Miata steering rack help needed....

My Challenge car utilizes a Miata steering rack and it's positioned so it passes between the harmonic damper and the oil pan on the LS engine. That presents another space issue......the hydraulic tube going to the passenger end of the rack  won't fit. in fact the bung it threads into touches the oil pan. I have one choice and that would be to cut the bung off and depower the rack. My concern is that the car would be a bear to steer on an autocross course running 275 or 295 purple crack tires.  I'm wondering what it would take to relocate the bung to be able to retain power steering. In the attached photo you can see the empty bung at the left . It needs to be rotated to a position about parallel to the bung with the banjo fitting attached. I could cut it off, weld up the hole and weld it into a new location, but I have no idea what's actually in there in terms of moving parts. Does the interior of the tube need to be properly smooth its entire length? What about cutting the tube someplace between the two bungs and welding it back together?

Any other ideas on how I might accomplish this? Keep in mind I'm doing stuff with angle grinders and a MIG welder, not proper machine shop equipment. I'm not much of a welder and anything I do would need to be leak proof, too.

It's a hollow tube inside and there's a cylinder/piston that runs back and forth. Whatever you do, you need it to be nice and smooth on the inside.

What year? The design changed with the NB, and the options might be different. I'm wondering about rotating the whole housing...

Actually, I don' think the year matters. Can you figure out how to rotate the steel tube where it enteres the pinion housing?

Here's what's inside. I took these pics in 2002 or 2003 so I'm not 100% sure, but IIRC the big cylinder sits at one end of the tube to support the rack. There's a smaller divider that is the piston that's just to the right of the cylinder here.

The piston, having a bad day. But this is what has to seal.

In reply to Keith Tanner :

I have two racks. One is from a 2003 I believe and the other I would have to see if the year was on the receipt. The one in the picture is the unknown year but has the big aluminum nut on the right end, not the easier to remove clip I see in some videos. The rack travel, stop to stop, is a touch longer than the distance between the two ports, so I assume the piston runs really close to that empty bung, possibly negating the chance to cut the tube and rotate it.

The later racks just disassemble differently, but they all come apart.

I think you're right about the depowered rack being tough with wide sticky tires.  The location of those bungs is pretty important as they pressurize/depressurize on either side of the internal seal based upon steering input.  I don't think you can just move them.  Somebody makes an aftermarket electric steering rack that retrofits to Miatas, I would definitely be looking into that.

The tube is staked at the pinion end, so I might be able to carefully cut that off , rotate it and stake it again. Would there be a seal or O-ring between the cast housing and the tube , or just a press fit with the staking to retain it?

Is the oil pan steel?  If so, can you put enough of a dent in it to give you the clearance you need?

Alternatively, can you use spacers to relocate the steering rack slightly?  This may mess up your geometry a bit, but might be able to correct that with tie rod end spacers?

I have never messed around with any LS engines or miata power steering racks, so I'm just spitballin' here :)

v

Keith, the two bungs/ports in your picture are much closer to being on the same plane than either of my racks. Do you remember what year your's was?

This discussion seems really familiar to me.  Didn't we have a similar one in the last 18 months or so?

In reply to APEowner :

I'll be 70 on my next birthday....there's a distinct possibility that I've started this discussion before.......

DeadSkunk (Warren) said:

The tube is staked at the pinion end, so I might be able to carefully cut that off , rotate it and stake it again. Would there be a seal or O-ring between the cast housing and the tube , or just a press fit with the staking to retain it?

 

You're the one with two racks, you tell us :)

The rack in my pictures is a 1990 unit, I think. Certainly not NB. That's the NA location of the bungs. Unfortunately, NA and NB racks have a different mount at one end so you'd have to do a little subframe surgery if you wanted to use an NA rack. 

In reply to ShinnyGroove (Forum Supporter) :

I think those are inline assist motors taken from Priii and some Saturn or something, you depower the rack itself.

You can definitely rotate the bungs, but I would be worried about moving them laterally.

Another thought. The piston needs a smooth interior and it must run between the two ports. Down by the pinion the only moving bit is the rack, which doesn't need smooth adjacent to the cast part. Maybe I could cut the tube near the casting and rotate it there. I just need to get someone competent to TIG weld it back together. The banjo port would end up underneath the rack , which shouldn't be an issue, even if I have to put a bash plate under there to protect the hydraulic tube from run over cones.

Keith Tanner said:

In reply to ShinnyGroove (Forum Supporter) :

I think those are inline assist motors taken from Priii and some Saturn or something, you depower the rack itself.

You can definitely rotate the bungs, but I would be worried about moving them laterally.

I think you could move the banjo port closer to the pinion without issue, but the passenger end port can't move laterally without the piston running over it...........I think..........maybe........

A rotated NA unit might be the way to do it. I can see the potential destruction of a rack in my future for scientific purposes.

I think welding the bung back in a different rotation has a high likelihood of slightly warping the main outer tube and making the bore eccentric, which would mess up the travel of the piston.  Unless you have an easy way to bore it back out when you're done I think this might be a tough project.  I like the idea about trying to change the rotation of the whole rack, It think dealing with the ears that mount the rack could be easier.

You've got PM. 

DeadSkunk (Warren) said:

In reply to APEowner :

I'll be 70 on my next birthday....there's a distinct possibility that I've started this discussion before.......

Pretty sure you did to the point that I was checking the dates on the posts.

Find a manual rack? I realize budget but maybe a reader can help with a good deal.

I was not happy with the depowered rack on the Molvo. The option was to figure out power  steering or go manual rack.

Happy to say the manual rack is the answer. Significantly easier to steer than the depowered rack.

I know you are in London from time to time, so next time swing by for a steering effort demo in the Molvo.

Pete

The problem with a manual rack is that it has a slower ratio, which can lead to some real elbow action in an autocross.

NB manual racks are rare beasts - only used on the 1999 base and the 50 (?) 2003 Club Sport cars. NA manuals are a lot easier to find.

Going manual will be a last resort. With wide gummy tires it would be a lot of effort, even with the slower NA manual rack.When I do see manual ones they seem to be pretty pricey any way. The effort is going to depend on the tires and also the front end weight, which I have no feel for yet. I'll work on dismantling one rack and see where the driver's side seal actually is in the tube and hope there's enough extra tube to cut and re-weld it. I just tried rotating it with a pipe wrench and a length of pipe, but no go. I don't have a wrench or socket big enough for the end nut either, so a trip to Menards will likely happen tomorrow.

Also, with the rack cranked all the way to the right you can just see the piston appear in the port, so there'll be no cutting the tube at that end.

In reply to therieldeal :

Sorry, I missed your post. The oil pan is aluminum and the point of contact is right below the mounting flange. The hydraulic line fitting and tube would need at least 1.5" of clearance. Had I realized this would have been an issue before I started construction I might have been able to set the engine back another 3" , or so and the rack would pass in front of the balancer, but that ship sailed quite a while ago.

My solution to a lot of caster and camber and a depowered rack was a bigger steering wheel. Works pretty good 

In reply to Dusterbd13-michael :

What do you run for tires and wheels, Michael?