[Driver72]

Originally Posted by BavarianBullet

Lol- I'm not so sure about the whole aerodynamic drag thing. The Cd only changes from .30 to .31 from the not-so-huge .8" difference in ride height so I doubt you'd notice anything on the 1/4mi. In fact there are some nice free calculators http://www.gtechprosupport.com/support/AeroDragCalc.htmthat show it's a whopping 1.5HP difference in aero drag losses at 100mph.

I've no evidence to back it up but I think the drivetrain loss from Xdrive is also pretty exaggerated in people's minds. You'd probably see similar or greater losses at speed if your tire pressure was off a bit.

I can't argue with the 220lbs of extra steel vs the 335i that the 335xi totes around though; that's about 19 more flywheel HP you'd need to have to run similar to a 335i in the 1/4mi.

Now, back on topic: anyone have some good numbers we can put together in one place as a sticky for those wanting to know?

So far we have the fastest 6MTs at 13.31 for both the 335xi and 335i (good work both of you BTW!). What about you 6AT guys out there? Can you top a 13.31?

Yes, as I said, the aerodynamic difference is small, but it's still there.
There is a pretty decent amount of drivetrain loss between RWD and AWD.
Usually about 3-4% more in AWD.
Think about it, it's a no brainer, power being sent down a driveshaft to 2 wheels compared to power being sent down a driveshaft through a device that divides the power and that is required to turn 4 wheels instead of two.

BMW should of made the transition to sending 100% of the power to the rear at 75 mph not 100 for U.S. bound cars, that would help.

The weight difference between the two cars is officially 243 lbs not 220.
That would require an additional 20-22 hp in the 335xi to match the power to weight of the 335i, and probably an additional 6-8 hp to compensate for the additional drive train loss.
So the 335xi would need an additional 26-30 hp to match the 335i in power to weight and drivetrain (and an additional 1.5 as you stated for the aerodynamics difference).
Sounds about right, considering in that video while they were in the rain, the 335i was pulling away at a rate you'd expect to see of a car with 30 more hp given equal power to weight and drivetrain losses.

Tires at 20 psi in RWD cars would not slow you down 30 hp worth (maybe 10-12 at most). This is based on experience at drag strips and lowering my tire pressure too much and seeing my times dip a bit, but not drastically.

[BavarianBullet]

Originally Posted by Driver72

Yes, as I said, the aerodynamic difference is small, but it's still there.
There is a pretty decent amount of drivetrain loss between RWD and AWD.
Usually about 3-4% more in AWD.
Think about it, it's a no brainer, power being sent down a driveshaft to 2 wheels compared to power being sent down a driveshaft through a device that divides the power and that is required to turn 4 wheels instead of two.

BMW should of made the transition to sending 100% of the power to the rear at 75 mph not 100 for U.S. bound cars, that would help.

The weight difference between the two cars is officially 243 lbs not 220.
That would require an additional 20-22 hp in the 335xi to match the power to weight of the 335i, and probably an additional 6-8 hp to compensate for the additional drive train loss.
So the 335xi would need an additional 26-30 hp to match the 335i in power to weight and drivetrain (and an additional 1.5 as you stated for the aerodynamics difference).
Sounds about right, considering in that video while they were in the rain, the 335i was pulling away at a rate you'd expect to see of a car with 30 more hp given equal power to weight and drivetrain losses.

Tires at 20 psi in RWD cars would not slow you down 30 hp worth (maybe 10-12 at most). This is based on experience at drag strips and lowering my tire pressure too much and seeing my times dip a bit, but not drastically.

Easy Killer. XIs are still BMWs...we're on the same team here.

off-topic but:

1) I guess it depends where you get your information from re the weight difference: 3825/3605 (6AT), 3814/3594 (6MT) = 220lbs http://www.bmwusa.com/Standard/Conte...fications.aspx

2) FWIW 3-4% of 300HP is 9-12HP and 6-8HP is a 1-2% loss. One point worth remembering is that it takes about 20HP to push a nearly 4000lb car along at 55mph of which a small fraction (5hp in the link provided) is rolling resistance and the rest is the wind. http://www.holtrv.com/pdf/understanding.pdf With that backdrop, how much HP is a front axle assembly really likely to draw?

I think we're in relative agreement that the XIs are probably slowed down 20-30HP (from weight mostly, IMO) vs a 335i which the conventional wisdom suggests is around 2+mph difference in trap speed on stock cars. ET is tough to call because of what should be a decent disparity in 60ft times in favor of the XI.

There is literally one unmodified 335xi listing on dragtimes at 101mph trap and BobVader's time/speed comes very close to matching the fastest 335Is around 13.3@103-104mph. Thus this thread attempts to bring more stock car comparisons to light as there are so many less variables vs tuned cars. The goal for me is to highlight some of the basic strengths and weaknesses of the 4 models (ok 6 for you E93 folks lurking out there).

I'll add my own experience to the list soon but please pile on with your timeslips to help set the standards for what we believe each car is capable of.

thanks

BB

[GeorgiaTech335coupe]

Another point: I'm not sure how many times BobVader pulled a 13.3 in his XI, but I consistently did it, as you can see on dragtimes.com. Just another piece of info to consider when making the comparison.

[Driver72]

Originally Posted by BavarianBullet

Easy Killer. XIs are still BMWs...we're on the same team here.

off-topic but:

1) I guess it depends where you get your information from re the weight difference: 3825/3605 (6AT), 3814/3594 (6MT) = 220lbs http://www.bmwusa.com/Standard/Conte...fications.aspx

2) FWIW 3-4% of 300HP is 9-12HP and 6-8HP is a 1-2% loss. One point worth remembering is that it takes about 20HP to push a nearly 4000lb car along at 55mph of which a small fraction (5hp in the link provided) is rolling resistance and the rest is the wind. http://www.holtrv.com/pdf/understanding.pdf With that backdrop, how much HP is a front axle assembly really likely to draw?

I think we're in relative agreement that the XIs are probably slowed down 20-30HP (from weight mostly, IMO) vs a 335i which the conventional wisdom suggests is around 2+mph difference in trap speed on stock cars. ET is tough to call because of what should be a decent disparity in 60ft times in favor of the XI.

There is literally one unmodified 335xi listing on dragtimes at 101mph trap and BobVader's time/speed comes very close to matching the fastest 335Is around 13.3@103-104mph. Thus this thread attempts to bring more stock car comparisons to light as there are so many less variables vs tuned cars. The goal for me is to highlight some of the basic strengths and weaknesses of the 4 models (ok 6 for you E93 folks lurking out there).

I'll add my own experience to the list soon but please pile on with your timeslips to help set the standards for what we believe each car is capable of.

thanks

BB

I'm not dissing the xi, just stating facts.
As I've said, I've owned AWD cars.
Have nothing against them just living in So Cal, AWD cars aren't really a necessity here.

As for weight, you can't compare the auto to the manual when listing weight.
If you look at BMW's website for auto vs auto or manual vs manual I believe the weight difference is 243 lbs if you use both coupes or both sedans too.

[BobVader]

Originally Posted by GeorgiaTech335coupe

Another point: I'm not sure how many times BobVader pulled a 13.3 in his XI, but I consistently did it, as you can see on dragtimes.com. Just another piece of info to consider when making the comparison.

13.312 is my best of 2 runs..the other is 13.475 at 102.83. Because I have make only 2 runs with the valet switch at stock map. My car is mod since I have my car. And I had make around 90-100 runs this summer with mod.

Maybe the rwd is better (little a bit) on roll start 60-150mph. But stop light to stop light...no way...awd rules.

my opinion.


**I have race against two m3 2008 (v8) on street tires... at track I prefer my awd...In 1st and 2th gear...bye bye m3. And in 3th and 4th gear the two car accelerate the samething. Maybe at 120mph the m3 is better... but the race is finish...Anyway here in Canada we have lot of snow in winter...**

**I practice at track and I do my runs very close runs after runs. With the practice I have see, by exemple, my car push very well when I shift at 6000-6200 rpm. At 6500-6700, my car is slower. etc.. I'm not sure if I lost 2-3% or 8-9% of my power with awd but I put each time my 345-350 hp at wheel on track.

Power is nothing without the traction...

A+

[BavarianBullet]

Originally Posted by Driver72

I'm not dissing the xi, just stating facts.
As I've said, I've owned AWD cars.
Have nothing against them just living in So Cal, AWD cars aren't really a necessity here.

As for weight, you can't compare the auto to the manual when listing weight.
If you look at BMW's website for auto vs auto or manual vs manual I believe the weight difference is 243 lbs if you use both coupes or both sedans too.

I understand re SoCal- I'm still thinking about moving to San Diego some day because I hate the snow in CT. If I was there, I probably wouldn't have got the XI either.

I haven't exhaustively researched the weight difference of the XI vs I but the link I posted (when you pull up both models) shows the difference as 220lbs with the same trans.

My 2c until proven otherwise is that the chief difference (on a 1/4mi track) in regards to HP losses is the extra weight of the XI. Perhaps it has something to do with 6MT rather than 6AT- meaning if we compared 2 automatics the differences might be more apparent by lessening the effect of the driver variable.

BB

[Chowbow]

Enough bench racing, we need some AWD 335s out there making some hard passes. If somebody wants to let me drive theirs I surely won't mind trying.

When I had my B5 S4, I was able to get a 1.81 60' stock, and deep into the 1.7x with a chip. And while most people said it wasn't possible to get much faster than 14.0 in that car, I ran a 13.89 in it, and my friend ran a 13.80 in it (his first run in it ever, and he drives very well, embarrassed me! :P).

So regardless of what the magazines and BMW says it can run, I'm sure it can go faster, particularly the xi models with somebody who's willing to really push it out of the hole.

[e90AW335i]

This is a good example of an xi run (props to xxlancexx):

http://www.dragtimes.com/BMW-335xi-Timeslip-15301.html

1/4: 12.426@108.66
60': 1.696


That run was done with a JBX, the JB3 should provide better results since the top end it much stronger.

[Chowbow]

Dang, that's a gnarly 60'!

[ToothDoc]

That's with no burnout and street tires too! 1.6x is insane! Totally NOT fair!!! LOL I don't buy into the drivetrain loss so much personally. I think it's more of a weight issue IMO. Sure there is 2x more stuff to move, but each stuff is moving only 1/2 the weight! About the only other issue is the additional rotational inertia but you can't count the tires or wheels because they're spinning also in 2wd. The rotational inertia of 2 additional CVDs, some gears and stuff is probably pretty low when compared to the overall kinetic energy of the vehicle moving.

[Driver72]

Originally Posted by ToothDoc

That's with no burnout and street tires too! 1.6x is insane! Totally NOT fair!!! LOL I don't buy into the drivetrain loss so much personally. I think it's more of a weight issue IMO. Sure there is 2x more stuff to move, but each stuff is moving only 1/2 the weight! About the only other issue is the additional rotational inertia but you can't count the tires or wheels because they're spinning also in 2wd. The rotational inertia of 2 additional CVDs, some gears and stuff is probably pretty low when compared to the overall kinetic energy of the vehicle moving.

Well, as stated, AWD usually loses about 4% more than RWD and 6% more than FWD
There is no disputing that AWD losses more in drivetrain losses than RWD, which loses a bit more than FWD.
That's been proven for decades, and through the law of physics.

This can easily be shown too simply by putting an extra 240 lbs into a 335i and do a rolling run (from 40-120) with a 335xi (this way, as long as the drivers are the same weight the weight of both cars would be the same). And rest assured, the 335i would still pull away. Not quite as quickly, but would still pull away a bit.

[ChuckBimmer]

Originally Posted by Driver72

Well, as stated, AWD usually loses about 4% more than RWD and 6% more than FWD
There is no disputing that AWD losses more in drivetrain losses than RWD, which loses a bit more than FWD.
That's been proven for decades, and through the law of physics.

This can easily be shown too simply by putting an extra 240 lbs into a 335i and do a rolling run (from 40-120) with a 335xi (this way, as long as the drivers are the same weight the weight of both cars would be the same). And rest assured, the 335i would still pull away. Not quite as quickly, but would still pull away a bit.

Man you are beating this thing to death.
By the way I have also owned a 2wd honda so I can compare it to a 335. Comparing a honda AWD to a BMW is ridiculous. Let return to the subject of of the OP. Thanks.

[Driver72]

Originally Posted by ChuckBimmer

Man you are beating this thing to death.
By the way I have also owned a 2wd honda so I can compare it to a 335. Comparing a honda AWD to a BMW is ridiculous. Let return to the subject of of the OP. Thanks.

Not really. When you have someone post that they don't think AWD has much of any more drivetrain loss than RWD, being such an inaccurate and uniformed idea, a clarification post is surely needed.
Not sure what owning a 2wd Honda has anything to do with a 335i or xi though?

[hotrod182]

i know that the sedan 335ia will pull off a 13.2x qtr mile. Even with a DA of 4691FT, the sedan ran a 13.465. Which would be a 13.1x at sea level.

Note: The Gtech is comparing two runs of the M3 smg vs two runs of the 335ia sedan.
The 335i is the green and blue results. You can tell the black and red lines are the M3 with the jagged SMG shift lines on the acceleration graph. This really empasizes the advantage a 335i steptronic trans has over a manual trans in the qtr mile. You can see the M3 was making more power here. But at the shift poings, you can see how the acceleration advantage is almost nullified right at the shift, and then the M3 has to build up an advantage again after the shift, showing the most gain in the long 3rd gear interval. So at slower speeds its the frantic shifting, high revving M3, against the torque rich, smooth shifting 335i. The 335i graph is fairly steady, with very mellow shift dips. The M3 is hard, slam you in the back style shifts, in the S6 launch control mode.

[94JZA80]

Originally Posted by ChuckBimmer

I agree with you the xi should be able to have faster 1/4 times. Even though the xi is ~200 lbs heavier it has the advantage because it can launch harder due to the better traction (4 wheels vs 1 wheel). Plus, the 60/40 split and transitioning to RWD at 100mph takes aways some of the drivetrain loss as it picks up speed. However, over 100mph I think there is a disadvantage but by this time the 1/4 mile is almost over. Just my 0.02 cents.

the key word is some - the 40/60 split drivetrain loss of the 335xi will be MUCH closer to that of a true 50/50 AWD system than it will be to a true RWD platform (or even a 25/75 split platform for that matter). so the 335xi's 40/60 split only helps marginally. that being said, i don't see how the 335xi's AWD launch advantage is going to more than offset its disadvantages (the extra weight and significantly greater drivetrain loss) in the 1/4 mile.

Originally Posted by ChuckBimmer

I agree with you that there is drivetrain loss and from 40mph to 100mph the "i" would be faster in a straight line. However, I am saying that xi has the "capability" for a faster 1/4 mile because of it's traction. Yes, xi traction is advantage is probably in the 1st 1/8 mile and this advantage is enough to be faster. BMW's awd is unique with a 60/40 split and transition into RWD at 100mph to reduce the drivetrain loss. This may be enough to have the advantage in the 1/4 mile??? Won't know until more testing is done. I really don't think there is much of an aerodynamic advantage in the 1/4 mile between them. That being said, I have yet to see faster trap speeds in the 1/4 from an xi (mainly tuned 335's).

but again, RWD doesn't happen until 100mph, at which point a stock or near-stock 335xi is already nearing the end of the quarter mile (i.e. it spent most of its run in AWD mode, so it therefore spent most of its run putting less power to the wheels than a 335i would have...AND it it had to lug an extra 250-lbs down the track).



i wholeheartedly agree with Driver72 on this one - a bone stock 335i/335xi in the high 12's is a pipe dream. on drag radials? sure...but that's no longer a stock 335. i've seen a bone stock Supra go 12.97 @ 108.xx. i've also seen a supposedly stock e46 M3 run a 12.9x @ 107.xx, but i cannot verify for sure that it was on the OEM tires (it could have been on drag radials or really sticky street tires). but on average they only run mid to low 13's - and that's with 105-108mph trap speeds, which is higher than any trap i've seen from a bone stock 335. now i'm sure alot of people are thinking "well, if e46 M3's typically go mid to low 13's, but dip into the high 12's once in a great while, then the 335 can do that too..." but again, look at the difference in trap speeds - even a slight difference in trap speed can mean a big difference in ET if you cut a good 60-ft.

[ChuckBimmer]

Originally Posted by 94JZA80

the key word is some - the 40/60 split drivetrain loss of the 335xi will be MUCH closer to that of a true 50/50 AWD system than it will be to a true RWD platform (or even a 25/75 split platform for that matter). so the 335xi's 40/60 split only helps marginally. that being said, i don't see how the 335xi's AWD launch advantage is going to more than offset its disadvantages (the extra weight and significantly greater drivetrain loss) in the 1/4 mile.




but again, RWD doesn't happen until 100mph, at which point a stock or near-stock 335xi is already nearing the end of the quarter mile (i.e. it spent most of its run in AWD mode, so it therefore spent most of its run putting less power to the wheels than a 335i would have...AND it it had to lug an extra 250-lbs down the track).

Boy, we can mentally masturbate this subject to death with no real conclusions. I am sorry to have brought this up causing this post to go into another topic. . If we are to continue this round about arguement we need to start a new post.

[BavarianBullet]

Originally Posted by Driver72

Not really. When you have someone post that they don't think AWD has much of any more drivetrain loss than RWD, being such an inaccurate and uniformed idea, a clarification post is surely needed.
Not sure what owning a 2wd Honda has anything to do with a 335i or xi though?

Considering no one, not even BMW, has released any concrete scientific numbers on a track or dyno showing what both models (i and xi) right off the assembly line will do on the same day, driver, conditions etc, what we're talking about is all theory and conjecture- by everyone..

The only thing not really in dispute is that the heavier car (335xi, 220 or 243lbs) has a disadvantage all other things being equal. But they're not equal and it's hard to compare across cars, drivers, weather, etc.

But I believe the proof is always in the pudding. Dynos may vary or not represent driving conditions etc but the 1/4mi does not lie. You mash the gas, pound some gears and in the end the result of what you brought and how you drive it will be printed on a piece of paper.

Get a few cars of each type to post their best 1/4mi times and the readers can do the math and come to their own conclusions. I don't want people to believe me, I just want them to contribute their time slips!

BB

[94JZA80]

Originally Posted by ChuckBimmer

Boy, we can mentally masturbate this subject to death with no real conclusions. I am sorry to have brought this up causing this post to go into another topic. . If we are to continue this round about arguement we need to start a new post.

c'mon now, the thread is asking about the quickest/fastest STOCK 335's to date, so i don't see how we're going off topic. besides, many people have already answered this question, all with 1/4 mile times in the mid to mid-low 13's, and traps not exceeding 105mph. and i know that, just b/c these are the average times and traps we're seeing doesn't necessarily mean that someone won't eventually come along and run a 12.9xx in his or her "stock" 335i/335xi. but the 335's have been out for quite a while now, so the evidence kinda speaks for itself - if a bone stock 335 were capable of running a sub 13-sec. 1/4 mile, we probably would have seen it already.

and i agree that there's no sense continuing a roundabout argument, but not b/c we've gone off topic...rather b/c we're all stubborn at heart and we're all going to believe whatever we want to believe - some here feel that we haven't seen the full potential of a stock 335 at the drag strip, and have given reasons for their beliefs. likewise, some of us here believe that if a stock 335 were capable of of high 12-sec. passes, it most likely would have happened already, and have also provided reasons for their beliefs. and i know this doesn't lead to any real conclusions, but i think that it is much easier to believe that the 335 is not capable of high 12's in stock form (based on the existing evidence to date) than it is to believe the opposite.

i know there is no way to prove that the 335xi's AWD launch advantage is enough to offset its additional weight and additional drivetrain loss without precision instruments and an unbiased test ground. i know there is no way to prove that the 335xi's AWD system is significantly or only marginally more efficient than the standard 50/50 split AWD system, again, without precision instruments. and so naturally some of us are bound to hypothesize one way or the other on these issues...and until someone does legitimately puts these issues to the test, i guess we'll have to agree to disagree.