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LT1 and Subaru Rack


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I bought a 04 Subaru Forrester Steering rack , as other had success with installing it, I seemed to have ran into a roadblock already. I set the rack in just to get an idea of what was needed to adapt it, as you can see in the picture the rack will have to be rotated back about 70 degrees to have the steering shaft positioned correctly, but this will also place the pressure line fitting in the center of the rack colliding with the crank pulley. The pulley is to close to the rack anyway,

 

My idea is to use a 20% underdrive pulley to gain some space, and relocate the rack lower and forward maybe .5 to .75 inches.

What advers effects will this have? I dont think moving it forward would hurt , It seems to me to be about the same as pulling on short steering arms. lowering it I'm not sure about.

 

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Also noticed that the Subaru tierod end has the same taper and thread as the Datsun, ( thats the datsun castle nut )

 

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That's strange? here are some pictures of my 2003 forrester rack and the fittings are at slightly different angles? I did have to modify the driver side motor mount stand on the crossmember quite a bit to get the rack to fit. but the fittings cleared the balancer. If you hadn't already modified it maybe you could return it or at least compare it to an earlier model forester.

 

Edit: Looking at your pictures carefully, I think they are the same racks. try clearenceing the driver motor mount stand first to see if you really do have a problem. Oh one more thing you'll have to clearence the crossmeber quite a bit to get the low pressure return line fitting to clear the X-member, you'll see what I mean in the 2nd picture.

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Thanks Fastzcars, yea its not as bad as I first thought, I stoped guessing and started chopping on my crossmember, Its a good start , but I'm still not comfortable with the clearance, I will have to lower it a bit , and or use a underdrive pulley, I tried to pull the pulley off the adapter but the damn thing is rust welded on, my stock pulley is 7.5 inches in diameter.

Your's looks like your engine is set back a bit more than mine maybe not, your damper must be smaller. What size pulley did you use?

The low pressure return port you mentioned is going to present quite a challenge. I see you adapted braided hoses on , any info you can share on that modification?

 

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The low pressure return port was the biggest challange for me. The hole in the crossmenber has to get closer to the rack mount , right up to it. What I ended up doing was slicing a star pattern in the xmember and hammering it down/in about 2 inches, ya you need at least that much clearence. Then I got an -6 to 16mm x 1.5 mm male to male adpater from McMaster Carr. Then to hook a hose to it I got a -6 45 degree slip fit hose fitting and clamped it. on the high pressure side I got a -4 to 14 x 1.25 mm adapter from MMC. I have go find my receipts to confirm the adapter sizes so don't quote me on them. The small braided lines are -4 , 20 and 24 inches long and the 4 ends were custom made with the stock fittings and -4 made fittings brazed together. I later found out the the size of the small lines are actually 12 mm brake line fittings, so you may just need to get regular 12mm Brake lines. Check out the post by ON3GO about hard barke lines for a source. The think that would be a better way of doing it. The size of my damper is 6 7/8 in it's a fluid street damper and it barely give's me room to install a serpintine belt, we're talking less than a 1/8 inch clearence, Ive since purchased a 6.5 in damper that gives me more peace of mind . I hope that helps. :icon54:

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Zspeed280, I can't answer how the subi rack feels like because my car is still in the body shop. But I can answer how the Miata rack feels, it was VERY responsive on the freeway. I guess the best reason was for parking manuvers. Add the wide sticky tires, the smaller 13 inch momo steering wheel and the car became a bear to park. Add a bad elbow to the mix and I NEEDED to have power steering. Now, each one of us are different and what is difficult for me may not be for someone else. You have to drive your car completed and test drive it before you decide if P/S is what you want. I hope that answers your question.:-D

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i was just curious..does adding the a rack from a different car give the same steering characteristics as the other? like the miata into the z, does it steer like a miata would?

 

I used to have an s2000 and loved the way that thing steered...tight like a go cart at speed and super easy down low. I want to do that swap (steering rack)

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zspeed280, I can't compare how the rack feels because I've never driven a miata to compare it to, but I can say that the miata rack in the Z made it quite responsive. It only took 2.5 turns from lock to lock. I'll give you an expample, went I took my car to last years MSA's autocross in fontana, I could keep my hands at 10 and 3 o'clock on the steering wheel to go around the whole course without repositioning my hands. Even John Williams, a local instructor who's been in autocross a quite few years, commented that it was way more responsive than a stock Z.

 

But one thing you have to keep in mind that the design differences between the cars, the way the rack is mounted, how much compliance the mounts and the steering joints have, the size and grippiness of the tires, the size and stiffness of the steering wheel, all have an effect on how the steering feels. Because each car is different, you have to ask this question, "Would I install a P/S unit in a SR20det engine Z?" probably not, the engine is so far back that most of the weight is off the front axle, making the stock rack quite suffecient. Would I install one in a SBC Z with a/c? I sure would. Would I install honda S2000 rack? sure I would, if "I" needed it. All I can say is GO for it. And make sure you take plenty of pictures.:-D :-D :-D

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well im dropping in a sbm so i may just check all the measurments mounts and all the engineering fun to figure it out :) i loved the way the s2000 handled...so i could mate the two :) I miss that car....

 

thanks for your reply to my question

 

David

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Thanks for the great Info Fastzcars, :icon14:

I modified my rack, and I think I have clearance I can live with now, with the stock pulley. Now I'm trying to find a inner tie rod that will work, the threads on the subaru rack are M16-1.5 , Moog has the EV162 that would have been perfect but its M16-1 :banghead: , I found this site

http://www.valleycruisersnb.com/BallJts.htm, great info, but nothing that will work, Does anyone have any specs on other manufactures Inner tie rods? To find parts everyone wants a make and year , but have no specs like thread size, makes finding stuff damn near impossible.

 

Mark said he got his u-joint from Borgenson , I will have to call them to see what they have available, I't looks to me that its 11/16 dia 36 spline shaft.

 

the Plumbing is next on the list...............

 

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If you pull the parts book at the auto parts store (usually stuck behind the counter because the employee's only know what's in the computer) you can typically find the info you're looking for. The chassis parts book often list ball joints and tierods by dimensions/pn's in the back pages. It is a pain but at least it circumvents the usual no-nothings behind the counter. Just ask to see the books. Tell them why so they don't insist on trying to find it in the "computer". Gawd, I wish we still had real auto parts stores...

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  • 4 months later...
  • Administrators
What about the 280zx rack, would that work in S30?

 

The short answer is no. Well, technically the answer is a maybe, but the work required to do it vs. just using a different rack makes it REAL hard to justify.

 

The ZX is a rear steer design, the S-30 is a front steer design. To utilize a ZX rack in an S-30 car would entail having to build a custom cross member, switch the T/C rods from rearward to forward as on the ZX to clear the tie rod ends. Then you would need to use ZX steering knuckles and being as the ZX steering knuckles wont bolt directly to the S-30 strut tube, you’ll have to have to find a way to get the ZX struts under the S-30 body and being as the ZX king pin angle is shallower, you’d have to relocate the upper strut mount, etc. etc. etc….

 

In short, it would just be way easier to use the entire ZX car than try to use its rack. The easiest solution for steering alternatives in the S-30 car, (like power steering for us older guys), is to use other front steer designs such as the Subaru, Miata, Ford Thunderbird etc. Those are the only racks I’ve heard of being using in the S-30.

 

 

I’d LOVE to see a sticky or FAQ posted with a list of the different racks people have installed in their S-30 cars…

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If I were building a track car I would most likely not do it, I would say the weight is about the same just from memory of moving them around, I haven't weight them. I found it on Ebay , took awhile but they are out there.

 

As for why?

 

Well this Z is a project , I'm not going to race it , It's not my daily driver, It's a hobby , a challenge to learn things, basically I'm doing it to see if I can. I'm in no hurry to complete it and when I'm done I will have a sporty fun to drive summer car that I can say " I made it" .

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