[Boss330]

Originally Posted by CanAutM3

I am sticking to the subject. On the F8X, part of the bracing is imbedded in the subframes.

Please point out the specific parts and where you see a difference between the F8x and G8x on this matter.

This is not a point you have made previously and it's telling that instead of answering my points about the various bracing elements that clearly are better/stronger than on the F8x you come up with a side argument about the subframes (which technically isn't a chassis brace element).

[Boss330]

Originally Posted by CanAutM3

I am sticking to the subject. On the F8X, part of the bracing is imbedded in the subframe designs.

Again, I am not saying they did a bad job on the G8X chassis rigidity, far from it, but there's nothing that has me go "wow, this is a game changer".

It is a "game changer" if they control the movement of the subframes much better and has better power transfer between them.
It's no use to have a stiff subframe, if the subframe isn't as solidly attached to the chassis and can move more...

You are moving the goalposts as we go I see... You have made several posts about the chassis bracing on the F8x vs G8x.
Your view has been that the F8x is just as good, if not better in this regard.
When asked to compare the two generations where pictures shows that the G8x's bracing elements clearly are superior at connecting and anchoring the subframes you suddenly introduce a completely new argument about the subframes...

[CanAutM3]

Originally Posted by Boss330

It is a "game changer" if they control the movement of the subframes much better and has better power transfer between them.
It's no use to have a stiff subframe, if the subframe isn't as solidly attached to the chassis and can move more...

You are moving the goalposts as we go I see... You have made several posts about the chassis bracing on the F8x vs G8x.
Your view has been that the F8x is just as good, if not better in this regard.
When asked to compare the two generations where pictures shows that the G8x's bracing elements clearly are superior at connecting and anchoring the subframes you suddenly introduce a completely new argument about the subframes...

It is just you that decided it is a completely new argument. If the subframe has extension elements welded to it that attach to the body in white that the base car does not have, I consider this added bracing:

[Boss330]

Originally Posted by CanAutM3

It is just you that decided it is a completely new argument. If the subframe has extension elements welded to it that attach to the body in white that the base car does not have, I consider this added bracing:

That is indeed a bracing element. I wasn't aware that it was welded to the subframe, but I was aware of that element.

Edit:
However if you feel that one little piece is just as good as the front AND rear shear plates as well as the full body width rear bracing on the G8x I just can't say anything more to you...

[VIERsr]

Originally Posted by CanAutM3

The F82C on street tires was faster than the E92GTS was on track tires. The G8X needs PSC2 to beat the F82GTS by a few tenths; on street tires it is slower. Good progress, but nothing extra-ordinary.

It's not fair though, the F82 had a huge mid-range torque advantage over the E92 GTS (twin-turbo vs NA), the G82 doesn't have that over the F82 GTS. That makes the difference.
Acceleration times between the E92 and F82 are incomparable (much faster the F82), between the F82 GTS and G82 they are almost the same, so the improved times of the F82 came from engine and chassis, on the G82 only from the chassis basically.

[Boss330]

Originally Posted by VIERsr

It's not fair though, the F82 had a huge mid-range torque advantage over the E92 GTS (twin-turbo vs NA), the G82 doesn't have that over the F82 GTS. That makes the difference.
Acceleration times between the E92 and F82 are incomparable (much faster the F82), between the F82 GTS and G82 they are almost the same, so the improved times of the F82 came from engine and chassis, on the G82 only from the chassis basically.

It seems there is a desire to diminish the G8x achievements and at the same time portray the F8x in a better light.

The drive reviews so far seem fairly consistent in how much of a step forward this chassis is. Front end is so much better and sharper. Traction is so much improved that Chris Harris thought he was in a X-drive model...

When the F8x was launched the reviews was quite mixed and before the LCI/Comp it was described as twitchy/nervous and hard to control at the limit. The LCI/Comp version vastly improved these characteristics on the F8x.

Some F8x owners try to degrade even the objectively more comprehensive, and better at anchoring the subframes to the chassis, bracing (while only showing to a F8x mini version of the G8x front shear plate and have no response to the quite substantially more comprehensive rear bracing (which now consists of shear plates and a center piece that connects both shear plates to create a side to side full body width brace) when pressed on the subject), argues that it's unfair to compare the LCI/Comp/CS versions of the F8x with the 991.2 since it was the 991.1 that was the current gen when the F8x pre LCI was launched... (so the 991.2 facelift counts but the F8x facelift does not???).

[VIERsr]

Originally Posted by Boss330

It seems there is a desire to diminish the G8x achievements and at the same time portray the F8x in a better light.

The drive reviews so far seem fairly consistent in how much of a step forward this chassis is. Front end is so much better and sharper. Traction is so much improved that Chris Harris thought he was in a X-drive model...

When the F8x was launched the reviews was quite mixed and before the LCI/Comp it was described as twitchy/nervous and hard to control at the limit. The LCI/Comp version vastly improved these characteristics on the F8x.

Some F8x owners try to degrade even the objectively stiffer, and better at anchoring the subframes to the chassis, bracing (while only showing to a F8x mini version of the G8x front shear plate and have no response to the quite substantially more comprehensive rear bracing when pressed on the subject), argues that it's unfair to compare the LCI/Comp/CS versions of the F8x with the 991.2 since it was the 991.1 that was the current gen when the F8x pre LCI was launched... (so the 991.2 facelift counts but the F8x facelift does not???).

I totally agree with you, there are a lot of haters here, but it's not the case of CanAutM3 , he always put on the table valid arguments and deep knowledge. Unfortunately he's leaving our boat But I'm sure if he drove it, he would also appreciate the objective improvements of the new M. After I drove it, I loved it, and I'm sure it could not be the opposite for any enthusiast.

[manuelf]

Originally Posted by CanAutM3

Base vs GTS:

• E92 8:05 --> 7:48 = 17 seconds faster
• F82 7:52 --> 7:37 = 15 seconds faster

Maybe not that fair your comparison?
The E92 in the 2017 supertest was with crappy manual instead of DCT!
So your first line is a manual to DCT comparo, while the 2nd line is DCT to DCT.

[Boss330]

Originally Posted by VIERsr

I totally agree with you, there are a lot of haters here, but it's not the case of CanAutM3 , he always put on the table valid arguments and deep knowledge. Unfortunately he's leaving our boat But I'm sure if he drove it, he would also appreciate the objective improvements of the new M. After I drove it, I loved it, and I'm sure it could not be the opposite for any enthusiast.

I agree, he is generally a very well informed, knowledgeable and great asset to these forums.
But on this topic he shows a atypical partial and non objective behaviour.

I noticed this when coming back to these forums after having been more or less absent for many years. It struck me that he usually came into the discussions about the G8x with the perspective of talking down the car and it's achievements and comparing it unfavourably with the F8x (In the threads I read, so I could have missed other more positive posts from him in other threads to be fair).

Chassis bracing is perhaps the most blatant example of his bias towards the F8x... On this topic he repeatedly refers to the chassis torsional stiffness in some posts as his reasoning, failing to take into account the main objective/improvement of the bracing over the F8x (anchoring down the front and rear subframe and transfer power to the unibody and between them). He also has argued that the bracing elements themselves aren't an improvement. And finally it was "good, but not a game changer"... In no posts have he been able to point out why the G8x bracing isn't better in his view, but he keep repeating that statement...

I was disapointed in his response both to the lap times (he argued that it's unfair to compare with the 991.2) but most of all to his quite regularly repeated statements re the not better chassis bracing on the G8x vs the F8x. When asked to pinpoint where the G8x isn't improved he could not reply (because as an engineer he realizes that the shear plate design front and rear as well as the side to side bracing at the rear is a much more comprehensive and more solid bracing than on the F8x, proving his previous statements to be not quite accurate). It was actually a bit embarrassing when the only thing he could point at to prove his previous statements was the mini version of the G8x front shear plate...

If the G8x is seen as a lesser developed/not a true M-car than the F8x was, a switch is easier to justify. Early on in the G8x phase it was all doom and gloom on social media about how the G8x would be a dog of a car and nowhere near the F8x. Some jumped ship at that time, which is fine. But move on! The G8x is heavier and doesn't have DCT which is two negatives, but in all other areas it seems to be a major leap ahead of the F8x.

[Boss330]

Back to the weight:

The M4 Comp is actually also "just" 98kg heavier than the 992 911 Turbo S

1597kg vs 1695kg

Make sure you watch the end of the video to get a nice surprise and a smile 😊

[VIERsr]

Originally Posted by Boss330

Back to the weight:

The M4 Comp is actually also "just" 98kg heavier than the 992 911 Turbo S

1597kg vs 1695kg

Make sure you watch the end of the video to get a nice surprise and a smile 😊

Actually the 'base' 911 (from 993 onwards) has never aroused any particular interest in me, I would only consider it on the Turbo or GTx versions. I really don't get all the hype for a 911 Carrera.

[CanAutM3]

Originally Posted by manuelf

Maybe not that fair your comparison?
The E92 in the 2017 supertest was with crappy manual instead of DCT!
So your first line is a manual to DCT comparo, while the 2nd line is DCT to DCT.

Indeed, but the base E92 was also fitted with optional track tires (a milder version of the original cup tires).

As another data point, the Sachsenring times in the OP show the same trend where there’s a greater gap between the base and GTS E9X than there is between the base and GTS F82 (3.7s vs 2.8s), and here the base E9X is a DCT on street tires.

The point here was simply to disprove the argument that the E92 GTS is “the worst special edition” as the other poster claimed.

[CanAutM3]

Originally Posted by VIERsr

It's not fair though, the F82 had a huge mid-range torque advantage over the E92 GTS (twin-turbo vs NA), the G82 doesn't have that over the F82 GTS. That makes the difference.
Acceleration times between the E92 and F82 are incomparable (much faster the F82), between the F82 GTS and G82 they are almost the same, so the improved times of the F82 came from engine and chassis, on the G82 only from the chassis basically.

The S58 also has a fair bit more grunt than even the S55 in the GTS, as demonstrated by the better 100-200km/h despite the increased weight.

And tires. The PS4S are not far off the old gen PSC2 on single flying lap and from what I’ve read, the new gen PSC2 are a good improvement over the old.

[VIERsr]

Originally Posted by CanAutM3

The S58 also has a fair bit more grunt than even the S55 in the GTS, as demonstrated by the better 100-200km/h despite the increased weight.

And tires. The PS4S are not far off the old gen PSC2 on single flying lap and from what I’ve read, the new gen PSC2 are a good improvement over the old.

Are we comparing S65 GTS/S55 (more than 1s faster 100-200) and S55 GTS/S58 (a couple of tenths faster)? Really? C'mon

[Boss330]

Originally Posted by VIERsr

Are we comparing S65 GTS/S55 (more than 1s faster 100-200) and S55 GTS/S58 (a couple of tenths faster)? Really? C'mon

Originally Posted by CanAutM3

The S58 also has a fair bit more grunt than even the S55 in the GTS, as demonstrated by the better 100-200km/h despite the increased weight.

And tires. The PS4S are not far off the old gen PSC2 on single flying lap and from what I've read, the new gen PSC2 are a good improvement over the old.

Originally Posted by VIERsr

Are we comparing S65 GTS/S55 (more than 1s faster 100-200) and S55 GTS/S58 (a couple of tenths faster)? Really? C'mon

Don't forget the G8x has a 8-speed gearbox with closer ratios (also mentioned in the article under the gear ratio chart). This means that, at least in theory, the engine can spend more time in the most powerful part of it's powerband and therefor accelerate quicker.

Btw, where do we have the 100-200 times from?

[CanAutM3]

Originally Posted by Boss330

I agree, he is generally a very well informed, knowledgeable and great asset to these forums.
But on this topic he shows a atypical partial and non objective behaviour.

I noticed this when coming back to these forums after having been more or less absent for many years. It struck me that he usually came into the discussions about the G8x with the perspective of talking down the car and it's achievements and comparing it unfavourably with the F8x (In the threads I read, so I could have missed other more positive posts from him in other threads to be fair).

Chassis bracing is perhaps the most blatant example of his bias towards the F8x... On this topic he repeatedly refers to the chassis torsional stiffness in some posts as his reasoning, failing to take into account the main objective/improvement of the bracing over the F8x (anchoring down the front and rear subframe and transfer power to the unibody and between them). He also has argued that the bracing elements themselves aren't an improvement. And finally it was "good, but not a game changer"... In no posts have he been able to point out why the G8x bracing isn't better in his view, but he keep repeating that statement...

I was disapointed in his response both to the lap times (he argued that it's unfair to compare with the 991.2) but most of all to his quite regularly repeated statements re the not better chassis bracing on the G8x vs the F8x. When asked to pinpoint where the G8x isn't improved he could not reply (because as an engineer he realizes that the shear plate design front and rear as well as the side to side bracing at the rear is a much more comprehensive and more solid bracing than on the F8x, proving his previous statements to be not quite accurate). It was actually a bit embarrassing when the only thing he could point at to prove his previous statements was the mini version of the G8x front shear plate...

If the G8x is seen as a lesser developed/not a true M-car than the F8x was, a switch is easier to justify. Early on in the G8x phase it was all doom and gloom on social media about how the G8x would be a dog of a car and nowhere near the F8x. Some jumped ship at that time, which is fine. But move on! The G8x is heavier and doesn't have DCT which is two negatives, but in all other areas it seems to be a major leap ahead of the F8x.

I really dislike “fanboysm” and I tend to challenge things when they are exaggerated better or worse than they are with actual data. I did the exact same on the F8X and E9X forums.

When folks pick and chose data points, such as particular lap times for example, to prove their view, there’s often a counterpoint to consider. Things usually aren’t binary.

I never believed the G8X would be a dog in terms of performance. The thing is that BMW has also made significant improvements to the F82 throughout its lifecycle culminating with the CS, significantly narrowing the performance gain. Previously, moving from one gen to the next, there was a sufficient leap in performance to keep me excited. What I am seeing from the test results so far is pretty much what I expected, and the leap from my F82cs to G8X is not enough to keep me excited. What also swayed me away are changes in direction in areas that are important to me.

Now back to chassis rigidity, we can only assess what we see. Anything else is only speculation. Yes, there seems to be more under body bracing on the G8X, but the F8X seems to have a much more intricate bracing imbedded within the chassis. As one example, a solidly mounted subframe cross member that widens the subframe attachment to the body in white is more effective and transmitting road forces to the body than a bolted brace. The structural “cage” that was added to the F8X front section is quite sophisticated with many anchor points, more so than what we have seen so far on the G8X. As an engineer, it should be obvious to you that this 3 dimensional structure on the F8X is quite effective at bracing the front suspension anchor points. I assume at this stage that the increased underbody bracing on the G8X is to offset the lesser imbedded bracing at the top of the structure. For the F8X, we have the benefit of having the technical training docs, I am eager for release of those docs on the G8X so we can learn more. ///M Chassis rigidity improved in the range of 40~50% from E46 to E9X and from E9X to F8X. We’re talking ~15% (according to BMW) from F8X to G8X.

On many posts, folks make it out the G8X was leaps and bounds better than the F8X in terms of chassis re-enforcement, using it as a way to justify the weight increase. That is the fanboysm portion I am debunking.

[manuelf]

Originally Posted by CanAutM3

Indeed, but the base E92 was also fitted with optional track tires (a milder version of the original cup tires).

As another data point, the Sachsenring times in the OP show the same trend where there’s a greater gap between the base and GTS E9X than there is between the base and GTS F82 (3.7s vs 2.8s), and here the base E9X is a DCT on street tires.

The point here was simply to disprove the argument that the E92 GTS is “the worst special edition” as the other poster claimed.

Ok. I see. But the whole discussion imho can't be fully scientific anyhow. Too many variables in the game ... and too few datapoints. If you now start to take into account:
- tire development
- weather conditions during tests/datapoints
- overall track tarmac change over the years

and so on ... you end nowhere...
I think the basic question here was: Was BMW M lazy with their last model engineering wise or not compared to its history.
IMHO not! I think you also have to take into account, that (track) performance can't be linearly enhanced over the years (with a given base technology).
This happens nowhere, when we look at tech! So when looking at the delivered performance by BMW M - which still looks like linear improvements in tracktimes over the generations, this looks like a great achievement to me and a clear sign, that M rather intensified its effort with the last generations ...

[CanAutM3]

Originally Posted by Boss330

Don't forget the G8x has a 8-speed gearbox with closer ratios (also mentioned in the article under the gear ratio chart). This means that, at least in theory, the engine can spend more time in the most powerful part of it's powerband and therefor accelerate quicker.

Btw, where do we have the 100-200 times from?

The 1st gear on the 8AT is so totally useless for a RWD application, it launches in 2nd gear . The DCT gear ratios are close enough to keep the S55 on boil at track speeds.

Autobild tested the F82 GTS at 8.5s vs the 7.8s in the OP for the G82C.

https://f80.bimmerpost.com/forums/sh....php?t=1272293

[Boss330]

Originally Posted by CanAutM3

The 1st gear on the 8AT is so totally useless for a RWD application, it launches in 2nd gear . The DCT gear ratios are close enough to keep the S55 on boil at track speeds.

Autobild tested the F82 GTS at 8.5s vs the 7.8s in the OP for the G82C.

https://f80.bimmerpost.com/forums/sh....php?t=1272293

I was looking for a 100-200 time, but I now understand it's derived from the 0-100 and 0-200 times 😉

I wasn't thinking of 0-100 when I mentioned gearing, but the 100-200 times (as that was the ET we where discussing).

From the gear ratio charts we can see that the F82 GTS have to start the 100-200 sprint at 4500rpm in 3rd, changing to 4th at just around 150km/h, dropping down to 5000rpm and revving to 7000rpm at 200km/h in 4th.

The G82 Comp start at 6000rpm in 3rd, changing to 4th at just around 125km/h, dropping down to 5800-6000rpm in 4th, changing up to 5th at just around 165km/h, dropping down to 6000rpm in 5th and reaching 200km/h at 7000rpm in 5th.

How much you actually gain from this shorter rev band in each gear I couldn't say, but probably more than the time lost on that extra gearchange.

For the S55 in the GTS it doesn't seem ideal to drop down to 4500rpm as it only has 400hp there (according to ABS dynograph).

The S58 has a slightly flatter top end curve from 5-7k, but it seem that you wouldn't want to drop much below 6k on shifts on that either. But at least it has over 500hp from 5000-7200rpm, so even dropping down to 5k still gives you more than 500hp.
The S58 makes 400hp at 4000rpm and roughly 450hp at 4500rpm.

I think the better acceleration times for the G82 is a combination of more power (522 vs 492 according to the mag) and closer gearing. Perhaps biggest contributor is the gearing, which is more of a disadvantage for the F82 than a big leap ahead for the G82 (the G82 wouldn't loose much time even if it dropped to 5k during shifts thanks to the S58's power curve).

The G82 is always above 500hp in the 100-200 sprint, while the F82 GTS drops as low as 400hp, due to larger gear spacing, during the same sprint.

The power to weight ratio with ABS' numbers are almost identical btw;

F82: 492/1599 = 0,30769
G82: 522/1695 = 0,30796

[CanAutM3]

Originally Posted by VIERsr

Are we comparing S65 GTS/S55 (more than 1s faster 100-200) and S55 GTS/S58 (a couple of tenths faster)? Really? C'mon

Not quite the right comparison for the discussions at stake . Here we're talking previous gen GTS vs next gen competition gains.

According to Autobild test data for 100-200km/h (to keep it consistent with OP topic):
E92GTS --> F82C = 0.5s (9.4 vs 8.9)
F82GTS --> G82C = 0.7s (8.5 vs 7.8)

As you can see, the G82C has at least as much improvement in acceleration over the F82GTS than the F82C had over the E92GTS. So yes, chassis improvements are present, but so are tire tech and power levels.

[CanAutM3]

Originally Posted by Boss330

I was looking for a 100-200 time, but I now understand it's derived from the 0-100 and 0-200 times ��

I wasn't thinking of 0-100 when I mentioned gearing, but the 100-200 times (as that was the ET we where discussing).

From the gear ratio charts we can see that the F82 GTS have to start the 100-200 sprint at 4500rpm in 3rd, changing to 4th at just around 150km/h, dropping down to 5000rpm and revving to 7000rpm at 200km/h in 4th.

The G82 Comp start at 6000rpm in 3rd, changing to 4th at just around 125km/h, dropping down to 5800-6000rpm in 4th, changing up to 5th at just around 165km/h, dropping down to 6000rpm in 5th and reaching 200km/h at 7000rpm in 5th.

How much you actually gain from this shorter rev band in each gear I couldn't say, but probably more than the time lost on that extra gearchange.

For the S55 in the GTS it doesn't seem ideal to drop down to 4500rpm as it only has 400hp there (according to ABS dynograph).

The S58 has a slightly flatter top end curve from 5-7k, but it seem that you wouldn't want to drop much below 6k on shifts on that either. But at least it has over 500hp from 5000-7200rpm, so even dropping down to 5k still gives you more than 500hp.
The S58 makes 400hp at 4000rpm and roughly 450hp at 4500rpm.

I think the better acceleration times for the G82 is a combination of more power (522 vs 492 according to the mag) and closer gearing. Perhaps biggest contributor is the gearing, which is more of a disadvantage for the F82 than a big leap ahead for the G82 (the G82 wouldn't loose much time even if it dropped to 5k during shifts thanks to the S58's power curve).

The G82 is always above 500hp in the 100-200 sprint, while the F82 GTS drops as low as 400hp, due to larger gear spacing, during the same sprint.

The power to weight ratio with ABS' numbers are almost identical btw;

F82: 492/1599 = 0,30769
G82: 522/1695 = 0,30796

Not quite sure where you are getting your rpm vs speed in gear numbers, but for the F8X DCT shifting 3rd and 4th at 7,500 rpm drops the rpm to ~5,600 in 4th and ~5,900 in 5th. And at 100km/h, the F82GTS is still in 2nd gear at ~7,000rpm.

The tighter gear ratios of the 8AT could be factor in the improved acceleration, but IMO not a significant one. I believe the main difference between the GTS S55 tune and the S58 Competition tune is how fat the power curve is, where the S58C has more area under the curve than the S55GTS, maintaining near peak power level over a much broader rpm band.

[CanAutM3]

Originally Posted by Boss330

Back to the weight:

The M4 Comp is actually also "just" 98kg heavier than the 992 911 Turbo S

1597kg vs 1695kg

Make sure you watch the end of the video to get a nice surprise and a smile 😊

Yes, and the TT-S has AWD, 4 wheels steering, active roll stabilization, 140 additional ponies and still weighs less

I can't wait to hear those giggles coming from the back seat