STI donor possibility - hear me out

[SkiRideDrive]

I am just thinking out loud here...

Off the top of my head the only thing I can think of that probably wouldn't work from the sti on the 818 is the 6 speed transmission (please fill me in if I am mistaken).

I was contemplating the idea of finding an STI donor (possibly even more likely to be wrecked by a teenage genius) and then selling the 6 speed and purchasing a 5 speed to replace it. Thus recouping some extra cash or perhaps being able to afford an RA or PPG 5 speed in the process. I'm sure the STI would also have a few other pieces on it that would be in demand by the Subie crowd which you could sell of as well.

This way, the motor would already be putting out the power numbers I would be looking for once I swap out some exhaust pieces and have it tuned.

Can anyone think of a problem with this idea?

Also, if this were a feasible option... which year STI's would be optimal?

Thanks for the feedback!

[RM1SepEx]

Since this is a "component" car that is indeed one of about 1000 options that could be taken. Parts can be sold off and replaced almost anywhere to either upgrade performance or provide kit compatability.

[Etos]

6 speeds aren't worth as much as they used to. It used to be you had to drop 5g on a 6 speed alone without anything else. Now you can get a 6 speed with all 4 hubs, CV and driveshaft for 3.5-4g. Some people still ask for more but they rarely sell for more now.

Honestly I wouldn't only look at the STi but rather look at what you want in your 818. What are your goals? Do you want a street car, track car, drag car, etc. WRX are ALOT cheaper then STis being a decently big problem going the STi route. What is generally better are the hubs, brakes, engine and turbo. But even the engine is not that much better, brakes on the WRX are good- on an 1800 pound car they'll be much better, turbo is not bad on a WRX cause it'll spool quite a bit sooner. The only flat out better part are the hubs but that's mainly cause 5x114 is a better bolt pattern for wheels then 5x100 and the STi hubs are alot sturdier. There's no official word on the 818 being able to use a STi hub but when I spoke to Jim he assured me he knows the advantages and would work on making it an option.

[Mechie3]

It all depends on the donor cost.

Interior sells for more
Wings sometimes sell for more (people like to trade more often than sell though, and wingless takes top dollar)
You might not be able to use the hubs, but you can sell them with the six speed and brembos.

Other than that, STI's aren't much different from 06/07 WRX as far as an 818 donor is concerned. 06/07 got the 2.5L engine (and some believe better heads) so power will be the same.

[SkiRideDrive]

Thanks for the feedback. I wasn't aware of the hub differences. How does the different hub affect the compatibility with the 818 chassis? Are the knuckles different?

My original plan has been the 06/07 I was just curious if this was a worthwhile consideration. I guess it all depends on what donors are out there when I'm ready to purchase.

[Mechie3]

Knuckles are wider where it mounts to the strut. Not sure if there are any other differences.

If you got an 04 STI, they use the 5x100 hubs (same as the WRX). 05+ use the 5 x 114.3 hubs.

[whitetiger]

IMO, the 5x114.3 hubs are worth it. IIRC, they can be installed(pressed) in to the wrx knuckle. do this in case the sti knuckle cant be use due to the increased width.

wheel selections for 5x114.3 are much better if considering wheels over 8" wide.

[SkiRideDrive]

Knuckles are wider where it mounts to the strut. Not sure if there are any other differences.

If you got an 04 STI, they use the 5x100 hubs (same as the WRX). 05+ use the 5 x 114.3 hubs.

Ah, I could see that being an issue.

http://www.youtube.com/watch?v=uN_jVWlSPmk

0:26 in & 1:17 in you can see the piece it looks like F5 will supply to connect the front knuckle to the upper control arm in place of the strut which seems to wrap around the knuckle and if the knuckle is indeed wider where it mounts to the strut, it looks like this piece would no longer fit.

[Xusia]

It was mentioned a while back that you could get STi power from a WRX engine simply by swapping the turbo and putting an STi tune on it. I don't know if this is true or not, but I recall reading it on this forum. Given the price difference of the donors, and potential hassle of incompatible parts, this might be a better option (assuming it's would work).

[Mechie3]

You can get sti power with a 2.5 and the stock WRX turbo too, if you change the downpipe and tune the ECU.

I'm interested in the hub conversion. Sounds interesting. If it's not commercially available I see two potential product offerings (or things I'll do for myself in the shop at work): 1: custom 5x114.3 hubs to press fit into WRX knuckles 2: Machined STI knuckles with thinner strut mounting tabs.

[Mechie3]

IIRC, they can be installed(pressed) in to the wrx knuckle. do this in case the sti knuckle cant be use due to the increased width.

This piqued my interest. In searching, all I could find was that 6Gun (now defunct) used to machine STI knuckles to fit WRX struts and machined STI hubs to 5x100. It was a way for WRX owners to get the stronger bearings (not an issue for the 818 IMO) without needing all new wheels, suspension, etc.

I found one person that machined down an STI hub to work with STI knuckles with some WRX brake work here, but it doesn't look like he made them fit WRX knuckles.

http://www.rspeed.org/forums/members-rides/8226-tsd-daily-driver-scoobaru.html

According to him the spline count, hub OD, and bearing race OD are all different. Rear hubs press in, but the fronts are bolt on the STI too IIRC.

I wonder if the STI hub can be machined to fit WRX hubs, or if you'd have to start from scratch.

[Rasmus]

I think it's a good idea. Might just be a wash with the extra cost of an STi donor.

[Zoolander428]

This piqued my interest. In searching, all I could find was that 6Gun (now defunct) used to machine STI knuckles to fit WRX struts and machined STI hubs to 5x100. It was a way for WRX owners to get the stronger bearings (not an issue for the 818 IMO) without needing all new wheels, suspension, etc.

I found one person that machined down an STI hub to work with STI knuckles with some WRX brake work here, but it doesn't look like he made them fit WRX knuckles.

http://www.rspeed.org/forums/members-rides/8226-tsd-daily-driver-scoobaru.html

According to him the spline count, hub OD, and bearing race OD are all different. Rear hubs press in, but the fronts are bolt on the STI too IIRC.

I wonder if the STI hub can be machined to fit WRX hubs, or if you'd have to start from scratch.


Certainly not a cheap alternative, but perhaps for those who really want to go the 5 x 114 route:

http://licmotorsports.com/store/256%2C246%2C457

[whitetiger]

You can get sti power with a 2.5 and the stock WRX turbo too, if you change the downpipe and tune the ECU.

I'm interested in the hub conversion. Sounds interesting. If it's not commercially available I see two potential product offerings (or things I'll do for myself in the shop at work): 1: custom 5x114.3 hubs to press fit into WRX knuckles 2: Machined STI knuckles with thinner strut mounting tabs.

or maybe FFR can make a slightly different component to allow their suspension to attach to the thicker sti strut mounting tab. pic of what im referring to

[Mechie3]

They could. My ideas were only in the event that they do not do something to accomodate STI knuckles. More than likely, it's a lower (if not lowest) priority for them at this point.

[Mike N]

Is the strut bolt pattern / location the same from STi to WRX? If so then making a wider bracket to fit STi and a shim / spacer to make it work with the WRX would seem to be a simple solution.

[Zoolander428]

Although not cheap, maybe this is a solution for the guys who really want the 5 x 114?

http://licmotorsports.com/store/256%2C246%2C457

[wooward]

I picked up a running clean titled 04 STI for $7200. Hope I can use it for the 818. If not, I'll just sell it and get a WRX.

[305mouse]

You got an STI for that cheap?

[Zodiac]

wow i see running ones going for like 17+. been checking salvage sites also. either gonna get a sti if i can cheap enough or a wrx and then buy the sti engine/harness/ecu. gotta look for the best deal you know.

[wooward]

I was scouring craigslist for a while. A former marine was trying to get rid of it. I essentially just paid off his remaining loan and it was mine. The AC doesn't work and the interior was dirty. Still though, it was a pretty good deal I think.

[Xusia]

um, YEAH!

[Zodiac]

lol yea cause the only interior you would need is the seats unless you get aftermarket. and pfft ac should be fairly easy fix. then selling off all the stuff we wont need for the car you should be at the 5k donor mark i'd think or close at least. good deal now i should look for something like that

[Shef]

I am just thinking out loud here...

Off the top of my head the only thing I can think of that probably wouldn't work from the sti on the 818 is the 6 speed transmission (please fill me in if I am mistaken).

I was contemplating the idea of finding an STI donor (possibly even more likely to be wrecked by a teenage genius) and then selling the 6 speed and purchasing a 5 speed to replace it. Thus recouping some extra cash or perhaps being able to afford an RA or PPG 5 speed in the process. I'm sure the STI would also have a few other pieces on it that would be in demand by the Subie crowd which you could sell of as well.

This way, the motor would already be putting out the power numbers I would be looking for once I swap out some exhaust pieces and have it tuned.

Can anyone think of a problem with this idea?

Also, if this were a feasible option... which year STI's would be optimal?

Thanks for the feedback!

It sounds like an 04-05 Forester XT would fit the bill very well. They actually have the same motor as the 04-05 STi in them (In 06 they got the same 2.5 as the WRX, which is a little different than the STi 2.5) and they come with a WRX 5 speed, though with a different final drive ratio than the WRX. But all suspension, exhaust, etc.. for WRX/imprezas bolt right up because the Forester is built on the same platform.

They can be had for around the same price as a 2.0 WRX but you get the .5 extra displacement, drive by wire throttle and variable valve timing to decrease lag. My friend just bought one for $7K.

I had a Stage 2 04 STi and now have an 04 Forester turbo that is signifigantly faster than the STi was (18G turbo on E85 in the Forester making 350awhp/365awtq @5300FT ASL).
I might even be selling it very shortly for around $8.5K...:)

Just something else to keep your eyes open for, plus they usualy aren't as beat on as the WRX you'd buy from a teeny bopper...

[305mouse]

i have never seen a fxt for the same cost as a wrx

[imnotted]

It sounds like an 04-05 Forester XT would fit the bill very well. They actually have the same motor as the 04-05 STi in them (In 06 they got the same 2.5 as the WRX, which is a little different than the STi 2.5) and they come with a WRX 5 speed, though with a different final drive ratio than the WRX. But all suspension, exhaust, etc.. for WRX/imprezas bolt right up because the Forester is built on the same platform.
I really like this idea. Are the heads the same between the FXT and STi? Is it just turbo, IC, and tuning that cause the 90hp difference between the two?