What makes the Boxer engine so special
 

Hi guys.

You can post your thoughts on the boxer engine here.
Posted an elementary explanation of the boxer engine on our blog. Let me know your thoughts. Thanks :thumbup:

http://www.durbansouthtoyota.co.za/b...-boxer-engine/

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nothing really. as far as i can tell its a pretty normal engine. there may be some subtle advantages but from an overall perspective its not important enough to be a deciding factor

Low profile allows for a much lower COG than most engines.

its a flat engine

IIRC, the flat or horizontally-opposed design may deliver more torque for a similarly displaced inline or v cylinder design. Perhaps due to where the power is delivered from the piston/cylinders relative to the rotational cycle of the crankshaft.

Packaging. You can mount one longitudinally in the space of a transverse 4.

The lower CG is a benefit as well, which is why you see them a lot in motorcycles.

what about a 4-cylinder radial engine?

Also less vibrations since horizontally opposed pistons cancel the vibrations out, or so subaru says. Blah Blah Blah sciencey stuff Boxer Hooray!!!!!

This ^^^^


That's definitely the biggest advantage.

As far as power goes for NA it is not as powerful as a Honda VTEC K series engine, but as far as we all can see the Boxer engine does seem to make/hold more power when going forced induction with just stock internals. :w00t:

usually what happens is that the engine is so wide that it ends up being placed higher in the car negating any cog advantage you would gain otherwise.

Yep. Pretty much this is all

Only it doesn't. Have you looked under the hood? It's low

says the guy who drives an inline engine.

It's flat so it's got a lower CoG, the pistons are opposed to each other so there's less material on the crank to balance engine vibration making the overall engine weight lighter and spins more freely because of less weight/material to move. Other than that I don't think there are many other benefits of a boxer. Versus an inline 4 I think there's a negative in that there are more moving parts such as the need for 4 CAMS vs just 2 if it were a DOHC configuration. There are always advantages vs disadvantages on motor designs. I used to be a big fan of the WANKEL because of it's only 3 major moving parts but the lack of torque, dependability, life expectancy, and gas mileage made me get rid of my second gen RX7.

Problem is they're wide and can't be pushed back as far for balance when front mounted and interfere with more advanced suspension options in the front because of it.

Is the WANKEL what is referred to as rotary engine? Those seem to really be out of the scene.

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Yes, they are the same.

The pistons are held together with a unicorn horn. Duh.

It allows the shifter to be mounted right on the tranny instead of using cables :)

The FA20 are special for throwing out the famous idle dip and CEL light from factory. :mad0259:

and that car with an inline engine has a lower cog than the frs.
that has nothing to do with it being a boxer motor as far as i know. im pretty sure thats a function of the engine being up front and the drive wheels out back

LFA, Porsche 911 GT3, and Ferrari 360 are the only cars built w/ a lower CoG than the FRS. I like miatas, Yours may be modified lower, but who cares that wasnt the question.
...oh ur so wrong

Boxer engine: flat design so its mounted lower, minimal vibrations, the square 86x86 bore and stroke provide wonderful balance throughout the engine and also reduces vibration, not to mention subaru has mastered the horizontally opposed.
"Using the boxer engine also allows it and other major components to be moved farther back toward the vehicle’s center point, resulting in an extremely neutral-handling chassis that laughs at the thought of understeer."

BADABING BADABOOM

Having owned one of the lowest stock Miata's ever produced, I think I am certified to add my two cents here.
If I recall correctly all miatas have a CoG height higher than even an s2000. I cant find the exact numbers right now, my google-fu is weak. The s2000 is higher still than a Porsche Cayman, and the FT86 cars are supposedly lower than all of the models mentioned above.

Now, obviously CoG height is not a 100% indication of overall performance, but I can safely say the FRS out-performs any miata I have ever owned -stock-.

EDIT: found some data finally http://www.ft86club.com/forums/attac...5&d=1320266607

460mm for the FS is roughly 18.1in, whereas the Cayman is 482mm. Im having problems finding credible sources for s2k and mx5 though. Conjecture seems to indicate 20-22'' for the S2k which I have a hard time believing.

Then why does it only have the same F:R balance as an iron-block, long inline-6 powered Supra?

Marketing hyperbole. Try again.

Edit: According to Keith Tanner (look him up), first gen Miatas' cogs was ~17" stock.

The fact that it's a boxer has no real correspondence with how it has a directly mounted shifter. Like fatoni said, that's because it's FR.


Honestly, what like about boxers is just the ridiculous noise they make. And fact that nobody knows what the hell they are.

It's unique. Not as unique as wankel-magic-pixie-unicorn-triangle engines, but unique nonetheless.

If by "unique" you meant "mass produced" then yeah.
Are boxer engines rare in the US?

Meaning they are not as common as inline or V-type engines.

Perhaps uncommon is a better word. Although as an FR Boxer, I suppose it is quite unique.

I heard something about the oil not draining down from the cylinders since they're aligned horizontally, which would help longevity?

Wow awesome graphic! Thanks :thumbup:

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Great info, @mattles, thanks!

"...maximizing the joy out of a corner" - gotta love it :happyanim:

It's great but not all magic. Wait until you have to change the spark plugs on a boxer!

F:R balance is only one axis of design/measure in the entire 'balance equation.' The CoG becomes a factor in other considerations, like side to side dynamics as well as corner balancing.

Eric G

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.

The balance example was to demonstrate how flowery the marketing guys get about this car. They say they chose the boxer so they could move it back to optimally balance the car. But it ends up with the same balance as the Supra. Look at the shock/strut towers relative to the front of the motor of both cars. Also the 53:47 on the FT86 is with 2 passengers (as seen in the above specs), whereas the Supra's is with 1.

The other thing is all these noobs throwing around COG like it's the Holy Grail of handling never thought twice about it until they encountered the hype machine.

The reality is the Subaru cooperation allowed the access to a north-south engine without having to spend a fortune on a new motor. That's it.

If the boxer was so great and COGs the be all and end all of handling , the cost is no object LFA would have had a flat 8.

Don't forget Volkswagen has been making them (flat 4 engines) since the late 30s (1938 I believe)

I don't disagree with you re: hyping up a car (that's what marketing is for), but I don't recall them saying they chose the boxer because of weight distribution - I thought the reason for choosing the boxer was always to lower CoG (rather than for weight distribution)?

Flat 10?

If all these guys are noobs, I guess that makes you an expert? Good, because I've been looking for an expert to ask why most of the JGTC Supra's swapped out the inline 6 for a 3S-GTE with the exception of the V8's used later.

Who cares about what gets the marketing guys all gushy over, as long as it sells more of these.

And the LFA was far from a cost is no object car. I can just about guarantee you that it's engine was designed to be built within Toyota's existing engine manufacturing facilities.

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.