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Login to post Forums » Grassroots Motorsports » De-powering my steering rack...I'm lost.

Dec. 4, 2008 1:57 a.m. skullsroad New Reader

I was getting some seriously wonky steering issues in my B13 Sentra S-ER. Vagueness, wandering and a detached sensation were not cutting it on the back roads. After a new pump, new pressure hose, B14 reservoir, Moog ball joints, Moog inner and outer tie rods, fresh fluid, wheel bearings (needed them) and an alignment, my problem was only marginally corrected.

So 2 days ago I gutted my pump, removed my shiny new pressure hose and reservoir, drained all the fluid and removed the return and send lines from the rack. I was not pleased. Steering effort is harder than any unassisted car I've ever driven. It even feels like it fights back.

I've been reading about this subject for a few weeks now and found that some people are looping lines with a breather filter. I'm not quite sure how this benefits the steering effort on a drained rack. Mine are currently left open.

I read about people opening up the rack and cutting off the seal inside. Is this my only option?
Dec. 4, 2008 2:06 a.m. thatsnowinnebago Reader

Cutting the seal is the best way to do it on a Miata, just be sure to pack the steering rack with lube of some sort. I'm not sure if the B13 has similar steering or not though.
Dec. 4, 2008 4:08 a.m. skullsroad New Reader

I have Mobil1 synthetic grease ready to go. Hopefully the B13 rack is similar enough, however, I'll have to wait until my brother gets his SVT Focus up and running and gives my daily driver back. Traffic in a gutted out, stiffly sprung, solid motor mounted car is fun for about 2 and half seconds.

Tomorrow morning I'll try to find some hose to loop the lines and see how much that does for me. I'm guessing nothing.
Dec. 4, 2008 6:36 a.m. GameboyRMH SuperDork

I hope you have big muscular arms if you're removing the power steering from a FWD car...
Dec. 4, 2008 8:31 a.m. neon4891 Dork

Part of the high effort is the ratio. A power rack has a quiker ratio than a manual rack. This leads to more effort needed, but that would be offset by the power asist. Plus you are fighting against the drive wheels. Not to thread jack, but last week I dealt with the same thing, my neon likes to spit out the PS/AC belt every few months.
Dec. 4, 2008 8:53 a.m. John Brown SuperDork

neon4891 wrote:

Not to thread jack, but last week I dealt with the same thing, my neon likes to spit out the PS/AC belt every few months.

Put the passenger splash shield back on.
Dec. 4, 2008 8:58 a.m. belteshazzar Dork

I wager there's a problem with the rack. I've pulled all the assist hardware off of P/S setups before, and once the fluids all out they felt great. Even on FWD cars. I did it on an E30 that was rolling on r-comps and it still wasn't too bad.
Dec. 4, 2008 8:59 a.m. belteshazzar Dork

On second thought, how's the steering shaft linkage? Is there a rag joint or anything that could be toast?
Dec. 4, 2008 9:02 a.m. Keith SuperDork

One thing to remember is that the rack is still trying to pump fluid/air when you move it. That's why people loop the lines, to let fluid move from one side of the piston in the rack to the other. Leaving them open as you have will let dirt/crud in there over time, wearing the internals and leading to higher friction.
Dec. 4, 2008 1:33 p.m. fiat22turbo SuperDork

I've noticed on my FWD cars that the steering rack mounting bolts have a tendency to work loose over time. Might be worth checking out the next time you're underneath.
Dec. 4, 2008 3:52 p.m. Paul_VR6 New Reader

I run my now non-assisted PS rack with the looped lines and although it's a bit harder to steer then a manual rack car, it's not horrible. I've done this on a few cars and I've always been pleased with how it turns out.

What's the ratio of your rack?
Dec. 4, 2008 4:01 p.m. Jensenman SuperDork

Never done it myself, but a buddy down here who races Spec Miata just runs a depowered rack by looping the hoses. He leaves about a pint of fluid in it to keep it lubed. If the pump is still in the system, it's like a big time restriction.

On a FWD car, torque steer with a manual rack or depowered PS rack shouldn't be too bad unless your wheels have a lot of negative offset. If your wheels have anywhere near stock offset you should be fine.
Dec. 4, 2008 8:35 p.m. bamalama New Reader

Jensenman wrote:

Never done it myself, but a buddy down here who races Spec Miata just runs a depowered rack by looping the hoses. He leaves about a pint of fluid in it to keep it lubed.

I did the same thing to my RX-7, it never crossed my mind to do it any other way.

Besides, no ps pump= less weight!
Dec. 4, 2008 9:24 p.m. daytonaer New Reader

I just did this to a very heavy fwd turbo car. You do not want to drain all the fluid, thats why people "loop" the lines. you do not need to bleed/burp whatever the looped line, thats just to prevent all the fluid from leaking out. I have heard (on the internet, so who knows....) that running a dry power rack can cause allot of friction that may seize the rack. So put some fluid in it?

In my own experience here, I do not really notice a heavy feel at speed, almost the same if driving normal. If I stop, its a bear to steer, once rolling its fine. Torque steer is not as bad as I thought it was going to be but my giant turbo does not build boost until around 3k rpm.

Also, did you change your alignment after you put in all those parts? That will make it drive nasty. Mine is 'toed out about to the max spec and tracks nice. Before I looked at the alignment I had some toe in and it was scary to drive.

As others have said, the wandering could very well be the tie downs for the rack itself.
Dec. 4, 2008 10:12 p.m. DeadHorse New Reader
neon4891 wrote:
1. Not to thread jack, but last week I dealt with the same thing, my neon likes to spit out the PS/AC belt every few months.
Does it happen at high RPM? Mine did it all the time on the track. an underdrive pulley cured it.
Dec. 5, 2008 3:57 a.m. skullsroad New Reader

Jensenman wrote:

Never done it myself, but a buddy down here who races Spec Miata just runs a depowered rack by looping the hoses. He leaves about a pint of fluid in it to keep it lubed. If the pump is still in the system, it's like a big time restriction.

On a FWD car, torque steer with a manual rack or depowered PS rack shouldn't be too bad unless your wheels have a lot of negative offset. If your wheels have anywhere near stock offset you should be fine.

The pump is on the car but it only serves as tension for the water pump. The wheels I have on the car currently are 35et compared to 40et stock. Although I have plans to run 15x7.5 Slipstreams with 225/45R15 Hankooks up front and 15x6.5s with 195/50R15 in back. Hey at least I'll save money on a gym membership.

I'll check everything else down there but I doubt anything is loose. Once I gutted the pump and removed the lines I got it aligned with zero toe all around (since its getting daily duty) and it steers and tracks fine.

The ratio I believe is 16:1. That is an interesting point about quicker ratios being harder to turn unassisted. I considered going for the Sentra E model rack which is manual but the ratio is like 24:1. Seems like I'll be doing a lotta steering wheel shuffle in the hairpins. Plus I think I would have to buy new tie rods and I've already spent $200 on this PS system.

I'll loop the lines this weekend to avoid damaging the internals of the rack. How would I go about filling it with some fluid? If I have to put my pump back together I'm going to blow a fuse!!
Dec. 5, 2008 7:50 a.m. HappyAndy Reader

skullsroad wrote:

How would I go about filling it with some fluid? If I have to put my pump back together I'm going to blow a fuse!!

gravity, a hose, some oil and a small funel.

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