What makes the Boxer engine so special

[DEnd]

Originally Posted by fatoni

im not really sold on that. i guess well see if they make a frs vert if they are still flaunting the cog. convertibles are usually heavier and all that weight is still well above the cog. if you put a steel roof on the frs the cog would go up quite a bit too.

Weight at the extreme ends has a large effect on the center of gravity. 5 lbs 3 feet from the COG has a larger effect than 10 lbs 2 inches from it. So while a convertible may be heavier than a coupe it can still have a lower COG. This may not always be the case, but it is well within the realm of possibility, especially with the first gen Miata. Given how floppy that chassis is I'm not sure a coupe would even be much lighter.

[Deslock]

Originally Posted by fatoni

the cog of the frs is impressive but its no where near groundbreaking. im pretty sure the c4 vette had a cog of about 14 inches. to this day im still pretty sure its lower than the frs.

I'm not sure if anyone claimed that the FT86's low COG was groundbreaking, but it's still exceptional, especially for a modern and reasonably priced car. And part of the reason for that is the boxer.

From what I've read the COG in the 1990 Miata was around 17", and the C4 was around 14-15".

The 1990 Miata was tiny and came with a 1.6L engine.

The C4 was in an entirely different class. Going by inflation, it'd start at ~$56k today... it was more than double the average price of a new car between 1984 and 1996, while both the FRS and BRZ are less than the average price of a new car.

Neither the NA nor the C4 would pass today's crash test standards.

Not that a boxer isn't without its disadvantages (no wishbone suspension in the front, for instance).

[fatoni]

Originally Posted by Deslock

I'm not sure if anyone claimed that the FT86's low COG was groundbreaking, but it's still exceptional, especially for a modern and reasonably priced car. And part of the reason for that is the boxer.

From what I've read the COG in the 1990 Miata was around 17", and the C4 was around 14-15".

The 1990 Miata was tiny and came with a 1.6L engine.

The C4 was in an entirely different class. Going by inflation, it'd start at ~$56k today... it was more than double the average price of a new car between 1984 and 1996, while both the FRS and BRZ are less than the average price of a new car.

Neither the NA nor the C4 would pass today's crash test standards.

Not that a boxer isn't without its disadvantages (no wishbone suspension in the front, for instance).

nobody is claiming that its groundbreaking but you have to admit, many people act like it.

that little 1.6 engine you speak of is heavier than the motor in the frs. you dont gain more than 200 lbs when you do an lsx swap and a significant portion of that is spent on the transmission, diff, axles, brakes etc. my point is that that motor is a tank so considering how little weight there is in the car, it would represent a larger percent of the overall mass and raise the cog. it just doesnt.

im not going to argue the crash standard or price. youre right. im just saying that its been done without a boxer motor.

either way cog is not nearly as important as the distance from cog to roll axis but i guess that neither here nor there.

[Kunzite]

Originally Posted by jmaryt

correct,however nothing special,as this type of engine has been around
for a long,long,time! of note: (b.m.w.)motorcycles. (o.m.c.) snowmobiles
all horizontally opposed designs,and of course the "german" flat six,which is
the original "boxer" design.

No, it's not (unless Karl Benz' design was a flat six, which I doubt).
Afaik Tatra, Citroen, VW were using flat engines, before Porsche.

[Deslock]

Originally Posted by fatoni

nobody is claiming that its groundbreaking but you have to admit, many people act like it.

Not that I've noticed in this thread, or in the blogpost it's about.

• Is the boxer the only reason the FT86's CoG is low? No, the car's small size, shape, and low roofline also contribute
• Does the boxer make it easier to design a car with a lower CoG? Yes
• Was that done with this car? Yes
• Is it exceptionally low? Yes, especially for a modern car
• Would the FT86 have had such a low CoG with a 2L I4, all else being equal? Probably not

Originally Posted by fatoni

that little 1.6 engine you speak of is heavier than the motor in the frs. you dont gain more than 200 lbs when you do an lsx swap and a significant portion of that is spent on the transmission, diff, axles, brakes etc.

I owned a '99 NB. Loved that car. But as you pointed out, Mazda's 1.6L (and 1.8L) are heavy, as are the Miata/RX7 trannies, which is one of the reasons a LSx/T56 swap is so popular.

Originally Posted by fatoni

my point is that that motor is a tank so considering how little weight there is in the car, it would represent a larger percent of the overall mass and raise the cog. it just doesnt.

The NA CoG was very low partly because the car was tiny, and was designed in the 1980s (when collision standards were very different). Putting it another way, you wrote:

Originally Posted by fatoni

i never once said anything bad about the frs in this post. i just said that a boxer engine does not mean lower cog for the car.

I'm as cynical as the next guy, but I doubt that the Subaru and Toyota marketing departments got all those engineers to make up BS about the boxer being used to attain a lower CoG.

[Eurasianman]

In regards to the talk about the convertible FR-S. Take a look at the convertible Camaro. I have not read a whole lot, but from what I have read, it handles a lot better than the coupe Camaro. Just thought I would throw that out there.

[DarkSunrise]

Originally Posted by fatoni

thats not what at all what i was saying. i never once said anything bad about the frs in this post. i just said that a boxer engine does not mean lower cog for the car. then you called me out for having an inline motor (in a car which happens to have a lower cog than the frs). i guess my point is that other than aesthetics, which are subjective, there really isnt anything special about boxers. they have pros and cons just like every other configuration we know of.

Actually that's exactly what it means.

[Mr 286]

Originally Posted by Dimman

It had everything to do with money. Toyota had nothing close to longitudinal motor that was suitable. Subaru did. Subaru had pretty much the whole suspension and brakes too. As well allowing the Toyota board to see the project as 'safer' and cheaper by splitting the risk. Seeing the mounting differences between the L6s and this H4 show that the platform may not be as 'purpose built' as people seem to think.

However they did a fantastic job on the car. This is neither 'because of' nor 'in spite of' the boxer motor. It was the most cost effective solution, but also much more identifiable as a Subaru engine, so they are hyping the shit out of its properties to make it look like Toyota was a bit more in control (however they did do some behind the scenes un-fucking of the motor, beyond just the D4-S).

That's it. Toyota hasn't made a flat motor in what, 50 or 60 years?

@Mr 286 Displacement rules probably played a role, but as you are probably alluding to it, balance and reducing the polar moment of inertia played a big role. See if you can dig up an engine bay shot of those JGTC Supras and compare with the FT86. Then consider that the 3S is 4 cylinders long with the same bore as the FA20 which is 2 cylinders long (plus all the other stuff, it's obviously not twice as long but I hope you see what I'm getting at).

However if you think I will be butt hurt about the mighty 2JZ being replaced with a lowly 3S (though I'm pretty sure it was a 4T race relative, but I'll have to research more on that...), realize that you're talking to a guy that has fantasies about putting a turbo 2AZ (Camry motor) into a Supra to knock 2-300lbs off the nose and achieve a 50:50-49:51 balance.

Cliffs:

Toyota got a good deal on the cost of the boxer.

It's not that I was expecting you to be butt hurt. The fact that you even mentioned the Supra let me know you're obviously a fan of the same Toyota products I am. I brought it up because you mentioned the Supra's balance, which while as good as it is; they still swapped out the inline 6 for the reasons you mentioned in your post (which is why I thanked your post).

[Mr 286]

Originally Posted by daiheadjai

Totally agree - Why would anybody hate on the 3S-GTE?
If it weighs less (than the 2JZ) and handles enough power to get the job done (i.e. JGTC and WRC), what's not to like?

Exactly. I never said anyone was hating on the 3S-GTE, and I definitely wasn't hating on it myself. Check my signature. I happen to have a 3S-GTE and have had several over the years.

[daiheadjai]

Originally Posted by Mr 286

Exactly. I never said anyone was hating on the 3S-GTE, and I definitely wasn't hating on it myself. Check my signature. I happen to have a 3S-GTE and have had several over the years.

Keep that.
My neighbour has a '91 NA as his toy - still looks better than most cars out there today (incl. the likes of the 7th gen Celica, RSX, Integra, Prelude, etc.)

[BoostedWrbBrz]

woulda been cool if they dropped the 2.5 4gr V6 from the is250 in this thing

[clevrname]

I'd rather have the 2GR if you're looking at Toyota V6s.


http://25.media.tumblr.com/tumblr_m5...brxbo1_500.gif

[fatoni]

Originally Posted by DarkSunrise

Actually that's exactly what it means.

in my opinion thats a lot like saying that using double wishbones instead of mac struts means that it will handle better.

[DarkSunrise]

Originally Posted by fatoni

in my opinion thats a lot like saying that using double wishbones instead of mac struts means that it will handle better.

The inline-4 car you brought out as an example (NA/NB Miata) actually has a higher CG than the BRZ/FR-S once you adjust for ground clearance. It also isn't built to conform to modern day crash standards.

To compare apples to apples, the current NC Miata is built to conform to modern day crash standards. Also comes with an inline-4. Its CG height happens to be 1" higher than the BRZ/FR-S. Coincidence you say?

What car with an inline-4 do you think would have the lowest CG height? Probably a Lotus Elise, designed from the ground up to handle well (expensive, lightweight, mid-engine, track-focused). CG height on the Elise? 470 mm, or about a 1/2 inch higher than the FR-S/BRZ.

I can't think of any modern cars with an inline-4 that have a lower CG height than the BRZ/FR-S. You can't tell me that none of that has to do with the fact that the single heaviest component on the FR-S/BRZ (boxer engine) happens to have a lower CG height than a comparable inline-4...