Can someone red pill me on the various nuances of All Wheel Drive systems between manufacturers?

Pic related for the front diff+sump

Too bad that I6 is so long. If you just used a V6 like any sane person, that front diff would've been completely ahead of the sump.

Still, oen of the most superior AWD systems there is.

I've driven on snow for 6 months of the year all my life, and I have made up a pretty clear idea of whats gud and what isnt when it comes to AWD.

I love Audi, and will probably always stay with them. I also like VW, but there are a few things about AWD that cannot go unsaid. When it comes to 4motion and quattro with TorSen diff, theyre the best cars ive ever driven in terms of grip and power. A4's, A6's, A7's, A8's, passats < 05, theyre all great with the "real" quattro/4motion system.

Haldex isnt like "REALLY FUCKING BAD", but the fact that theyre FWD with AWD "when needed" is just not so great. It doesnt mean that its bad, because FWD is by far better than RWD when it comes to driving in slippery conditions. But those times when I've tried a haldex system in loads of snow and ice, it just shines through that this system is pretty weak. It kind of kills engine power, and the amount of time it takes the rear wheels to respond is too long from time to time.

TorSen diff AWD a best, Haldex not really a shit, but the whole FWD with AWD when needed stuff is pretty gay anyways.

Good luck spinning a V6 to 8,500rpm back in 1989 reliably enough for warranted sale and 600hp+ racing

Throwing a driveshaft through the sump works fine and lets you enjoy that delicious I6

>Good luck spinning a V6 to 8,500rpm back in 1989 reliably enough for warranted sale
The R32 (first sold in 1989) had an 8000RPM limit. The Z32 had a 7200RPM limit. Both produced 280hp in twinturbo form, warranty and all. RPM doesn't even amtter if you're making the same HP, and I don't think any manufacturer cares about HP after tuning.

>Delicious I6
Delicious understeed thanks to an extremely long engine, with the CoG in the wrong place, well over the front axle. Also, iron block, so even more weight in the wrong location.

>8000RPM limit
In factory road trim, in racing form they'd pull out to 8,500rpm.

The 300ZX also wasn't designed for racing like the 32, it didn't need stand up to the abuse that the RB was expected to.

RPM does matter because HP is torque x rev, more rev = more power and with 80s turbo tech a wider powerband.

Of course nissan cares about HP after tuning, the road cars had to be the same as the race versions, so the engine and drivetrain were built to take 500-600hp. Doing this reliably in the 80s and 90s meant you just couldn't do a V6, it's only now in the 00s that it's become viable, hence why the R35 is.

>Delicious understeed thanks to an extremely long engine
Length itself does nothing to handling
>CoG in the wrong place
Block is inline with the transmission and tunnel as in any other car, hence the cut out sump
>well over the front axle
Better than in front of it
>iron block, so even more weight in the wrong location
The absolute worst of the 32-34 GTRs were 55/45 before you factor in fuel and driver weight, this really isn't the end of the world. By the time you take a 33 vspec and put the battery in the boot you're talking 52/48 which means with the proper RWD with occasional AWD setup, essentially no understeer.

GTRs were always setup with slight oversteer tendencies and the 32 especially with it's slow updating computer for the front power was actually quite hektik

>The 300ZX also wasn't designed for racing
You've never heard of IMSA, have you?

>HP=torque*RPM
So with HP at 280 each, and the R32 making more RPM, it actually had less torque. Great.

>so the engine and drivetrain were built to take 500-600hp
See above. The IMSA V6's started out at 650hp, and by the end of their cycle were pumping out closer to 800.

>Length itself does nothing to handling
The longer an engine (in a front engined setup), given an idnetical firewall, the more weight it's going to put forward, and the more it'll tend to understeer. Understeer is abd for performance. Using your AWD system as a band aid for this problem isn't solving the problem.

>Block is inline with the transmission and tunnel as in any other car
So, given that same transmission position, it's CoG is about one an a half cilinder further forward compared to a V6. Pic related.

>Better than in front of it
Worse than behind it.

>52/48
So still ridiculously front heavy for a RWD-biased car. Most proper RWD racecars try and work towards a 40/60 distribution.

It lacks a proper locking differential for the front wheels in most cases. ATTESA also lacks a center differential contrary to what some people are saying. As a result in order to do anything between full 50/50 and 2/98 torque split you're going to be slipping clutches. If you're constantly in low traction instead of just occasionally skidding those clutches are going to get incredibly hot and fail if pushed too far.

If this sounds familiar, it's because the Focus RS has this exact same problem because in track conditions the car is constantly under steering and needs the rear wheels to kick in to correct it.

True 4WD cars are going to have three differentials that can be locked at will to minimize power loss and avoid heat generation from traction control schemes to deal with open differentials or slipping clutches to achieve a desired torque distribution.

ATTESA doesn't have a center diff. That's the reason why it's relatively efficient for road car use because you aren't constantly paying for the efficiency loss for AWD.

ATTESA has a transfercase with a wet multi plate clutch that determines how much power is sent to the front wheels. This is part of the transmission and is under the shifter for the R32-R34 GT-R and back under the rear seats for the R35 GT-R.

You can tell because there's no rear seat headroom in the R35 GT-R compared to the R32-R34 GT-R. Similarly, you can tell that the transmission tunnel is enormous on the R32-R34 GT-R because the floor pan is not flat like a traditional FWD or RWD car where the driver and passenger place their feet.

ATTESA is great for roadgoing vehicles that may see some snow but it's not going to be ideal for something like a Toyota Land Cruiser.

This is definitely not true either. I have books and actual wheel weights from SAU that all say that the R32 GT-R was 60/40. Nissan did a lot of heroics with the R33 with weight saving including relocating the battery to the trunk and making the car itself much longer than the R32 to drive the weight distribution to 55/45. For the R34 they still were dealing with an iron block I6 and were constrained by the need to reduce length and wheelbase so weight distribution remained at 55/45.

If you read some engineer interviews on the R34 GT-R in retrospect, they were disappointed that they could not make the car that they wanted. It was going to move to aluminum block at minimum, if not a V6 to try and truly resolve the weight distribution issues. The engine would also be pushed back to make it closer to a midship platform. Things like the brakes were also planned for upgrade but Nissan going near bankrupt in the late 90s meant they just used the R33's Brembos.

You can see a lot of these elements in the R35 for a reason. The weight distribution is 52/48.