The advantages of a NA engine?

[mkoesel]

Originally Posted by swamp2

Come on now, we've all agreed that 7200 is the very likely minium redline for the next M3. It is not awe inspiring but ~7000 can mean 6800 as well.

Right. By ~7000 RPM, I meant 7000 at a minimum but not much more.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

It is simply the classic numbers vs. feel debate. BMW may have been able to extract a bit more torque from the car but probably only at a higher displacement. It's resulting power curve would look a lot more like the 335i. The unfortunate result would be a big hit in the feel department. I like numbers too, love em in fact. As you know I like to discuss and debate them. However, one can't loose sight of the highly emotional aspect of performance car driving.

Mostly disagree, except on the emotional aspects, which I take to mean that for many of us, getting our G receptors stroked from time to time is fun. Think roller coasters, fast cars, etc.

Perhaps I hadn't made my point clear about the E46. It too has a pretty flat torque curve, revs high, etc., but it makes a fair bit more torque per liter than the current M3 V8. There's no particular reason why the V8 couldn't make 327.5 pound feet of torque at around 4900 rpm, thereby equaling the torque per liter production of the E46. That's a substantial improvement over the current 295 pound feet, wouldn't you say?

I expect that retuned car would be making significantly more torque than the stocker at 3900 rpm, and in actuality would be making more torque everywhere except for below around 2000 rpm, and of course the the torque would be equal at 8300.

Such a car would be noticeably quicker than the current model, on either drag strip or road course.

Quicker than that if it could be shifted at 9000 rpm without blowing up.

[bruce.augenstein@comcast.]

Originally Posted by pbonsalb

I think those little turbos are spooling hard at 1400 rpm. BMW claims the new twinscroll single turbo N55 is spooling hard at 1200 rpm. They are tiny turbos on the N54 (the single turbo is also small and runs out of steam sooner than the twins on the N54) and between the 500 rpm idle speed and 1400 rpm, they start moving. It takes very little exhaust gas energy to get those tiny wheels going. BMW is not putting out deceptive data when it reports the torque/rpm figures for the N54.

I have been on a few dynos and have never started a run at 500 rpm or even 1500 rpm. I would not do that to my car. But on the street, I have floored it off the line many times. The N54 pulls like a V8 and it would not do that if nothing was happening until 4000 rpm. Those little turbos are spooling at ridiculously low rpm.

Of course, those little turbos are not spooling hard at 1200 or 1400 rpm. Not if you're cruising at 12-1400. They're just ticking over at that point, and when you floor it, it takes time for them to spool up and provide max boost, thereby leading to max torque. Hence my assertion that max boost boost at 12-1400 rpm is only practically available on a dyno. Out in the real world, forget it. By the time the turbos spool, you're at way more than 12-1400 rpm.

The only exception is if you floor the car in a high gear at, say, 1000 rpm - but why would you do that if you want to accelerate hard? You wouldn't. You'd downshift and then mash the gas. You'll still have some lag, but much less, because exhaust flow is much stronger at higher rpm.

My overall point in this regard is that NA is better than a turbo car at low rpm (given similar specs), since the turbo car's specs fool you if you don't consider big lag at low rpm.

[bruce.augenstein@comcast.]

Originally Posted by MVF4Rrider

They would have to be spinning hard at 1,400 rpm as the motor produces 279.7 lb-ft of torque at 1,302 rpms, which is over 98% of the peak torque of the motor. The motor peaks at 3,009 rpms (283.6 lb-ft) and carries roughly the same amount of torque through 5,008 rpms (274.6). Now that's a flat torque curve. Unfortunately it nose dives to 203.6 lb-ft by 6,717 rpms and well under 180 by redline.

See my reply #201 above.

[Dodge2Dub]

Originally Posted by bruce.augenstein@comcast.

Perhaps I hadn't made my point clear about the E46. It too has a pretty flat torque curve, revs high, etc., but it makes a fair bit more torque per liter than the current M3 V8. There's no particular reason why the V8 couldn't make 327.5 pound feet of torque at around 4900 rpm, thereby equaling the torque per liter production of the E46. That's a substantial improvement over the current 295 pound feet, wouldn't you say?

Isn't that more than achievable by modifying the car with a 3.63 LSD?

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Yes, pretty much agree.

Only on the dyno - yes
The real world involves shifting - yes

However, since you are such an advocate of the lazy high torque at low rpm type of car, you are the person who would be flooring the car in 6th at 2000 rpm!

In actuality, what I like is effortless power in everyday driving, but if I wanted a bunch of it at any given instant, I'd be downshifting just like you rpm-crazy madmen.

[swamp2]

Originally Posted by pbonsalb

The N54 pulls better than an S65 off the line in daily street driving. Try them both. I own both engines and have done this plenty of times.

Absolutely not. A modded N54 when launched "drag style" can pull slightly better than the M3 in first gear only.

Now if you want to mash the gas in some high gear at very low rpm or some other "lazy" style of driving there also may be cases when a stock 335i can put more torque to the wheels than the M3. However for a stock 335i the cases where is can put more torque to the wheels is extremely limited if any. There has been numerous posts on this topic along with all of the requisite spreadsheets of analysis as proof.

[Ken37.73]

Originally Posted by jackka

Hey there, fellas.

I always wondered why it was that the M division decided to go with a 414/295 engine when they could have easily made it much more. Especially the torque output. Why do you think that is?

I think it's perfect to be honest. Would like it as much if it were the same as a C63 lump. The balance of engine / chassis / grip / driveability / practicality is, for me, perfect.

[MVF4Rrider]

Originally Posted by bruce.augenstein@comcast.

See my reply #201 above.

The turbos are definitely working at low rpms. The same motor (I don't recall the N designation, but it's from the E46 330) without the turbos produced 167.1 lb-ft at 1,500 rpms. The N54 produces 280.6 lb-ft at the same rpm. I'm not saying the turbos are peaking or anywhere close to it, but they are making an appreciable difference vs. the same motor without them. I have 7,000 miles using a N54 in Germany. Its best attribute is off-idle/low rpm power. So much so you can skip gears during normal driving. You really can't tell what gear you're in half the time.

[pbonsalb]

Originally Posted by bruce.augenstein@comcast.

Of course, those little turbos are not spooling hard at 1200 or 1400 rpm. Not if you're cruising at 12-1400. They're just ticking over at that point, and when you floor it, it takes time for them to spool up and provide max boost, thereby leading to max torque. Hence my assertion that max boost boost at 12-1400 rpm is only practically available on a dyno. Out in the real world, forget it. By the time the turbos spool, you're at way more than 12-1400 rpm.

The only exception is if you floor the car in a high gear at, say, 1000 rpm - but why would you do that if you want to accelerate hard? You wouldn't. You'd downshift and then mash the gas. You'll still have some lag, but much less, because exhaust flow is much stronger at higher rpm.

My overall point in this regard is that NA is better than a turbo car at low rpm (given similar specs), since the turbo car's specs fool you if you don't consider big lag at low rpm.

Sure, and the S65 is not making 295 lbs of torque at part throttle, either, and you probably are not driving around at 4000 rpm everywhere you go. With the N54, anytime you are above 1400 rpm, those tiny turbos are so much closer to full spool. Mash the gas and full boost arrives in a split second. Again, I have both engines and drive both cars regularly. I don't have "big lag at low rpm" with the N54.

[pbonsalb]

Originally Posted by swamp2

Absolutely not. A modded N54 when launched "drag style" can pull slightly better than the M3 in first gear only.

Now if you want to mash the gas in some high gear at very low rpm or some other "lazy" style of driving there also may be cases when a stock 335i can put more torque to the wheels than the M3. However for a stock 335i the cases where is can put more torque to the wheels is extremely limited if any. There has been numerous posts on this topic along with all of the requisite spreadsheets of analysis as proof.

"A modded N54 when launched drag style can pull slightly better than the M3 in first gear only." That is absolutely ridiculous. A modded N54 makes about 100 lbs more torque than the M3. A modded N54 out torques the S65 from about 1500 rpm to about 6500 rpm.

A stock N54 out torques an S65 until the S65 finally reaches its peak torque at 3900 rpm. Anywhere in that 1500 to 4000 rpm range, 300 lbs of torque is just a mash of the gas away with the N54. You really need to drive the cars and get away from the speadsheets and trend analyses and internet data stuff. I like my S65 also, but it is not the be all and end all of engines.

I do agree that if you drive both the S65 and N54 around at 4000 rpm, the N54 has no advantage. However, I spend a lot of my driving me between 500 and 4000 rpm. The S65 is fine in that range. I have no complaints. But a stock N54 is just as good if not better in daily driving in that range. This "terrible turbo lag" stuff is internet lore from the 80s that you have been reading. Don't swallow it all.

[MVF4Rrider]

Originally Posted by pbonsalb

"A modded N54 when launched drag style can pull slightly better than the M3 in first gear only." That is absolutely ridiculous. A modded N54 makes about 100 lbs more torque than the M3. A modded N54 out torques the S65 from about 1500 rpm to about 6500 rpm.

A stock N54 out torques an S65 until the S65 finally reaches its peak torque at 3900 rpm. Anywhere in that 1500 to 4000 rpm range, 300 lbs of torque is just a mash of the gas away with the N54. You really need to drive the cars and get away from the speadsheets and trend analyses and internet data stuff. I like my S65 also, but it is not the be all and end all of engines.

I do agree that if you drive both the S65 and N54 around at 4000 rpm, the N54 has no advantage. However, I spend a lot of my driving me between 500 and 4000 rpm. The S65 is fine in that range. I have no complaints. But a stock N54 is just as good if not better in daily driving in that range. This "terrible turbo lag" stuff is internet lore from the 80s that you have been reading. Don't swallow it all.

[mkoesel]

Originally Posted by pbonsalb

"A modded N54 when launched drag style can pull slightly better than the M3 in first gear only." That is absolutely ridiculous. A modded N54 makes about 100 lbs more torque than the M3. A modded N54 out torques the S65 from about 1500 rpm to about 6500 rpm.

Just curious, did you happen to check up on this part of his post:

"There has been numerous posts on this topic along with all of the requisite spreadsheets of analysis as proof."

If not, I'd strongly consider it.

Remember:
- Gearing multiplies torque, so without doing the math, you cannot accurately deduce which car makes more torque at which RPM.
- Simply owning both cars means nothing, since you cannot measure torque effectively with your buttocks.

[Voltigeur]

Originally Posted by jackka

Hey there, fellas.
Would love to buy one now but that would delay my retirement too far back and I want to retire as early as possible.

Props to you: hardly meet any Americans who have this goal, I usually get "I want to work as long as possible.." - I'm with you, life's too short and early retirement - if funded well - means more travel and driving time!

Re OP: love the linear response of N/A. It's why I'd take a 458 > MP4-12C (despite latter's perf advantage) as well as sound.

I do really relish the gobs of torque my 335d has in DD - especially 50 - 80 mph. Turbo lag not an issue. But for spirited, focused, driving give me the M3's S65 V8 every time.

[swamp2]

Originally Posted by pbonsalb

A modded N54 makes about 100 lbs more torque than the M3.
...

You really need to drive the cars and get away from the speadsheets and trend analyses and internet data stuff. I like my S65 also, but it is not the be all and end all of engines.

1. Do indeed have a look at some of the history posted here on this forum on this topic as mkoesel pointed out.
2. Torque at the crank is largely meaningless. It is the wheels number that matters. Why can you not get this through your head?
3. As I mentioned I have driven both cars, own the M3, have driven multiple 335i and gotten on them good. I have not driven a modded 335i.
4. Spreadsheets and physics based simulation can tell you as much or more about how a car will feel. You do realize that science/math/engineering is predictive right? You do realize that ALL cars are designed with extensive simulation (and lower forms of that such as engineering spreadsheets). Why? Becuase it works, that simple. You need to learn more and rely a bit less on your inaccurate butt-o-meter.

OK, I give up, I'll cut right to the chase. Here are the simulations.

Note the accuracy of the stock M3 M-DCT 1/4 mi times, 0-60 times, 0-100 times, etc. The 335i here is with 420 hp, 420 ft lb. I know you can get more, but this is also pretty generous, you'll need full bolts ons + race gas to put down these numbers. Something along the lines of Proceed v2+bolts ons+race gas (not sure if that is still the model designation). Either way I'm going with a very high performing 335i.

The conclusions are:

1. Modded 335i pulls quite a bit harder in 1st than the M3 (as I stated). Look at the acceleration vs. time graph to see this. This is what we know and feel as "pull" it is nothing more than the acceleration curve, period. It does pull slightly harder in other gears as well but that is pretty well a wash even with that amazing 420 ft lb. If the mods were a step or so down the results would be exactly as I stated prior - pulling harder in 1st gear only.
2. M3 still takes 0-60 time and most other time to get to speed X contests.
3. M3 takes the 1/4 mi time and trap.
4. 1/4 mi for the modded 335i is right in line with reported results from the drag strip, ~12.7 s.
5. To give it credit, the high torque to the wheels does get this car physically ahead and it maintains a bit of distance across the gears. In a street race this typically qualifies as a win.

This is a pretty classic example of hp/redline/gearing vs. equivalent (a bit more even in this case) power and WAY more torque.

The Proceed v1 or anything with 400 hp/400 ft lb or less is not a contest it will be close at 400/400 but the M3 will win. Again it will pull a bit harder in 1st and then it is all to the M3, both street race (position) and drag race (times).

Any more questions?

[MVF4Rrider]

Originally Posted by swamp2

Any more questions?

He's not the first guy duped by aftermarket tuning companies. They all prey on those who think biggest peak number wins. Wins a what is the question? Well I guess it gives them something to talk about on forums and at the tuning shop as you hand over more cash. Personally I think the best way to quicken your car is to sell it and buy one that's quicker. I'll take understated over overstated as well (at least that's what I tell myself until I one day decide I must own a Ferrari).

[Erhan]

Originally Posted by MVF4Rrider

Personally I think the best way to quicken your car is to sell it and buy one that's quicker.

+1.

[pbonsalb]

Originally Posted by swamp2

5. To give it credit, the high torque to the wheels does get this car physically ahead and it maintains a bit of distance across the gears. In a street race this typically qualifies as a win.

Thank you. We were discussing the better daily driver and you acknowledged it above. I daily drive on the street. You can have your simulations and all the internet data you can load onto your spreadsheets. I like my S65, but I am not overly hung up on M3s.

[swamp2]

Originally Posted by MVF4Rrider

He's not the first guy duped by aftermarket tuning companies. They all prey on those who think biggest peak number wins. Wins a what is the question? Well I guess it gives them something to talk about on forums and at the tuning shop as you hand over more cash. Personally I think the best way to quicken your car is to sell it and buy one that's quicker. I'll take understated over overstated as well (at least that's what I tell myself until I one day decide I must own a Ferrari).

Yes, I more or less agree. However, to be fair, tuning a turbo with relatively low cost software, as long it is done conservatively and with safety of the engine and cooling in mind, can add significant and real world performance gains.

[swamp2]

Originally Posted by pbonsalb

Thank you. We were discussing the better daily driver and you acknowledged it above. I daily drive on the street. You can have your simulations and all the internet data you can load onto your spreadsheets. I like my S65, but I am not overly hung up on M3s.

To me that does not make it a better daily driver. The exact 100 ft lb margin of torque you mentioned would not make the car the winner in the time to distance race! Also this particular 420/420 car is highly modified, pushing too hard on an already weak-ish cooling and fuel system and is running race gas. If you call that a great daily driver that's fine we can agree to disagree on that point.

You can have all of your infinite wisdom on the supreme importance of high crank torque values as well. Mocking science and engineering is a bit absurd don't you think? You could not have any of your favorite daily drivers anywhere close to what they are with out immense amounts of both. Perhaps we should argue about plate techtonics, evolution or global warming instead ?

I personally prefer a realistic combination of science and seat of the pants.

You're never to old to learn and I've personally learned a ton from other knowledgeable forum members here.

[MVF4Rrider]

Originally Posted by swamp2

Yes, I more or less agree. However, to be fair, tuning a turbo with relatively low cost software, as long it is done conservatively and with safety of the engine and cooling in mind, can add significant and real world performance gains.

Yes, but mainly in the lower half of the rev range where it's already good. Making the power band more peaky makes the power less predictable, and traction is challenged as it is in low gears at low speeds under hard throttle. Most reputable tuning companies still allow the power to massively taper off at higher rpms as they know the motor can't handle the boost. Personally I think adding more power to a 135i/335i/335is just brings out the shortcomings of the clutch and suspension even more so (especially the clutch). My stock 135i was not very fun trying to power out of turns for two reasons. First, the rear suspension was easily upset by road imperfections (seemed to bounce off of mid corner bumps--very harsh), and second, the nature of the power delivery. A higher more peaky lower half power would worsen both of those aspects. I guess when I think of performance enhancement I don't necessarily think straight line. As I lived in Germany at the time of the 135i, had I kept it I was going to change out the suspension and add a rear deck spoiler. But in the end I hated the cars high speed character. Just had to work too hard to go 140 mph and up. Plus, aerodynamics are horrible as the car was not very stable at high speed (hence the desire for the spoiler). It would walk all over the lane requiring constant steering input. The Z4 M Coupe I replaced it with was so much better at everything it did. Extremely planted at speeds well over 150 mph. I could go on and on...

What's this thread about? DCT vs. 6MT? I forget...

[swamp2]

Originally Posted by MVF4Rrider

Yes, but mainly in the lower half of the rev range where it's already good. Making the power band more peaky makes the power less predictable, and traction is challenged as it is in low gears at low speeds under hard throttle. Most reputable tuning companies still allow the power to massively taper off at higher rpms as they know the motor can't handle the boost. Personally I think adding more power to a 135i/335i/335is just brings out the shortcomings of the clutch and suspension even more so (especially the clutch). My stock 135i was not very fun trying to power out of turns for two reasons. First, the rear suspension was easily upset by road imperfections (seemed to bounce off of mid corner bumps--very harsh), and second, the nature of the power delivery. A higher more peaky lower half power would worsen both of those aspects. I guess when I think of performance enhancement I don't necessarily think straight line. As I lived in Germany at the time of the 135i, had I kept it I was going to change out the suspension and add a rear deck spoiler. But in the end I hated the cars high speed character. Just had to work too hard to go 140 mph and up. Plus, aerodynamics are horrible as the car was not very stable at high speed (hence the desire for the spoiler). It would walk all over the lane requiring constant steering input. The Z4 M Coupe I replaced it with was so much better at everything it did. Extremely planted at speeds well over 150 mph. I could go on and on...

Great info. You've spent more time with the new turbo 6 than I have. Obviously, these are some of the subtleties you can get from driving that you can not get from simulation . Perhaps also obvious, my comments about the value of simulation (at least with the level of tools I have) relates much more to straight lines rather than curvy lines. Nonetheless some of the banter here always resorts to a drag racing type of debate. I don't really street race myself, but I do enjoy very high acceleration in a straight line. I also enjoy the canyons and track as well.

Your comments go to what usually comes up in the classic 335i vs. M3 debate (with anyone remotely informed involved...). Those who like to corner fast as well as street/drag race more or less know, appreciate and can feel how the extra $ in the respective price tags appropriately reflect the gained capabilities you get for that extra $. You still do get those stubborn ones that insist a 335i with mods that cost less than the new price difference between the cars can yield an overall better performer. Maybe with no/free labor costs you can get close...

Originally Posted by MVF4Rrider

What's this thread about? DCT vs. 6MT? I forget...

No, no it is about how a new rear diff ratio WILL make your car much faster... No I mean it is about how must faster a GT-R is than an M3. Hell I forgot.