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Subaru swap


nbesheer

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I just think that the only reason to use a Subie engine would be because of how short it is, from crank pully to flywheel, to be able to devise an AWD set-up. I can't see the CG being changed enough, to warrant using a boxer type engine in a conventional front engine RWD set-up.

At least that's the only reason I would use a boxer engine, to use AWD.

 

Once you look at the fact that there's still a lot of parts that are at conventional hight in comparison to a typical V or inline engine, especially when using a turbo set-up, where the turbo is mounted above the engine. to keep the weight behind the front axle, for the benifits that are being mentioned. To move the turbo forward of the engine would still hang it in front of the front axle, moving the weight forward upsetting the balance of the chassis, and taking away soemwhat from the overall goal.

 

Also the chassis/fram modifications needed to fit the width of the Subie engine would be better placed forward of the axle IMO, so as to not have to brace the hell out of everything, that also adds a lot of weight that will be mostly above the centerline of the engine (to keep good ground clearance), also negating most effects of a lowered CG.

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I just think that the only reason to use a Subie engine would be because of how short it is, from crank pully to flywheel, to be able to devise an AWD set-up. I can't see the CG being changed enough, to warrant using a boxer type engine in a conventional front engine RWD set-up.

At least that's the only reason I would use a boxer engine, to use AWD.

 

 

 

Once you look at the fact that there's still a lot of parts that are at conventional hight in comparison to a typical V or inline engine, especially when using a turbo set-up, where the turbo is mounted above the engine. to keep the weight behind the front axle, for the benifits that are being mentioned. To move the turbo forward of the engine would still hang it in front of the front axle, moving the weight forward upsetting the balance of the chassis, and taking away soemwhat from the overall goal.

 

Also the chassis/fram modifications needed to fit the width of the Subie engine would be better placed forward of the axle IMO, so as to not have to brace the hell out of everything, that also adds a lot of weight that will be mostly above the centerline of the engine (to keep good ground clearance), also negating most effects of a lowered CG.

 

Well then for you I would say there is no reason to use a boxer engine. That rt is prob the hardest, least cost effective way I could possibly think of.

 

Mounting that engine in front of the CROSS MEMBER would be close to impossible and would completely destroy the weight distribution and handling of the car.

 

I don't mean to rag on you but there is nothing in this post that makes sense.

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Hmm, lots of activity. I'd like to pass on a few statements to regard some posts:

 

Making your framerails pass over the engine would put them up to the tops of the strut towers; extremely "not feasible" and flimsy.

 

The engine's advantage (short height) etc. does indeed give it a very low CG, but if you had to shove the thing way forward to put an AWD trans onto the back of it you'd have a timing cover in front of the factory radiator placement. Also not very useful. Your CG would be low but forward.

 

The engines aren't that expensive. Just because ppl sell them used on the forums for a lot does NOT mean that an enterprising fellow couldn't buy one brand new from the dealer for less if they were wise enough to simply check. :wink:

 

Subies are cool and all but they aren't the greatest for massive power output. I would say, however, that it'd be ridiculous to think that the 2.0 or 2.2 engine would be a 'better' choice from engine output and reliability points of view. The 2.5L USDM STi belts out so much so easy now it's ridiculous. Just because Subaru's have a very strange mod path (and if you don't follow it you can blow the engine up) and have one of the world's dumbest (and most dangerous) tunes from the factory doesn't mean they aren't tough if you know what you're doing.

 

All of this is, of course, my two cents.

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It still doesn't clear the width issue. It won't clear anywhere except perhaps between the headlights. :ugg:

 

Ya, but I didn't say it would. I was responding to another members post.

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Well then for you I would say there is no reason to use a boxer engine. That rt is prob the hardest, least cost effective way I could possibly think of.

 

Mounting that engine in front of the CROSS MEMBER would be close to impossible and would completely destroy the weight distribution and handling of the car.

 

I don't mean to rag on you but there is nothing in this post that makes sense.

 

 

How does none of it make sense, all of it does, when you sit back and think about actually fitting a boxer engine where it was never intended to go.

 

I realize the weight balance would be upset, I also mentioned that the rad would not be able to be re-installed in the factory loaction, and suggested that may it be installed over the transmission, an idea taken from desert trucks that place the rad in teh back of the vehcile, though that is more for protections and weight distrobution, to get more weight over the rear wheels that when they are airbourne, that they come down rear wheels first.

 

I have also said that the frame rail could be placed under the heads, or as would probably be used a combination of both (above and below). A frame rail that is placed over though can very easily be made strong, with proper planning, and triagulation from other bracing. Also realizing that the frame rail in front of the front axle center line, doesn't really need to be any stronger than enough to support the engine weight (and power transfer into the chassis).

 

I just don't understand why one would want to use this engine (subie) for any other reason than to use it in an AWD application, due to it's short length.

It has been shown that V8s will provide excellant weight distrobution, and wouldn't be surprised if the change in CG is so little (if any) that it makes no difference on the track, comparing a V8 equipped (If you want to compare somthing a little closer use a V6) and a boxer engine equipped S30. Most V8s that I see swapped into S30s are also almost completly behind the center line of the front axle, with usually only the water pump and other belt driven accessories being forward of that axle CL, which results in a better weight distrobution than what the Datsun factory provided with the I6.

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Hey fellas’ this thread is starting to show signs that it is on its way to turning into personal attacks which we do not want. Simmer down fellas…. Everyone posting thus far has some good points, you all just need to keep in mind that our own ideal power plant for the S-30 is not everyone elses ideal power plant and just because we can’t see any reason to use one power plant over another, does NOT make that power plant a ridiculous choice. This is HybridZ, ALL engine conversions, are welcome.

 

Keep in mind guys, NO auto manufacturers ever intended their 4 cylinder’s, 6 cylinders whether they were inline or V, V8’s, V-10’s, or even V-12’s for the S-30 engine bay, but we do it anyway. We all have our reasons why we choose the engine we choose, and for some applications those swaps work and perform as intended, for others, those swaps are far from ideal.

 

There is a seat for every arse and an arse for every seat. Put another way, there is a power-plant for ever Z and a Z for every power-plant. Lets try to be mindful and respectful of that.

 

Thank you,

Paul Ruschman

HybridZ staff

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I just want to throw out my $.02 here. I’m in no way an expert on the Suby, though it does have my interest for various reasons.

After weighing one and looking over the long block, physically in size, and especially its LIGHT weight, this engine could have positive attributes useful for a front engine sports car.

As Sixshooter pointed out, the Suby engine mated to its Suby transaxle offers AWD capability. Could make for a fun S-30 rally car or extreme northern hemisphere daily driver…

 

The Suby 4 cylinder is very compact in length and height and especially its mass.

 

As for overall weight. The Suby offers approx 150-200 weight savings over a SBC V-8. For the hardcore track guys, 150-200 lbs is quite significant. If the Suby tranny is used, the crank centerline is higher than traditional front engine rear drive layouts which does place the Suby CG at a similar height in the chassis with other V-types power plants. If the Suby is adapted to a traditional rear wheel drive transmission, this lowers the Suby crank centerline low in the chassis and by design, this lowers the CG of the single largest component of the car, the engine. With the Suby's light weight and very low CG when used with a say, a Datsun transmission in a rear drive configuration, the Suby power plant starts to look quite attractive for some applications. As stated already, the engineering/fabrication trick is to get it to fit within the engine bay of the S-30, i.e. frame rails, etc. A fabricator/engineer is only limited by his imagination. More technically challenging projects have been tackled in the past…

 

Hmmm.. If the Suby 4 cylinder can be made to fit the S-30, what about the Suby flat 6?... or as mentioned already, flat 8? Or flat 10 or flat 12... (that would be true Hybrid, a 4 cyl and a 6 cyl mated together... :lmao: )

 

Here is a thread with various engine weights, including a Suby EJ22;

 

http://forums.hybridz.org/showthread.php?t=125246

 

 

Suby EJ22; WET, oil and coolant.

 

MINUS

Alternator, damper, flywheel, exhaust manifolds

 

214.8 lbs.

 

EJ22aSmall.jpg

 

EJ22bSmall.jpg

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Somehow I KNEW you were gonna bring up that weight braap...

 

...sure does make one want to put one in a Z. Even the flat 6 would offer a very low weight, and a low CG if you can figure out how to fit it.

 

Did you have the flywheel and/or exhaust manifolds when you weighed this? Any guess how much they'd add? I'd say.... 30-40 pounds together?

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Somehow I KNEW you were gonna bring up that weight braap...

 

...sure does make one want to put one in a Z. Even the flat 6 would offer a very low weight, and a low CG if you can figure out how to fit it.

 

Did you have the flywheel and/or exhaust manifolds when you weighed this? Any guess how much they'd add? I'd say.... 30-40 pounds together?

 

That was minus the flywheel and exhaust manifolds. Those parts were not an hand during the weighing, sorry. Depending on the exhaust manifolds material and design, I could see another 30-40 lb for flywheel and exhaust manifolds.

 

Ron Tyler has been looking into the Suby as well for a different project.. Maybe he’ll chime in with some info…

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Suby flat 6

 

Holy ♥♥♥♥,i didnt even think of that what an idiot.The suby eg33 (3.3l)is a god damn beast of an engine,and a friend of mine has a couple in great shape.Those engines with openish exhaust have that rally porsche sound and are quite strong.I believe somewhere around 235-245 horsepower stock.They are going to be about the same width just another cylinder longer,if you can get an ej2x to fit you should be able to get eg to fit and still have room in front.Not an engine you hear much about,since there really arent many svx's driving around but people have boosted those things and made very powerfull motors.

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Svx was one of my 1st automotive loves lol. Isn't there a issue on what trans can be used? I know the svx didn't come manual but is there one that bolts up?

 

And would you guy the awd section to convert to wrd if there was one or just adapt a proven rwd trany of another make?

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And would you guy the awd section to convert to wrd if there was one or just adapt a proven rwd trany of another make?

 

Oh yea,that part lol.

 

I dont think you could use an awd tranny,you dont really want to be putting all your power through a viscous center diff.I would think it would have to be adapted to a proven rwd tranny.However there still is the er27 subaru h6 out of the xt6.Also a beastly motor and it has the option of being bolted up to any ea series trans,meaning any PT or FT 4wd trans.In this case running in 2wd would be feasible but im not sure how much power it could take before problems show up,good thing is a good tranny is like 200 bucks so you wouldnt lose much.

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I don't think it'd be the best solution, but I know guys in STIs and EVOs convert to RWD using the stock AWD tranny. Not sure how, but I know they do.

 

But I don't think that's a very good soluton. You'd be carrying extra weight in the tranny, and i'm sure it's not as compact as a RWD tranny.

 

But that does seem to be the big hold up, aside from needing to totally hack up the front end and install some tubing.

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If the Suby tranny is used, the crank centerline is higher than traditional front engine rear drive layouts which does place the Suby CG at a similar height in the chassis with other V-types power plants. If the Suby is adapted to a traditional rear wheel drive transmission, this lowers the Suby crank centerline low in the chassis and by design, this lowers the CG of the single largest component of the car, the engine.

 

I disagree with the mating to a different tranny lowering the engine, at least by any significant amount. I'd have to look for the pics but when I was researching a mid engine RWD project that I was going to build, I was looking at using the Scooby tranny, as the output shafts were just behind the bellhousing, allowing me to almost fit the engine in a longitudal position behind the (front) seats of what was then the project Sunbird. The input shaft was no higher than that of a traditional RWD tranny, or at least not enough to worry about, since even RWD trannies will differ in where thier hight can be in relation to the input shaft CL. Some hang thier weight below this CL some place it more beside. In most stock applications though, like the T5 for example, most of the guts are hung below this center line. Even the FWD transaxles I've used hang most of the guts below the input shaft centerline, and usually have the bottom of the tranny about the same hight as the bottom of the oil pan. Most RWD trannies I've used seem to hang the tranny lower than the oil pan, quite a bit of that is due to trying to keep the interior floorpan low for interior space reasons, and for the front of the oil pan to clear the crossmembers and steering.

Basically it comes down to the crank centerline being about the same location no matter what engine is used, due to driveline angles. There are ways to move this, but if it's not done right, this can put severe stress on the driveline and the first thing to go usually is the universal joints, between the tranny and the diff. Rectifying this in an IRS car is even more complicated, because just lowering the diff, then takes the stress off the tranny to diff U-joints, but then places them on the axle U-joints (or CVs as the case may be), due to the axle and the lower control arm now acting around two different arcs.

So then lowering the inboard LCA points would seem like a solution, but then ruins the camber gain under compression.

 

I also don't see being able to lower the Scooby engine, due to the crossmember being in the way, unless it really is short enough to be completly behind the crossmember. I know I measured one of these engines a while ago, as I was going to buy a Forester and swap a V6 into it (It had the common head gasket problem, and was on it's 4th driver side head gasket), and although the engine itself wasn't much shorter than the V6 I wanted to swap in, there wasn't enough space make it fit nicely behind the grill and have cooling, etc, so I didn't buy the car. If it would fit behind the crossmember it would look kinda neat like that, and could then maybe set up a cantilever suspension system to look even more trick, and use up some of that space.

 

Just also consider that you can place the engine too far rearward and make the car handle poorly. By taking too much weight off the front wheels, the car will want to push more through the corner, than it would with more weight over the front axle. You would then have to weight transfer using the brakes instead of simply letting off the loud pedal, which will in the end make for slower lap times.

 

Some of you expressed concern with hanging the weight of the engine in front of the front axle, when's the last time you heard of a poorly handling Scooby? ;) The fact that the front wheels are powered will help pull the car through the corner, besides that engine by the looks of it is quite light, and from what I remember the engine length isn't that far forward. Just look at a Scooby, there isn't much sheet metal forwad of the front wheels, though possibly more than an S30, I really think that could be doable, and make for a very unique swap. I would consider it myself, if the races that I want to enter would allow front frame rail (and major suspension) modifications, so I am limited there. A FWD front suspension set-up or maybe even the Scooby front suspension set-up could be used for the conversion. You can even move the engine and transaxle back slightly from having the axles exactly inline with the front axle centerline, though this does put a little more stress on the CVs, it gets worse the more being off line you go.

 

BTW, it seems that there are a few people that think I'm raging on this swap or somehow saying that it's a bad idea, please don't read any more into what I write than what is there, I am only pointing out other aspects of this, or for that matter, any swap. I think it would be a good swap, I just think that maybe some of the reasons are for the wrong reasons. I've seen far too many people start stuff like this to realize that there really is no benefit over taking an easier path, or that the "problem" they were trying to "fix" was made worse. I've been around cars long enough to have seen this re-occur more often than you might believe.

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