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Discussion Starter #1
Ok, so I'm in the process of building a lightweight NA Autocross car out of my '97 Brighton Coupe. I just picked up a burnt '06 STI and would like to swap everything from the under carriage over minus the 6MT and rear Diff. My reasoning for this is that I want to use the STI Brembo's, BBS wheels, coilovers and aluminum control arms/lateral links (for the wider track width). But since I rarely even get into 3rd gear on the autocross track and I'm just running a NA 2.5L motor, the 6MT would just end up being over kill and extra unneeded weight...

My problem is that I'm having trouble finding a definitive answer regarding the use of 5x114.3 hubs with a '98 RS Trans and Diff. I know the stock axles on my Brighton are a different length then the ones in the STI, plus they mount to the transmission differently... Would I need to get custom axles made or has anyone modified the STI axles with a base model Impreza inner axle joint?

Any input or feedback would be greatly appreciated, just please stay on topic and don't clog up my thread. And yes, I did do several searches, but most threads are people with WRX's converting to STI hubs...

Thanks!
 

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The downside to that is you have to use the 6MT axles/diff and trans to use the hubs, almost nothing is compatible with the original drivetrain. Custom axles will run you more than its worth, ive had custom bearing races machined for me to use STi shafts with WRX cups and they failed both times.

if you have the whole car, you can sell the rest of the parts off to put that money towards custom axles.
 

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Discussion Starter #3
Hmmm, well that throws a bit of a wrench in my plans... Really the main reason I picked up the STI was for the Brembo's and aluminum control arms/laterall links. If I were to ditch the 5x114.3 hubs, both front and rear Brembo's should still bolt right up to any '02-'07 WRX hubs/knuckles as long as I use '04 STI rotors, right? And as far as the aluminum control arms and laterall links go, I should still be able to use them if I go with WRX hubs, right? Would I be able to use my stock Brighton axles or do I need the longer WRX axles due to the wider track width on the GD? If that's the case then, I'm not sure if the WRX axles will bolt to my RS trans & rear diff... Gosh, what ever happened to Subies being like Legos? I've always built normally aspirated GC/GM/GF's so dealing with these parts off of turbo cars is new to me... :-(
 

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They are like legos but theres a catch when moving to the big leagues with STI parts.

To use brembos, you need sti front rotors and in the rear youll need adapter rotors for brembo calipers on WRX hubs. I ran GD length lateral links on my RS for years, best suspension upgrade you can do, i tore a boot but never had any issues beyond that. WRX axles will work with any 5mt parts from our cars.
 

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Discussion Starter #5 (Edited)
Makes sense... So what you're saying is, I can run my '98 RS trans & rear diff with '02-'07 WRX hubs/knuckles and axles along with '06 STI aluminum front control arms and rear lateral links? I'm guessing that my Brighton axles wouldn't be long enough, right? Would they even fit right in the WRX hubs?

Then I would either need '04 STI front and rear rotors and the Godspeed oversized parking brake shoes plus the caliper brackets if I'm using '02-'05 hubs/knuckles...

Rear Impreza Brembo Fitting Kit - Godspeed Brakes

Or I could go with '04 STI front rotors and the DBA rear rotor adapter kit from FastWRX which also comes with the caliper brackets needed if I'm using '02-'05 hubs/knuckles...

Rear Brembo Adapter Kit (02-05 WRX) - Brakes


Please correct me if I'm wrong with any of this... ;-)
 

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Yes your axles will work in WRX hubs. You can use WRX axles to help with the added track as well but again, ive run my RS axles for years at GD track width without issues.

For the rear, yes the oversize shoe kits + brackets will work, or adapter rotors. Your call.
 

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Discussion Starter #7
So wouldn't shorter axles add negative camber as long as there was enough play in the lower strut mounts? I don't see how longer axles would add to the track width because the lower control arm length is fixed... Maybe I'm misunderstanding you, if so then please enlighten me!
 

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No the axles dont effect any geometery with the suspension. What im saying is you CAN use longer axles with the added width, but you dont have to.
 

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Discussion Starter #9
Gotcha, I was trying to picture the knuckle with the two lower strut bolts removed and pivoting on the lower ball joint... It made sense that a shorter axle would result in negative camber. Thanks for the clarification ;-)
 

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Discussion Starter #10
So after giving it some thought, it seems like my cheapest option would be to trade my '06 STI hubs/knuckles and rotors for a set of '04 STI hubs/knuckles and rotors. Then I can just directly bolt on my Brembo's with no need for brackets, special rotors or oversized parking brakes, right? That way I can use my '98 RS trans and diff, as well as '06 STI aluminum control arms/lateral links and keep my stock Brighton axles...
 

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Well youll need adapter rotors or pads for the rear regardless. If you go with the 06 parts you'd need new wheels too. If you are going to get rid of that stuff and your interested in shipping shoot me a PM id be happy to take some of it off your hands.
 

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Discussion Starter #12
I see, so if I go with '04 STI hubs/knuckles then I run into the same issue as I have now with needing to use STI axles, diff & trans... The only difference would be that I'd get the 5x100 bolt pattern.

I already have '06 BBS's, if that's what you mean...
 

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Discussion Starter #13
So to summarize really quick...

To run Brembo's on a Non-STI:

'02-'05 WRX knuckles require rear caliper brackets and either adapter rotors or oversized parking brake pads. The fronts are fine, they just need '04 STI rotors.

'06-'07 WRX knuckles just require either adapter rotors or oversized parking brake pads for the rear and the fronts just need '04 STI rotors.


STI Aliminum control arms & lateral links are a direct replacement and will work with any knuckle assemblies... The supposed 20mm wider track width is just because they are longer then the steel '93-'01 control arms & lateral links.
 

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So to summarize really quick...

To run Brembo's on a Non-STI:

'02-'05 WRX knuckles require rear caliper brackets and either adapter rotors or oversized parking brake pads. The fronts are fine, they just need '04 STI rotors.

Yes. 93-07 impreza/wrx hubs are the same.

'06-'07 WRX knuckles just require either adapter rotors or oversized parking brake pads for the rear and the fronts just need '04 STI rotors.


STI Aliminum control arms & lateral links are a direct replacement and will work with any knuckle assemblies... The supposed 20mm wider track width is just because they are longer then the steel '93-'01 control arms & lateral links.
Yes, you gain 15mm per side.
 

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Discussion Starter #15
Gotcha, for some reason I thought it was 10mm per side but 15mm is even better!

So you're saying that '93-'07 Impreza/WRX hubs are all the same but the knuckles are different for '93-'01, '02-'05 & '06-'07?
 

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all impreza hubs/knuckles are the same 93-07 for 5mt/auto cars. The only hubs that are different are 04 sti which are still 5x100 but the rears are for brembos, and the 05-07 are 5x114 which is a whole other ballgame.
 

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04 sti fronts are different also (bigger hub for bigger sti axle. Not interchangable.)

10mm is 04 sti or wrx sedan.

06/07 rears from wrx are already setup for 2pot brakes so not brackets needed just special rotors for brembo only.

Donno if banshee said it already but his info is all good. Youll love the wider track. But you rub everywhere if your lower than 1"
 

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Discussion Starter #18
Excellent, thanks for the great info!

So it's 20mm wider track width for '04 STI and all years WRX sedan, but '05+ STI is 30mm wider?

Thanks for the heads up, but I'll be running fender flares and coilovers, so I'm not too worried about rubbing.
 

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Yes. WRX links are 10mm wider per side so +20mm total width
STI links are +15mm per side so +30mm total.
 

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Discussion Starter #20
So if I don't keep the STI hubs, then that brings up another issue... My BC Racing ER Coilovers are for a '05-'07 STI, so I priced out replacement lower brackets for 5x100 hubs at $50 a piece. Just for kicks I tried test fitting the STI lower brackets to a spare 5x100 knuckle assembly that I had laying around and surprisingly the rears fit! Do you see any reason why I couldn't just get new front 5x100 lower brackets and call it good? If that's the case then the only difference between '05-'07 and '93-'01 struts is the front lower brackets and the rear top mounts, right?
 
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