Steering rack mods

Dreadknought

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Hey guys. Been a few years since I've been on here on account of a truck plowing through the front of the mustang.

But now it's getting new life as a street legal track toy. And the mods will be EXTENSIVE. Currently it's gutted and the radiator is in the trunk.

What I need from you guys at the moment is if anyone has any knowledge on mods to the steering system. More specifically for improved feedback and quicker ratio. I'm having to replace the rack anyhow due to the accident. That having been said, id like to do the work myself if possible instead of just buying parts. Money is at a premium if I'm going to get it back on the road anytime soon.
 

Dreadknought

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Right. After checking out Lito's thread again, I'll go epas eventually, but for now I'll work with what I have. Suspension wise is covered. MM caster camber plates, ST coilovers, Strano adjustable sways. That was already an incredible difference. Would like to see what else is on the table.
 

b.mad

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Theres not much aftermarket out there for racks. Might be worth doing some research for an OE part, such as the Boss 302 Laguna Seca.
 

Sky Render

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I would look at converting your front control arms to the later '11+ BOSS spec, specifically the ones with taller ball joints. Replace the rear bushings with polyurethane, because the hydraulic racks have no issues with stiffer bushings. Install a bump steer kit as well.

Theres not much aftermarket out there for racks. Might be worth doing some research for an OE part, such as the Boss 302 Laguna Seca.

He said he wasn't converting to EPAS.
 

Dreadknought

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Yeah I already have the steeda x5? Bumpsteer kit and balljoints. Funny thing is, when I initially I stalled the balljoints, I lost a lot of "percieved" front end grip.

I'm contemplating putting a restrictor valve of some kind on the pressure line leaving the pump, allowing me to tune the amount of steering assist.
 

Norm Peterson

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I'm contemplating putting a restrictor valve of some kind on the pressure line leaving the pump, allowing me to tune the amount of steering assist.
Not sure about that - reduced flow is likely to result in the power assist not being able to keep up with what you want from it during rapid steering inputs.

Used to be there was a torsion bar in the steering whose stiffness affected steering feel. I don't know if power-assisted R&P units use that approach.

Firmer control arm bushings should improve steering response and actually reduce the amount of steering input slightly.


Norm
 

Juice

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IMO, for me the V6 rack feels great. And I like the ratio as-is. But it's probably the same as the GT rack.
 

Sky Render

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Steering lines are very high pressure. I wouldn't mess with making your own stuff unless you have some experience with high-pressure hydraulics.
 

travelers

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Parker-Hannifin might have what your looking for. That one in your link is a nice piece.
 

kerrynzl

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I'm contemplating putting a restrictor valve of some kind on the pressure line leaving the pump, allowing me to tune the amount of steering assist.

I'll chime in on this one, seeing that I've played with power steering on race cars.
First off "pressure is pressure and volume is volume" they serve 2 different purposes.

The most volume needed in a power steering is "lock to lock" [usually parallel parking at idle speeds]
whereas feel is pressure.
Manufacturers put restrictors in the hoses to reduce volume, and the vane pump is on "bypass" at anything over idle speeds

When driving at 170mph with too much volume ,it can be quite frightening. So these restrictors are needed. But this comes at a price.....speed usually means high RPM so the poor pump recirculating fluid on bypass can aerate the fluid [and usually overflows the reservoir]

If the car is dedicated to the track or not a soccer mom grocery getter a good mod is to underdrive the pump.
I usually underdrive them too the point where I get some shudder in the steering [doing lock to lock] and it requires a blip of the throttle.

If the steering has no feedback you need to reduce pressure. This can be done by shimming back the bypass valve at the pump reducing seat pressure [I've played with Saginaw & Aisin pumps, where I also drilled out the orifices on the bypass valve to increase volume back to the reservoir, then reduced the pressure of the relief valve springs]

On the FR500C steering, Ford revised the spool valve in the rack to increase effort and driver feedback [this can be done by increasing the diameter of the torsion bar in the spool]

The torsion bar mod increases effort required to turn the steering [and is linear with engine speeds]
 

Dreadknought

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I'll chime in on this one, seeing that I've played with power steering on race cars.
First off "pressure is pressure and volume is volume" they serve 2 different purposes.

The most volume needed in a power steering is "lock to lock" [usually parallel parking at idle speeds]
whereas feel is pressure.
Manufacturers put restrictors in the hoses to reduce volume, and the vane pump is on "bypass" at anything over idle speeds

When driving at 170mph with too much volume ,it can be quite frightening. So these restrictors are needed. But this comes at a price.....speed usually means high RPM so the poor pump recirculating fluid on bypass can aerate the fluid [and usually overflows the reservoir]

If the car is dedicated to the track or not a soccer mom grocery getter a good mod is to underdrive the pump.
I usually underdrive them too the point where I get some shudder in the steering [doing lock to lock] and it requires a blip of the throttle.

If the steering has no feedback you need to reduce pressure. This can be done by shimming back the bypass valve at the pump reducing seat pressure [I've played with Saginaw & Aisin pumps, where I also drilled out the orifices on the bypass valve to increase volume back to the reservoir, then reduced the pressure of the relief valve springs]

On the FR500C steering, Ford revised the spool valve in the rack to increase effort and driver feedback [this can be done by increasing the diameter of the torsion bar in the spool]

The torsion bar mod increases effort required to turn the steering [and is linear with engine speeds]

Fantastic. This is the kind of info I'm looking for. Wouldn't happen to know off the top of your head how one would go about increasing the diameter of the torsion bar? I'm sure it's not as simple as pull apart, fab new bar, reinstall....
 

kerrynzl

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Fantastic. This is the kind of info I'm looking for. Wouldn't happen to know off the top of your head how one would go about increasing the diameter of the torsion bar? I'm sure it's not as simple as pull apart, fab new bar, reinstall....

Understand reducing pressure will reduce power assist, whereas increasing the torsion diameter still gives the same amount of power assist BUT requires more driver input.

If you're going to put super fat tyres on the front with lots of caster , the torsion bar mod is best.

I cant speak for anybody in the USA, but look for somebody that reconditions power steering boxes and racks [they can do this mod, easily]

Over here we were using early Mitsubishi Galant 14:1 steering boxes on old Mustangs to get rid of that awful ram system [we play with the torsion in them]
 

buster

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very interesting thread.
I find my 2007 GT steering too twitchy at speed, like its to fast or over assisted. My wifes fiat 500 has better steering on the move than my mustang.
 

Sky Render

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very interesting thread.
I find my 2007 GT steering too twitchy at speed, like its to fast or over assisted. My wifes fiat 500 has better steering on the move than my mustang.

Check your alignment, specifically toe.
 

Pentalab

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Check your alignment, specifically toe.

I have heard that the oem ford toe alignment was toed slightly inwards...to reduce tramlining. Then I hear that drag racers want the toe set to zero. Then the track folks sometimes set the toe slightly outwards. What's optimum for various applications ? Right now I'm toed slightly outwards..along with aprx -1.7 deg of camber on both fronts. What's worse for tire wear? I'm lost with all the conflicting info.
 

kerrynzl

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I have heard that the oem ford toe alignment was toed slightly inwards...to reduce tramlining. Then I hear that drag racers want the toe set to zero. Then the track folks sometimes set the toe slightly outwards. What's optimum for various applications ? Right now I'm toed slightly outwards..along with aprx -1.7 deg of camber on both fronts. What's worse for tire wear? I'm lost with all the conflicting info.

You need Toe-in for Pos camber and Toe-out for Neg camber to counteract camber thrust [the tyres steering like a pair of cones]
Toe-out [too much] makes a car twitchy under braking on uneven surfaces. With 1.7 deg of neg camber you could get away with zero toe.
On the track we are more concerned with lap times than tyre wear.
 

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