Login


12232007, 01:09 AM  #23 
Second Lieutenant
2
Rep 225
Posts 
Indeed. I'm mostly curious to find out how much, if any, this engine is underrated and what can be had from a proper ECU tune.

Appreciate
0

12232007, 02:10 PM  #25  
MacroRisk
35
Rep 2,519
Posts 
European Commission curbs power race
Quote:
http://www.economist.com/business/Pr...ry_id=10342303
__________________
Just thinking of something not so witty ///M3 E92 '09 Jerez Black  6MT  Ext Fox Red  Tech  Prem  19s Heated Seats  iPod Smartphone  Euro Deliv June 09 Sold: 540iT / 530i / 323i 

Appreciate
0

12232007, 02:42 PM  #26 
First Lieutenant
12
Rep 342
Posts 
They are already making a 4.4 L TT for the X6 (for now) making 400hp/450tq but its probably much heavier and directly against the efficient dynamics philosophy not to mention the M division philisophy of "less is more". So I just don't see them using the turbo setup anytime soon for the M division. If F1 racing starts accepting turbo, than all bets are off.

Appreciate
0

12232007, 09:58 PM  #27 
Banned
39
Rep 2,533
Posts Drives: 95 Avus M3 and 07 E90 Fam Car! Join Date: Nov 2006
Location: So Cal, Simi Valley

yup just like everyone has stated, a nice ECU tune, intake, racing cats, and straight through pipes with an eissenmann exhaust at the end would yield some nice numbers.

Appreciate
0

12232007, 11:07 PM  #29  
Major General
118
Rep 6,902
Posts 
Quote:


Appreciate
0

12252007, 10:29 PM  #30 
Captain
12
Rep 624
Posts 
Most of you are complaining about the torque curve dropping after 7K RPM. FYI, the Honda S2000 (considered THE most high strung production by most) has peak torque at 7500, peak HP at 8300 and redlines at 9K. In other words, its torque starts dropping 1500 rpm before redline.
The M5 engine sacrifices low and midrange torque for the high RPM torque (= HP) so you have to drive it to redline to make it feel fast. The M3 should feel a lot punchier in normal or even spirited driving due to its flat torque curve. Plus I'd guess they were trying to make the M3 get a bit better fuel economy than the M5's miserable 11/17 rating. As SWAMP said (and I've agreed all the way along) they are saving that torque curve for the CSL. If the 3.6L flat six in a GT3 Porsche can make 415 HP (386 WHP, 115 HP/liter ), I am sure the M engineers can pull 450 HP or more out of the 4 liter for the CSL.
__________________
Driving sideways: It's not faster, but damn it's more fun!

Appreciate
0

12252007, 10:55 PM  #31  
Brigadier General
145
Rep 4,021
Posts Drives: 2008 335xi Coupe Join Date: Feb 2007
Location: The land where we kill baby seals

Quote:
It can hit 450 hp getting more torque in the last 20003000 rpm. This is where the engine spends its time during WOT acceleration. Driveability and flat torque curves are great for getting lattes at Starbucks. I want an uncompromised torque curve in the last 3000 rpm of the rev range.
__________________
"Aerodynamics are for people who cannot build engines"......Enzo Ferrari


Appreciate
0

12262007, 09:38 AM  #32  
Chief Warrant Officer 4
6
Rep 661
Posts Drives: 335I, X5 4.8i Join Date: Feb 2007
Location: Back in the US

Quote:
Also, Eisenmann exhaust is absolutely a must have. Got it on the 335i now and love it. I saw they were working on a sytem for the M3 and plan to add this as my first mod.
__________________


Appreciate
0

12262007, 10:07 AM  #33 
Major General
116
Rep 8,034
Posts 
The TT stuff is all baseless speculation, and wishful thinking for some. It's simply not going to happen for the E92. High level BMW exec said FI is not favored by the M division and will not be happening for this product cycle (that interview was posted somewhere on this forum, so search for it if you don't believe me). He said he can't rule it out for other generations, but those are 6+ years away. Historically, M engines have not been messed with too much in a given product cycle, except for small displacement bumps. I can see retuning and replacement of things like intakes, exhaust, and cams for the CSL, but that's an entirely different car. If BMW was really pressed for it, maybe they'd bump the displacement to 4.2 or 4.3 liters for the M3, but I doubt it given the car is kicking some serious ass on the track the way it is.

Appreciate
0

12262007, 10:13 AM  #34 
Chief Warrant Officer 4
6
Rep 661
Posts Drives: 335I, X5 4.8i Join Date: Feb 2007
Location: Back in the US

Thanks. It was nice to ponder on that for a few minutes. In 6= years I'll be looking for the next M3 while holding on to this one.
__________________

Appreciate
0

01012008, 07:05 AM  #35  
Colonel
29
Rep 2,178
Posts 
Quote:
__________________
2015 f80 M3, 2010 GT3RS


Appreciate
0

01012008, 11:41 AM  #36 
Banned
4
Rep 471
Posts 
the torque of this engine is pretty well maxed out...but it doesn't matter...it's all about gearing...
for those who care: peak T = (V x mep)/(4 x Pi) that simple where: V = displacement mep = mean effective pressure basically a function of the comp ratio and volumetric efficiency also: T = HP x (5252/rpm) for this engine HP ~ 52 x rpm/1000 is a close approximation for >3000 rpm: .rpm.....HP 4000...208 6000...312 8000...416 check the curve, it's close... http://carnews.roadfly.com/wpconte...dynospecs.jpg it appears from the curve max HP will be 450460 at 9000...taking eff into consideration...with different cams/etc. substituting: T = (52 x rpm/1000) x (5252/rpm) simplifying, rpm cancels: T = 52/1000 x 5252 ~ 273 lb ft... this tells me that you will be hard pressed to get more torque than it's rated 295... also note from T = HP x (5252/rpm) as rpm increases the ratio 5252/rpm goes down, ie, torque decreases by extending rpm's, they can extend the HP line, but it will still droop, so although they can extend the torque, it will not increase... want more torque, get a bigger engine engine...or lower gears 
Appreciate
0

01012008, 12:27 PM  #37 
Banned
4
Rep 471
Posts 
after looking at the curve...the torque is ~flat to 8300 (HP peak)
doesn't get any better than that rpm......T % of peak 1000........65 2000........85 3000........95 4000.......100 5000.......100 6000.......100 7000........98 8000........92 8300........90 so at HP peak it still has 90% of it's max torque...only a drop of 10%! in other words the rpm increase from 6000 to 8300 is ~38%, you would expect the T to drop close to that, yet it only drops 10%... doesn't get any better... 100% ~3500 to 6500 >95% from 3000 to 7500 >90% from 2500 to 8300 (peak HP) that's electric motor stuff... 
Appreciate
0

01012008, 12:45 PM  #38  
Brigadier General
145
Rep 4,021
Posts Drives: 2008 335xi Coupe Join Date: Feb 2007
Location: The land where we kill baby seals

Quote:
This is nice accurate analysis.....but how much faster would the car be if 100% of the torque was available in the last 2500 rpm? Screw flat torque curves, let Lexus have that crown.
__________________
"Aerodynamics are for people who cannot build engines"......Enzo Ferrari


Appreciate
0

01012008, 01:21 PM  #39 
Captain
16
Rep 640
Posts 
Have any of you driven the car? You can argue all you want about the torque curve, keep in mind gearing, which no one has discussed, also affects drivability.
I've driven the car in town, stop and go traffic and on the autobahn. With every seat in the car occupied the M3 pulls very nicely, even from low rpm. Does it have big block Chevy torque? No, but no one is expecting that. I found that even from 2,000 rpm the motor is very tractable and responsive. Why don't you wait and drive it and then decide if all the debate about the level of torque, where it drops off, etc matters. The engineers have to make compromises and I think the BMW M philosophy of 500 cc per cylinder is the perfect displacement is suspect, but that's what they've chosen to do, and within those contraints the motor is a pretty spectacular performer. 
Appreciate
0

01012008, 04:32 PM  #40  
Brigadier General
145
Rep 4,021
Posts Drives: 2008 335xi Coupe Join Date: Feb 2007
Location: The land where we kill baby seals

Quote:
I really do look forward to driving it as soon as possible....but as I wrote above somewhere, I would have preferred more performance in favor of a flat torque curve anyday of the week. Why build an enthsiast car with a compromised torque curve?? Driveability? Fuel Economy?
__________________
"Aerodynamics are for people who cannot build engines"......Enzo Ferrari


Appreciate
0

01012008, 07:39 PM  #41  
Lieutenant General
215
Rep 10,201
Posts 
Quote:
…….hp/tq/redline/hp peak@/tq@peak hp M3: 343/269/7900/7900/228 CSL:360/273/8000/7900/239 Although the S54 was fairly maxed out (highly stressed) at 106 hp/l and 83 ft lb/l the M boys still found room for improvement. Although the CSLs peak tq only increased by 1.5% its tq increase at peak hp went up by almost 5%. Note that the rpm at which the peak hp is obtained did not change! This was accomplished almost entirely through improvements to “breathing” (intake/exhaust). Which is more important during very spirited driving when the car will typically be above 5000 rpm? Since the S65 is “only” producing 105 hp/l and 74 ft lb/l, I suspect there is substantial room for more. I’d expect the CSL to have AT LEAST: 450 hp, 8500 rpm redline, 300 ft lb AND 270 ft lb at hp peak (vs. approx 258 ft lb at peak hp in the base S65). A bit more on redline: The S65 is really quite oversquare compared to the undersquare S54. The bore to stroke ratios are 1.2 vs. 0.94. A B/S of about 2.0 allows F1 engines to get very close to 20,000 rpm. We have heard rumors of BMW S65 durability testing at 910k rpm. The piston accelerations of the S65 do not even match those of the S54 until 8700 rpm. Furthermore, the S65 has smaller and lighter pistons. Putting all of this together if BMW was happy with the stress and safety factors in the S54 connnecting rods/pistons/crankshaft/etc. at 7900 rpm they should be equally happy going to at least 8700 rpm in the S65. 

Appreciate
0

01012008, 07:47 PM  #42  
Lieutenant General
215
Rep 10,201
Posts 
Quote:
As you might know from many of my post, I am a big advocate of science applied to cars. Science and engineering are just as important to a deep understanding of a vehicle as seat time. Note I said understanding not achieving the best lap time. 

Appreciate
0

01012008, 07:55 PM  #43  
Banned
4
Rep 471
Posts 
Quote:
360/343 x 228 = 239 so the T increased proportionally to the HP...not greater the new V8 is 25% larger, yet has only 13% more T...this tells me they must have limited T in the midrange (cams, timing, etc.), to make it flatter...which implies the hi/lo extremes are not 'fiddled' with... especially since the mep of the engine should be higher (due to a higher compression ratio... I think with some cams and flow improvements this engine will reveal pretty good HP/midrange torque gains... 

Appreciate
0

01012008, 07:55 PM  #44 
Captain
16
Rep 640
Posts 
I agree, the one thing that would have added more power and performance would have been direct injection FI. No one at BMW has told me why it was not considered since lower model i.e. 335 (in US) have it, but not the new M3. Probably a cost issue, but how much would this have added to the car? Maybe for year 3 or beyond upgrade?

Appreciate
0

Post Reply 
Bookmarks 
Thread Tools  Search this Thread 

