Another 510

40 year old design and home-brew geometry vs. modernish design and supercomputer geometry? I really don't see how a 240Z rack thrown into a steering box car is better than a subframe swap. Have you driven both 240's (Z and SX)? Night and day!

You were right about the Volvo. (very, very right) I'm right about this.

-Dave

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eyesoreracing
40 year old design and home-brew geometry vs. modernish design and supercomputer geometry? I really don't see how a 240Z rack thrown into a steering box car is better than a subframe swap. Have you driven both 240's (Z and SX)? Night and day!

You were right about the Volvo. (very, very right) I'm right about this.

-Dave

I don't think we're disagreeing.
SOMETHING EASY AND QUICK that doesn't cost a lot.
Struts with a means to swap in fresh spares in typical service time. Ears or socket.
Ears is easier.
BETTER junk more commonly available..

If that means a sump mod or so whatever..
Now front mount RACKS do have the advantage in that swaps are faster in front, and steering column mods are easier because one doesn't HAVE TO do a special high angle intermediate shaft with the 2 u-joints---small differences in where the pinion shaft is aiming can be accommodated when there's a longer run of shaft..

goddammit John, how the hell are we supposed to argue if we aren't disagreeing?

If I remember correctly when do steering stuff, you want the inner tie rod pivots to be at the same distance/width as the inner control arm pick-ups as to prevent excessive bump steer. Nowadays there are lots of options available aftermarket for kits . Here's an article on an install , tho not real technical.

http://www.hotrod.com/techarticles/hrdp_0705_rack_and_pinion_steering/installation.html

Also somehow came up with this link on quick racks...

http://www.rollingthundershow.co.uk/sale_wanted.htm

really neat for sale ads from Brit stock cars. Vauxall, Starlets and so on. Pretty cheap prices. The worlds fastest Starlet down the page aways.....

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heymagic
If I remember correctly when do steering stuff, you want the inner tie rod pivots to be at the same distance/width as the inner control arm pick-ups as to prevent excessive bump steer. Nowadays there are lots of options available aftermarket for kits . Here's an article on an install , tho not real technical.

http://www.hotrod.com/techarticles/hrdp_0705_rack_and_pinion_steering/installation.html

Also somehow came up with this link on quick racks...

http://www.rollingthundershow.co.uk/sale_wanted.htm

really neat for sale ads from Brit stock cars. Vauxall, Starlets and so on. Pretty cheap prices. The worlds fastest Starlet down the page aways.....

Hey Gene, bear with me for a second.
I also labor under the same impression the the tie rods inner pivots are 'spooooooooosed to be about where the control arm inner pivots are

BUT!!!!
As soon as you turn the steering wheel the rack slides over and the inner rack pivot point is now over ----------> there inboard of where it WAS and on the other side way outboard.....

So how down to the mm important can it be??

its a lot more complicated than either of you are describing, which is why you should install a complete system.

Broken record...

-D

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eyesoreracing
its a lot more complicated than either of you are describing, which is why you should install a complete system.

Broken record...

-D

But of course.
That's what I've been saying since---are ya ready?-----1985
Escort MkII was the suggested complete front end then.
Whole fawkin thing.


But tell us why or how "it's more complicated?"

(Can you imagine how good it would have been? The stuff is the same stuff I build now, and it works good, it would have been light years ahead of everybody but Buffum and Millen, who DID have MkII Escort stuff in his Mazdas)

Only wussies worry about things like putting a rack of the wrong width, in the wrong location, and creating awkward continuously varying ackerman or horrendous bump steer...

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Tim Taylor
Only wussies worry about things like putting a rack of the wrong width, in the wrong location, and creating awkward continuously varying ackerman or horrendous bump steer...

Well nobody wants to do something wrong, but who says production stuff is "right"?

I know Ford reposition the placement of the rack on the 4x4 Sierra/Escorts in GpA but the question remains---when the rack is turned the inner pivots of the rack aren't exactly were the control arm inner pivots are---and yet we don't all die?

With the Mk2 rack, would you seriously want power steering, or would it be fine without?

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1fastben
With the Mk2 rack, would you seriously want power steering, or would it be fine without?

Ben that's a hard question. On my Saab with a very quick 2,2 turns the 'weight" is perfect on gravel but the Saab really, honestly is a very much different hub/knuckle/flange and flange to centerline of wheel design than 510 or "510" or 210 or even the escort..

The Saab has--and was co-equal with Citroen in releasing in a mass produced car----what's called "Zero Scrub radius steering".
In other words if ya draw a line thru the upper and lower ball joints which they pivot around, and continue that down to the ground you'll see that that is right in the middle of the tire contact.

Contrast that with old school rwd stuff where the ball joint --the steering axis---is inboard of the tire contact patch and the hub and bearings are a certain distance outboard--and then the wheel is dished deeply moving the contact patch far away from the point the steering pivots about..
That adds a lot of mechanical advantage to the wheel tire combo and really is what drove PS in rwd cars.

So I'd say depending on how deep your wheels are, how fat tires you use, it might feel a bit heavy but back when I was helping all the Opel boys, I got them quick racks, non PS, and none of them complained....so unless you're a limp-wristed girl-boy, probably no problem...
Is this you?

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john vanlandingham
Well nobody wants to do something wrong, but who says production stuff is "right"?

I know Ford reposition the placement of the rack on the 4x4 Sierra/Escorts in GpA but the question remains---when the rack is turned the inner pivots of the rack aren't exactly were the control arm inner pivots are---and yet we don't all die?

Without knowing what the original pivot points were as well as where they moved it to. Well, you don't know anything about what they were trying to accomplish so that is anecdotal at best.

Does the cars steering geometry generate ackerman with angled arms (classic) or rack placement (continuously varying), will it get roll understeer or oversteer in a corner, what are the respective slip angles of the inner and outer tires under different loading conditions...and that's just the highlights of the variables a factory engineer is looking at when they design steering geometry. We're not all gonna die if you do it wrong but the car will still handle like shit if you do.

The odds are stacked against you with anything other than a subframe swap where the only variables to screw up are angling the mounting and the change in wheelbase. Listen to Dave...

I did a bit of all this when building the Celica. I didn't use a different rack, but I re-engineered how the whole front end worked. The arms got moved down and inboard 3". The tie rod was moved to above the steering arm, to compensate for the 3" drop and I'm using a faster power steering rack without power assist. I cut the amount of bump steer to about 1/2 what the factory had and the steering effort, even crawling over rocky river beds in the desert, is minimal. Someday, I might hook the power steering back up, but for now I'll take the slight bump up in HP. I did model the suspension in SolidWorks ahead of time, didn't just hope, so I had a pretty good idea it would work out fine. So, having the inner tie-rod end pivot at the same area as the arm pivot isn't always the case, but it does help.

-Jon

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john vanlandingham

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heymagic
If I remember correctly when do steering stuff, you want the inner tie rod pivots to be at the same distance/width as the inner control arm pick-ups as to prevent excessive bump steer. Nowadays there are lots of options available aftermarket for kits . Here's an article on an install , tho not real technical.

http://www.hotrod.com/techarticles/hrdp_0705_rack_and_pinion_steering/installation.html

Also somehow came up with this link on quick racks...

http://www.rollingthundershow.co.uk/sale_wanted.htm

really neat for sale ads from Brit stock cars. Vauxall, Starlets and so on. Pretty cheap prices. The worlds fastest Starlet down the page aways.....

Hey Gene, bear with me for a second.
I also labor under the same impression the the tie rods inner pivots are 'spooooooooosed to be about where the control arm inner pivots are

BUT!!!!
As soon as you turn the steering wheel the rack slides over and the inner rack pivot point is now over ----------> there inboard of where it WAS and on the other side way outboard.....

So how down to the mm important can it be??

In theory..the outer tie rod is somewhat in line with the center of the knuckle or ball joint, so the inner tie rod aligns with the inner pivot. The tie rod is about the same length as the control arm. If there is much of a difference between the two the ratio becomes skewed and the the wheel turns from the droop or compression rather than actual steering input...and yes that is a simplifiction.

The whole enchilada is the way to go as Dave describes.

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heymagic

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john vanlandingham

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heymagic
If I remember correctly when do steering stuff, you want the inner tie rod pivots to be at the same distance/width as the inner control arm pick-ups as to prevent excessive bump steer. Nowadays there are lots of options available aftermarket for kits . Here's an article on an install , tho not real technical.

http://www.hotrod.com/techarticles/hrdp_0705_rack_and_pinion_steering/installation.html

Also somehow came up with this link on quick racks...

http://www.rollingthundershow.co.uk/sale_wanted.htm

really neat for sale ads from Brit stock cars. Vauxall, Starlets and so on. Pretty cheap prices. The worlds fastest Starlet down the page aways.....

Hey Gene, bear with me for a second.
I also labor under the same impression the the tie rods inner pivots are 'spooooooooosed to be about where the control arm inner pivots are

BUT!!!!
As soon as you turn the steering wheel the rack slides over and the inner rack pivot point is now over ----------> there inboard of where it WAS and on the other side way outboard.....

So how down to the mm important can it be??

In theory..the outer tie rod is somewhat in line with the center of the knuckle or ball joint, so the inner tie rod aligns with the inner pivot. The tie rod is about the same length as the control arm. If there is much of a difference between the two the ratio becomes skewed and the the wheel turns from the droop or compression rather than actual steering input...and yes that is a simplifiction.

The whole enchilada is the way to go as Dave describes.

I know all that, Gene---remember everything I have owned since about 1970 has had a rack on it except 4-5 vans and a Volvo Amazon I had for 5 months.
Remember also I supplied racks to one Colt and one RX-3.
I understand the "ideal" relationship but I wonder just how much deviation from ideal is "OK" (in other words "Pretty damn good" which is ALWAYS the measure I shoot for---it is CARS we're dealing with and the one thing that that guy Hurst and I see eye to eye on is "All cars are pieces of shit---it just depends on what kind of shit" thus it follows that if all cars are pieces of shit---it would be folly to even imagine "perfection" so we shoot for "pretty damn good" which is attainable rather than an idealized concept)

But you follow what I's saying?
Looking dead on like in this drawing:


Is all fine and good but crank the rack over ---which sometimes we do to go around corners---and that pivot for the rack moves ----------------------> 5 inches over while oddly, the pivot for the control arm doesn't.

And yet we don't have terminal whatever and flip instantly and die...

The point is there MUST be a RANGE of positions to place the rack in relationship to the fixed items within which the steering would be "Pretty damn good"

It matters not what physical hunk o stamping is used but rather where the rack itself ENDS UP, whatever you do to get it there.

Obviously I understand that slamming in whole set ups is the easiest thing---as I said I asked Millen in the last century and that rwd RX7 was Wankel motor, Mazda sheet metal and the rest was Escort.
That RX-3 was all Volvo since even 20 years ago it was already clear to me that that was the ideal donor car---since people were too dim to use the whole fawkin thing...