Underdog Motorsports - 2015 STI Steering Rack Swap

Really glad to hear the joint bolts right up. Did you cut the tie-rod ends (as per underdog?) or just use the thinner jam notes?

 

I just got the DAMD flat bottom wheel. Looking forward to this.

 

Stock OBXT is something crazy like 3.5 or 3.7. It's more then the stock LGT.

Shop said they didn't cut, just used the thinner lock nuts. Stock Outback is 16.5:1 3.2 turns lock to lock.

b071dc0, did you experienced the same issue like oldskoolbiker of steering wheel not returning automatically to its original zero position? If yes how did you/plan to sort it out? I am seriously into this mod chasing the parts right now, but would like to know is that issue something I just have to live with, or maybe thee is a way to rectify it by getting some more 15 STI parts on the steering column side (or something else...)

I really don't want to have the s.wheel which is not coming back... :-/

Thank you for sharing your experience and I really appreciate your work, courage, time and money to do this mod! :-)

Your question was already answered but no I'm not experiencing any problems like that. My toe is set in a little. Not sure if I'll keep it like that, I just didn't want any toe out. We used old school methods of setting toe by overlapping two yardsticks and measuring front and back of the most middle we could access in between the tires.

Like I said I did suspension too which involved whiteline top hats, set to positive caster, which is said to increase steering effort. So that might attribute to the slight harder steering I feel. Maybe harder isn't to word, firm might describe it better.

Oh and no need to thank me! I wouldn't have considered it without underdogs initial post. I'm glad I could give some input on the VDC. I'm always reading over things that have been addressed years ago, it's about time I get to give input.

Edit: I also wanted to add my mistake of following the general description torque specs of 50 something foot lbs for the steering rack mounting bolts. I should have known better. It seemed like alot of torque for such a small bolt. After I stripped one out I did some reading and realized the service manual lists the wrong torque specs in some of their general descriptions. To fix the stripped nut, I got a standard size tap of 7/16ths fine thread, just slightly larger than the metric bolt, and ran it through the welded nut. I was able to get it through without drilling a hole and the standard bolt tigtened down just fine.

Hey Damirg, the short answer is no. No one has done it. The issue I see with it is how the steering rack mounts to the engine crossmember. You need to compare pictures of how the 2.5xt / LGT rack mounts to the crossmember and compare it to how your steering rack mounts up.

Good luck.

I have "knocking bug" inside steering rack of my car.

So thinking about how to fixe it

http://legacygt.com/forums/showthread.php/knocking-steering-rack-my-outback-xt-251110.html?p=5361501#post5361501

Friends, tell me, please, will 34110AG07A 34110VA120 fit my 2005 model year Outback XT 2,5 turbo AT ?

Regards

It should work. But only one installed on an Outback so far had been done at a shop. Sometimes they have a higher tolerance for mods to get it too fit.

One installed - on your car?

I just experienced an issue with the VDC after having the 2015 STI rack installed. I did a pull on an on-ramp and at the end of that ramp there is a sharp turn before gettimg onto the highway. My car has so much power when I did the pulll the traction control kicked in and then when I went around the turn it kicked in again with no reason to kick in. Later in that same drive when I got off the highway on the exit ramp I went around a sharp turn and the traction control kicked in again for no reason. I suspect this is the VDC getting confused with the steering angle sensor. I've had no issues up to now so it may have something to do with the initial kick on of the traction control.

On the drive home no issues but I didn't kick in the traction control.

I just experienced an issue with the VDC after having the 2015 STI rack installed. I did a pull on an on-ramp and at the end of that ramp there is a sharp turn before gettimg onto the highway. My car has so much power when I did the pulll the traction control kicked in and then when I went around the turn it kicked in again with no reason to kick in. Later in that same drive when I got off the highway on the exit ramp I went around a sharp turn and the traction control kicked in again for no reason. I suspect this is the VDC getting confused with the steering angle sensor. I've had no issues up to now so it may have something to do with the initial kick on of the traction control.

 

On the drive home no issues but I didn't kick in the traction control.

When are you going to a track day? Curious to hear your feedback from there.

Traction control is pointless in these cars anyway, especially on the track. It would only slow you down.

Makes sense, intuitively, that it would freak out. It sees more angle/yaw than it thinks the current steering input should allow for (at the old ratio, anyway), and comes on way early.

When are you going to a track day? Curious to hear your feedback from there.

I run at the track with the Traction Control disabled, so don't expect an issue at the track. Just expect improved performance.

So seems the issue hasn't came back. Looks like the steering angle issue may only come up if you've done something that will cause the TC to kick in.

Did you have the VDC re-calibration done?

No details please.

FXT owner designed a device to scale-up the steering angle signal so his '15 STI rack would play nice with his VDC. Post #512 here.

I'd like to report that I have created a steering angle sensor proxy and seems to have the VDC issue solved.

 

I have the 15 STI steering rack installed on my 11 Forester XT (SH9), it was really nice except that VDC kicks in engaging breaks when doing hard turns. The issue persists even you turned the VDC off, so I think this is what gsrcrxsi said that you cannot completely turn VDC off on WRX/FXT.

 

It's quite annoying so I started looking for solutions and decided to create a device to scale up the steering angle signals. The steering angle for stock SH9 is 580 degrees if you turn the wheel all the way left, and it's 440 degrees for 15 STI steering rack. So I need to scale up around 31%.

 

I used Arduino Uno with 2 CAN BUS shields, intercepts messages from steering angle sensor, scales the angle up, and forwards. VDC reads messages from steering angle sensor and sends out its own messages (probably for ECU to read) with angle info in it. So I borrowed a Subaru DST-i which can be used to diagnose VDC and read the angle sent by VDC and confirmed that VDC accepts the scaled-up angles. Road test also confirmed that VDC no longer kicks in in those corners it used to. http://forums.nasioc.com/forums/images/smilies/banana.gif

 

 

 

 

 

The same steering angle sensor is used on 08-14 STI/WRX/FXT so I think the SAS proxy approach should work on all these models.

My 2015 STI steering rack was just delivered. It's very clean.

It looks like FXT have 19:1, I think Outbacks have 16.5:1. Hopefully, that's a nice to have and not needed.

I know there is a VDC re-calibration procedure which is supposed to be done when an alignment is completed. It basically resets the steering angle sensors I saw it done when I was having an alignment done.

This seems to be the procedure. Requires the Subaru select monitor

http://i.imgur.com/RE0A5UC.png

I have hadn't an alignment yet, but on an Outback VDC appears to be an issue. Going downhill it will turn on.

Using the SSM might resolve it. Hopefully once I get a professional alignment it will mostly be resolved.

Edit. VDC seems to be getting better. Unsure what's happening. VDC / Traction control off button seems to work. There is a really steep swoopy turn near me that I can reliably get it to turn on at. With traction control off it doesn't turn on.

From reading here though, the system doesn't seem to be fully defeatable (the button just seems to raise the limit). I get an alignment tomorrow and then I'll drive it more so I can report back on how it actually feels.

Right now it feels "right", not darty at all.

Some notes from my installation.

I removed the power steering reservoir from it's mount (three 10 mm bolts) this allowed me to drop the OEM rack down and undo the hardlines. There was no way I could get them undone without dropping the rack.

http://i.imgur.com/iGbecSr.jpg

http://i.imgur.com/Blvf0RK.jpg

Also cut the tie rod ends to allow for a little more adjustment

http://i.imgur.com/Xhs2lV8.jpg

http://i.imgur.com/tEZSBiD.jpg

Once aligned rack has plenty of adjustment

http://i.imgur.com/g4ugK3j.jpg

Screwing the hardlines back on was very difficult. I couldn't level the rack into position with them attached. So I had get the rack up and then tighten them down. I was only able to hand tighten them using a crow's foot wrench head, but I haven't seen any leaks in 2 days, so it appears to have worked.

http://i.imgur.com/k1dQvfj.jpg

And this is where I can reliably get VDC to kick on in both directions. There is something about going down that seems to activate it more than going up. Turning it off does make a difference.

http://i.imgur.com/dSHxiY7.jpg

I am really enjoying the steering feel. My steering feel mods are: whiteline LCA inner and outer poly pushing, perrin steering dampener lockdown, and DAMD wheel. Adding the STI rack on top of that was perfect. The steering is a little heavier, but just feels right. This does not feel like a quick rack, it feels like how all Subaru's should come from the factory.

Underdog - any chance you could fix the pics in your original post? Theres a few that aren't showing up. I really appreciate you dedicating the time to document all this for the forum! It's people like you that make this place so great!

I'm planning on incorporating this mod into my massive suspension overhaul. Although it's not required I'd like to "while I'm in there" reroute the power steering lines so they will be out of my way when it comes time to install a rotated turbo setup.

Found some good info on nasioc about making custom lines which will also be compatible with the '15 STI rack.

My car is on the road now with a 2015 STi steering rack. I haven't put the car through the paces yet. ABS and VDC light turned on after sitting for a few months at home. ABS is now off after doing a lap around the block, but VDC light stays light. I don't think this has anything to do with the new steering rack. It only was an issue between now and a month ago and what happened between then is the battery died.

The only thing left I need to get done to finish the steering rack installed is to get an alignment done and getting the steering wheel straightened.

For the life of me I've had the hardest time centering the steering wheel when attaching it to the u-joint. It's off by a notch and I struggled for a few hours removing it and re-inserting it but I can't seem to get it on the right notch.

I think I might just take it into a shop and have them straighten the wheel during the alignment... or would it be as simple as me unmounting the steering wheel and reinstalling it to correct the angle?