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PostPosted: August 15, 2011, 9:39 pm 
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Joined: September 8, 2007, 8:45 pm
Posts: 91
Location: Central MA
Had my first major disappointment with the build this week - my steering rack is not going to work. I have the entire BMW E30 car as a donor and I was hoping that the rack and entire front suspension would work well but no luck - the rack pinion gear end runs right into chassis. I even went to the extent of ripping apart the rack to see if I could shorten the pinion gear down so that it would clear with a swapped u-joint but the power steering pinion gear can't be shortened via diy methods without some serious creativity that I'm just not sure I want to try. So I'm going to target the cheaper of 2 other options - the E21 BMW or the MR2 - both manual racks. Measurements and ratios look decent and I can get them for $100, so either seems like a good option. The only problem with the E21 is that its a rear drive rack, but my upright has the original control arm mounting point that I can use on the rear side of the upright. Moving to a rear steer gives me more clearance which is a plus.

More pics later. Also found my steering column and shafts are about 1.5 foot short - amazed its that much shorter in my donor but its an easy fix.


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PostPosted: September 25, 2011, 12:25 pm 
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Joined: September 25, 2011, 10:28 am
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Location: Lancaster, Pa
any updates?


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PostPosted: October 7, 2011, 9:54 am 
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Joined: September 8, 2007, 8:45 pm
Posts: 91
Location: Central MA
No, no more progress as its been a real pain finding a rack that'll work. Finally purchased a MK2 from europe that appears to be the best match for a book build - assuming I flip it over and make it a rear steer which I like the thought of. Just need to get my hands on it and make sure it'll work before I do much else. Engine needs to be rebuilt still, but haven't had time to get the work done to reassemble (balancing and head shave). These are all good winter items.


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PostPosted: October 7, 2011, 3:39 pm 
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Joined: January 2, 2009, 1:45 pm
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Location: Halifax, Nova Scotia
If you are after rear steer then there must be loads of FWD rack possibilities out there.

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Isuzu Pickup/SR20DE, +401 COLD frame
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PostPosted: October 7, 2011, 6:15 pm 
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Joined: September 8, 2007, 8:45 pm
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Location: Central MA
Warren Nethercote wrote:
If you are after rear steer then there must be loads of FWD rack possibilities out there.


Yes, there are, but the trick is finding one that is narrow enough to work well with the book sized front end.


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PostPosted: October 9, 2011, 3:41 pm 
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Joined: April 2, 2009, 4:12 pm
Posts: 252
Location: Denver, CO
modifiede30 wrote:
Warren Nethercote wrote:
If you are after rear steer then there must be loads of FWD rack possibilities out there.


Yes, there are, but the trick is finding one that is narrow enough to work well with the book sized front end.


I'll chip in my suggestion of a MK1 Rabbit steering rack. It's not very wide and if you get a GTI rack, it has a pretty decent turning speed.

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PostPosted: October 9, 2011, 10:50 pm 
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Joined: September 5, 2006, 11:00 pm
Posts: 769
Location: Columbia SC
Racks are pretty easy to shorten if they have a steel tube style housing. One of the Ten Lotus/ Locost
Seven Commandments: Thou shalt not use a power steering rack.

RX7 manual rack, cut rack and tube about 5 inches. Cut the rack on the non gear end of course. Tap and thread the end. Used a pipe cutter on the tube and made a jig to weld it together. works perfectly.

Big tap M20 x1.5! Still have it in my toolbox, really good high speed tool steel. Can't remember if the rack was hollow or solid. BMW racks are hollow. The power racks are not suitable to be shortened from my experience.

Don't let people tell you not to thread your own rack. It's fine if you have a little experience with machining.
Use a VERY high quality tap and drill the rack on a lathe. Or get a machine shop to do it for you.

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PostPosted: October 10, 2011, 7:38 am 
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Joined: July 17, 2008, 9:11 am
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Location: West Chicago,IL
Quote:
One of the Ten Lotus/ Locost
Seven Commandments: Thou shalt not use a power steering rack.


I wonder why you say this. Is there something inherently unsafe? Depowering a PS rack should be every bit as good as a manual rack and yougenerally get a more favorable rack ratio. I depowered my RX7 rack and would do it again. The process was pretty straight forward.

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“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766


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PostPosted: October 10, 2011, 11:06 am 
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Location: Columbia SC
Most power racks are very hard to shorten. Many of them have some flex or damping built into the input shaft which makes them undesireable for manual applications. This is true for BMW racks and the Alfa racks. Might not be an issue with Mazda (Koyo) racks.
Even in Mazda circles it's prefered to find a manual rack rather than depowering one.

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1988 Volvo 240 5 Speed ( For Sale)
2002 Toyota Tacoma
1999 BMW M3


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PostPosted: October 10, 2011, 11:54 am 
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The Mazda power racks do have the torsion bar on the pinion. This should probably be welded solid if used as a manual rack. They aren't designed for manual use but can be adapted. The Mazda rack could be shortened.

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2002 Toyota Tacoma
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PostPosted: October 10, 2011, 12:44 pm 
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Joined: July 17, 2008, 9:11 am
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Location: West Chicago,IL
Yeah, I welded the pinion shaft up. I can't find the website that I used for reference but they showed doing that. Many sites don't mention that step. The RX7 (koyo) rack is constructed very much like the Miata rack. It was very easy to depower and shorten. Since in a Locost the rack has to be shortened anyway, depowering a PS rack really doesn't take much more work at the time.

Flyin'Miata's website shows the steps to depower a Miata rack so I'm not sure about the preference of a manual rack in Miata circles. Even they don't mention welding of the pinion.

Good points. I just wanted to know if there was some caveats I had not seen or read yet. I can't speak for the BMW racks. I'll have to take your word.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766


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