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

[SUB-FT86]

Ryephile is on the money!!! Most sports cars are not 50/50 in balance. Hell even the cayman $ is rear bias and handles well.

[ydooby]

But isn't 50/50 the easiest to maintain a drift? Isn't drifting what made the original 86 famous? 50/50 may not be important at all for grip-driving, but is quite crucial for drifting, when it's mostly up to the car's natural balance to maintain the drift angle.

[old greg]

Originally Posted by ydooby

But isn't 50/50 the easiest to maintain a drift? Isn't drifting what made the original 86 famous?

You might want to look up the weight distribution of an AE86. And as has already been repeated ad nauseum, there's a lot to the way a car handles (sideways or not) than simple weight distribution.

[Ryephile]

Originally Posted by ydooby

But isn't 50/50 the easiest to maintain a drift?

No, you're oversimplifying. From my Google search it seems the AE86 had a 53/47 distribution, curiously identical to the leaked spec sheet. What's important are the wheel rates versus corner weights versus tire grip versus powertrain torque available. Of course, that ratio will change depending on application. With drifting, you want less grip and more powertrain torque in the rear end than the front proportional to the cars' weight distribution. Of course, Scandinavian flicks with huge e-brake levers and tons of driver experience helps compensate for any inadequacies the car setup may have.

[rmagic]

Originally Posted by Ryephile

Ok, so you think the spec sheet is erroneous? What grounds do you have that the torque peak is more or less than that? Are you just going off a hunch, or hope, that the peak BMEP is in the 190's "just cuz", or some assumption that there simply "must" be a noticeable delta between peak torque and peak power BMEP? I'm willing to believe you, but you're going to have to lay down something more concrete than "they did it back then with something else".

New engines are released all the time with lackluster specs despite new technology...just look at basically anything Honda has done lately. Also, discounting the ever-changing emissions regulations is at your peril, as it does make an impact to performanc



Seriously? Stop repeating what some advertisement told you. Are you saying that Ferrari, Lotus, and Porsche aren't "true sports cars"? They all have noticeably rear-biased weight distributions. That doesn't mean their polar moments aren't better [or worse] than a bloated new BMW that has a "magical" 50/50 distribution. Blurting out one spec isn't anywhere near the whole picture; go back and combine polar moments along with corner weights, CoG, fuel tank distribution, driver location, instant centers, and suspension geometries [i.e. camber curves, bump-steer, and anti-dive] to start to get a competent picture of how each car behaves. Any half-wit can get a car to balance out 50/50 static, it takes skill to make it actually handle and be communicative to the driver.

Racing for 20 years and I still read as much as I can, I think we should tell are opinion and not reply like 10 years old, I get your point . lotus or porsche or Ferrari they want the engine in the back thats how they want to design the car, mostly for Ultimate rear traction and every year with there newer car they push the engine closer to the center of the car or change to longer Wheelbase to achieve better Weight distribution. As I mentioned it doesn't mean the car will have a bad handling because of it .When you driving nissan 370z and Mazda Rx8 you will feel the difference , it doesn't mean 370z is slower car or it has bad handling or is not a sport car.

[Dimman]

Originally Posted by Ryephile

Ok, so you think the spec sheet is erroneous? What grounds do you have that the torque peak is more or less than that? Are you just going off a hunch, or hope, that the peak BMEP is in the 190's "just cuz", or some assumption that there simply "must" be a noticeable delta between peak torque and peak power BMEP? I'm willing to believe you, but you're going to have to lay down something more concrete than "they did it back then with something else".

New engines are released all the time with lackluster specs despite new technology...just look at basically anything Honda has done lately. Also, discounting the ever-changing emissions regulations is at your peril, as it does make an impact to performance.




Seriously? Stop repeating what some advertisement told you. Are you saying that Ferrari, Lotus, and Porsche aren't "true sports cars"? They all have noticeably rear-biased weight distributions. That doesn't mean their polar moments aren't better [or worse] than a bloated new BMW that has a "magical" 50/50 distribution. Blurting out one spec isn't anywhere near the whole picture; go back and combine polar moments along with corner weights, CoG, fuel tank distribution, driver location, instant centers, and suspension geometries [i.e. camber curves, bump-steer, and anti-dive] to start to get a competent picture of how each car behaves. Any half-wit can get a car to balance out 50/50 static, it takes skill to make it actually handle and be communicative to the driver.

I'm supporting it a bit with "they are doing it now with something similar (2GR)" as well as the fact that we're getting two different 'semi-official' numbers, and the fact that there are basically NO modern production engines that have that tiny spread. Of the two specs thrown out one is ~170 lb-ft the other is this 151 lb-ft, working with a semi-official CR of 12.5:1. With the LFA, they tossed around the 90% of peak torque from X to Y rpm.

What I'm trying to piece together is how these figures came about, in the sense that C&D probably didn't pick 170 lb-ft out of their ass. But neither is TMC/FHI going to be 100% up-front with info until release. But they are probably not going to out-right lie to the journalists. Maybe they said "Around 170 lb-ft peak torque." Maybe someone working on the brochure asked about torque and some smart-ass engineer said 151 lb-ft @ 6600 rpm. Not lying, but not the whole truth. So maybe peak is 168 lb-ft and it still makes 90% of peak at 6600 rpm (151 lb-ft).

These are hype-driven leaks, but to remain somewhat secret, the facts have to be obscured. But they can't outright lie.

[Kostamojen]

Originally Posted by Dimman

With the short, rear-mounted H4 instead of the long iron L6, they needed to fight to get the distribution to 53/47 with a light hood and rearward battery?

Something isn't adding up...

The entire drivetrain minus the rear diff and prop shaft are well in front of the middle of the car:



Plus, the front suspension/subframe is heavier than the rear suspension/subframe. Even with the battery being movied and engine being moved, its not enough to get that much weight farther back in the car.

Subarus with the AWD you only have to add the weight of the front diff and axles (only about 50lbs total) along with the small change in engine location to compare how the weight distribution of this car works out.

Getting this chassis to 50/50 would require ADDING weight to the rear, not worth it.

[Matador]

Originally Posted by Kostamojen

Getting this chassis to 50/50 would require a rear transaxle

[Kostamojen]

A rear mounted transmission would have been awesome!

But the price for the car would have skyrocketed

[Neutral_Eyes]

Reading this makes me feel bad about wanting to modify their car after putting so much work into it.

[rmagic]

Does anyone know about the weight of the engine?

[old greg]

Originally Posted by Kostamojen

Getting this chassis to 50/50 would require ADDING weight to the rear, not worth it.

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.

Originally Posted by rmagic

Does anyone know about the weight of the engine?

Expect the longblock (ie: without flywheel, manifolds or accessories) to weigh ~200 lbs based on the weight of DOHC EJ longblocks.

[rmagic]

Expect the longblock (ie: without flywheel, manifolds or accessories) to weigh ~200 lbs based on the weight of DOHC EJ longblocks.[/QUOTE]



Thanks , so it is a light weight engine. It is possible they couldn't get the engine back as far as they want to because of the width of it.

[old greg]

Originally Posted by rmagic

Thanks , so it is a light weight engine. It is possible they couldn't get the engine back as far as they want to because of the width of it.

It's possible, there were probably some clearance issues with the steering column and rack. But for all we know the engine might be right up against the firewall. We won't know for sure until someone leaks a much better underhood shot than what we've seen so far.