Who will be first to swap new 2.4 into previous gen

[why?]

Originally Posted by nikitopo

Maybe trying to keep the low center of gravity? Tim Schrick is participating in the VLN Endurance Racing Nürburgring championship and he replaced the engine with an older EJ20 motor. This year replaced it again with a six-cylinder EG33 motor.

https://www.motul.com/de/en/news/eve...z-in-the-world

Originally Posted by nikitopo

I don't think you can have a lower COG with engines other than a boxer. It not only about how much low or high the engine sits in the bay. It is about the overall height of the engine and of not being top heavy. The main advantage of a K24 swap would be its higher power output and lower weight, so you would have also a bit better front to rear weight distribution with the expense of a bit worse COG. I believe K24 weights around 413 lbs. (including transmission), while FA20 is in the range of 480 lbs.

Supra's cog is lower.

[HKz]

Originally Posted by why?

Supra's cog is lower.

and I remember the original 86 launch docs said the LFA & 360 had a lower CoG and they used V configs..perhaps not the best cars to compare to a twin lol. perhaps for cheaper applications boxer is easiest way to achieve low CoG.

but idk CoG is cool but also a bit overrated IMO..thought experiment, hypothetically you could take say a higher riding sports car and put slabs of metal underneath the car to make it have a "better" CoG than the twins, doesn't mean much then right?

[Ohio Enthusiast]

Originally Posted by why?

Supra's cog is lower.

Car and Driver says that Toyota's claim isn't true.

[ZDan]

Originally Posted by nikitopo

Not sure how the lower c.g. of a boxer engine is overstated, if twins managed to have one of the lowest numbers of the segment.

They have a commendably low c.g. with the flat engine mounted high. They'd have a similarly low c.g. with a V-engine mounted low. C7 c.g. was measured at 17.5", quite a bit lower than its flat-engine Porsche 911 and Cayman contemporaries, 0.6" lower vs. FT86.

Even with a tall upright I-4 (mounted low), the twins would probably be no higher (I'd bet lower) than 18.5" c.g. height. Frankly the flat-4 has a bigger negative in FR application due to the engine having to sit quite far forward for steering shaft clearance. 18.1" c.g. height is great, but 55/45 is kinda crap, again I'd rather have 18.5" c.g. height with more rearward f/r distribution.

[Tokay444]

Originally Posted by nikitopo

I don't think you can have a lower COG with engines other than a boxer. It not only about how much low or high the engine sits in the bay. It is about the overall height of the engine and of not being top heavy. The main advantage of a K24 swap would be its higher power output and lower weight, so you would have also a bit better front to rear weight distribution with the expense of a bit worse COG. I believe K24 weights around 413 lbs. (including transmission), while FA20 is in the range of 480 lbs.

The engine can have a cog on the oil pan. If you mount it on the roof, what good does that part specific cog do you?
Yes, the cars have a low cog. No, it's not specifically because of the Boxer engine.

[Lantanafrs2]

Plug and play. No radiator required

[nikitopo]

Originally Posted by why?

Supra's cog is lower.

It has been discussed here. I won't open the same topic again.


In general my feeling is that some people are really not happy that Toyota went with a Subaru engine. Then they will just throw whatever kind of arguments and hypothetical facts, no matter the reasoning and what real facts indicate. It is what it is.

[why?]

Originally Posted by nikitopo

It has been discussed here. I won't open the same topic again.


In general my feeling is that some people are really not happy that Toyota went with a Subaru engine. Then they will just throw whatever kind of arguments and hypothetical facts, no matter the reasoning and what real facts indicate. It is what it is.

of course people are pissed Toyota went with a boxer 4 that has next to no development. Add in the torque dip and the fact it sounds like a farm tractor and you take one of the strengths of the original 86 and totally wreck it.

[ZDan]

Originally Posted by Tokay444

In general my feeling is that some people are really not happy that Toyota went with a Subaru engine. Then they will just throw whatever kind of arguments and hypothetical facts, no matter the reasoning and what real facts indicate. It is what it is.

That's not the case for me. I've never owned a Toyota and never a huge fan of most of their sports/sporty cars. Love the 2000GT but honestly 240Z is the better car. I also love the original AE86, for what it was (lightweight, rwd, but a bit crude with live rear axle). The FT86 is not really a modern AE86 anyway, it's a modern S13 240SX.

Having done vehicle design and layout, I have opinions about flat/opposed engine architecture in cars (and motorcycles!) based on facts. It's not the end of the world, but there *are* tradeoffs, and the "low-c.g." argument is usually tremendously overstated. Yes, it is beneficial that the cylinder heads are low. But it hurts that the bottom-end, harmonic balancer, flywheel, clutch, and the front of transmission are mounted *high*. I would bet there *is* a slight net benefit vs. a lower-mounted upright inline-4, but I bet it's near enough a wash vs. DOHC V4, which would be *my* choice for a small lightweight sports car. I'd actually bet on the V4 having a slight advantage but there wouldn't be much in it either way.

Indeed, it is what it is! I love the car and generally have few complaints. My 1st one being that I wish it were a shorter-wheelbase cab-rearward 2-seater, which would fix the F/R weight distribution. 2nd is engine architecture, again I'd prefer a V4 but ain't no automakers doing that anyway, but Subaru would be well qualified to develop one! Inline-4 *would* be able to sit lower and further aft vs. the flat-4, somewhat addressing the F/R distribution without tremendously impacting c.g. height.

[nikitopo]

Originally Posted by why?

of course people are pissed Toyota went with a boxer 4 that has next to no development. Add in the torque dip and the fact it sounds like a farm tractor and you take one of the strengths of the original 86 and totally wreck it.

Torque dip is almost gone in new engine and I've heard people saying it sounds better too. No?

[nikitopo]

Originally Posted by ZDan

I'd prefer a V4 but ain't no automakers doing that anyway, but Subaru would be well qualified to develop one! Inline-4 *would* be able to sit lower and further aft vs. the flat-4, somewhat addressing the F/R distribution without tremendously impacting c.g. height.

Subaru was dogmatic for years even on moving to a direct injection engine design. They are not that flexible to changes and sometimes it is for the best, because it gives them time to improve things gradually year by year up to perfection. This situation is changing lately for them, by working more closely with Toyota, but there are still old voices within the company. You also mentioned several times about the F/R distribution issue. Don't want to go off topic here, but STI had a different suspension setup on their JDM tS cars (the ones with the STI Bilstein suspension) with softer rear springs that transfer more weight to the rear. There are different ways to *fix* issues and although might not seem optimal, they still give them an option to not ruin the vehicle's practicality (i.e. being a 2+2 seater).

[ZDan]

Originally Posted by nikitopo

Subaru was dogmatic for years even on moving to a direct injection engine design. They are not that flexible to changes and sometimes it is for the best, because it gives them time to improve things gradually year by year up to perfection.

I dunno, the perfect embodiment of a somewhat difficult-to-package engine may be dogmatic to a fault... They should do the V4, they already have cylinder heads for it!

mentioned several times about the F/R distribution issue. Don't want to go off topic here, but STI had a different suspension setup on their JDM tS cars (the ones with the STI Bilstein suspension) with softer rear springs that transfer more weight to the rear.

Softer rear springs do not "transfer more weight to the rear". Weight transfer during acceleration is a function of c.g. height, wheelbase, and acceleration rate. Softer springs either end won't change that.

There are different ways to *fix* issues and although might not seem optimal, they still give them an option to not ruin the vehicle's practicality (i.e. being a 2+2 seater).

If it *must* be a 2+2, V4 mounted as far aft as possible would help.
"Fixes" mean big compromises, the best "fix" is to improve the weight distribution to something more reasonable for an FR sports car. 55/45 is garbage. Even V8 nose-heavy Mustangs and Camaros do better...

50/50 would greatly reduce load on the outside front during cornering and give more total lateral grip. It'd also improve braking performance. In addition to being able to put the power down better. Faster!

[nikitopo]

Originally Posted by ZDan

I dunno, the perfect embodiment of a somewhat difficult-to-package engine may be dogmatic to a fault... They should do the V4, they already have cylinder heads for it!

If Toyota wanted a V4 engine, then they would look somewhere else or they would develop it themselves.

Originally Posted by ZDan

Softer rear springs do not "transfer more weight to the rear". Weight transfer during acceleration is a function of c.g. height, wheelbase, and acceleration rate. Softer springs either end won't change that.

I didn't mention during acceleration, but let's leave it there.

Originally Posted by ZDan

If it *must* be a 2+2, V4 mounted as far aft as possible would help.
"Fixes" mean big compromises, the best "fix" is to improve the weight distribution to something more reasonable for an FR sports car. 55/45 is garbage. Even V8 nose-heavy Mustangs and Camaros do better...

50/50 would greatly reduce load on the outside front during cornering and give more total lateral grip. It'd also improve braking performance. In addition to being able to put the power down better. Faster!

Not sure why a car that is praised for its handling ability, has now a garbage weight distribution. 911's have an even more garbage weight distribution with the majority of the total weight on the rear, but they have worked with suspension geometry for decades and they are well established in car's history.

Subaru have their expertise on building boxer engines and it is what is. They don't have the capacity having different engine designs. I am mentioning it again that they even had a big trouble moving into direct injection! Something that looks a "fix" for you, could mean a (financial) disaster for them.

[ZDan]

Originally Posted by nikitopo

If Toyota wanted a V4 engine, then they would look somewhere else or they would develop it themselves.

I never said anything about Toyota...

I didn't mention during acceleration, but let's leave it there.

In any context, your comment about JDM tS having "softer rear springs that transfer more weight to the rear" doesn't make sense. Softer rear springs don't transfer more weight to the rear under braking, acceleration, or cornering. If they went with softer rear springs, they moved roll stiffness distribution forward, which would further load up the outside front during cornering and keep the rears more evenly loaded. Good for drive, but bad for front grip...

Not sure why a car that is praised for its handling ability, has now a garbage weight distribution.

55/45 is crap for an FR performance car. Yes, the car is well set up and very fun to drive! But grip is *far* from optimized... With 50/50 weight distribution, I would have won my time trial easily on Sunday vs coming in 2nd by less than a tenth...

911's have an even more garbage weight distribution with the majority of the total weight on the rear, but they have worked with suspension geometry for decades and they are well established in car's history.

Rear bias is BETTER for a rear-drive performance car. 50/50 is *not* "perfect". It is better than 55F/45R, but 45F/55R is *better still*. Mega-performance rwd cars will generally have ~45/55 to ~40/60 weight distribution.

Forward weight distribution means the outside front is doing way more than it's fair share during cornering, so you're losing grip there. Could try to correct for that with more rear roll stiffness, but before long you'll overcome the Torsen diff's ability to deliver power to both rears, so kind of a dead-end. Even with a good ramp-type clutch diff, you're only going to be able to put so much power down on corner exit. This is already a minor issue even at stock 205hp.

Forward weight distribution in an FR performance car is bad for:
1. braking: fronts are relatively overloaded with ~75% of the load and rears underutilized carrying only 25%
2. cornering: outside front overloaded, way beyond the linear portion of the grip/load curve, while outside rear is underutilized again
3. accelerating: less load on the driven rear wheels = less drive grip.

Subaru have their expertise on building boxer engines and it is what is. They don't have the capacity having different engine designs. I am mentioning it again that they even had a big trouble moving into direct injection! Something that looks a "fix" for you, could mean a (financial) disaster for them.

There are better ways to do things. But yeah, it's easier to stick with what you know. But is it really the best long-term strategy? At this stage, probably not worth the investment as we move to other types of power units...