Underdog Posted December 2, 2014 Share Posted December 2, 2014 2015+ STI Steering Rack Upgrade Why? The '15+ STI rack has a quicker ratio (13:1, ~2.4 turns lock-to-lock) as compared to the BP/BL LGT/Spec.B (15:1, ~2.8 turns lock-to-lock) and OBXT (17:1). The quicker ratio increases steering response - i.e. less input at the steering wheel for equivalent angle at the front wheels - and also increases steering heft. This makes for a very noticeable improvement in steering feel. The only time I would not recommend this is for users who want the car set up as more of a grand touring highway cruiser - not to say the rack is problematic for highway use, but it is much more direct and engaging than the stock rack. What parts are needed? At a minimum you need only the rack itself (34110VA120). Optionally, you can also swap out the '15+ STI u-joint (34170VA030) which is solid as compared to the damped version on the LGT/Spec.B. PLEASE NOTE: The OBXT uses subframe spacers requiring a longer u-joint. OBXT owners can use the Perrin Steering Lockdown Kit (PSP-SUS-565), cut and weld in a length of steel rod, or remove the body lift (a project in itself). I also installed the Cusco rack braces (692 026 ALHD) and Whiteline rack bushings (KSR207, you will use the smaller 45.5mm ID bushing included in the kit), but these are not necessary, and the STI rack comes with new braces and bushings anyways. The OUTER tie rods appear to be identical to the BP/BL, and the rack comes with new outer tie rods. I am using the Whiteline roll-center correction kit tie rods (KCA313). Are any other modification(s) required? Due to the wider front track of the STI, the tie rods will need to be adjusted almost completely to their inner limit in order to achieve zero toe on the BP/BL platform. By using a M14x1.5 jam nut (e.g. P/N 91938A130 from McMaster-Carr) and trimming ~3-4 threads off the INNER tie rod, you can pick up a few extra millimeters of adjustment. ***This is not strictly necessary*** but is simple and gives you a little margin with your front toe adjustment. Unfortunately we can not swap to the LGT inner tie rods because the stub thread that attaches to the rack itself is M20x1.5 on the STI and M18x1.5 on the BP/BL. To date I have not found another inner tie rod that is a drop-in solution. Fortunately trimming the inner tie rod is simple! Details below. Otherwise all you need to do is tweak the hardlines coming off the rack ever so slightly to mate to the BP/BL power steering hoses - no special tools or parts required for this. As these cars get up in years and miles, some owners are opting to replace their power steering pump with the '15+ STI unit, which is spec'd for the higher demands of this rack. That said many owners have and continue to use their factory LGT pump without issue. Trimming the inner tie rods (OPTIONAL - SEE ABOVE): 1. Thread two M14 nuts onto one INNER tie rod. Set the outermost nut so that 3-4 threads are exposed. This will serve as a guide for your hacksaw/sawzall/bandsaw/cutting wheel. 2. Cut the exposed threads off. Slow and steady. Use 3-in-1 oil to keep the blade cool (not for abrasive cutting wheels). Keep the cut perpendicular. 3. Thread the two nuts further on to the tie rod, exposing the cut end you just made. 4. Use a file to dress the cut end of the tie rod. Use a metal bristle brush to clean out the threads. 5. Remove both nuts. They will reshape small imperfections in the thread. 6. Repeat on the other inner tie rod. What about VDC? It appears that only the OBXT owners are having trouble with the VDC kicking in at odd times after installing this rack. This is likely due to the extreme difference in ratios between the OBXT and STI racks. LGT owners do not seem to be reporting any issues. Regardless, this is an easy problem to circumvent, as the VDC can be disabled with a press of a button. Work-arounds to keep VDC are beyond the scope of this thread, but as some info has already been posted please feel free to discuss. A brief word about P/S fluid: With the quicker rack, particularly where caster has been added to the front suspension, or aggressive alignment settings are used, it becomes increasingly important to maintain your power steering system. For this reason I recommend flushing the system at the time of the rack install, and using a high quality fluid like Motul Dexron III Technosynthese (1L, P/N 105776). Motorsports users may want to consider additional cooling, as required. Replacement Parts (For Reference Only): 34168FG000 - '15 STI Inner Tie Rod Lock Washer 34128AG000 - '15 STI Inner Boot Band Pictures (moved to attachments due to hosting issues): 1. STI tie rods adjusted for max toe in. Just slightly inboard of LGT tie rods which are set for zero toe on my lowered LGT. 2. RH bushing braces 3. LGT/STI/Cusco LH braces 4. LGT (right) and STI (left) u-joints 5. LGT and STI P/S lines - good clearance to hydraulic lines. May need to tweak hard lines ever so slightly to get good alignment. 6. P/S lines installed 7. STI u-joint installed. Fits just like the LGT joint. 8. Cusco LH brace 9. RH brace 10. Rack installed - bottom view 11. Rack installed - side view 12. Rack installed - top view 13. Rack Label 1 The Crimson Dynamo Link to comment Share on other sites More sharing options...
Chris GTO TT Posted December 2, 2014 Share Posted December 2, 2014 Damn I didn't even think about the VDC steering angle information I might not be able to do this if it causes a problem with the VDC. Wonder if simply resetting the steering angle like after an alignment will be sufficient... 2003 Baja 5MT 2016 Outback 2.5i Premium w/Eyesight Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 Really not sure with the VDC stuff. I believe the steering angle sensor is incorporated into the roll connector assembly so it's possible swapping that over would send "correct" information, but I'm not sure if it will play nice with whatever algorithm is at work behind the scene. Going to take an adventurous VDC-equipped LGT/OBXT owner to find out. In fact - this applies to my plan to swap the LGT rack into my OBXT as well. Who knows... I may end up tackling this in the spring. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Nightmaresmk Posted December 2, 2014 Share Posted December 2, 2014 Can't wait for this review. definitely a future upgrade for my outback. Link to comment Share on other sites More sharing options...
doobaruGT Posted December 2, 2014 Share Posted December 2, 2014 I'm already planning my springtime replacement! Subscribed! Updated parts list since original part-out here. Original Full part-out of my LGT HERE! Link to comment Share on other sites More sharing options...
doobaruGT Posted December 2, 2014 Share Posted December 2, 2014 From where did you source the parts? I think I recall a link from the other thread for $500 on the rack alone. Updated parts list since original part-out here. Original Full part-out of my LGT HERE! Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 (edited) I am an OEM and aftermarket parts distributor so I sourced these parts from myself. I can provide these racks for $640. One of my competitors is selling them at dealer cost but way overcharging for shipping, like they do for short blocks. Kickbacks anyone? If they didn't charge 3x actual shipping costs it would have been cheaper to order from them rather than my wholesale distributor. The reality is that even at $640 I am only making single-digit margins. Anyways, this felt incomplete without some pics of the rack installed in the car so I installed the OEM bushings and put the rack in the car so we could get an idea of clearances for the hydraulic lines and any other fitment issues. Everything bolted up without issue. More pics in the first post. Edited December 2, 2014 by Underdog The Crimson Dynamo Link to comment Share on other sites More sharing options...
doobaruGT Posted December 2, 2014 Share Posted December 2, 2014 Perfect! Now I have a date to execute and a supplier Updated parts list since original part-out here. Original Full part-out of my LGT HERE! Link to comment Share on other sites More sharing options...
whitetiger Posted December 2, 2014 Share Posted December 2, 2014 this is an interesting mod. too bad it wasnt around when i had my LGT. Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 Your LGT lives on via the AP Suretrac rear diff in this car. The Crimson Dynamo Link to comment Share on other sites More sharing options...
whitetiger Posted December 2, 2014 Share Posted December 2, 2014 nice, you need to do the ppg center. you NEED to do it Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 I would but I bought the JDM STI 5MT DCCD center diff we PMed about a few months ago. Have that and a FLSD, MapDCCD controller, and Moore Performance blast plates going in currently - but that is a different thread. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Rhitter Posted December 2, 2014 Share Posted December 2, 2014 hmm - curious about the VDC. Hopefully someone else who actually knows what they are doing will tackle that piece and I can just copy them. My OBXT build Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 You could always just disable the VDC. The Crimson Dynamo Link to comment Share on other sites More sharing options...
ragman Posted December 2, 2014 Share Posted December 2, 2014 I can provide these racks for $640. For comparison sakes, what do new LGT steering racks sell for? Link to comment Share on other sites More sharing options...
Underdog Posted December 2, 2014 Author Share Posted December 2, 2014 For comparison sakes, what do new LGT steering racks sell for? For my '06 LGT the original replacement would be $630. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Max Capacity Posted December 3, 2014 Share Posted December 3, 2014 that's with a 2015 STi rack. what about other STi racks, will any of them fit. I'm sure you can get aftermarket rebuilt racks for less money. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Underdog Posted December 3, 2014 Author Share Posted December 3, 2014 Did a lot of measuring and I'm going to be right at the inner-most adjustment limit due to the longer inner tie rods. While probably not strictly necessary, I would prefer to have a bit more positive adjustment range. Rather than modify the STI inner tie rods and buy thinner jam nuts to pick up ~4mm of positive adjustment, I'll just replace them with LGT inner tie rods. The STI rods do not appear to be different from the LGT rods in any other way than length, so assuming they fit it would be crazy to not just do it right. Ordered new LGT inner tie rods, lock washers, and inner boot bands. P/Ns will be added to the first post. that's with a 2015 STi rack. what about other STi racks, will any of them fit. I'm sure you can get aftermarket rebuilt racks for less money. The GR rack should fit but I don't think there is any difference in the ratio. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Max Capacity Posted December 3, 2014 Share Posted December 3, 2014 Thanks for answering my question. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Rhitter Posted December 3, 2014 Share Posted December 3, 2014 The 2015 STI has VDC, would the 2015 steering rack have whatever is needed built into it? I guess that would require taking the rack to the dealer and seeing if they could "pair" the sensors. My OBXT build Link to comment Share on other sites More sharing options...
Underdog Posted December 3, 2014 Author Share Posted December 3, 2014 The steering angle sensor is in the roll connector behind the steering wheel. There are no sensors built into the rack itself. I don't know if the sensor is scaled differently or if the algorithm takes care of scaling, so there would need to be more research before slapping parts into a VDC car. Could always disable the VDC in the meantime. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Rhitter Posted December 3, 2014 Share Posted December 3, 2014 hmm I guess potentially you could replace the steering angle sensor with one from an STI (if the VDC logic is controlled by that sensor) My OBXT build Link to comment Share on other sites More sharing options...
Underdog Posted December 3, 2014 Author Share Posted December 3, 2014 I would imagine that the sensors are the same - just measuring the angle of the steering wheel - and the scaling is applied within the algorithm. Purely speculation though. If the sensor is indeed outputting the steering output angle and not the steering wheel angle then I suppose it would be possible to retrofit the STI roll connector, assuming it fits. The Crimson Dynamo Link to comment Share on other sites More sharing options...
Rhitter Posted December 3, 2014 Share Posted December 3, 2014 (edited) I read through this thread: http://forums.nasioc.com/forums/showthread.php?t=1757077 Unfortunately no one was able to figure it out - quicker rack = VDC off. Bummer. Hopefully I can figure out something (maybe there is a value in the ECU that can be modified). Would really really like the STI rack with VDC . It also looks like only the STIs are able to turn off VDC? All others have to turn off VDC, ABS, and EBD. Edited December 3, 2014 by Rhitter My OBXT build Link to comment Share on other sites More sharing options...
Underdog Posted December 5, 2014 Author Share Posted December 5, 2014 (edited) Unfortunately the LGT inner tie rods will not swap in. The LGT inner tie rod male threads (to connect the inner rod to the rack) are M18x1.5 and the STI inner rods are M20x1.5. Back to modifying the STI inner tie rods and getting a thinner jam nut. Please note: the thread for the inner/outer tie rod connection is the same between the LGT and STI (M14x1.5), so LGT outer tie rods and the Whiteline KCA313 replacements will work. Edited the first post with this information. Edited December 5, 2014 by Underdog The Crimson Dynamo Link to comment Share on other sites More sharing options...
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