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PostPosted: February 28, 2011, 11:56 am 
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Who says you couldn't put a different motor in the spot of the Subie. You'd have plenty of room whereas if you just design for a transverse 4 then you're kinda stuck. This seems like a better alternative or should I say a more flexible alternative.

V6s and V8s would fit easier and the car would handle better if put in the Subie slot.

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PostPosted: February 28, 2011, 12:24 pm 
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My only problem with the subaru design is that I would want an STI transmission for the strength and factory helical limited slip front differential. I'm not very familiar with the WRX transmission and what options are available for a limited slip front differential to install in it. I avoided the WRX transmission and bought two different 05 STIs because I knew I was more likely to take the car to the drag strip than an autocross or open track event. I'd still like the FFR car if they designed it around a Honda/Toyota FWD drivetrain but not as much as I like it with the subaru powerplant.

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PostPosted: April 17, 2011, 9:13 am 
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carguy123 wrote:
Dilbert based upon responses at all the other forums using the Subie engine was a stroke of genius. It seems that only on this forum is anyone's nose turned up to the subie engine.


I think it's a great idea until you start to want to improve the Sub engine and box and then it will become a money pit especially when they go "bang" and Subs do go "bang".

I think theres better options for the inevitable improvements people will make long term.

rust_bucket wrote:



-heck, maybe I'll get nuts and submit a design concept of my own. Maybe the winner will get a free kit. :lol:


You guys are suckers or in the least very cheap, they will reap the rewards not you - if you submit a design register the design first.


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PostPosted: April 17, 2011, 2:33 pm 
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cheapracer wrote:
I think it's a great idea until you start to want to improve the Sub engine and box and then it will become a money pit especially when they go "bang" and Subs do go "bang".

That matches what I have observed many, many times. They are decent if you keep the power down, but when you start to want real power the scoobie engines seem to be very prone to going boom. Locally the Evos seem to consistently roll into the shop for upgrades & clutches with the occasional engine or transmission failure; the scoobies seem to be in for rebuild after rebuild.

There's even one (very good) guy in the shop that does nothing but major surgery on the scoobies. Locally (within about 300 miles) we are one the preferred places to get Evo work done (in addition to scoobies); despite this we can occasionally go up to a month without having an Evo in for work. Most other makes & models seem to be far more robust when modded than the scoobies as well.

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PostPosted: April 17, 2011, 4:38 pm 
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KB58 wrote:
ffrgtm wrote:
An ls6 weighs 297 lbs... about 20-30lbs off of a 13b. With torque tube and transaxle its 450.
Without a picture of a complete LS6 on a scale I don't believe it. That's less than a all-aluminum 4-cylinder 2.4 liter Honda engine.
Well, it just so happens we have a few of said pics around here, and you're right to be skeptical of somebody claiming the LS6 to weigh <300lbs. I too would really like to see a source for that absurdly low claimed weight. Short block maybe? Seems to me that somebody may have been drinking too much of the FFR kool-aid.

Page 1 of the "Engine weight summary" sticky in the "engines and drivetrains" forum...LS1 from an 02 Vette = 456lbs with manifolds but no accessories. Can't see if that is with or without flywheel/clutch, but either way a far cry from <300lbs. Also page 5 in the same thread shows a complete LS1/T56 drivetrain with no manifolds, but at least some accessories and I believe with clutch/flywheel, to be (sans published approximate T56 weight) in the upper 480lb range. So fairly consistent numbers from two independent photographic sources. Decently light for a V8, but nothing that would seem to defy the laws of physics either.

cheapracer wrote:
rust_bucket wrote:
-heck, maybe I'll get nuts and submit a design concept of my own. Maybe the winner will get a free kit. :lol:
You guys are suckers or in the least very cheap, they will reap the rewards not you - if you submit a design register the design first.
Agreed. In this social networking media age, all sorts of companies are taking advantage of people being revved up at the slight potential for 30 seconds of "fame" and a nominal reward, while really just providing mass quantities of free labor hours and resources from which the company will directly profit. Hell, the Local Motors business model is specifically based around this concept. Maybe I just value my time (and intellectual property) too much as a "professional" to give it away, essentially free, for others financial gain...But then again, maybe I'm just jealous that I didn't think of it first.

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PostPosted: April 17, 2011, 10:59 pm 
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From all my research, a running LSX engine starts around 420 Lbs, and increases from there depending on what is bolted onto it.
Flywheels are heavier than flex plates, cast manifolds different to headers, aircon compressors, steering pumps, etc... it all adds up.
You will never see two weights the same, but 450 Lbs complete and ready to run would not be an unreasonable average for a production version pulled straight out of something.
They are very light for the capacity, but still a pretty big lump to steer and stop.

The subie motor is low wide and flat, and not that heavy for it's capacity, and the turbo version has been well developed.
In mid engined RWD configuration, the gear linkages will require some real ingenuity, and that will either make or break it as a desirable sports car power package.
The subie gearbox/diff has some fairly tall ratios that may not suit a much smaller higher revving inline engine. Alternative ratios may be difficult to come by and expensive, even if (?) available.

I know of someone that put a rotary engine in a subie a long time ago, much lighter up front, more power, it showed real promise, but the gear ratios were totally unsuited to the engine which is what let it down.


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PostPosted: April 17, 2011, 11:37 pm 
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Yes the early WRX drivetrain was relatively weak, but the bigger reason you see more in the shop is that there are more of them out there, like probably 5 times as many (which is a big plus for donor selection).

I don't think the transaxle will be any problem in a 1800# RWD car, the available traction very effectively limits the torque you can put through the drivetrain and even stock power levels (227hp) will be plenty in a car that light, so no need to stress the engine.

On the plus side being able to log and tune the factory ECU with nothing more than a $169 cable/interface and free software is a wet dream after 14 years of "tuning" turbo imports with piggybacks and bandaids.


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PostPosted: April 18, 2011, 12:12 am 
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Glen wrote:
Yes the early WRX drivetrain was relatively weak, but the bigger reason you see more in the shop is that there are more of them out there, like probably 5 times as many (which is a big plus for donor selection).


Being in a car that is now affordable to clueless high school kids doesn't help either - fortunately that will help the car's popularity as a donor for kit cars. :)

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PostPosted: April 18, 2011, 3:42 am 
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Glen wrote:
Yes the early WRX drivetrain was relatively weak, but the bigger reason you see more in the shop is that there are more of them out there, like probably 5 times as many (which is a big plus for donor selection).

Sorry; I should have said STi's as opposed to just scoobies. We do see our share of WRXs as well, but I was predominantly limiting my failures comparison to the Evo and STi. The last time I walked through, there were 4 or 5 scoobies in the storage garage waiting on rebuilds or new engines plus one in the shop having an engine put in. We only had two Evos in for work. One for a new clutch and e85 conversion (plus tuning); the other was there to have his tune (from another source) re-worked on the dyno.

Glen wrote:
On the plus side being able to log and tune the factory ECU with nothing more than a $169 cable/interface and free software is a wet dream after 14 years of "tuning" turbo imports with piggybacks and bandaids.

That is a huge plus. There is free tuning software available for Mitsubishi, Subaru, some GM products and even some Honda ECUs. Much better than needing to buy a stand-alone to be able to do serious tuning.

My personal bias is based strictly on observed engine failure rates. I've played with both cars on the track and think they are both fantastic to drive.

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PostPosted: April 18, 2011, 11:31 pm 
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Driven5 wrote:
Agreed. In this social networking media age, all sorts of companies are taking advantage of people being revved up at the slight potential for 30 seconds of "fame" and a nominal reward,


Thats the one.

Anyway for those here looking at the thread to see interesting designs which I'm sure many are then I highly recommend browsing this site - http://www.productdesignforums.com/


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PostPosted: April 19, 2011, 5:54 pm 
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It's kind of funny, with my overactive brain I had been sort of planning out a mid engine subaru based car over the last few weeks. It seems like a good, cheap platform for a one donor build.

The concerns I have are:

-I understand only the STI have limited slip in the front diff. Looks like probably $1500+ to get one otherwise.
-does the tailshaft block off plate support the shaft correctly? Typically the driveshaft yoke supports it inside a bushing.
-as discussed, the subies don't like more power so you're stuck with under 250bhp reliably.

Nice to see they are getting better about tuning though.

Cheers.
Cory

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PostPosted: April 19, 2011, 7:13 pm 
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I was confusing this thread with the 4WD thread. Sorry.


Last edited by Warpspeed on April 19, 2011, 7:31 pm, edited 1 time in total.

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PostPosted: April 19, 2011, 7:20 pm 
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Looks like people have had good luck with the cheap OBX LSD (<$400 on ebay)
http://forums.nasioc.com/forums/showthread.php?t=700370

I haven't seen how the block-off plates are done, but the tailshaft would be completely removed when the plate is installed.
You have a valid concern though as the layshaft is supported by the center diff in stock form and that would need to be addressed in the kit.

A locost is very fast with a stock miata powertrain, this will be much faster even with a stock WRX drivetrain.


Last edited by Glen on April 19, 2011, 7:41 pm, edited 1 time in total.

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PostPosted: April 19, 2011, 7:38 pm 
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Oh and the factory five forum is a mess, but they keep one clean thread of the weekly winners of the body design contest
http://thefactoryfiveforum.com/showthread.php?1239-Official-Updated-Weekly-Design-Contest-Winners

Also, they are supposedly unveiling the chassis at the Mitty next weekend.


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PostPosted: April 20, 2011, 12:38 am 
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Good to know there are other options. I've only seen the torsen-gleesen front diffs.

Regarding the support of the Saker cars RWD-delete.... it looks like the shaft is not supported correctly.

http://www.dunebuggyarchives.com/static ... ersion.pdf

Looks to me like they are removing the bearing just in front of the center diff (pressed onto diff) and not-reinstalling it. Also, that shaft may need a thrust bearing which is located rearwards of the center diff. I'm not sure w/o seeing one closer.

One would do better to weld up the center diff, machine down what you don't need and make a plate to support a bearing..... or just weld the diff and not worry about the extra 5" of length (and weight).

Cheers.
Cory

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