow for a speed bump at about 20 ..then try to accelerate briskly on the other side of the bump ...but ... catch the turbo sleeping and it takes too long to spool .... have also had the same problem cruising up to give way signs (for example) then flooring to get across traffic and slight delay (enough to be dangerous at times) ....

I suspect some of this has to do with the 4WD getting its act together? anyway ..there's flat spots that shit me ...especially when the 35d is suppose to have most of it torque spent by 2000 rpm ... but when you sit there waiting it certainly doesnt feel like that ... I drive in DS now to keep revs a little higher ..that seems to help a fair bit .....

In terms of 50i I read a motoring review that mentioned a little lag ..but once again this could be more about the '2nd gear start' that some are referring to on the new 8 speed box ?

When the 50i, 40d and 35i arrive I'll go and drive then using these sort of real-world driving scenarios - I'm sure I won't be disappointed ...but everyone has different expectations so no right or wrong answer I suppose ...just personal preferences ... good discussion though ..thanks for inputs

Fraser - went for 200km drive today (resetting BC) and avg was at 10.2 !! that's more like it (and I was pushing it here and there in the 110km zones) ... took your advice and headed for some hills to mix up the run-in terrain a little ... no doubt when school runs start again tomorrow I'll be heading back to 16 ;(

I think you're talking about an automatic gearbox and real world physics with a 2500 kgs vehicle rather than turbo lag!

[anzer]

The auto and weight don't help, agree ..but there's lag in my view that occassionaly catches the 35d out ... I often wonder if the balancing of the TT on the 35d is not well tuned from factory ..I think the 40d has gone single turbo with twinscroll (like 740d) ..so should be interesting to compare ...same with 35i which has gone N55

[Fraser]

Originally Posted by anzer

The auto and weight don't help, agree ..but there's lag in my view that occassionaly catches the 35d out ... I often wonder if the balancing of the TT on the 35d is not well tuned from factory ..I think the 40d has gone single turbo with twinscroll (like 740d) ..so should be interesting to compare ...same with 35i which has gone N55

I thought we are talking about 50i, and to a lesser extent 35i. You can't talk about turbo diesels and turbo petrols in the same breath. Completely different. 40d is still twin, sequential turbos, like the 35d. The main diff is that the 40d's small turbo is now variable geometry whereas with the 35d the small turbo is fixed geometry.