Rack And Pinion exploration

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S15DET
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Re: Rack And Pinion exploration

Post by S15DET » 12 Nov 2010 20:02

Does anyone know if this is the stock rack on this Ford Focus? It's a picture of a Focus with a Cobra motor, so I figure that the rack might not be a Focus rack, but it looks narrow and easy to mount. I thought it might be worth a look.
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thisismatt
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Re: Rack And Pinion exploration

Post by thisismatt » 12 Nov 2010 20:17

S15DET wrote:it looks narrow and easy to mount
...but it's front steer (trailing tc rods, moves the wrong way for rear steer, plus it's hydraulic assist)
I'm your huckleberry.

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S15DET
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Re: Rack And Pinion exploration

Post by S15DET » 12 Nov 2010 21:16

Fudge, mised the front steer part.
A friend gave me a GM EPS unit that I plan to investigate when I get home. Should fit under the dash OK, pedal assy may need to be adjusted, but the power controller will take the most work.

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Re: Rack And Pinion exploration

Post by fo0manchu » 15 Nov 2010 00:17

one more option for non-power rack is the bmw 320i (e21 model). Anyone ever try this? I got an extra rack lying around, guess i'll mock it up and see.

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dislexicdime
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Re: Rack And Pinion exploration

Post by dislexicdime » 15 Nov 2010 01:03

what about a starlet rack any one tried that?
L series only have one header!

i need another garage mine is full of part's

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kayakdude07
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Re: Rack And Pinion exploration

Post by kayakdude07 » 16 Jun 2012 19:19

Stumbled across this thread today. It is essentially the same thing that we are all after.
http://www.toymods.org.au/forums/tech-c ... inion.html

Highlight of it was this picture that one of their members posted...
Image
Jordan || '72 2 door KA project || '72 2 door goon project- Flintstones powered (dad's)

Rheis
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Re: Rack And Pinion exploration

Post by Rheis » 10 Aug 2012 18:02

I came across a company called flaming river that seems to have many manual rack and pinions available even narrowed ones for the drag race guys? check it out http://www.flamingriver.com go to find your product select manual rack and pinion and hit submit

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Re: Rack And Pinion exploration

Post by akara » 06 Sep 2012 17:31

just wanted to chime in here, i went ahead and did some junkyard part exploration and ended up using an 81 280zx power steering rack and some s12 parts to do it on the cheaps and keep it nissan. I got it for $40 and rebuilt it myself using OEM nissan seals for the peace of mind, $30 total for the seals.

I know the distance between the 510 LCA pivots is something like 22", the 280zx rack is 1-1.5" too long, so around 1/2" per side. I thought that this would be acceptable, my car is a street car not a racing car, and I am using the S12 steering arms that are flatter and reduce bumpsteer by being shorter. I have a feeling it will be barely noticeable if at all by me.

In order to clear the sr20det block I had custom power steering hoses made for the rack, and offset the rack housing 2" towards the drivers side when I welded the stock S12 rack and pinion brackets onto the flipped 510 crossmember, The steering still bottoms on the S12 steering arm stoppers and doesnt bottom out the rack so it just perfectly fits. I am using the S12 steering column knuckle shortened 1 inch, along with another U joint from a nissan NX and a copper bushing in the firewall. I would like to change the bushing to a bearing but for now it works.
Right now I am in the process of relocating my power steering pump to the A/C location using a plate. Can't wait to have a 510 with power steering and a lower ratio because I plan on having lots of caster and a small steering wheel! :D :D :D

Here's some pics i could find,
Image
Image
Image
Image

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Re: Rack And Pinion exploration

Post by akara » 20 Jan 2013 11:39

icehouse wrote:The biggest problem I had was the narrower racks got in the way of the SR engine block. I'm hoping the new one I got will work... Do you have any closer pics? How close is the tie rod pivot points to the stock 510 ones?
Just wanted to add to this thought and update my post above. I've found that the clearance that the SR20 block provides is actually a big factor in getting this rack and pinion setup to work.
On my car, I had to mount my rack and pinion housing 1.5" (roughly) to the drivers side in order to make the pinion not hit the block and also in order to get the steering column u joints to not bind. My pinion is situated only 1/4" from the block, and I had to grind off an aluminum boss on the block to create this clearance, so I have the rack housing as centered as my engine block will allow. When you mock this up with the suspension at full droop, it looks like I would be able to get away with offsetting the rack housing, because the steering knuckles still hit the LCA stops when I turned to the left, without the inner tierod bottoming out on the rack housing.
HOWEVER! I recently found out the hard way once I dropped my car onto the ground that the bumpsteer effect caused by the rack being too long causes the available steering angle at ride height to be greatly reduced.
So to recap the current issue I have with the 280zx rack in my 510 is that I cannot get enough steering angle without the inner tierod bottoming out on the rack housing, and I cannot move the rack housing without hitting the engine block. I get about 25deg of angle and I would like to have somewhere around 32deg like a stock car. I cannot even make a frickin u turn in my cul de sac!! :cry: :cry:
I noticed in one of his posts S15DET mentioned on his car with the MR2 rack, his inner tierods also bottom out on the rack housing, however he never mentioned anything about poor turning radius/steering angle. It would be cool if he could chime in with what his turning radius is. After making this discovery I am wondering if the rack housing on the MR2 rack is more narrow than the 280zx rack, making it more suited to clear the Sr20 block.

here is what I have planned to address this issue in order from easiest to hardest
1. raise front end ride height, add bumpsteer spacers and realign
2. shorten a spare set of steering arms for quicker steering and more angle (would have it TIG welded and braced)
3. inner tierod spacer/machining? (might worsen bumpsteer?)
4. rack housing machining/modification? (not sure how difficult or expensive this is, I am not a machinist)
5. and finally the last option which is to switch my whole setup to the MR2 rack since I've seen it proven in S15DETs car, but I would like more info regarding turning circle before I go down this path.

P.S. I know this is in the archived forum but I am still exploring! :D

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Byron510
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Re: Rack And Pinion exploration

Post by Byron510 » 20 Jan 2013 23:08

I've got a non power rack out of a ZX - apparently a pretty rare item. But I also wrote this off as a useful donor based on the width alone. It was my understanding that the ZX rack and the MRII rack were the same width between the inner tie rod ends.

Keep us posted on your progress, thank you for chiming in.

Byron
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because the opposite never works.

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icehouse
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Re: Rack And Pinion exploration

Post by icehouse » 21 Jan 2013 12:30

akara wrote:
icehouse wrote:The biggest problem I had was the narrower racks got in the way of the SR engine block. I'm hoping the new one I got will work... Do you have any closer pics? How close is the tie rod pivot points to the stock 510 ones?
Just wanted to add to this thought and update my post above. I've found that the clearance that the SR20 block provides is actually a big factor in getting this rack and pinion setup to work.
On my car, I had to mount my rack and pinion housing 1.5" (roughly) to the drivers side in order to make the pinion not hit the block and also in order to get the steering column u joints to not bind. My pinion is situated only 1/4" from the block, and I had to grind off an aluminum boss on the block to create this clearance, so I have the rack housing as centered as my engine block will allow. When you mock this up with the suspension at full droop, it looks like I would be able to get away with offsetting the rack housing, because the steering knuckles still hit the LCA stops when I turned to the left, without the inner tierod bottoming out on the rack housing.
HOWEVER! I recently found out the hard way once I dropped my car onto the ground that the bumpsteer effect caused by the rack being too long causes the available steering angle at ride height to be greatly reduced.
So to recap the current issue I have with the 280zx rack in my 510 is that I cannot get enough steering angle without the inner tierod bottoming out on the rack housing, and I cannot move the rack housing without hitting the engine block. I get about 25deg of angle and I would like to have somewhere around 32deg like a stock car. I cannot even make a frickin u turn in my cul de sac!! :cry: :cry:
I noticed in one of his posts S15DET mentioned on his car with the MR2 rack, his inner tierods also bottom out on the rack housing, however he never mentioned anything about poor turning radius/steering angle. It would be cool if he could chime in with what his turning radius is. After making this discovery I am wondering if the rack housing on the MR2 rack is more narrow than the 280zx rack, making it more suited to clear the Sr20 block.

here is what I have planned to address this issue in order from easiest to hardest
1. raise front end ride height, add bumpsteer spacers and realign
2. shorten a spare set of steering arms for quicker steering and more angle (would have it TIG welded and braced)
3. inner tierod spacer/machining? (might worsen bumpsteer?)
4. rack housing machining/modification? (not sure how difficult or expensive this is, I am not a machinist)
5. and finally the last option which is to switch my whole setup to the MR2 rack since I've seen it proven in S15DETs car, but I would like more info regarding turning circle before I go down this path.

P.S. I know this is in the archived forum but I am still exploring! :D
I did the same thing. The ZX rack is much to narrow for the SR. I still don't see why the rack has to be so narrow. The S12 rack and cross-member I used worked out great. I've often thought about doing a solid works model of the stock suspension and the S12 to see mathematically what happens differently. After doing a few setups I don't see any reason not to do it again. I've thought about using the MR2 rack but as of now haven't tried it. My end conclusion is anything feels better than a wore out steering box. Rack and pinion with Byron's brackets in the back is just amazing!
"People don't like it when shit doesn't match their rule of thumb." Sam

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S15DET
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Re: Rack And Pinion exploration

Post by S15DET » 21 Jan 2013 13:21

I have turn plates at home, I'll use them to measure max steering angle. How does one measure actual turning radius, is it inside-wheel to inside-wheel, or car center to car center, or something else? I'm nearing 45k miles on my MR2 rack and no issues with the rack or stering linkage to report. I had a pretty rubber seal at the firewall pass-through that the turbine heat pretty much wiped out so I need to re-think that. The pass side rack bushing has some play but I bought a new bushing from Toyota for about $5 that should fix that, I'm talking about bushing inside the end of the rack housing that supports the shaft.

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Re: Rack And Pinion exploration

Post by akara » 12 Feb 2013 20:47

hey guys, just a quick update.
I fixed my steering angle problem by switching to 280zx steering arms and extending my LCA's a little and then realigning.
The steering angle is still less than a 280zx but I can turn around on a cul-de-sac and do u-turns no problem now!
I have about 2 full rotations lock to lock, much much faster steering than stock.

I guess the moral of the story is if you're going to use a 280zx rack it would be wise to use the 280zx steering arms also!

There is some bump toe out with this setup, it is only really noticable when you hit a very large spoon drain/dip on only one side of the suspension. I also must note here that I am only running 200lbs springs on the front. If you were on a smooth track you would never notice this, and on the street it is a fair compromise over the box at this point.

I must say, even with a huge amount of caster the steering effort is only slightly more difficult than the box, and it is NOT worth hooking up the power steering. In fact I am worried this will make the car less stable. I am extremely happy with the outcome of this little sub-project. I own a stock 510 in addition to my "project" car and I will tell you right now the difference in steering is frightening!
When I drive the 2dr I am all over the damn road because I cant get used to the feeling of a car that drives straight!! At highway speeds I only move the wheel like half an inch and it changes lanes real quick! Then I get into my 4dr and I feel like I'm in a damn 50's movie!

If I were to do it all over again I would probably use an MR2 rack, and might revisit this in the future but for now im callin it good!!
Thanks for your input guys if anyone is curious about anything I've done feel free to PM me

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Re: Rack And Pinion exploration

Post by Byron510 » 12 Feb 2013 20:56

Thank you for posting up your findings and diving impressions.

This is a project that, like many, I would like to tackle on my hot rod as well. I too have a stocker - Ole Blue - to fall back on. But to tell you the truth, Ole Blue on its stock 155 R13's is no hot rod, so the comparison.. well...not much of a comparison. However the Bronze with its wide tires and small steering wheel takes a considerable amount of effort to steer, while old blue is actually quite enjoyable... even if I chase it all over the road at times. I guess it's what makes it an old car. But to be honest, Ole Blue doesn't need much chasing, it's pretty well behaved to tell you the truth. Maybe it's because everything can only happen in slow motion! :lol: :lol:

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Re: Rack And Pinion exploration

Post by 510-Trevor » 20 May 2013 13:48

With regards to adding a rack and pinion on a rear sump swapped car, has anyone tried changing to front steer and relocating the TC rods. Could you use something like this:
1984 300ZX TC Rods And Mounts
http://www.ebay.ca/itm/380509677538?ssP ... 1423.l2649
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1972 Yellow 4dr

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