Manual Steering for '85 740

[MisterBLC]

Everyone,

I'm working on a '85 740 Turbo project and I am thinking of converting to manual steering for simplicity. I am thinking of two options

1.) Simply keeping the PS rack and plugging the appropriate hoses. Has anyone run this on their 7/9 series? How was the steering effort?

2.) Swapping in a manual rack from a early 240. I am thinking that this would give a much better steering feel but I am not sure how interchangeable the 2's and 7's are in terms of racks. Has anyone attempted this? Are the racks interchangeable at all between the 2's and the 7's?

Any other options for manual steering on the 7/9's?

Thanks!
Brian

[woodywhat]

you should get more sleep {2.30am?} dont think 7/9 series racks fitt, measure inner ball 2ball space{allinges with inner wishbone space} ifrc its wider than 2 seires. to get man rack go to wreckers with a tape mesure and check all makes/modles withman racks as any with the same inner spacing can be made to fit,

[CerebralAilment]

Did you ever go anywhere with this?

[Super Matty P]

FWIW, I did a PS to Manual conversion on 2 of my rx7's. Just capping off the stock rack is fine but doesn't reduce the weight of the steering feel. I imagine it would be worse on a much heavier volvo. The trick is to disassemble the rack and remove the "washers" inside the rack that restrict the flow of fluid left and right. Essentially you just want to hollow out the stock PS rack and then fill it with fluid and weld it shut. Doing this gave the quicker ratio of the PS rack but the ultra-light feel of the manual rack.

This has me thinking about doing this on my car now. I'll check to see if my JY buddy has a spar rack!

[MisterBLC]

I haven't had a chance to play with it much but I did find a manual 240 rack in the junkyard and snagged that for cheap...if I can figure out a way to mount it I may be golden. Otherwise I may opt some sort of power rack modification

[Wilford Brimley]

Let me tell you right now. IT ****ING SUCKS. I have no ps right now and it straight up blows.

[JohnLane]

Brian try this.

Drain the fluid out. Pull the belt. Run the steering left-right-left-right with the return line off to get all the fluid out. Don't let any ick get in the rack.

Drive your car around without power steering for a week and see if you can stand it. With no belt you won't hurt the rack or the pump driving it like that for a week.

My dollar in a bet says that you've put the belt back on it and refilled it with fluid on day three on the outside..... In particular if you have to parallel park anywhere.

Pro-tip.... When you refill it...... Don't refill the reservoir all the way to the top.

[towerymt]

The manual rack ratio on a 240 is way too slow.

The power rack ratio is pretty decent on a 240.

Removing the PS pump and capping the rack or looping the hoses is how most do it on 240s, just leaving the power rack in place. I like the feel. We did 2hr stints in our 24hr lemons car (91 245) last weekend in 85+F heat and the steering effort is nothing to complain about. We're running 225/50/16 tires with a ZF power rack w/o assist.

[drj434343]

Brian, everyone else here must only track their cars; I've never had a problem with the ratio on my 240 manual rack, with the school bus steering wheel no less. I think it gives you another 1.5 rotations lock to lock. Nice to have when parking, but the extra travel for speed maneuvers never feels less...sporty. I'm willing to move my arms to a greater extent while driving, and the extra turns actually gives you more resolution when choosing corners.

No one here has bothered to answer the original question. I don't know myself, but I hope someone has attempted this and can comment.

[towerymt]

I drove the manual rack on the street some too. The feel is great, the effort is great, but the sawing on the wheel to make even normal turns was annoying. I just didn't like it simply for the slowness. If you don't mind the ratio, you'll probably like it otherwise.

When racing, I really didn't like trying to catch a slide or make a tight turn. It also required releasing and gripping the wheel a lot because of the slower ratio.

[ryanfay]

As for the original question about the interchangeablity of 2 and 7 racks: obviously it is possible, just how much effort are you willing to invest? The mounts are VERY different systems. The 7/9 rack is tucked up in the crossmember, whereas the 240s have it in front. If you go this route, why not just make your own crossmember so the rack doesnt sit so low. This is why I feel that 7/9 cars have more bump steer.
I am retrofitting my 240 crossmember to run a ford xratty rack. The advantages aside from being 15lbs lighter and 2.65 turns lock to lock are that you can easily adjust the height of the rack. Afterall the steering system is integral with the suspension (I know someone will argue otherwise). So by controlling the height of the rack, one is capable of adjusting for changes in travel, camber, ride height etc. all the while having control on bump steer.

[towerymt]

Originally Posted by ryanfay

I am retrofitting my 240 crossmember to run a ford xratty rack. The advantages aside from being 15lbs lighter...

What are the weights of the two racks?

[JohnLane]

Originally Posted by towerymt

What are the weights of the two racks?

Well come on! Everyone knows that the manual rack weighs 4.5lbs!

The 'advantage' of the X-Ratty rack is 2.6 turns lock to lock with many other dimensions that are eerily similar to the Volvo. Disadvantages? You'll end up cobbling something to make it work and it is Just steering. That and you'll likely end up having to deal with the banned troll which is what it is.

As it goes....

4.5 turns in the manual rack

3.5 turns in the powerrack.... Still not up to standards.

2.6 turns......

I have a quickrack in the rallycar..... 2.5 turns lock to lock with power assist..... Slow steering sucks! Those of you who are trying to talk yourselves into believing that slow steering is OK..... You've not driven a car with proper steering!

[towerymt]

Originally Posted by JohnLane

Well come on! Everyone knows that the manual rack weighs 4.5lbs!

uh, ok. the ford rack isn't manual at 2.6 turns is it?

fortunately I already have quicker steering, but I had to add weight to get it. in the form of these: http://www.pbase.com/towerymt/image/128509986.jpg

I agree it's very nice.

[ryanfay]

xratty zf 10lbs
240 zf 19 lbs
both measured dry and w/ out tie rods or boots

[Super Matty P]

xratty?

[Lando]

Originally Posted by towerymt

uh, ok. the ford rack isn't manual at 2.6 turns is it?

fortunately I already have quicker steering, but I had to add weight to get it. in the form of these: http://www.pbase.com/towerymt/image/128509986.jpg

I agree it's very nice.

Nice, so it bolts onto the knuckle and just increases the radius arm? The rack will still end up having to travel farther, and i'd imagine it hurts the turn radius, so its not a gain without some sort of trade off. But cool nonetheless!

[Wilford Brimley]

Originally Posted by Super Matty P

xratty?

Xr4TI

[Mueller]

Originally Posted by ryanfay

xratty zf 10lbs
240 zf 19 lbs
both measured dry and w/ out tie rods or boots

Seemed more than that...I'm getting weak

I'll PM you a link for the steering rack couplers.

[ryanfay]

Originally Posted by Mueller

Seemed more than that...I'm getting weak

I'll PM you a link for the steering rack couplers.

It might... Thats using the people scale with rack, then without rack.

[towerymt]

Originally Posted by Lando

Nice, so it bolts onto the knuckle and just increases the radius arm? The rack will still end up having to travel farther, and i'd imagine it hurts the turn radius, so its not a gain without some sort of trade off. But cool nonetheless!

Shorten the steering arm (I use the middle hole), so the rack travels the same as before, but the ratio is changed. There is more steering angle, so the tires rub the inner fender at full lock without adding steering stops.

http://www.kaplhenke.com/index.php?o...d=85&Itemid=33

The rack has the same turns lock to lock as without the spacers, of course, but for a given degree of steering wheel rotation, the wheels are being turned further.

We should measure steering angle on a stock 240 and then measure lock to lock turns covering the same range and see how it really compares. It's noticeably quicker, especially autocrossing through a slalom or getting a slight bit of oversteer on the track and having to countersteer. I rarely have to take my hands off the steering wheel except for slow/tight corners.

[ajmacdon]

I post this in every power to manual thread I find as it's news to most people. There's a giant, soft spring in your power rack that is not in a manual rack, de-powered power rack doesn't feel any better than power, you have to take this spring out! See the vid for full details:

http://youtu.be/_4DiSopjNfo

[towerymt]

Originally Posted by Lando

Nice, so it bolts onto the knuckle and just increases the radius arm? The rack will still end up having to travel farther, and i'd imagine it hurts the turn radius, so its not a gain without some sort of trade off. But cool nonetheless!

The travel of the rack is fixed. The length of the steering arm is changed, so for the same rack travel, the steering angle measured at the wheel is increased. The wheel turns FARTHER, so turning radius would be improved. But tire rubbing is likely since the wheel is turning farther.