|
Post Reply |
|
Thread Tools | Search this Thread |
06-03-2014, 10:06 AM | #1 |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Interesting Chris Harris review (of Cali T) - sheds light on other Turbo options
No, he doesn't mention the M3/M4 (or when his long awaited video will be uploaded) but it is interesting to read his review and get the technical details of how Ferrari dealt with the 'problem' of replacing an NA engine with a Turbo engine.
http://pistonheads.com/news/default.asp?storyId=30096 In a nutshell, witchcraft, but it works. (longer version: artificially limiting torque in lower gears so one is lulled into sensation that you need to rev it out to max to get all the power (even though power actually peaks below redline)). I guess if the F80 were being sold for 3 times as much, BMW could have engineered seperately mapped torque curves for each gear like those Eye-Talians did. |
06-03-2014, 10:13 AM | #2 |
Captain
75
Rep 991
Posts
Drives: 2015 BMW M4
Join Date: Apr 2014
Location: Fairfax, VA
|
I'm starting to wonder if the cake is a lie
__________________
2015 ///M4 F82 [ Mineral Grey | SO Ext | 19" Black | 6MT | CFRP Interior | LED | Executive | Side/Top Cameras | Adaptive M Suspension | HK Surround ] :: will code locally for rum, beer, or chicken; PM as desired :: Instagram: IMrMark |
Appreciate
0
|
06-03-2014, 10:16 AM | #3 |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Don't fret.
In this post (on how he almost failed his motorcyle exam) he starts off noting that he has many overdue videos...... http://mobile.pistonheads.com/;s=SfY...+Blog#topicTop |
Appreciate
0
|
06-03-2014, 10:17 AM | #4 |
Captain
75
Rep 991
Posts
Drives: 2015 BMW M4
Join Date: Apr 2014
Location: Fairfax, VA
|
"It's in the mail - I promise!"
__________________
2015 ///M4 F82 [ Mineral Grey | SO Ext | 19" Black | 6MT | CFRP Interior | LED | Executive | Side/Top Cameras | Adaptive M Suspension | HK Surround ] :: will code locally for rum, beer, or chicken; PM as desired :: Instagram: IMrMark |
Appreciate
0
|
06-03-2014, 10:22 AM | #5 |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Hmmm....heard that one before, have you?
I guess other than waiting on his video, the only thing really left to come are the North American press drives (which, if memory serves, should be coming up sooon.......) Oh, yeah, and actually getting my own paws on one and deciding for myself. That too. |
Appreciate
0
|
06-03-2014, 10:45 AM | #6 |
Captain
75
Rep 991
Posts
Drives: 2015 BMW M4
Join Date: Apr 2014
Location: Fairfax, VA
|
amen to that!
__________________
2015 ///M4 F82 [ Mineral Grey | SO Ext | 19" Black | 6MT | CFRP Interior | LED | Executive | Side/Top Cameras | Adaptive M Suspension | HK Surround ] :: will code locally for rum, beer, or chicken; PM as desired :: Instagram: IMrMark |
Appreciate
0
|
06-03-2014, 11:27 AM | #9 | |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Quote:
In fairness to Harris, he really did thrash the original Cali - from that position, I took the praise he was willing to give the Cali T as genuine. I just thought it was interesting to see what other car cos are doing to deal with the world where turbos are a matter of every day life. BMW took the honest 'it is a turbo, lets see how we can make it better but still appreciate what it is and what it brings' approach (which gives lots of low end torque, but may result in short shifting...to whatever extent that is a real 'problem') whereas Ferrari went with the attempt to recreate an NA engine, which may reduce short shifts but loses some of the whiz-bang fun of a turbo. Put another way, if the woman you are dating has kids, should she be upfront about it or should she hide them from you? (though if we go much further down the comments on the Cali, we get significantly OT, I actually originally read the review because I have a co-worker who is in love with the California and I was interested to see how the new one was doing - as I read, I thought it was an interesting comparison of approaches.) |
|
Appreciate
0
|
06-03-2014, 11:35 AM | #10 |
Major General
5457
Rep 7,037
Posts |
BMW do not have room to do what Ferrari did. If they put in a linear map the car would be slower than the E9X. They would have needed something like an FI S65 to do that and then what's the point?
|
Appreciate
0
|
06-03-2014, 11:43 AM | #11 | |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Quote:
(as I at least hinted at in the OP, I don't think this is the way that BMW should have gone - I guess it works for the Cali, but I think the approach of BMW with what they have done is a better philosophical approach which, I hope, will work out just fine in practice). |
|
Appreciate
0
|
06-03-2014, 12:13 PM | #12 | |
Major General
1712
Rep 5,108
Posts |
Quote:
Ferrari have also downsized their engine and have found room for the individual map in each gear. Looking at the S55 power graphs, there is plenty of room to turn boost down in the lower regions of the range and stil make more power than the S65. |
|
Appreciate
0
|
06-03-2014, 12:14 PM | #13 |
Captain
131
Rep 690
Posts |
A lot of these exotics are kind of similar to the S65,S85. they are high revving, and favor HP over torque. but the difference is these motors make way more power, and cars are lighter. thats why people refer to the S65 has having a exotic feel. (although not saying they are exotic)
The high revving, high HP motors have a certain sound and power characteristic that people love. Its more of a race engine feel. Adding a trubo, the engine will have a different feel. |
Appreciate
0
|
06-03-2014, 01:19 PM | #14 |
Brigadier General
2307
Rep 4,341
Posts |
Unlimited torque can just lead to wheel spin and or traction control stepping in. Remapping the torque curb might not be so bad! Personally I found the biggest factor in the 1M was managing the torque. I think a lot of you turbo M car newbies are in for a surprise. Granted the M3 is getting better and slightly wider rubber than 1M did but actually mapping the torque curb higher might give you faster times! I remember the car and driver tests of the ford GT40. They put an asterisk after a 3.5 second 0-60 time. It said "probably faster if we could control wheel spin." A more progressive torque curb is not a bad thing!
|
Appreciate
0
|
06-03-2014, 01:35 PM | #15 | |
Banned
43
Rep 1,147
Posts |
Quote:
|
|
Appreciate
0
|
06-03-2014, 03:59 PM | #17 | |
Advocatus Douchebagus. Sex Marxist.
2415
Rep 3,415
Posts
Drives: Lucy.
Join Date: May 2012
Location: Canada
|
Quote:
I don't get that channel here in Canadia, but didn't hear that it included any M3/M4 info. Most of the reviews called it a not-great version of TG. |
|
Appreciate
0
|
06-03-2014, 05:15 PM | #18 |
Major General
5457
Rep 7,037
Posts |
Mathematically it would. Both engines peak at pretty much the same power. The S55 can deliver peak power up to 7000 rpm. The S65 at 8300 rpm. With a linear power delivery the S55 will peak earlier and have a steeper angle on it's "curve". When you shift you will end up with lower power given the same gearing. And if you make gearing shorter on the S55 you will not be able to get the same top speed in the highest gear. You would also need more frequent shifts.
In practicality there are always other factors as heat buildup, wind resistance, the little weight difference, better tires etc. and ways to tweak and fiddle with parameters. It might not have been much slower if at all but the performance difference to the outgoing M3 would be way too small to impress anyone. |
Appreciate
0
|
06-04-2014, 01:52 AM | #19 | |
Major General
1712
Rep 5,108
Posts |
Quote:
But wouldn't BMW, just like Ferrari, have made sure that the power curve would allways be above that of the predecessor during shifts? My guess is that a "power manipulated" S55 would have a different top end HP number than the current S55. And in doing that there should be no reason why BMW couldn't do the same as Ferrari have done. But on a different note, I'm not sure that what Ferrari has done would necessarily be right for the M3/M4. |
|
Appreciate
0
|
06-04-2014, 05:28 AM | #20 | |
General
21105
Rep 20,741
Posts
Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal
|
Quote:
I guess they could have reduced the torque of the S55 below 5500rpm without negatively affecting maximum acceleration. But I am very glad BMW did not limit torque in different gears as Ferrari did. At least this way we are getting the full benefit of the S55. Last edited by CanAutM3; 06-04-2014 at 05:38 AM.. |
|
Appreciate
0
|
06-04-2014, 05:54 AM | #21 | |
Major General
1712
Rep 5,108
Posts |
Quote:
I wouldn't say the graph is totally useless, because obviously a F8x with a different S55 engine characteristic, would obviously also have gearing factored in to provide better acceleration than the E9x. It's not like the M engineers wouldn't figure that out... They could match the power and gearing so that the S55 always had more power in the next gear compared with what the S65 delivered. After all, this is what Ferrari has done... But again, glad BMW didn't artificially limit the torque of the S55 to create a "NA charade" characteristic. Active Sound seems like a minor thing compared with what Ferrari have done to create a artificial engine characteristic |
|
Appreciate
0
|
06-04-2014, 06:25 AM | #22 |
General
21105
Rep 20,741
Posts
Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal
|
Or they could have simply selected gear ratios that maximize the power plateau of the S55 as it is (you know, that long term gripe of mine ). This would require 7300rpm shifts in every gear to maximize acceleration. Isn't that what Ferrari is trying to mimic?
|
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|