rack & pinion options for 69 F body?

[steve g]

I'm a newbie just getting started with pro-touring. I've got a 69 Firebird convertible that I'm gettting ready to start on. I've seen the Steeroids kit, but are there any other options for a rack & pinion? Will any other late model units work? Budget is a consideration.

[derekf]

Hi Steve, welcome to the site.

Given that budget is a concern, I can think of many, many places that extra money would be better spent than on a R&P conversion.

Take a look at http://www.chevelles.com/techref/shea_3.html to see a list of power steering boxes, their ratios, effort, and travel - swapping in a better Saginaw box may get you all the improvement you're looking for at a much lower cost.

[baz67]

Steve, welcome also there is some bumpsteer issues with the steeroids kit. Like dered said a new box with a better ratio with new tie rods, idler arm and pitman arm would be money well spent.
Brian

[steve g]

Derek,
I currently have the variable ratio power steering 16:1 - 12.4:1 with 2 1/2 turns to lock. Some of the aftermarket ones I've seen advertised as quick ratio are 12.7:1 with 3 1/8 or 2 1/2 turns lock to lock. Forgive my ignorance as a newbie, but how much of an improvement would that be over what I have for $350.

[derekf]

I'm cheap and I'll be the first to admit it.

I can't see spending 350 for someone's "aftermarket" version of a Saginaw box, when I could spend a fraction of that getting one from a 'yard.

The biggest thing I'd look for was amount of travel - you'd hate to end up with either
a) a huge increase in turning radius (which you'd get if the travel decreased)
or
b) tires rubbing at full lock (if the travel increased)

It looks like (from the chart), your existing box has 32 deg 15 min of travel. If I were you, I'd probably look at one of the XH code boxes from 85-93 Camaro/Firebirds. Those boxes are 12.7:1 constant ratio.. I'm sure there's a formula to convert that to turns lock-to-lock but I don't know what it is.

As for how much improvement the box change would give - that's pretty subjective, but the difference in T-bar diameter gives more of a directly-connected feel than the old "floaty steering".

I would imagine it'd also apply to aftermarket boxes, but the fittings changed in 1977 and you'd need to adapt the hoses to the new box. Check out http://www.chevelles.com/techref/shea_1.html for some more good info on PS upgrades.

[TurboLark]

Derek,
Could you explain to me what the difference between tese 2 boxes would be please?

1969
AG
F-8 cyl
16-12.4:1
15-21
0.175 Dia
32deg 15min
and

1970
BN
F-8 cyl
16-12.4:1
24-30
0.195 Dia
37deg

Both of those are F body boxes. Obviously the 70 box turns a bit more, but what effect will the different effort and t-bar size do? What do those 2 numbers mean?
Thanks.
Phil

[Pzary3233]

Phil,

How about a 1977 WS6 Box from a Trans Am? I know that is a 2.5 turn lock to lock box. I have heard of MANY people doing that swap on the First Gen Firebird List that I belong to. The only thing with that is the need for custom hoses if you get a 78 or later T/A box. Also you need a Rag joint from a mid 80's full size truck.

[derekf]

Ok..

The BN box has a larger T-bar. Steering effort will be a little higher and you'd feel a bit more "connected" to the car - think more Vette and less Caddy.

Travel is a lot larger on the BN box - that's degrees of travel for the pitman arm and it's governed by stops inside the box. If you were to put the BN box in a 1st-gen, you'd likely start rubbing the tires on the frame when you got close to lock in each direction.

I'm not too sure what's in the 77 WS6 box - if it's an AZ code box, then it's 14:1 ratio with a .185 inch T-bar and 33 1/2 degrees of travel. If it's an XT box, it's a variable ratio 16-13:1 with a .175 inch T-bar (travel remains 33 1/2 degrees).. if it's something else, I don't know anything about it. If you've got someone with one of those cars handy, the code should be stamped on the case.

[TurboLark]

Ok..

The BN box has a larger T-bar. Steering effort will be a little higher and you'd feel a bit more "connected" to the car - think more Vette and less Caddy.

Travel is a lot larger on the BN box - that's degrees of travel for the pitman arm and it's governed by stops inside the box. If you were to put the BN box in a 1st-gen, you'd likely start rubbing the tires on the frame when you got close to lock in each direction.

I'm not too sure what's in the 77 WS6 box - if it's an AZ code box, then it's 14:1 ratio with a .185 inch T-bar and 33 1/2 degrees of travel. If it's an XT box, it's a variable ratio 16-13:1 with a .175 inch T-bar (travel remains 33 1/2 degrees).. if it's something else, I don't know anything about it. If you've got someone with one of those cars handy, the code should be stamped on the case.

Thanks Derek. So if the t-bar size increases, so does effort. Is the effort listed in ft/lbs, inch/lbs?

[derekf]

As T-bar size increases, so does effort. I don't know if that's in/lbs or ft/lbs though. I'd think in/lbs.

I didn't write the sheets I've been referencing - user JIML82 on Chevelle Tech would be the author.