Subaru power plant update needed?

[oab_au]

.Subaru power plant update needed?

The power plant that Subaru has used, since inception has served it well to date, But if they are to make it in todays market, a change is necessary.
I know am treading on "sacred juicey spots", but it has to be pondered. The four cylinder units are perfect, the six cylinder is a different case. Subaru needs another six in the line up. The redesign six in the Outback, was the cheap way out, that won't work in a smaller floor pan. Sure it shorten the motor at the front to squeeze it in, but it made it very front under steering from the amount of weight on the front wheels.
The SVX got away with it because it is a expensively heavy auto, (the expensive bits add the weight), even then the designers had to resort to adding ballast to the back end, in the form the huge muffler and the double skinned boot lid with spoiler, plus sweeping the front half shafts 4"(100mm) forward to gain good balance. Which on this auto is dammed near perfect, but I can't see them building another expensively heavy auto like this again.

To get the six into a smaller floor pan, Legacy or Impreza, the weight has to be moved rearwards. I am sure they won't change the boxer layout, they could turn it east west maybe, though it wouldn't solve weight problem.

I think the solution would be for Subaru to bite the bullet and move the front diff out from behind the flywheel, forwards to below the engine, as Nissan and the rest do. This would move the weight back for a more balanced layout in a smaller pan.

This change would make, a M3 smoker out of the Impreza a probability.
Any how thats the way I see it, what do y'll reckon?.

Harvey.

[huck369]

Originally posted by oab_au
.Subaru power plant update needed?

I think the solution would be for Subaru to bite the bullet and move the front diff out from behind the flywheel, forwards to below the engine, as Nissan and the rest do. This would move the weight back for a more balanced layout in a smaller pan.

Move the diff forward? That just puts more weight up front, plus the front diff has to remain nearly square between the front wheels.

Also the Subie Motors are incredibly light, the 2.2L 4-banger only weighs about 185lbs with accessories(that's less than I do), I don't know off hand what the SVX motor weighs, but probably around 250lbs. if I were guessing.
Note: a Subie tranny weighs more than a 2.2L Subie engine, making me glad it's behind the engine.

Maybe a single overhead cam 6 would help shrink the package, and keep the weight down, something like the 2.7L they put in the XT6's.
A 2.7L six in an Impreza would be a blast.

My 2 cents

[1994SubaruSVX]

what they really need to work on is their tranny's. based on my experience (SVX) they have horrible automatic transmissions for their boxer 6's. in order to create any longevity they gear them low which kills any performance you could have from the increased hp and torque. just my thoughts on this, maybe i am way off base. but look at the new nissan altima, v-6 with 240 hp and pretty damn good off the line performance for a heavy 4-door car. nissan has found a way to give you hp and torque with an automatic transmission and not destroy off the line performance.

A 6-cylinder Outback weighs a good deal more than an AWD SVX.

Yep.



--Brad

There is nothing wrong with the Subaru Auto trans design. It does exactly what it was intended to. Namely, it saves the drive train undue stress from over accelerating from a stop. The car is heavy for many reasons but because it is heavy it takes a good deal of force to move it from or to a rest. The trans could be made to hook up solid as a rock as soon as you touch the throttle. However, then you would not complain any longer about the trans but would say the CVs and bearings are lousy (well, the bearings ARE lousy ) so you could "beef up" the halfshafts and bearings to take the additional stress being delivered by the trans only to find out the suspension components (struts, strut mounts, bushings, etc.) are now failing.

It's all about balance, the SVX is balanced for its indended us. Namely a "luxury sport coupe". NOT an off the line race machine. Some of the cars mentioned on this thread as having better off the line perfomance are front drive cars. Take an SVX with only front wheel drive and you may find a machine with possible better acceleration performance. The all wheel drive components add weight and drag. If you want the SVX to *really* rocket off the line remove the rear seat and bolt the engine in there with a very short drive shaft to a live axle rear end. My guess is you'll give up of the car's cornering capabilities as well as giving up some of your wallets stuffing.

The car's horsepower and balance allow for exeptional expressway maneurvering and that's what this car is really all about.

Just my two pennies worth.

[mohrds]

You dipping into the O'dules a bit early today?

I agree with you mostly, I think that the car was designed as and is a great touring car, however I don't think that the medeocre performance was an issue of overall design planning, but more of a side effect of being Subaru's first dive into the boulevard cruiser market.

Other companies at the same time made heavy cars with much better specs. Look at the Mitsu 3000 VR4 for 1992 with a 0-60 of 5.8sec. compared to our 7 sec ride. Granted, it drives a lot rougher than our cruisers, but they did manage to transfer more power to the ground without self destructing.

If Subaru had know in 1989 what they know now...

Doug

Doug? Nice to see you up so early No Dooleys yet my friend. Not that it would matter.

Anyway. I think you're right about the "first dip" part of the equation. I also think the car was/is the product of what I call "allowed engineering". Basically what happens is the engineer is asked how much space/weight/cost something is going to require and then the form and function arrive secondarily. Instead of being *told* what all the criteria are they are allowed the freedom to "fill a vacuum" and do so.

When you speak of the Mitzi's "rough ride" you elude to a symptom of the suspension, perhaps, being designed to handle the more aggressive power transfer. Everything is a trade-off. I'd prefer to have the car be a little bit lighter, but then would give up some of the traction associated with the down force on the tires. I did not, however, buy the car to drag race, I bought it to go around corners and watch people dissapear in the rear view mirror. And it does a *damn* fine job of that.

[mohrds]

I'm not complaining about the car, but I do ocassionaly yell "Come on Bessie! You can do it! Get a move on!" when I'm trying to leave a stop light.

She never listens...

Doug

[Jamsvx]

I notice that the SVX was compared in acceleration to the 3000GT VR4. In the (many) comparisons between the SVX and other cars that I have come across (blatant plug for http://www.geocities.com/jamsvx/articles.html) the SVX is most often compared to any or all (depending on the review) of the following:

300ZX
RX7
R32 GTR
3000GT
BMW 3 series coupe.

But!

The reason for doing this is because realistically, the closest car that I can think of (at least in Australia's market in 1992) was the BMW 8 series....like the SVX a hugely overengineered, incredibly heavy car that despite power on paper, was a slug.....however, in transcontinent blasts, there would be no equal. Try sitting in a GTR or 3000GT at 250kph for any period of time!

Naturally, no magazine was going to compare what appeared to be a coupe priced at c.$70,000AU (and which appeared to be an attempt by Subaru to get into a price bracket where it did not belong - hence reluctance of people to spend that much on a Subaru then cf: happily spend it now on a WRX Sti!) to a $200,000 German coupe so the SVX was compared to cars that it really should not have been:

3000GT: twin turbo V6, 5 speed -- its a sports car (no matter how much it weighs it was designed AS a sports car)
R32 GTR: twin turbo inline 6, 5 speed -- same thing, designed as a sports car
RX-7: 13B rotary twin turbo -- sports car

(see a pattern????)

300ZX: non turbo V6....ahh, now this is more realistic (ignoring the twin turbo that we did not get and which was really a 3000/GTR/RX7' ish engine in a car not conceived to combat in that market.

3 series coupe (except M3)....another more realistic competitor....although the 328 5 speed would murder an SVX off the line (a comparison that allowed the 8 series to remain in the stratospheric price battle with the Mercedes SL and S coupe series without the 'insult' of being compared to the upstart Japanese maker of rugged cars favoured by farmers - a sentiment of the time at least here in Oz)

What else could you compare it too??? My opinion is that the closest realistic Japanese competitor to the SVX was the Eunos JC Cosmo 20B (http://www.3rotor.com) but in the global market, the Honda Legend Coupe is the best example. And yes, a review of SVX -v- Legend is on my site! :-)


I've said it years ago on Yahoo and I'll say it again: give me a WRX and an SVX.....give me a destination X miles away (through all manner of road conditions....and I am 100% confident that the SVX will reach there at the same time as the WRX. Choose an environment that the SVX was designed for.....red-light derbies were certainly not in contemplation!

Slighlty off topic and just my opinion sans SVX !!!

Jamsvx

[SVXphile]

<I've said it years ago on Yahoo and I'll say it again: give me a WRX and an SVX.....give me
a destination X miles away (through all manner of road conditions....and I am 100% confident that the SVX will reach there at the same time as the WRX. Choose an environment that the SVX was designed for.....red-light derbies were certainly not in contemplation!>

...and you will get there in more comfort. Well said jamsvx. If someone wants to buy an SVX and modify it to accelerate quicker...fine. But I wouldn't criticize the design for not being Corvette-quick; it wasn't designed to be. All Subaru had to do was install a 5-speed; how much quicker would that have made it? High 6's 0-60 perhaps? They only came with an automatic, so the "cruiser" mode was on Subaru's drafting table from the beginning. Sure the car can, and has, been successfully modified, but something to compete head-to-head with an RX-7 was not what the folks at Fuji had in mind. I love mine just the way it is, and I hope it lasts to 300,000 miles.... Don

[oab_au]

What was the result. 9 replies but no one address the problem that I posed. I don't think you blokes are paying attention. Y'll went off on your pet thing.

Now I won't mark y'll down a grade yet, i'll make the question easey now try to apply youselves, there may be gold stars awarded here

The facts; Subaru has not put the six cylinder motor in the Legacy like they should have by now.
I feel it's bcause, the car would have too much weight over the front wheels, causing excessive under steer.

The question; How are they going to cure this problem, to achive the goal, and also do it well enought, to also fit it into the smaller Impreza body.

My theory; If transmission was redisigned to remove the front diff, from behind the engine to a place under the engine, the engine and gear box, would move back by about 12"(30cm). Instead of all the engine hanging out over the front wheels, only the front couple of cylinders would overhang.(make sense now Huck?) This would move the weight away from the front to a more evenly balanced installation.

OK, get to it, you have 5 days, before I mark the test and award gold stars.

Harvey.

"My theory; If transmission was redisigned to remove the front diff, from behind the engine to a place under the engine, the engine and gear box, would move back by about 12"(30cm). Instead of all the engine hanging out over the front wheels, only the front couple of cylinders would overhang.(make sense now Huck?) This would move the weight away from the front to a more evenly balanced installation. "

The main problem I see with moving the diff under the engine is that the engine would have to move up. This poses two problems. First it raises the hood line, something Subaru has successfully kept low on the horizon for better visibility and aerodynamics. Second, raising the engine up moves its weight up. This raises the car's center of gravity which, I think, would erase any benefit gained by moving the weight rearward.

As for a six in an Impreza (there exist Legacys with the new H6 powerplants already) I think the solution to the problem is to make a "smaller" six. At least from a displacement standpoint. Subaru has always used the flat platform so I don't see them moving to a straight or "V" design any time soon. My personal solution would be to leave the engine in the Impreza as it exists today (2.5L) but to supercharge, rather than turbo, the thing. I also think the SVX would give the "off the line" performance some people want if it was pumped this way.

Can't say I have other ideas on how to move the weight over or behind the front wheels short of some serious redesign.

Just my two pennies worth.

I've always loved AWD cars, something about the transfer of power to *all* wheels just always made too much sense.

In that vein (when limited to a front engined layout) my dream set-up would have the engine/trans combo stay the same, but utilizing a dry sump engine oiling system, run the front propellershaft *underneath* the oilpan and terminate with a diff *in front* of the motor. Also the transfer case (same spot, behind the trans) would be primary rear drive with the fronts kicking in when needed a'la Nissan Skyline (R34 V-Spec is my dream car , anybody know a grey market importer other than Motorex or BestJapanCar.com? ).

Now, if I had my druthers, the *ultimate* layout would be a mid-engined version of the same thing. Trans forward of the engine, forward propellershaft going to a front mounted x-fer case/diff (like Porsche) while the rear shaft goes *under* the oilpan to a diff placed far rearward of the block.

I fully realize that both these setups make dropping the pan a chore, but for a setup with AWD *and* an ultra-low center of gravity, I for one would be more than willing to pay the price.

Oh, and I prefer my stars in Ti-6AI-4V (aircraft grade Titanium), thank you very much.

[huck369]

Originally posted by oab_au





The question; How are they going to cure this problem, to achive the goal, and also do it well enought, to also fit it into the smaller Impreza body.

My theory; If transmission was redisigned to remove the front diff, from behind the engine to a place under the engine, the engine and gear box, would move back by about 12"(30cm). Instead of all the engine hanging out over the front wheels, only the front couple of cylinders would overhang.(make sense now Huck?) This would move the weight away from the front to a more evenly balanced installation.

OK, get to it, you have 5 days, before I mark the test and award gold stars.

Harvey.

The answer could be make a new tranny, that mounts in the rear of the car to allow the engine to move back some and distribute more weight to the rear, then an offset front diff. This would mean there would have to be two different drive shafts, but would really balance out the car, and allow more room for the engine up front.

This is the set-up I think Subaru should look at, but what do I know anyway

[Beav]

I didn't realize there were so many F1 drivers out there that required tinkering with a solid design (for an under $30k car anyway.. ) I suppose if it were really of any consequence they could mount the tranny ahead of the engine, a la Saab....

Beav