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Discussion Starter #1
It was a regular topic of complaint; the Turbo Lag, or at least as perceived.
Today, just for fun, I experimented with standing starts to see if I could experience it but I couldn't.
Now, I have read that a software upgrade was introduced to eliminate the alleged momentary hesitation said to occur when accelerating away. Trying to achieve a "fast getaway" from say, a roundabout was cited as a manoeuvre when it was regularly experienced.
My question is simple; are you aware of any such upgrade or did we all just get used to the car.
 

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Hi Pekem
Will have to check as not aware of a specific bulletin about turbo lag as we have not had one of our customers complain.There are many updates and various "fixes"also software updates come out for engine ecu and it maybe that later mapping is an improvement as it is a constantly evolving,so it maybe that later cars dont suffer as mapping changed to improve feel and any early cars can be programmed to a latter level.
 

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Discussion Starter #4
Thanks for that :)
Are you saying that a kind of remapping to improve performance could be introduced via software and because you were not looking for it specifically you would be unaware of it happening :?:
 

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can i post now please :)

or are we waiting for Jag M/T to answer the latest Q ;)

i've done a search back through the previous discussions about lag, and i'm not convinced that what's being discussed is actually turbo lag.

i wonder if the roundabout issue is down to the 'corner recognition' system.

also, i think a lot of the various ecus in the XF will actually adapt themselves to driving style, and that's maybe why your car (Pekem) is behaving differently to what it was before. it's certainly mentioned in the manual with regard to Sport mode on the gearbox.

it's an old trick with a lot of cars to reset the ECU, go and give the car a hammering, and hey presto, it feels quicker and crisper on the next drive :) (disclaimer - i haven't tried it with my XF, and i'm not suggesting anyone does, but i think the tech is there)

i can't see the V6 diesel suffering majorly from lag. certainly the demo car i drove didn't :)

fwiw my understanding of turbo lag is the time taken to go from vacuum pressure (i.e negative boost, no throttle) to positive boost in the appropriate gear for the speed at that time. in a car developed to be an executive cruiser it should be barely perceptible.
 

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Discussion Starter #6
bob said:
can i post now please :)
Thank you for patience Bob; you are very welcome to post now :)
I might just add that I am sure some will regard it as OTT having to wait for a response from the Service Team but it is done to ensure that the first response is that of a trained Jaguar Technician and that opinions expressed by members subsequently is regarded as just that,members opinions.
Additionally, if the post is bombarded with members views at the outset, there is a danger of the post being overlooked and a response delayed. :)

With regard to the substantive issue of "turbo lag" I will bow to your obvious superior knowledge of such matters. I used that term because others have used it and I made the assumption, rightly or wrongly, that it described the condition that I did experience on fast acceleration from a standing start, others certainly used the example of the roundabout.
It was a hot topic at one time and the fact is that it isn't now. Your explanation may be the answer; all I can say now is that I was not able to induce the lag, for whatever reason, when I tried it the other day. :)
 

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I feel my XF is better than the 54 plate S-Type I had BUT I have not put my foot flat to the floor yet as I'm still running it in - that will be the time to really decide.

I've certainly got no complaints so far. In fact, I was sitting in a pub in a small rural Somerset town last night when a bloke walked in, went to the bar owner who he knew, and demanded to know who owned the Jag outside and promptly accused thim of buying it! The conversation then developed and I owned up, which prompted West Ham v Hull City to be forgotten about for five minutes whilst everyone went out to look at it! Five other people were already outside gawping, so I then had a crowd gathered around my car which was parked in a one-way street.

The consensus was positive :D

... and no-one missed a goal...
 

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pekem said:
bob said:
can i post now please :)
Thank you for patience Bob; you are very welcome to post now :)
I might just add that I am sure some will regard it as OTT having to wait for a response from the Service Team but it is done to ensure that the first response is that of a trained Jaguar Technician and that opinions expressed by members subsequently is regarded as just that,members opinions.
i do get the point mate, and i'm not going to pretend i'm an expert. i've got a basic understanding of stuff though, and i'm actually interested in how things work.

tbh i don't get the argument that we should wait for the response of the "service team" or the thread could be diluted. i think discussion is healthy, and in all honesty i think this section of the forum is a waste of time. if we're going to have actual Jag service bods on board they should be getting involved throughout the technical area.

incidentally, my first post on this thread which you deleted - i actually clicked through the front page, and didn't realise it was in the 'ask service' forum. that's why i answered.

as someone who is a bit of a car geek i find the technical aspects of the Xf a lot more interesting than the endless bumping and new threads related to how popular particular colours or options are :|
 

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I agree with the editing of threads, all comments should be able to be posted, this is not a Jaguar sponsored forum, it is a free discussion point for all things XF both good and bad. Most of the time it is a question to see if others have the same issue as opposed to a definitive service question, so let others feed in to the question.
I am very dubious about hiding these technical posts away.

I disagree however that the car doesn’t suffer from turbo lag, it's awful for a twin turbo 2.7 the throttle response is very poor. Try one of the competitor cars and come back and say you don’t notice a difference. Just to moving off normally you use up 1/2 the throttle travel, it’s not great.
If there is an update do all cars automatically get it when if for service of do you have to request it?

Before you wade in Pekem, I love my XF and spent 8 hours in it yesterday navigating London (Partially thanks to the dodgy sat nav logic I might add). But I still enjoyed it!
 

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Have you tried it with the DSC turned off?
 

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rclifford said:
I disagree however that the car doesn’t suffer from turbo lag, it's awful for a twin turbo 2.7 the throttle response is very poor. Try one of the competitor cars and come back and say you don’t notice a difference. Just to moving off normally you use up 1/2 the throttle travel, it’s not great.
If there is an update do all cars automatically get it when if for service of do you have to request it?

!
Just a little bit from the delete post i made - i can't be bothered to type it all again!
Mine was delivered late Nov and there is no lag (unlike the test car i drove). It moves off instantly from rest at speed if you wish it to & definitly uses 1st gear
 

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I agree with Bob.
I have not experienced anything I would describe as turbo lag in my XF, although I have experienced the slow start from standing at junctions etc. That is not turbo lag.
Use the gear paddles to hold a gear, get the revs to 2000rpm on a fairly neutral throttle, then floor it. If the full torque doesn't come on immediately that's turbo lag.

Martin
 

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I'm suprised ther is still so much of a divide with this "turbo lag" problem or not?

What I have experienced is as follows:

When sat at a complete standstill, push the throttle to the floor, for the first 1/2 second or so, the car will do very little, when the engine does kick in it breaks your neck and shoots off. There is no denying that there is a definite period of inactivity.

I spoke with my service department in Germany and their answer was different to any others I've had. They explained that as the throttle is on a "drive by wire system" (no physical link between the throttle and the engine) When you plough the accelerator into the floor, the ECU takes control and stops the full power being transferred to the wheels, avoiding wheelspin etc. This by all accounts is what we are all refferring to as turbo lag.
Any comments service?
 

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Hi zx10 ben
I think it is a the way the power is delivered and controlled by the ecu.The delivery isnt instant and when the vehicle is gunned gives the turbo lag impression as then the main power band comes in and you launch off.
 

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zx10ben said:
When sat at a complete standstill, push the throttle to the floor, for the first 1/2 second or so, the car will do very little, when the engine does kick in it breaks your neck and shoots off. There is no denying that there is a definite period of inactivity.
fwiw, my non-turboed petrol XF does the same ;)
 

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Don't push the throttle to the floor!

It will cause the ECU to try to check whats happening with the traction control system & hence cause a delay with the torque converter on the auto box.

With the 2.7D there is more than enough torque for quick getaways by moderate use of the throttle
 

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Having had an x-type 2.5 petrol, s-type 3.0 petrol and 08 XJ 3.0 petrol 2 XFs and awaiting the third, the only two out of my bunch to leave me with a worried look of disappointment staring at the ass of the car in front of me disappearing into the horizon were the two XFs. One last chance is this new 3.0 Diesel. Please, please please let me be the one who is gone with the wind.

PS. as for wheelspin, foot to the floor in the x-type, s-type and XJ, they all rocketed from standing start without spinning and these would do 0 - 60 faster than my wife's new kitten with his ass on fire!!! :lol:
 

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SN08 TOM said:
Having had an x-type 2.5 petrol, s-type 3.0 petrol and 08 XJ 3.0 petrol 2 XFs and awaiting the third, the only two out of my bunch to leave me with a worried look of disappointment staring at the ass of the car in front of me disappearing into the horizon were the two XFs. One last chance is this new 3.0 Diesel. Please, please please let me be the one who is gone with the wind.

PS. as for wheelspin, foot to the floor in the x-type, s-type and XJ, they all rocketed from standing start without spinning and these would do 0 - 60 faster than my wife's new kitten with his ass on fire!!! :lol:
thankfully my reaction times on seeing the lights go green have saved me from said disappointment.

i agree about throttle response though. my S-type's take-off was virtually instant, and TC on or off, the grip was there in the dry. wet was a different story :oops:

the XF has the pause when you stamp your foot down whether DSC is engaged or not in my experience. it's not a major thing, but it's there. i think it's more obvious with DSC on.

the only time i've had wheelspin problems is in atrocious conditions and under provocation from the 'nut behind the wheel' ;) i've not managed to encounter this in the Xf yet, even on a trackday :)
 

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PaulCP said:
Don't push the throttle to the floor!

It will cause the ECU to try to check whats happening with the traction control system & hence cause a delay with the torque converter on the auto box.

With the 2.7D there is more than enough torque for quick getaways by moderate use of the throttle
Yeah I fully understand this thing about jently applying the throttle. My point is that you don' always have the luxury of "massaging" throttle. If you are on a side road wanting to pull out of a busy B road etc. In any other car you can put the foot to the floor to pull out quickly, I dont want to have to counter the ECU's decision making by faffing around with degrees of pressure.
 

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I had a scare following a split-second decision at a roundabout the other day. Engine revs were minimal, and having made the 'go' decision I floored the throttle and got the frihgt of my life... very little happened for about 1.5-02 seconds - a very long time when you've made a questionable 'go' decision. The advice about the system having a think about what I was up to makes sense apart from I now drive the car 'DSC fully off'. I have since found a work around for this and that is to apply a modicum of throttle until to get a response then floor it. It's not something I make a habit of to be honest but the system lag definitely caught me out and I needed to figure out a way around it.
 
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