RE: G Power launches 440hp M140i upgrade
Discussion
ManOpener said:
Mr Whippy said:
And yes it lags. Put it in 5th (in the 8spd auto) at 50mph, go WOT.
Does your head snap back? No. That’s lag.
Does your head snap back? No. That’s lag.
You clearly have no idea what "lag" is.
What you're describing, albeit hilariously badly, is boost threshold.
And what makes you think a 400bhp tune will make that worse? Even if it only made extra power on-boost, it wouldn't magically start boosting later or producing less power off boost.
Edited by ManOpener on Saturday 29th September 07:57
More boost = more change between initial WOT torque output and peak = more perceived lag.
50mph in 5th is on the ‘peak’ torque plateau of the 140i, supposedly.
Laggy lag lag.
Mr Whippy said:
I know what lag is.
Then why are you continuing to describe something (vaguely resembling) boost threshold? I mean it could just be that you're bad at explaining, I suppose, but your example is frankly ridiculous.Lag is effectively hesitation caused primarily by the time it takes for the turbocharger exhaust turbine to spin up to a speed at which it is pressurising inlet air (things like pipework length, intercooler size and design also affect lag).
Boost threshold is relative to exhaust flow and therefore engine speed. Principally it is the point in the rev range which exhaust flow is sufficient to spin the compressor up, but more widely also how the climb up to peak boost scales across the rev range.
Mr Whippy said:
More boost = more change between initial WOT torque output and peak = more perceived lag.
As per the above, this is not lag. Raising peak boost via wastegate changes from, say, 18psi to 21psi neither increases the lag (as the turbine itself and the associated pipework remains the same), not does it increase boost threshold. It will probably push peak boost higher in the rev range and change the engine's power curve, but nominally it affects neither.Mr Whippy said:
50mph in 5th is on the ‘peak’ torque plateau of the 140i, supposedly.
It's almost like you don't understand gear ratios. If what you were experiencing was "lag", it would be gear independent. It's pretty hard to think of many ways BMW could have reduced turbo lag and lowered boost threshold on the B58. A small, twin scroll, turbocharger on a comparatively large displacement engine with an air/water heat exchanger in lieu of a standard intercooler is about as much as you can realistically do.
Edited by ManOpener on Saturday 29th September 13:12
Mr Whippy said:
ManOpener said:
Mr Whippy said:
And yes it lags. Put it in 5th (in the 8spd auto) at 50mph, go WOT.
Does your head snap back? No. That’s lag.
Does your head snap back? No. That’s lag.
You clearly have no idea what "lag" is.
What you're describing, albeit hilariously badly, is boost threshold.
And what makes you think a 400bhp tune will make that worse? Even if it only made extra power on-boost, it wouldn't magically start boosting later or producing less power off boost.
Edited by ManOpener on Saturday 29th September 07:57
More boost = more change between initial WOT torque output and peak = more perceived lag.
50mph in 5th is on the ‘peak’ torque plateau of the 140i, supposedly.
Laggy lag lag.
I have had laggy turbo cars, V8's, NA sixes and out of all of them, this is the car that is most on its game all the time, its small, very torquey and have a very intelligent, rapid gearbox, I have tired putting the gearbox into S so it doesn't change gear itself and never has it seemed lacking.
Put a standard M135i next to an E90 M3 in the same scenario, hmm, wonder what would happen, and guess what its not the M3 pulling away.
Its a fairly small twin scroll turbo, on a large capacity engine, it isnt (as standard) that highly boosted, standard BMW I6's produce 265 bhp, the turbo adding 60 bhp, the engine itself has a fairly high compression ratio (By turbo standards) which is another contributor to languid off boost performance, take the turbo off and you basically have a very similar engine to any other BMW 3.0 six, so in the rare occasions its apparently off boost it will just perform in a similar manner as they are the same capacity and CR, but then you get the turbo swelling the mid range and adding power right round, it just feels more like a higher capacity engine rather than a boosted one, you arent massively aware of the turbo waking up producing boost, I know what that feels like, our Galaxy would leave you waiting if you caught it off guard.
Peak torque is from 1300 rpm, if the turbocharger wasnt doing anything it would be much higher up, so even before that, its making boost as that is peak torque, 331 lb ft as standard,
Standard max boost is about 0.65 bar, an A45 AMG, for comparison is 1.6, perhaps why remaps are quite effective on this engine (and the B58) and possibly why it won engine of the year in 2014.
https://www.bmwblog.com/2014/06/25/n55-3-0-litre-s...
Amit-o7ntq said:
Can’t put the power down so what’s the real point. I could appreciate the appeal if they were Xdrive. A Mapped Golf R with the same power figures would be all over it. Surely?!
In the dry it puts it down fairly well considering, the further you go above standard the more it struggles for traction, an LSD helps but its a limitation of having two driven wheels. The M135i/M140i tends to fare better as a drivers car in tests but the Golf is very good, horses for courses, in the UK 4wd makes sense for wet days, and its not like you cant leave the house if you have 2wd (thats when it snows with a BMW
) you just have to slow down and be smoother with your inputs.Depends on what you want, and having a surfeit of power over grip, is generally more fun than the other way round.
Amit-o7ntq said:
A Mapped Golf R with the same power figures would be all over it. Surely?!
Depends on the measurement. From 0-60, probably. But 30-70 the M140i is between half a second and a second faster than a Golf R depending on whose measurement you believe.The R is undoubtedly faster point to point, especially in adverse weather, but I know which one I'd rather own.
Edited by ManOpener on Monday 1st October 07:57
Strong bump.
Following this thread with interest.
Got an m140i myself, main reason was to get something over a 4 pot before they become extinct, i was in 2 minds to swap it tbh as its not what i was expecting but then its good at everything rather than being a one trick pony.
Im wanting to maybe go down the route of fitting an LSD, Bilstein coilovers and maybe then a remap to 420.
How would this likely manage on stock width rear tyres?
The thing is this puts me into m2 territory but the problem is ive already bought the car now and to sell it i would loose a couple of grand anyway in part ex/second hand values so im kind of stuck and dont know whether to just keep the car and upgrade it as above then hopefully keep it for a while.
Ive also been made aware M cars generally cost more to maintain and basic parts are more and insurance etc.
Following this thread with interest.
Got an m140i myself, main reason was to get something over a 4 pot before they become extinct, i was in 2 minds to swap it tbh as its not what i was expecting but then its good at everything rather than being a one trick pony.
Im wanting to maybe go down the route of fitting an LSD, Bilstein coilovers and maybe then a remap to 420.
How would this likely manage on stock width rear tyres?
The thing is this puts me into m2 territory but the problem is ive already bought the car now and to sell it i would loose a couple of grand anyway in part ex/second hand values so im kind of stuck and dont know whether to just keep the car and upgrade it as above then hopefully keep it for a while.
Ive also been made aware M cars generally cost more to maintain and basic parts are more and insurance etc.
bigenginesmallcar said:
Im wanting to maybe go down the route of fitting an LSD, Bilstein coilovers and maybe then a remap to 420.
How would this likely manage on stock width rear tyres?
I'd strongly advise going wider at the rear. How would this likely manage on stock width rear tyres?
You can run up to a 255/35 rear without modifications a 265/35 with a small (~3mm) spacer, though the latter can also be impacted by different suspension options. A square 255/35 setup is also possible but usually requires negative camber and spacers at the front.
Finding wheels in the right offsets is usually the biggest challenge, the F2x platform has extremely high rear offsets (around ET58/ET60 with a 9.5" rear alloy)
HM-2 said:
bigenginesmallcar said:
Im wanting to maybe go down the route of fitting an LSD, Bilstein coilovers and maybe then a remap to 420.
How would this likely manage on stock width rear tyres?
I'd strongly advise going wider at the rear. How would this likely manage on stock width rear tyres?
You can run up to a 255/35 rear without modifications a 265/35 with a small (~3mm) spacer, though the latter can also be impacted by different suspension options. A square 255/35 setup is also possible but usually requires negative camber and spacers at the front.
Finding wheels in the right offsets is usually the biggest challenge, the F2x platform has extremely high rear offsets (around ET58/ET60 with a 9.5" rear alloy)
bigenginesmallcar said:
I mean surely the grand it will cost going to 255 tyres on the wheels would be better spent towards an LSD? It cant make THAT much difference.
The thing to consider is the moments where you would need that additional grip at the rear and decide if those are the moments you are in when having the most fun... You're aiming for M2-levels of power, and I've never heard M2 owners complaining about how they floor it at 50mph in the dry and just do a big wheelspin. Extra traction will help you off the line, but at some point between 0 and 174mph traction stops being the limiting factor in your acceleration. So...
If your intention is drag-racing, then spend your money on more rear grip... you might find stickier tyres are sufficient without going for wider wheels. To put it into numbers, my car will do 0-62mph in the high-5s on a typical bit of good, clean, dry tarmac, but on Elvington with a sticky rubbery launching zone I was reliably getting 0-62 in 5.0s and was hitting the point of being limited by engine power and mechanical sympathy
. That was with everyday tyres (not fancy "fast road" type tyres). Get yourself some Micky T's or similar and engine power will become your limiting factor for acclerationBut, if you want to whizz around the track (or even country lanes) then you are rarely in the 0-30mph bit of your performance envelope where you are truly traction limited (being able to deliberately spin the wheels at 30mph is different to having the wheels spin up at 30mph because you really need more grip). I would say if this is where you find your fun, an LSD will give you much more bang for your buck than some wider wheels and tyres.
donkmeister said:
bigenginesmallcar said:
I mean surely the grand it will cost going to 255 tyres on the wheels would be better spent towards an LSD? It cant make THAT much difference.
The thing to consider is the moments where you would need that additional grip at the rear and decide if those are the moments you are in when having the most fun... You're aiming for M2-levels of power, and I've never heard M2 owners complaining about how they floor it at 50mph in the dry and just do a big wheelspin. Extra traction will help you off the line, but at some point between 0 and 174mph traction stops being the limiting factor in your acceleration. So...
If your intention is drag-racing, then spend your money on more rear grip... you might find stickier tyres are sufficient without going for wider wheels. To put it into numbers, my car will do 0-62mph in the high-5s on a typical bit of good, clean, dry tarmac, but on Elvington with a sticky rubbery launching zone I was reliably getting 0-62 in 5.0s and was hitting the point of being limited by engine power and mechanical sympathy
. That was with everyday tyres (not fancy "fast road" type tyres). Get yourself some Micky T's or similar and engine power will become your limiting factor for acclerationBut, if you want to whizz around the track (or even country lanes) then you are rarely in the 0-30mph bit of your performance envelope where you are truly traction limited (being able to deliberately spin the wheels at 30mph is different to having the wheels spin up at 30mph because you really need more grip). I would say if this is where you find your fun, an LSD will give you much more bang for your buck than some wider wheels and tyres.
bigenginesmallcar said:
Tbh i dont think id go wider as it means a whole new set of wheels which is a large cost, also the wider tyres also increase the risk of aquaplaning.
Personally, I wouldn't either. LSDs are much more noticeable when you're driving.I wouldn't necessarily want grippier tyres either if it's a road car. Obviously you want the absolute best stopping performance, but lateral grip is a far more subjective topic. Great for lap-times, not so much fun for driving on the road and being able to "feel" and finesse the car. There's a very good reason that Toyota put Prius tyres* on the GT86.
*JDM Prius with sports package
donkmeister said:
bigenginesmallcar said:
Tbh i dont think id go wider as it means a whole new set of wheels which is a large cost, also the wider tyres also increase the risk of aquaplaning.
Personally, I wouldn't either. LSDs are much more noticeable when you're driving.I wouldn't necessarily want grippier tyres either if it's a road car. Obviously you want the absolute best stopping performance, but lateral grip is a far more subjective topic. Great for lap-times, not so much fun for driving on the road and being able to "feel" and finesse the car. There's a very good reason that Toyota put Prius tyres* on the GT86.
*JDM Prius with sports package
J4CKO said:
Put a standard M135i next to an E90 M3 in the same scenario, hmm, wonder what would happen, and guess what its not the M3 pulling away.
Just saw this.My mate has a e92 m3
We were racing on the Autobahn
It was pretty even when in the right gear etc
If he was a gear out then it'd be bye bye.
The noise of the v8 though is amazing.
bigenginesmallcar said:
I mean surely the grand it will cost going to 255 tyres on the wheels would be better spent towards an LSD? It cant make THAT much difference.
I'd absolutely go differential first but you're still going to be traction limited trying to put ~430bhp and ~450lb ft through 245 rear tyres. That's 100bhp and nearly 200lb ft of torque more than an E46 M3 on a significantly narrower tyre (the E46 came with 255 or 265 rears)...J4CKO said:
deltashad said:
Looks cheap boy racer with those callipers also. Were performance cars in the early 90s not kicking out this sort of power with much less weight? Not exactly progress.
Early Nineties would be a Sierra/Escort Cosworth with a fully built YB engine for 450 bhp, bigger turbo, different cams, porting, different pistons, bigger injectors etc, it would need an uprated clutch as well. It would more than likely be horrendous on fuel and potentially a bit fragile. Similar deal with Imprezas, Evo's and even Skylines.The Lotus Carlton was the fastest thing around at the time with 375 bhp, just over what these make standard.
Compare and contrast with buying a standard M140 and getting it mapped and a bit of the exhaust change.
I bought an E82 125i late last year mainly because Mrs BC said I had to get rid of the Skoda and I couldn't find a nice unmolested E82 135i anywhere and I've been really impressed with it (aside from M-Sports Suspension but that was made more bearable by getting rid of the run flats)
If I sold the LC I'd have no hesitation in going for a 240i as a replacement fun car - actually I think I'd probably daily it!!!
Gassing Station | General Gassing | Top of Page | What's New | My Stuff