seems half of us don't like the stock PS, but for different reasons.
i always thought it was too heavy and ponderous for PS.
so i custom ordered a bag of pscv springs $80 and modded the pscv.
so ~4 yrs later i can't imagine how i tolerated the stock ps for 10+ years. Works AMAZING.

kudos to all that do all types of ps mods!

 

more info please

 

1st u put a fish scale on the rim and see how many #'s it takes to move it parked, running.
then compare it to other cars u like.
Nobody owns a fish scale, so u are stumped
end of story

 

There are two springs on the control valve. Do you remember if you replaced one or both of them? Did you go heavier or lighter?



Jim

 

A- lighter(large spring)
i did experiment with B (lighter) i'd have to check my parts bag to try and figure what is in there now.
helps to learn how to leave the cv on the car
http://community.webtv.net/MATTGRU/Quickwaytoreseal

 

Need more info. Where did you get the springs from? This sounds very interesting for those of us still using the stock PS.

 

springfast.com.
of the 27 for $87.89
~22 were out of spec. (i was going to send them back)
but since i only needed 1, i tried the best 1 and it works.
i recommend anyone except them.

 

Tell you wha't comical is finding a vette power assist setup/valve/the works under the engine hatch of a Mercruiser outdrive....with a chebby engine in there from about 20 years ago....olde tyme boat....
Chapparell....

 

Here are the specs for a 40 lb big spring (Spring A in the above drawing).

1. Wire Size: 0.097 inch
2. Total Coils: 2.9
3. Active Coils: 1.4
4. Rate: 200 lb/inch (approx)
5. Load: 40 +/- 2 lbs at 0.38 height
6. Pitch Diameter: 0.77 inch
7. Materail: Music Wire
8. Both ends to be closed and ground square
9. Free Height: 0.58 inch
10. Max Outside Diameter: 0.88 inch
11. Min Working Height: 0.279 inch (No set permissable at this height)
12. Spring must not bind in 0.91 inch diameter bore when compressed to minimum working height.
13. Solid Height: 0.278 inch max
14. Min Inside Diameter: 0.66 inch
15. Direction of Coiling: Not important

 

i had a painful injury. needed easy steering.
now it's healed, i'd never switch back!
i'd try a hardware store spring if i had it to do over.

 

I want to keep an eye on this one.

 

came across my AFTER notes:
cold 3.75#(fish scale on rim, parked, running)
warm 2.75# (i'd say many will find this a tad light)
BEFORE? i'd say (no notes yet) 6 warm, 7 cold.
my 67 ford is ~4.
05 mustang v6 8.5 cold
i hope this helps

 

Good info for those of us who enjoy the technical and modification aspects of our hobby.
I'm in that half that didn't like the stock steering on my '69. My reason was the lack of response on quick steering maneuvers (the wheel would require excessive effort during autocross directional transitions). A friend offered up to me the change he made to his p/s setup. He swapped out of the original pump the high pressure port orifice fitting for a larger (orifice) one out of another model GM pump. All the difference in the world. I can now swing the wheel back and forth, and the wheel doesn't fight me.

 

69427
1st i tried a new pump. no change. it leaked. got another. no change.
then i boosted the pressure. no change. modded pscv-success, set pump spring back to stock.

thanks for sharing; might help someone.

 

Wow, I have the opposite problem. I think that the steering is too light. So I guess I'd have to go with a heavier spring?

Does anyone know if there are easier mods to decrease steering assist? Other than taking the belt off the pump.

 

perhaps a lighter pump spring?

 

The autocross problem was a lack of flow. The 1/4 inch ID pressure hoses don't help the situation. The problem with higher flows is that you automatically get higher fluid temperatures. You want just enough flow to allow quick evasive type turns without having sudden, abrupt, high steering efforts. The throat of the discharge fitting can be drilled out which will allow more flow. The problem is that you really don't know what the result is. That is why some people have complained about jerky steering when they drilled out the fitting. They have disturbed the surface finish of the throat of the fitting and may have caused a burr to cover a very small hole (called the P-hole) that intersects the throat.

By going in and disturbing the diameter and surface finish inside the fitting, you really don't know what you might end up with. But if you want to try, here is a guideline.

As a rule of thumb, for every 0.016 inch on the diameter that the throat is opened up, the pump will flow an additional 1/2 gallon per minute.

0.1144 inch throat diameter = 2.0 gallons/minute
0.130 inch throat diameter = 2.5 gallons/minute
0.144 inch throat diameter = 3.0 gallons/minute

You should strongly consider adding a return line fluid cooler to keep your fluid temperatures in line.

Pickup trucks and SUVs typically have flows in the 3.0 gallons/minute range. You might want to just swap fittings. If you just try and change the discharge fitting itself, remember these things:

Most Saginaw fittings before 1980 had 5/8 female threads and sealed with a 45 degree flare seat. Starting in 1980 the discharge fitting was changed to a female 16mm thread with an o-ring seal. You will need to change your pressure hose if you change from 5/8 flare to 16mm o-ring.

Continue to use the flow control valve (the slider valve behind the discharge fitting) that came with your original Corvette pump. That control valve is set for a 1000 psi maximum pressure. You don't want any higher pressure than the one that came in your pump. The hoses and control valve seals were not designed for higher pressures.

Jim

 

How do you change out the pump spring?

 

unscrew pressure line fitting

 

And it just slides out? And how much lighter can I go? Is there any general rule of thumb for this sort of thing?

By the way, my PS pump is currently broken. I have to replace it anyways, does anyone sell a low flow pump that I wouldn't have to modify?