[300hp]

Originally Posted by Jamesons Viggen

We are talking about two different things. I will clarify below.

Not to be rude, but this is not very debatable like we seem to make every Xdrive vs RWD topic.

I am not talking about benefit or not at any other time then from a dig.

Fact is, like I said, identical cars, but one carrying 150lbs more weight is simply not going to be faster than the other. It's just not. It only changes when traction is added which is what xDrive brings to the table.

The other fact is, the magazine tests that some of you live and die by, they don't own these cars, they are perfectly happy to abuse them in order to get good numbers.

A small amount of wheelspin is a good thing, we are talking about 328/428s here(not 335's here JDong-where traction of the RWD model is more of an issue). RWD 328/428 cars don't sit there and smoke em endlessly. So if you are going to out launch one in xDrive, to take advantage of the added traction you need more revs.

300hp, you kind of said it yourself. You can easily, with your brain turned off get a 5 second 0-60. Yes. But again, we are talking about those jaw dropping magazine times. The 4.4 with PPK. THOSE times, to get every last shred of advantage from the launch. That is what I am talking about. Those are more abusive than a RWD launch as they require more revs. I have a few hundred 1/4 mile launches. RWD cars like mind, you need about 2500rpms tops to get out of the whole. AWD, you need quite a bit more to make a real advantage out of a well launched RWD car, something like an EVO or WRX for example often require about 5k rpms.

Again, this is not hypothesis or some debate. It's facts and physics. Fact is, Turbo+AWD in the real world, very easy to bog the launch when not given enough revs. This made racing EVOs and WRXs on the street fun when kids thought they could get 0-60 in 5 seconds like the mags but with a 2500rpm launch.

Here is a recent example:

"
"And so, here’s how we hit 60 mph in 4.8 seconds: We held the engine at the 6700-rpm redline, jumped off the clutch, shifted out of first at about 5300 rpm, and held on to second until the car hit the redline in second at 61 mph. To get down to a repeatable 4.8-second time, we subjected the WRX to this mechanical mayhem 14 times. To its credit, it didn’t utter a peep of discontent. The clutch didn’t slip, no driveshafts turned into fusilli, and the six-speed ’box shifted and responded exactly as it did when we started. Will you try this with your new WRX? We doubt it. We doubt it. And if instead you just ease off the line, your times will likely be somewhere closer to our 6.3-second rolling-start 5-to-60-mph figure."
"

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Now let's be clear before 300hp comes back with some kind of magazine article or defensive post on xDrive. If anything, I am pointing out the benefit of xDrive...TRACTION, and mostly at launch. My point is, there is technique to exploit that benefit and if not used, then the benefit is marginal.

I think if you are discussing manual transmission cars then you are spot on. You need to abuse the clutch to get the best out of the engine with both rwd and awd.

I am discussing the transmission that gets the most out of each available horse the engine has on offer, that's an automatic transmission paired with xdrive.

And yes MT has their discussion of how they launch the car, 2000rpm let go of brakes and boom, 4.6 to 60 with the AT and rwd. No abuse there. Same with xdrive paired with the AT, I am sure those with launch control can confirm this.

So I think we are both right but we are just discussing two different transmissions that each of us prefers

[300hp]

Originally Posted by jdong

If your pavement is not perfect (e.g. too wet, too cold, etc), you WILL lose traction during a WOT launch on a RWD or FWD car. I had this happen all the freaking time in my AH3. Even on 1->2 shifts on highway onramps when hitting bumps.

You can either upgrade to track quality ultra high performance tires, or you can attempt to turn off ASR/DSC so that your car does not attempt to avoid wheelspin, which is wasteful on your tires and makes a scene out of aggressive takeoffs.

A 150lb weight increase (e.g. 3% of the curb weight) is not as catastrophic a handicap as you make it out to be. The technique you quoted is virtually how EVERY magazine does their launch tests -- AWD or RWD. The manufacturer supplied number is a more accurate estimate of the car's non-brake-torqued / non-launch-controlled 0-60.

The only "exploitation" here is that AWD in a sports sedan application will consistently shave off tenths of seconds due to recuperating the valuable time lost by wheelspin. And that's something that easily overcomes the marginal weight gain of such systems.

Does this apply to the N20? Probably not as much as to a more powerful BMW. It's a relatively low power low torque engine. It will likely matter if you live in a climate where you choose to have all-season tires rather than the max performance compound optimized to your climate.

+100000000

Agree with this. Manual transmissions need to be a abused to get the most off the line, doesn't matter if it's rwd or awd.

We have already established that the weight difference of awd and rwd is equivalent to a tank of gas. It's negligible at best and it's now a known fact that the traction advantage offered by xdrive far outweighs the incremental weight through the 1/4.

This is not an attempt to justify xdrive but it's far more important to get the facts right.

[Jamesons Viggen]

Originally Posted by 300hp

I think if you are discussing manual transmission cars then you are spot on. You need to abuse the clutch to get the best out of the engine with both rwd and awd.

I am discussing the transmission that gets the most out of each available horse the engine has on offer, that's an automatic transmission paired with xdrive.

And yes MT has their discussion of how they launch the car, 2000rpm let go of brakes and boom, 4.6 to 60 with the AT and rwd. No abuse there. Same with xdrive paired with the AT, I am sure those with launch control can confirm this.

So I think we are both right but we are just discussing two different transmissions that each of us prefers

Originally Posted by 300hp

+100000000

Agree with this. Manual transmissions need to be a abused to get the most off the line, doesn't matter if it's rwd or awd.

We have already established that the weight difference of awd and rwd is equivalent to a tank of gas. It's negligible at best and it's now a known fact that the traction advantage offered by xdrive far outweighs the incremental weight through the 1/4.

This is not an attempt to justify xdrive but it's far more important to get the facts right.

Magazines typically abuse an auto trans too

It's called brake overlap or brake torquing.

I do it all the time in the wife's AWD auto when I want to burn someone from the light. I load the tq convertor to 2800rpms and I am GONE.

Now granted, you are allowed less control, less freedom with an auto on how much revs it will hold and it is surely more damaging and leads to higher cost repairs than replacing the clutch on a manual. Never said it was good to do lol. But every now and then, it sure is fun.

[300hp]

Originally Posted by Jamesons Viggen

Magazines typically abuse an auto trans too

It's called brake overlap or brake torquing.

I do it all the time in the wife's AWD auto when I want to burn someone from the light. I load the tq convertor to 2800rpms and I am GONE.

Now granted, you are allowed less control, less freedom with an auto on how much revs it will hold and it is surely more damaging and leads to higher cost repairs than replacing the clutch on a manual. Never said it was good to do lol. But every now and then, it sure is fun.

The things you are not supposed to do are what makes life fun