AWD FT-86 Diagram
 

When the whole AWD debate was raging over at Nasioc, I made this diagram to show that AWD really was feasible for the FT-86. I recently watched Ultimate Factories Lamborghini this weekend and saw a clear view on exactly how they do AWD. Surprisingly, I was exactly right :) On the Lambo, the secondary drive shaft runs parallel to the crank, attached directly to the block. The rear diff is also attached directly to the block. For a Subaru motor, the secondary shaft would have to be offset, prolly to the bottom right or left of the crank.

http://lh6.ggpht.com/_Lsykl2SA2ts/TQ...WD%20FT-86.jpg

This image is just for your enjoyment. I don't expect it to ever be a reality for this car. Enjoy!

Further indulging: so if Porsche ever wanted to make an AWD Cayman, as is available in Forza, would it be in a layout like this?

We had this debate long time ago... bout 2 months ago? Yeah, we had that example along w Legacy B4 racing setup, Skyline setup, & how boxer engine was small enough so just move the engine bit more forward & it's possible.

Thanks for the diagram

Yeah, saw the discussion but didn't see any pixels. I like pixels.

true, it's nice to seen it w a pic

the Legacy B4 GT300 has a drivetrain similar to your diagram.

http://www.subaru-msm.com/global/sgt2009/machine.html

http://www.subaru-msm.com/global/sgt...gs/09015_2.jpg
http://jonsibal.com/bpimages/subB4_2.jpg

yup, and it's been posted at least 3 times before.

Loving that exterior shot of the Legacy though :w00t:

I don't think the problem is whether or not they can do it but, rather, do it and keep a $20-$25k price tag.

:sigh: probably get closer to 30k if AWD

The thing is this needs to sit 4 adults, if anything Toyota said is true... So having it awd means engine can't be behind the axle, or the wheelbase needs to become longer

wait what?

If it was Subaru FT STI come w AWD system over 300hp/300tq for over $30k, I think, no one gonna complain. I for one won't

4 adults? Where did you read that tiny little detail?


The AWD controversy was played out very thoroughly here. The problem with AWD in the FT-86 is the solutions aren't cheap. Not that they are impossible.

An unfortunate bump #3. I bet this car has AWD of this thread's design, a reverse Lambo style. Its so so believably hideous looking.

Official video of the new Ferrari FF

http://blogs.cars.com/.a/6a00d83451b...61b9970c-800wi

awd would be nice for the winter but there are many downfalls to it. price for one, second increased weight, third engine closer to the front inducing more understeer, bigger turning ratio, less steering feedback. also 2wd is enough to put down 260hp/260ftlbs

i hope toyota can give me AWD under 15k
i will pray for a new material.
:slap:

All wheel drive is better than half wheel drive all the time. Just like brakes on all of your wheels is better than brakes on half of your wheels. One could argue that the weight, expense, complexity, etc...of rear brakes isn't worth it because front brakes do most of the work. If a person made that argument about brakes they'd get laughed at. But the two things are the same...apples to apples.

Subaru could easily modify the oilpan so that a driveshaft could go right up the middle to a front mounted diff. If you look at the way they mount the new engines, it would be a cinch. They moved away from a firewall mounted pitch rod to a mount on the front of the engine. The Lambo has an offset rear diff, but that allows them to mount the engine lower. A Subaru boxer has to sit up high because the exhaust ports point straight down.

Now, if Subaru went to a head design like Ford's latest diesel engine and made it a dry sump...they could drop the whole thing about SIX INCHES. Oh, and the turbo would sit right on top of the engine for perfect oiling, perfect exhaust port balance, perfect intake route, perfect downpipe route, and easy maintenance. My 2 cents.

^ The argument about 2 brakes is completely wrong. If you only had two (front) brakes, every time you applied the brakes in ANY sort of hurry, the rear of the car would flick around and you would spin out. The same cannot be said about 2WD. If the brakes were on the rear, all of the weight would transfer to the front of the car under braking and you would lose a lot of braking power (meaning it would be more dangerous).

I completely agree with people that say FWD is inferior compared to both RWD and AWD - making the front tyres do all of the work is about the worst possible way you could design any sort of performance car. RWD doesn't follow this suit, as it (almost fully) evens the load between front (turning) and rear (applying power) tyres - i.e. it's about as close to perfect as possible. AWD IMO is *just* worse than RWD, UNLESS you have some sort of system like the GTR's where torque is only distributed to the front tyres when they start to lose traction. AWD is less efficient, has more drivetrain power loss and adds more weight, NONE of which are good for a performance car.

The ONLY exception to that, IMO, is when the car has too much power that it is uncontrollable in normal conditions (unheard of in a $20K production car) and is trying to apply that to either, or both, sets of wheels. Then driver skill comes in just as much as a good car setup or AWD system.

You fail to realize no matter how much you bitch and moan, this car is going to debut rwd. You also fail to realize that the setup you are talking about is Expensive, and will not happen in a car at this proposed price point.

are you drunk? AWD is only superior to RWD in low-grip conditions, all else equal. also, brakes are EXTREMELY simple and cheap compared to drivetrain components.

the part about the brakes is sort of right. agree about the AWD part.

yes. mo diffs = mo money = mo problems. :iono:

I wanted to go there, but I'm off today, and enjoying some Guinness, so thanks for picking up the slack.

:bellyroll:

:happy0180:

I think AWD is better for high-powered applications, which is why the GT-R is so quick in spite of its weight. The main perks are that you can step on the gas quicker on corner exit, better launching. It's not only about front vs rear, either. The GT-R's Attesa ET-S can distribute torque left and right as well.

That said, for a 200-ish horsepower car I think the disadvantages of AWD outweigh RWD--that is, weight and drivetrain loss.

My understanding is that the highest possible cornering speed is achieved with somewhere around 5% of torque going to the front wheels. However the weight required is more of a handling penalty than the extra torque is a benefit. This is from an all-out circuit racing point of view. MR is still the best.

Well I think that... they are both good. A front engine AWD car driven spiritedly over twisty back roads takes a handful of different skills compared to a mid engine RWD car. The FT-86 as AWD would behave similar to RWD due to weight distribution. The only absolute benefit it would have of AWD would be for crazy high HP situations, or the few who drive this type of car in cold/wet climates.

An AWD FT-86 equipped with snows in the winter could be ferociously fast and fun, but it would take an extra handful of skill to compensate for the lack of weight and therefor grip over the front axle on slower maneuvers. The weight imbalance is what gives Subaru's their unmatched grip in harsh conditions, much like the superior grip a 911 has under acceleration on dry tarmac.

Want to try mid AWD for yourself? Check out the McRae R4 in the game Dirt, which you will have to manually set up its settings for tarmac.

So in case Toyota is reading, here is what I want to see: just like the AWD Celica, the FT-86 needs a motorsport only AWD version, all the trimmings, gutted with quick rack and the like. I would absolutely love to have one of those in my garage.

Weight imbalance also makes them a bit 'pushy'.

In circuit racing MR is dominant mainly because AWD is banned in all the significant racing venues. Formula One, LeMans, you name it.

JGTC (now Super GT) had AWD, but it got banned because the GT-R was far too dominant. I think that speaks volumes as far as its viability in circuit racing. As for being pushy, yeah they usually want to understeer.

For drivetrain layout, don't forget mid-engine AWD a la the Lambos =)

Keep it relevant, track junkies, this is a street car remember ;)

Cars only understeer when they run out of front grip before the rear, simple as that. Even RWD cars will push unless the driver uses technique to ensure the center of weight and grip is properly balanced for-aft as needed for the situation.

Properly weight balanced and with the proper driver, AWD will have no impact on how a car handles. It only affects what is in its name, power delivery.

in theory, the ultimate track car is the Red Bull X2010 in GT5. it's MR. so there. :respekt:

Myth.

I don't want to get into the awd/rwd argument... but speed is about grip. Making the tyres work to their full potential. And yes, the reason why F1 dosn't use awd is because it was banned. Actually surprised that Newey didn't design a MAWD X1, maybe it slipped him. Perhaps the KERS also drives the front wheels?

Anyway, for the intent and purpose of the FT-86, awd is useless. A GT4 spec honestly, would be welcome, but you know you get what you pay for, so expect it to cost a pretty penny were it to happen.

Toyota 86 GT4, i like the sound of that, wouldnt mind forking over the extra coin either

Current mechanical and aero grip levels are such that they are faster RWD than they could be AWD with the extra weight. They would need to chop the tires in half or double the power on the F1 cars before an AWD system would be competitive.

And yeah, there weren't any AWD AE86's...

AWD = http://xa7.xanga.com/3cec61246933219...z149070958.jpg

One wheel drive? Like your Tacoma with open diffs all around?
:D :D :D

who said anything about open diffs?? ;)

the proper interpretation is "AWD = training wheels" :happy0180:

I mixed up the acronyms, but it's no myth. The JTC became the JGTC after FIA changed its rules/regulations for Group A. With the debut of the R32 in 1990, it dominated, with all six cars taking the top six positions. It dominated to the point where they became a one-make race. Toyota tried firing back with a Supra, then three Corollas before giving up. Diversity only came into the picture after FIA changed the regulations and banned AWD. Don't think it's coincidence.

Think you're overstating the significance of weight. In Group A back in the day they packed 200 lbs+ more weight of ballasts, still didn't bridge the gap between AWD and RWD. If weight were such an insurmountable obstacle, why would they need to ban AWD?

Oh and KERS only goes to the rear wheels. It's part of the reason why teams were ambivalent about it, because that weight was at expense of ballasts to the front to even out the weight distribution.

I'm not a fanboy of AWD, just want to counter the notion that it's only good for handling in the snow and wet.

AWD has its place, but it should be clear at this point that both the FT86 and its Subaru counterpart (216a or whatever it's going by nowadays) are going to be RWD only. i think we can all agree on that, yes?

i agree

Yes, and I as I said before at lower HP and a lower pricepoint AWD just doesn't make sense =) Have no objections with the Suby being RWD.

i just love it when we all get along. :happy0180:

You don't have the whole picture. AWD wasn't the only factor in the GT-R's dominance. It saddens me to admit that the R32 GT-R is a VASTLY superior car to the MA70 Supra that was its competition in the day. Plus there were assorted other homologation rules.

Without knowing the whole rules, someone could make the ridiculous assumption that diesel makes for the best sports cars because Audi's won LeMans about a billion times in a row with diesel cars...

There are many race series that penalize winning teams with ballast to create parity. But even with it stacking up, the best teams will still win. It's quite possible that in addition to being a better starting platform, the Nissan team was better and more organized, with better drivers, pit crew, etc... And AWD was a good excuse for the other teams to complain about, instead of spending more money or working harder.

Weight isn't the only thing. It's also about how a tire generates grip laterally. Or how that is distributed through all four wheels when cornering. Maximum theoretical lateral grip overall is generated with something like less than 5% of torque going to the fronts, which are also steering the car. If AWD were allowed next year in F1, it would not be competitive. These guys aren't just hammering on the brakes, changing direction, and feathering the throttle to prevent wheelspin on exit. They are maintaining the momentum of their cars through the corners with the tires. AWD is great for going when traction is limited, but it negatively affects turning and lateral grip, which is more important for overall speed.

The KERS example is interesting. It applies to AWD as well. In the KERS example, teams opted to not use it even though it gave a power/passing advantage due to the weight/balance penalty. The same would be true of an AWD system in F1. The minor potential increase in cornering ability from the extra front wheel torque would be much more offset by the weight/balance penalty, potential aero complications, power losses, etc...

I will post up some quotes from a Racecar Engineering magazine article if I can find it...

The absolute fact is that MR drivetrains are the best for all-out on track performance. So long as there is sufficient traction. (as of modern times, demonstrated by trying to slow the cars down by messing with the tires, that is not a problem)

Anyways, I was an early proponent of the fact that the Subaru wouldn't be AWD, not for any other reason than that they stated they wanted to put then engine a bit more towards the center of the car, which precluded Subaru's standard AWD system. Plus, while possible, it was extremely unlikely that they would engineer a completely different AWD system just for one supposedly inexpensive (through shared development) car.

Enjoy the RWD with its centralized engine and sharp turn-in everybody!

So now that we have come this far knowing about the car, we know it will not be AWD. People on the Subaru forums are still hoping for it.

The question is now, why is the motor so far forward compared to my prediction? I really expected it to be more like this:

http://www.s2ki.com/s2000/uploads/ga.../phpsrFLDh.gif

Is it because the Subaru block is so wide, it cuts into your foot room? What other corners did they cut to make it 50/50 weight distribution with the block completely on the front axle still?

http://www.ft86club.com/forums/attac...4&d=1320902199