New FR-S BRZ Technology Info! Engine specs, CoG, Drag Coefficient, Dimensions, etc.

[Marrk]

Originally Posted by Kostamojen

After all this talk of designing the car with the engine "low and to the rear," it looks like the engine is on top of the front axle. I would call that "ridiculous," not "revolutionary."

But maybe the car handles well despite this.

[Kostamojen]

Originally Posted by Marrk

After all this talk of designing the car with the engine "low and to the rear," it looks like the engine is on top of the front axle. I would call that "ridiculous," not "revolutionary."

But maybe the car handles well despite this.

Its not revolutionary, just common sense.

I just put this together to illustrate the change in engine location:



I also made this photo awhile ago as a drivetrain/suspension comparison photo, as it shows it even better along with how the suspension layout is the same:



(Yes, I know I stretched the FT/FRS/BRZ out a bit to the wrong size, but the point was to match up the suspension components)

[Marrk]

Thanks for the illustration, Kost'.


I'm sure we have all seen "front-mid-engne" cars with the engine placed fully aft of the front axle. I think I was hoping to see this on the FT-86.

[switchlanez]

Originally Posted by Kostamojen

A rear mounted transmission would have been awesome!

But the price for the car would have skyrocketed

Front-mounted tranny for RWD is news to me (always changed tranny oil at the rear of my FR/MR cars). What are the pros and cons of a front-mounted vs. rear-mounted RWD transmission?

[Kostamojen]

Originally Posted by switchlanez

Front-mounted tranny for RWD is news to me (always changed tranny oil at the rear of my FR/MR cars). What are the pros and cons of a front-mounted vs. rear-mounted RWD transmission?

What, do you only work on Ferrari's for a living? LOL! j/k

Its rare to have the transmission completely located in the rear, there is a short list on Wikipedia of Front engine, RWD cars with rear mounted transaxles: http://en.wikipedia.org/wiki/Transaxle

Most RWD cars have the transmission up front with the engine, and a differential in the rear.

But in the case of this Subaru/Toyota venture, they already had a drivetrain layout that would work fine for RWD, there was no need to invent an entirely new drivetrain. All they did was get a transmission that deleted the front differential and center differential from Subaru's All-wheel drivetrain and kept the rest.

I figured this was all common knowledge though... Guess there aren't too many Subaru folks here.

Originally Posted by Marrk

I'm sure we have all seen "front-mid-engine" cars with the engine placed fully aft of the front axle. I think I was hoping to see this on the FT-86.

One of the reasons a boxer motor can't go any farther back is due to the width of the motor. It would completely intrude on footwell space if it moved any farther back, and the car would have to be a 2 seater with a really long hood to accommodate it.

Thats kind of what I hoped for from the start, but they kept a lot of practicality with this car in place and didn't move it that far back.

[Matador]

Originally Posted by switchlanez

Front-mounted tranny for RWD is news to me (always changed tranny oil at the rear of my FR/MR cars). What are the pros and cons of a front-mounted vs. rear-mounted RWD transmission?

......

Originally Posted by old greg

Or just moving the front and rear wheels forward by 3 inches. The car would have been 50/50 if the powers that be had wanted it that way, with no fancy transmissions or BMW-esque tomfoolery required.

And to go along with that a healthy increase in weight, if you wanna keep the same proportions that it....

[Marrk]

Originally Posted by switchlanez

Front-mounted tranny for RWD is news to me (always changed tranny oil at the rear of my FR/MR cars). What are the pros and cons of a front-mounted vs. rear-mounted RWD transmission?

I can't think of any reason to move it to the rear except to achieve a better total weight distribution in a front-engine car. My 944S2 had the tranny (transaxle, I guess we must say) in the rear.

[Marrk]

Originally Posted by Kostamojen

One of the reasons a boxer motor can't go any farther back is due to the width of the motor. It would completely intrude on footwell space if it moved any farther back, and the car would have to be a 2 seater with a really long hood to accommodate it.

Thats kind of what I hoped for from the start, but they kept a lot of practicality with this car in place and didn't move it that far back.

Yeah. I think I was accustomed to thinking in terms of two-seaters. My bad.

[Ryephile]

I know it's way off topic, but there are at least a couple front engine/rear transaxle setups out there; the Nissan GT-R and Corvette being the first to come to mind. The benefit of moving the trans to the rear means you can move the engine closer to the middle of the car. The total polar moment of inertia may or may not be improved, but the weight distribution is definitely pushed rearward. It certainly allows for shorter overhangs and/or more room for aerodynamic refinement, since all the powertrain is within the wheelbase.

-->Kostamojen: Very cool comparison drawings! It's cool to see the engine in the FT-86 is almost a full engine-width rearward, and noticeably lower. The struts being so much shorter on the FT-86 does have me concerned about total suspension stroke, but we'll have to wait and measure when it hits the streets.

[ForReal-Someday]

Thank you for the comparison photos. Has anyone discussed the caster angle that this car has. You can see in this comparison that it is quite aggressive compared to the forester. Doesn't caster angle create more camber when the wheels are turned? Did they do this to offset the camber loss that is associated with strut type suspension when it is under compression? Do I even know what I'm talking about?

[old greg]

Originally Posted by ForReal-Someday

Do I even know what I'm talking about?

You seem to.

From the side view it doesn't look like there's any more caster than the Forester, if anything it looks like there's less. Caster does create camber when the wheels are turned (positive camber on the inside tire, negative on the outside). More isn't always better though, in fact too much caster is just as bad as not enough. How much is enough depends on a lot of things, like what tires you're using, KPI angle, roll stiffness, camber curve, static alignment, Ackerman, where you're driving, etc. The other neat thing caster does is it causes increased lateral load transfer (less grip) in the rear, and decreased lateral load transfer (more grip) in the front.

[Matador]

Originally Posted by Ryephile

I know it's way off topic, but there are at least a couple front engine/rear transaxle setups out there; the Nissan GT-R and Corvette being the first to come to mind. The benefit of moving the trans to the rear means you can move the engine closer to the middle of the car. The total polar moment of inertia may or may not be improved, but the weight distribution is definitely pushed rearward. It certainly allows for shorter overhangs and/or more room for aerodynamic refinement, since all the powertrain is within the wheelbase.

LFA, Benz SLS, Ferrari 599 (I think), Most front engined Porsches, Alfas... the list goes on.

[Dimman]

With regards to the weight distribution being the same as my old Supra (prior to lightening) I think I see where I'm making a mistake.

Even if the the FT86 has the same 53/47, the weight is more centralized, so the polar moment of inertia will be much less.

My bad.

[Cessblood]

Originally Posted by ryridesmotox

only time will tell if this motor will be able to handle extra power well... .

It better handle extra power and abuse cause Toyota and Subaru made the FT86/FRS/BRZ for tuners. They know some owners will want to take the path of boosting and some other owners will take the path of all motor. I'm one of the future owners that want to boost this baby. Boosting is like a drug to me. I'm hooked lol. Anyway if it's fun to drive, imagine how fun it will be to drive with a turbocharger in the engine bay. With the high C.R. it's going to be kind of hard to boost this baby safely.