M3 or M4 for staged track build out?

[MaynardZed]

Originally Posted by nicknaz

Check out that review where a magazine put the f80 against an old school e30 m3 touring car. The looked at the data and the dct shifts were actually a key reason why the f80 was able to (barely) beat the e30 lap times. I think some similar data is being shown in the dct vs 6mt thread.

Personally, for a track car I think dct is very interesting.

A lot of variables to say definitively the DCT is what produced the win? Didnt the touring car have a dog box transmission anyway?

[CanAutM3]

Originally Posted by ///Mobbin

Voting is tied again at 5 vs 5!

I saw a new Mineral Gray M4 in my parking garage at work today, it looked amazing and thus MGM is the color of the day again!

Build of the day:
M4, 6MT, Mineral Gray, Cloth Seats, Carbon Roof, Passive Suspension, 18's, and Harmon Kardon - MSRP $66,575

This is turning into quite the stripper/track build, I like it!

Ditch the Harman Kardon, it adds useless weight through additional speakers and amps .

[nicknaz]

Originally Posted by MaynardZed

A lot of variables to say definitively the DCT is what produced the win? Didnt the touring car have a dog box transmission anyway?

I was just quoting what they wrote in the infographic at the bottom of the article

*The new M3 edged the old thanks to superior muscle. Interestingly, the new car's engine wasn't the key, but its dual-clutch gearbox, which let 2015 leap ahead every time 1987 had to shift. Sub-100-mph acceleration and corner-exit speeds were surprisingly close

http://www.roadandtrack.com/car-cult...roup-a-bmw-m3/

Anyway, for myself (1 weekend a month at best) I know the DCT makes the experience easier/more fun so I was pretty clear on checking that box when ordering my car. I used a manual 328 for HDPE for a while, and the DCT Z4 has been definitely more fun for me.

[MaynardZed]

Originally Posted by nicknaz

I was just quoting what they wrote in the infographic at the bottom of the article



http://www.roadandtrack.com/car-cult...roup-a-bmw-m3/

Anyway, for myself (1 weekend a month at best) I know the DCT makes the experience easier/more fun so I was pretty clear on checking that box when ordering my car. I used a manual 328 for HDPE for a while, and the DCT Z4 has been definitely more fun for me.

Got it. I would propose to the author though that the drop off on upshifts is due to the massive torque of the S55 vs. the drop in torque for the high strung four banger. Nevertheless, the article makes me want to own an E30!

I feel you on the challenges of manuals on the track. I money shifted my E36 last year which cost me $4k and my heel toeing is so spotty I just installed special aluminum pedals to "help me out" this past weekend. I guess I'm just not willing to give in and I relish the challenge of perfecting it. I've driven manuals on the street for decades, but driving them on the track is very different and I've had to "unlearn" some things for sure.

[CanAutM3]

Originally Posted by nicknaz

Check out that review where a magazine put the f80 against an old school e30 m3 touring car. The looked at the data and the dct shifts were actually a key reason why the f80 was able to (barely) beat the e30 lap times. I think some similar data is being shown in the dct vs 6mt thread.

Personally, for a track car I think dct is very interesting.

The R&T comparison of the E30 and F80 is like an apples to orange comparison. It cannot be used as valid comparison of the DCT vs 6MT.

Even if I ended up getting DCT myself (after a long debate), I am not convinced it offers a big performance advantage at the track, if any at all. While it does gain on every up shift, it also loses in between shifts due to the extra weight and increased losses. Further, the 6MT also has slightly better ratios. While the DCT had a clear performance advantage over the 6MT on the E9X. That advantage is not so clear on the F8X IMO.

A non-negligible advantage of the DCT worth mentioning though is the safe guard against money-shifts .

[nicknaz]

Originally Posted by CanAutM3

The R&T comparison of the E30 and F80 is like an apples to orange comparison. It cannot be used as valid comparison of the DCT vs 6MT.

Even if I ended up getting DCT myself (after a long debate), I am not convinced it offers a big performance advantage at the track, if any at all. While it does gain on every up shift, it also loses in between shifts due to the extra weight and increased losses. Further, the 6MT also has slightly better ratios. While the DCT had a clear performance advantage over the 6MT on the E9X. That advantage is not so clear on the F8X IMO.

A non-negligible advantage of the DCT worth mentioning though is the safe guard against money-shifts .

You should email R&T with that and tell them to re-do it with a 6MT F80 and while they are at it, bring some other F80s with and without CCB and adaptive suspension so we can get some comparable lap times for the different possible combos of 6MT vs. DCT, adaptive vs. passive suspension, CCB vs base brakes

What do you think of the PDK only 991 GT3 as a data point in the MT vs. DCT discussion? I thought manufacturer's claim is that PDK is clearcut faster than MT ?

[CanAutM3]

Originally Posted by nicknaz

You should email R&T with that and tell them to re-do it with a 6MT F80 and while they are at it, bring some other F80s with and without CCB and adaptive suspension so we can get some comparable lap times for the different possible combos of 6MT vs. DCT, adaptive vs. passive suspension, CCB vs base brakes

What do you think of the PDK only 991 GT3 as a data point in the MT vs. DCT discussion? I thought manufacturer's claim is that PDK is clearcut faster than MT ?

The GT3 with its naturally aspirated engine has a peakier power curve and benefits from tighter gearing. That is where DCT shines (as it did on the E9X).

IMO, the DCT on the F8X was not optimized for the F8X application. It received a hand me down gearbox from its bigger brothers F1X M5/6. It is a beefier unit to handle the extra torque from the S63Tu and it is therefore 89lb heavier than the the 6MT on the F8X. Further, the broad power plateau of the S55 does not benefit as much from tight gearing, hence losing some advantages of the DCT. See here for my long rant on the F8X DCT .

[///Mobbin]

Originally Posted by CanAutM3

Ditch the Harman Kardon, it adds useless weight through additional speakers and amps .

I need something to take out later when I strip the interior and do the full track conversion!

[///Mobbin]

Originally Posted by CanAutM3

The R&T comparison of the E30 and F80 is like an apples to orange comparison. It cannot be used as valid comparison of the DCT vs 6MT.

Even if I ended up getting DCT myself (after a long debate), I am not convinced it offers a big performance advantage at the track, if any at all. While it does gain on every up shift, it also loses in between shifts due to the extra weight and increased losses. Further, the 6MT also has slightly better ratios. While the DCT had a clear performance advantage over the 6MT on the E9X. That advantage is not so clear on the F8X IMO.

A non-negligible advantage of the DCT worth mentioning though is the safe guard against money-shifts .

Thanks for the continued discussion on DCT vs 6MT all. It's really the hardest decision for me actually. I've now read over the various threads on this topic.

My takeaways:
-unlike in the e9x, this DCT was not optimized for this platform
-the DCT gear ratios are not ideal for track duty
-the manual was re-engineered, lightened, and optimized
-the manual gear ratios are better for track duty
-the DCT adds 89lbs to the car
-there are still some DCT benefits though such as constant power during shifts

More so than any other benefit though, there are 2 aspects of DCT that intrique me the most. First, my increased concentration on other things as a result of decreased concentration on pedal work (though this may become a non-factor as I get more seat time in). Second, increased smoothness. What I mean here is overall, with every shift throughout a lap, I am envisioning upsetting the car less (main benefit during cornering of course).

How much weight should I give to these aspects? In terms of skill level I am intermediate to intermediate+ with aspirations of advanced fwiw.

And thanks again for the continued input!

[nicknaz]

Originally Posted by CanAutM3

The GT3 with its naturally aspirated engine has a peakier power curve and benefits from tighter gearing. That is where DCT shines (as it did on the E9X).

IMO, the DCT on the F8X was not optimized for the F8X application. It received a hand me down gearbox from its bigger brothers F1X M5/6. It is a beefier unit to handle the extra torque from the S63Tu and it is therefore 89lb heavier than the the 6MT on the F8X. Further, the broad power plateau of the S55 does not benefit as much from tight gearing, hence losing some advantages of the DCT. See here for my long rant on the F8X DCT .

Personally, I think that thread is a case of overanalyzing the situation.

You laid out the bottom line yourself in another thread

DCT tend to trap more in the 117~119mph range while 6MT tend to be in the 114~117mph range.

The thing is, as with any real world testing, results will vary. So you will see some 6MT cars trap faster and and have a better ET than some DCT. But on average, the DCT will be faster.

I would definitely take that 2-3mph trap speed advantage during the drag race on the straight at any road course.

OP I think dct will help you for sure

[CanAutM3]

Originally Posted by nicknaz

Personally, I think that thread is a case of overanalyzing the situation.

Yes, I have a tendency to do that . I just have that urge to understand everything in depth .

Originally Posted by nicknaz

You laid out the bottom line yourself in another thread

I would definitely take that 2-3mph trap speed advantage during the drag race on the straight at any road course.

OP I think dct will help you for sure

Don't confuse drag racing and road racing.

A big portion of that 2~3mph advantage comes from the 1-2 and 2-3 shifts. On a road course, you rarely need to go as low as 2nd gear. You will not get that much advantage (2~3mph) on the straights of road course.

What is really interesting is comparing in-gear acceleration. Both the 6MT and DCT have the same 5th gear ratio and BMW quote a faster 5th gear 80-120km/h for the 6MT. I think that is very telling.

Further, on a road course, the 89lb advantage will pay dividends not only while accelerating, but also when braking and cornering, so pretty much everywhere around the course. Less weight also means less stress on the tires, brakes and load bearing components.

I am not saying 6MT will always be faster around a road course. But the DCT advantage is not as clear cut as it was on the E9X. I believe that for the F8X, it will be track dependent; where DCT will be faster on some tracks while 6MT will be faster on others.

[CanAutM3]

Originally Posted by ///Mobbin

Thanks for the continued discussion on DCT vs 6MT all. It's really the hardest decision for me actually. I've now read over the various threads on this topic.

My takeaways:
-unlike in the e9x, this DCT was not optimized for this platform
-the DCT gear ratios are not ideal for track duty
-the manual was re-engineered, lightened, and optimized
-the manual gear ratios are better for track duty
-the DCT adds 89lbs to the car
-there are still some DCT benefits though such as constant power during shifts

More so than any other benefit though, there are 2 aspects of DCT that intrique me the most. First, my increased concentration on other things as a result of decreased concentration on pedal work (though this may become a non-factor as I get more seat time in). Second, increased smoothness. What I mean here is overall, with every shift throughout a lap, I am envisioning upsetting the car less (main benefit during cornering of course).

How much weight should I give to these aspects? In terms of skill level I am intermediate to intermediate+ with aspirations of advanced fwiw.

And thanks again for the continued input!

Very true, there are other benefits to DCT such a the ability of shifting mid corner without upsetting the balance and increased driver focus as you stated.

It is the sum of those advantages that got me to choose DCT for my car. But going for an all out track car, I think I would pick the 6MT.

[MaynardZed]

Real world data point 6MT vs. DCT at No Fly Zone AZ. 3 upshifts over 1/2 mile with approximate 50 mph roll:

My 6MT car w/Dinan tune top speed 144.5mph
Member BitchinManWheels DCT Dinan car top trap 144.9mph

http://f80.bimmerpost.com/forums/sho....php?t=1068885

Not a perfect comparison since we ran on different days and I was power shifting my car which I wouldn't do on a road course (unless I was going for that fictional DE trophy ).

[FTS]

Originally Posted by CanAutM3

Very true, there are other benefits to DCT such a the ability of shifting mid corner without upsetting the balance and increased driver focus as you stated.

It is the sum of those advantages that got me to choose DCT for my car. But going for an all out track car, I think I would pick the 6MT.

I certainly agree about the weight disadvantage, it is really significant I think, especially since it is at the front.

However, I think, or more hope at this time, that the DCT's advantage is really in shifting approaching corners and mid-corner. Based on my very limited street experience, I am able to use it as the 4th control input and each day I find that more and more invaluable; we always had (1) steering, (2) brakes, (3) throttle, and now (4) the transmission anywhere

[nicknaz]

Originally Posted by CanAutM3

But the DCT advantage is not as clear cut as it was on the E9X. I believe that for the F8X, it will be track dependent; where DCT will be faster on some tracks while 6MT will be faster on others.

has anyone actually obtained F80 lap times to make a comparison? All of the gearbox and suspension discussions I've come across are based on opinions/preferences and extrapolations (including this one)

Good point about track dependency. The CA tracks I've been to require 2nd gear (sears point and buttonwillow cw 13 in particular come to mind)

[Merli]

If I had to choose between M3 and M4 for a fun, occasional dedicated track car (by OP's description - he's not a professional driver, just does HPDE days now and then and wants to have fun), I would pick the Porsche Cayman GTS/GT4 (depending on what I could get), or Lotus Exige S.

But if I had to choose, I'd choose the M4 for weight reasons, with DCT and non-adjustable suspension.

[FTS]

I don't know Merli, DE Championship is serious business, every year we try endlessly being creative to get to the golden award

[Merli]

[MaynardZed]

I MUST get some stickers with that trophy on it. Gonna stick it on a few guys cars at my next "race".

[adc]

For bodyshell, I'd say go with whatever is more practical for daily driving, it will help until you make the decisive track-only move. 50 lbs and a 2% CD advantage will not make any difference for an amateur HPDE driver. A sedan on the other hand can make loading and unloading track wheels and paraphernalia much easier.

And for transmission, go with whatever will give you the most satisfaction on track. That counts far more IMO than the 1 sec advantage you might get with one or the other. If you like to shift on your own then there's nothing like the feel of a 6sp, and if you want to play Alonso then DCT is the only way to go.

Having fun is what we're supposed to do at the track. JMHO.

[///Mobbin]

Originally Posted by CanAutM3

I am not saying 6MT will always be faster around a road course. But the DCT advantage is not as clear cut as it was on the E9X. I believe that for the F8X, it will be track dependent; where DCT will be faster on some tracks while 6MT will be faster on others.

The weight advantage and thinking that the performance advantage may be track dependent makes me lean 6MT. Then I really would enjoy driving the 6MT more on the street before it transitions into a track car anyway. There may be some ease of service benefits to 6MT also.

Originally Posted by CanAutM3

Very true, there are other benefits to DCT such a the ability of shifting mid corner without upsetting the balance and increased driver focus as you stated.

It is the sum of those advantages that got me to choose DCT for my car. But going for an all out track car, I think I would pick the 6MT.

How excited are you everytime you downshift mid-corner though!! Despite how much I would enjoy that every single time, I think I still lean 6MT. Wish I could do a back-to-back test drive on a road course!

Originally Posted by FTS

I certainly agree about the weight disadvantage, it is really significant I think, especially since it is at the front.

However, I think, or more hope at this time, that the DCT's advantage is really in shifting approaching corners and mid-corner. Based on my very limited street experience, I am able to use it as the 4th control input and each day I find that more and more invaluable; we always had (1) steering, (2) brakes, (3) throttle, and now (4) the transmission anywhere

I definitely see your point. I also like the minimal amount of time it takes away from your concentration for that input to occur.

Originally Posted by nicknaz

has anyone actually obtained F80 lap times to make a comparison? All of the gearbox and suspension discussions I've come across are based on opinions/preferences and extrapolations (including this one)

Good point about track dependency. The CA tracks I've been to require 2nd gear (sears point and buttonwillow cw 13 in particular come to mind)

Track times will tell, just hard to have 2 similarly setup cars, 1 proficient driver (whose familiar with the cars), and a fair go at setting lap times in each car, to occur all at once. I suppose a few folks "best lap times" at the same track could be compared but there are so many other variables there I'm not sure it would be valid.

Someone please approach a magazine about setting this test up, would make for a great article!

Originally Posted by Merli

If I had to choose between M3 and M4 for a fun, occasional dedicated track car (by OP's description - he's not a professional driver, just does HPDE days now and then and wants to have fun), I would pick the Porsche Cayman GTS/GT4 (depending on what I could get), or Lotus Exige S.

But if I had to choose, I'd choose the M4 for weight reasons, with DCT and non-adjustable suspension.

Thanks for your input and I absolutely agree with you, I just don't think I'm quite ready to have 2 cars quite yet. That and I don't make it to the track enough yet to justify it (yet!). As my kids get older and I have more time to spend at the track I think a GT3 or GT4 would be perfect and I'm willing to be patient getting there.

Also, why would you go for the DCT?

Originally Posted by adc

For bodyshell, I'd say go with whatever is more practical for daily driving, it will help until you make the decisive track-only move. 50 lbs and a 2% CD advantage will not make any difference for an amateur HPDE driver. A sedan on the other hand can make loading and unloading track wheels and paraphernalia much easier.

And for transmission, go with whatever will give you the most satisfaction on track. That counts far more IMO than the 1 sec advantage you might get with one or the other. If you like to shift on your own then there's nothing like the feel of a 6sp, and if you want to play Alonso then DCT is the only way to go.

Having fun is what we're supposed to do at the track. JMHO.

Good point on the loading/unloading track wheels and equipment at the track. I keep forgetting that. I have an S4 now and have had zero issues hauling gear around. My last car was a PDK C2S and I definitely experienced the opposite there. This was the car I started tracking on but I wanted a more practical DD and ended up with the S4. I had originally pre-ordered a highly optioned M3 and was set for european delivery but backed out of it when I bought the S4 (6MT). I am glad I did now bc I have had more time to think about what I ultimately want.

Thanks for your thoughts on the transmission choice as well. It's all about having fun in the end.

One thing we haven't discussed is how smooth does the rev-matched-downshift make for a corner-entry-downshift (perhaps I can rely on that when I don't want to heel-toe?). I'm still learning heel-toe fwiw but I am committed to becoming proficient at it.

[///Mobbin]

12 votes for the M3, 13 votes for the M4!