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Anyone Installed a Merkur XR4ti PS Rack in their 240?

Anyone tried a foxbody rack? They seem to be pretty widely available, not too expensive, and come with pretty good ratios. My buddy says his mustang is ~2.5 lock to lock. Also, there's a huge aftermarket of racks for them if you want to spend $$.
 
mikep said:
number ratios work for gearboxes where you measure degrees. Not so much for rotating to linear. 17:1 what?

Edit: Steve, measure the turns vs distance the rack shaft moves. Then you can compare apples to apples.
Click to expand...

Ok, Mike, since you asked, I dug it out of the garage attic. One turn moves the shaft 58 mm give or take a couple mm.

p1010104.JPG
 
Interesting point on the outers. Isn't that how Ben's quick steering thingamabob works? By pushing the connection off center; more off center = quicker?
 
SteveMD said:
I vaguely recall someone, maybe John, saying that over the years, the XR4Ti came with 2 different racks, 2 different ratios. I have the waffle-pattern housing rack. Not sure which ratio it is.
Click to expand...

You have the "nice" Z rack...2.65 turns lock to lock..

Note that just like here, most basic measurements are never stated and 99% o the Xrattists just repeat what they saw on the orumz.
re the available racks here is the skinny:
ALL waffle pattern/aluminum body racks are the nice 2.65 turns rack

The "lore is the steel bodied racks made by Cam Gears/TRW in Luton, Beds,England are "the slow racks" at about 4.1 BUT! as with everything on Fords and especially Xratties, nothing is sacred...
it turns out that some TRW/Cam gears racks are also 2.65 turns and I've encountered 3.

So Z cool, TRW cam Gears CHECK!Now with racks screw all this ratio talk and really turns lock to lock.
Volvo common ZF rack moves 55mm per turn of pinion
Xratty ZF rack moves 64mm per turn of pinion

Xratty is quicker rack and one o the best things about the car
 
J_Jones said:
Interesting point on the outers. Isn't that how Ben's quick steering thingamabob works? By pushing the connection off center; more off center = quicker?
Click to expand...

Only works for the steering arm. The tie-rod end can be way off center, but the forces act in a direct line from the inner tie-rod ball to the center of the outer tie-rod hole. It doesn't matter how you get there, the forces are in a line. Offset ball joints are used for clearance and more steering lock before they hit the wheels.

Anyone know the stroke of a mustang rack vs volvo rack? The mustang rack is a little narrower (1.75in: 45 vs 46.75)

There are readily available 2.25 and 2.5 lock to lock racks for fox bodies.
 
culberro said:
Only works for the steering arm. The tie-rod end can be way off center, but the forces act in a direct line from the inner tie-rod ball to the center of the outer tie-rod hole. It doesn't matter how you get there, the forces are in a line. Offset ball joints are used for clearance and more steering lock before they hit the wheels.

Anyone know the stroke of a mustang rack vs volvo rack? The mustang rack is a little narrower (1.75in: 45 vs 46.75)

There are readily available 2.25 and 2.5 lock to lock racks for fox bodies.
Click to expand...

They're big and fat and mount spasmodically, a big horisontal lug and I hain't NEVER seen a 2.25 Mooseangst rack.
Piccies or it din't harpoon.
 
mikep said:
number ratios work for gearboxes where you measure degrees. Not so much for rotating to linear. 17:1 what?

Edit: Steve, measure the turns vs distance the rack shaft moves. Then you can compare apples to apples.
Click to expand...
For comparing rack A to rack B, yeah. But generally the "steering ratio" of a car will be the ratio of steering wheel input to the achieved wheel angle.

I've done quite a bit of internet searching in the past trying to find suitable alternatives, and the problem is that even though the Volvo rack is slow on our cars, it also has a lot more travel than most other racks have, so this means using even a "fast" rack from another car (like the Mustang) would be even slower than stock. The Flaming River 3.3 turns lock-to-lock rack has 5.25" of travel, so 1.6" per turn, ~40mm per turn, which is much slower than the Volvo rack. It would be great if someone found some faster readily available alternative, but from my searching it seemed like the XR4ti rack has the fastest travel per turn of production racks I came across.

And then I installed Ben's quick steer roll correction spacers and I was happy as a clam with much faster steering than stock.
 
Poik said:
For comparing rack A to rack B, yeah. But generally the "steering ratio" of a car will be the ratio of steering wheel input to the achieved wheel angle.

I've done quite a bit of internet searching in the past trying to find suitable alternatives, and the problem is that even though the Volvo rack is slow on our cars, it also has a lot more travel than most other racks have, so this means using even a "fast" rack from another car (like the Mustang) would be even slower than stock. The Flaming River 3.3 turns lock-to-lock rack has 5.25" of travel, so 1.6" per turn, ~40mm per turn, which is much slower than the Volvo rack. It would be great if someone found some faster readily available alternative, but from my searching it seemed like the XR4ti rack has the fastest travel per turn of production racks I came across.

And then I installed Ben's quick steer roll correction spacers and I was happy as a clam with much faster steering than stock.
Click to expand...

Thanks for pointing details like that out....never even thought about some of that!
 
Poik said:
For comparing rack A to rack B, yeah. But generally the "steering ratio" of a car will be the ratio of steering wheel input to the achieved wheel angle.

I've done quite a bit of internet searching in the past trying to find suitable alternatives, and the problem is that even though the Volvo rack is slow on our cars, it also has a lot more travel than most other racks have, so this means using even a "fast" rack from another car (like the Mustang) would be even slower than stock. The Flaming River 3.3 turns lock-to-lock rack has 5.25" of travel, so 1.6" per turn, ~40mm per turn, which is much slower than the Volvo rack. It would be great if someone found some faster readily available alternative, but from my searching it seemed like the XR4ti rack has the fastest travel per turn of production racks I came across.

And then I installed Ben's quick steer roll correction spacers and I was happy as a clam with much faster steering than stock.
Click to expand...

So with the BNE quick steer and a Xratty rack, it's like you sneeze and you end up in the next lane? That's what I call quick steering ;-)
 
SteveMD said:
So with the BNE quick steer and a Xratty rack, it's like you sneeze and you end up in the next lane? That's what I call quick steering ;-)
Click to expand...
Well I don't have both, I gave up on the idea of fitting a faster rack and just got the quick steer roll correction spacers instead for my 245, and am totally content. Still looking to find some alternative rack for my 242 though.
 
SteveMD said:
Notice that the outer tie rod stud is off-center. Wonder how that affects ratio.
Click to expand...
it doesn't.

J_Jones said:
Interesting point on the outers. Isn't that how Ben's quick steering thingamabob works? By pushing the connection off center; more off center = quicker?
Click to expand...
See below.

culberro said:
Only works for the steering arm. The tie-rod end can be way off center, but the forces act in a direct line from the inner tie-rod ball to the center of the outer tie-rod hole. It doesn't matter how you get there, the forces are in a line. Offset ball joints are used for clearance and more steering lock before they hit the wheels.
Click to expand...


The best answer, and what I was too sick to type yesterday:
Poik said:
For comparing rack A to rack B, yeah. But generally the "steering ratio" of a car will be the ratio of steering wheel input to the achieved wheel angle.

And then I installed Ben's quick steer roll correction spacers and I was happy as a clam with much faster steering than stock.
Click to expand...
Towery said that the fastest setting on the adapters was too fast.
The middle setting is supposedly magical (I haven't driven with a set yet)
And the slow setting? I don't know how close that is to stock.

We were brainstorming and looking at Corolla parts when that fast steer roll center corrector idea was hatched.

I took a bunch out of the 82 corolla arms (3/4"?), this is the only pic I have online. I just found the rest of the pics on my computer.

72296804.jpg


Nascar teams (and possibly other people) use slow gear boxes for superspeedways, just like Beardmore Taxis in the UK had really slow boxes to avoid upsetting the passengers. But they would achieve very sharp turn angles if you wound them long enough.
NASCAR teams also use different thickness torsion bars in the spool valve to tune the power assist.
 
There seems to be some misinformation in this thread as well, something isn't adding up with the 55mm per turn on the Volvo rack. Anybody have a 240 rack handy they can measure? Both lock-to-lock, as well as total travel?
 
Poik said:
There seems to be some misinformation in this thread as well, something isn't adding up with the 55mm per turn on the Volvo rack. Anybody have a 240 rack handy they can measure? Both lock-to-lock, as well as total travel?
Click to expand...


What doesn't add up?

Where do you think the 55mm rack travel per turn came from?

Right out back on the bench over there Kevin Hawkinson and I compared some Z 240 rack against a ZF Xratty rack

Of course there are maybe 4-5 variants o the 240 Z rack...

Derp derp
 
I think the ZF racks are like ~3.5 turns lock-to-lock. At 55mm/turn, that's ~192.5mm total stroke, which would be quite a bit more than the XR4ti rack. Last time I had a 240 ZF rack in front of me I think it had 165mm of travel. Would be good to get some other measurements as well.
 
I'll do some measuring when I can. I need to get a 242 ready to crush, and Chris has a 93.
Right now I'm flinging mucus about, and too tired to cuss.

John V said:
You have the "nice" Z rack...2.65 turns lock to lock..

Note that just like here, most basic measurements are never stated and 99% o the Xrattists just repeat what they saw on the orumz.
re the available racks here is the skinny:
ALL waffle pattern/aluminum body racks are the nice 2.65 turns rack

The "lore is the steel bodied racks made by Cam Gears/TRW in Luton, Beds,England are "the slow racks" at about 4.1 BUT! as with everything on Fords and especially Xratties, nothing is sacred...
it turns out that some TRW/Cam gears racks are also 2.65 turns and I've encountered 3.

So Z cool, TRW cam Gears CHECK!Now with racks screw all this ratio talk and really turns lock to lock.
Volvo common ZF rack moves 55mm per turn of pinion
Xratty ZF rack moves 64mm per turn of pinion

Xratty is quicker rack and one o the best things about the car
Click to expand...
Good info, Thanks.


SteveMD said:
Cool info, Mike. Hope you are feeling better.
Click to expand...
hack..
thanks.
 
mikep said:
I'll do some measuring when I can. I need to get a 242 ready to crush, and Chris has a 93.
Right now I'm flinging mucus about, and too tired to cuss.


Good info, Thanks.


hack..
thanks.
Click to expand...


Sumpin' is going around. Yesterday and the day before I was like "duh" horrible scrtchy throat, could not use voice, huge fatigue, buckets of snot..couldn't muster enough energy to cough...poooor me..:oops:

What attacked youse Mike?
 
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