just shimmed out PS pump for the steeroids set up

bobs77vet

bobs77vet

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well i needed a new PS pump and decided to shim out the valve to reduce the 1200 - 1300 psi output pressure down to what the R &P units require. speed direct said about 900 psi was ideal and i bought the borgenson shim kit and went at it on the new (auto zone rebuilt unit) PS pump....it required taking off the high pressure side fitting on the back of the PS pump and then taking out the valve body and removing the 7/16 nut and adding these little shim washers....these things were like about the thickness of a business card....added 4 of them. took about 8 minutes to do and then put the pump back in the car and test drove it.....it really took away the over sensitivity and gave back road feel to the steering wheel i am very impressed.

i am contemplating adjusting the alignment to more positive caster and adding a spreader bar. my alignment is good now i wonder if i can just guess at the caster adjusment by doing the same adjustment to both sides?
 
If the alignment is good now I wouldn't risk messing it up by guessing at the adjustment, on the other hand if you record what shim changes you made you can always go back to where you started....

I already have my steering rack (on the shelf) and I'm planning on buying the newer style (smaller) power steering pump with the external reservoir. Will those shims work on that pump as well? Did the shim kit come with instructions or did you just guess at the 4 shims ??
 
if you are not going with the stock pump i would just look for the pump designed for the R&P unit.....this is what Eric in the tech dept told me about the stock PS pump with the steeroids ..."For better steering feel we recommend 2 gpm and about 900 psi. That is a fair amount lower than a typical pump at 1100-1300 psi and 3-3.5 gpm. We do have a shim kit for the pumps to reduce the pressure output. We also recommend the maximum amount of positive caster be dialed in to help improve the steering feel."...

the kit came with instructions and i will photo copy them and post them its not much ....the shims are really small and I do not know if the flow was reduced when the pressure was reduced.....the instructions came with a matrix for the shims and corresponding pressure output.

so if i can easily adjust the caster with out screwing my alighnment up i would like to try. i have to read up on this because i am not sure what i actually have to adjust....is just the shims in the upper arms cross shaft?
 
bobs77vet said:
these things were like about the thickness of a business card....added 4 of them.
Click to expand...

Hi. :)

I just installed a Steeroids kit and i wonder if you may have a measurement of the thickness of the shimming required?

4 buisnesscards, is that like 4 milimeters?

//Ricky.
 
Ricky said:
bobs77vet said:
these things were like about the thickness of a business card....added 4 of them.
Click to expand...

Hi. :)

I just installed a Steeroids kit and i wonder if you may have a measurement of the thickness of the shimming required?

4 buisnesscards, is that like 4 milimeters?

//Ricky.
Click to expand...



individually measured with my in expensive digital HF caliper. shim was .43mm using a feeler gauge as a standard and calipers i got .016"/.406mm my pump had one shim in it that i removed and put 4 shims so .43 x 4
 
bobs77vet said:
if you are not going with the stock pump I would just look for the pump designed for the R&P unit.....
Click to expand...

I think the newer style pump is pretty much the same pump as the stock C3, just with an external reservoir.
This is what I was looking at:
http://www.summitracing.com/parts/SUM-340206/

Without the reservoir there's more room under the alternator bracket...

Not sure if are any other differences between "type1" and "type2" saginaw pumps...
 
i bet Jim Shea is the guy to ask if there are any differences... or maybe even speed direct tech section
 
Are you sure it's talking about caster? My understanding is that's fairly tricky to change on the c3. Sure, minute changes are no big deal but any significant change is a little more involved. I would think they're talking about camber, but that's just me.
 
Thanks.
b300d6a2.gif


Found the kit at Summit.
5b1c0e2f.gif


http://www.summitracing.com/parts/BRG-899001/
 
clutchdust said:
Are you sure it's talking about caster? My understanding is that's fairly tricky to change on the c3. Sure, minute changes are no big deal but any significant change is a little more involved. I would think they're talking about camber, but that's just me.
Click to expand...


i dont know.... that was a direct copy and paste from my email from them ....i dont know that much about alighnment i guess i have one more thing to learn about.....
 
To get significant caster you need offset cross shafts in your upper A frames.
 
68L71 said:
To get significant caster you need offset cross shafts in your upper A frames.
Click to expand...
I thought it would take something like that. The other way would be some aftermarket upper A-arms that relocate the ball joint. I was wracking my brain trying to figure out how you're going to make caster changes to the front of a c2/c3 suspension and just couldn't imagine how you would do it without some replacement/reengineering of bits and pieces.
To the OP, the difference is fairly easy to understand. Caster is the relationship of the upper and lower ball joints as you look at the spindle with the wheel off. If the upper ball joint is positioned behind the lower ball joint, the car is said to have "positive" caster. The opposite would be "negative" caster. About the only car I've ever heard of that runs negative caster is some of the M-Bs. Caster is measured in degrees.
Camber on the other hand, is similar but looking at the spindle from either the front or back. This is typically adjusted by placing or removing shims between the upper A-arm cross shaft and the frame pick up points (where your spreader bar would go, which I highly recommend). This is a far easier adjustment to make, and with a stock or mostly stock front suspension, your camber and toe adjustments are going to make the biggest difference in how responsive the car is.
My personal suggestion is to leave the caster alone if this is primarily a street driven car with a mostly stock suspension. But feel free to play to your hearts content (or your tire wear) with both toe and camber.
I personally run about -1* negative camber and 0 toe, maybe slight (1/32") toe in. This type of set up is a pretty good compromise for a car that is driven hard on the street with maybe an occasional auto-x or track day, but I like my car feeling edgy.
CASTER
A really nice description of camber HERE
 
Thanks for bringing up this topic! The steering on my 78 is
way to touchy after adding the Steeroids package. I thought I would
just have to live with it. Once again thanks! The parts are on order.:yahoo:
 
JE Caudle said:
Thanks for bringing up this topic! The steering on my 78 is
way to touchy after adding the Steeroids package. I thought I would
just have to live with it. Once again thanks! The parts are on order.:yahoo:
Click to expand...

Back '01-02 winter, with the vette in many pieces all over the joint....

I put in the rack conversion...the steeroids/VBP rack out of a junkyard '92 Grand Am...looking new to the car, nice and clean...

so when cobbling up the plumbing, I already had a '88 vette pump/serp drive setup that had been modded for the stock steering...by plugging in the valving from the OEM '72 pump....worked fine....still does...I guess I got lucky in that the reports I heard are that the stock '72 needed like 900 lbs and X flow...and the old steering worked fine, the rack does also....

I lucked out, for a simple adaptation to a flare fitting instead of a Oring type deal....

:crutches::waxer::D
 
ok the almost two week driving impression is in ( i have not done anything to the alignment).....wow what a difference the car has totally lost its "twitchiness". i added the shims on the pump on the work bench. but i know you could do this on the car i would recommend this modification for any one putting in a R&P unit.
 
bobs77vet said:
ok the almost two week driving impression is in ( i have not done anything to the alignment).....wow what a difference the car has totally lost its "twitchiness". i added the shims on the pump on the work bench. but i know you could do this on the car i would recommend this modification for any one putting in a R&P unit.
Click to expand...

Thanks!, looking forward to get rid of this twitchy steering response!.
 
bobs77vet said:
well i needed a new PS pump and decided to shim out the valve to reduce the 1200 - 1300 psi output pressure down to what the R &P units require. speed direct said about 900 psi was ideal and i bought the borgenson shim kit and went at it on the new (auto zone rebuilt unit) PS pump....it required taking off the high pressure side fitting on the back of the PS pump and then taking out the valve body and removing the 7/16 nut and adding these little shim washers....these things were like about the thickness of a business card....added 4 of them. took about 8 minutes to do and then put the pump back in the car and test drove it.....it really took away the over sensitivity and gave back road feel to the steering wheel i am very impressed.

i am contemplating adjusting the alignment to more positive caster and adding a spreader bar. my alignment is good now i wonder if i can just guess at the caster adjusment by doing the same adjustment to both sides?
Click to expand...

Did you do this on the stock pump? I just added the 4 shims to my 1991 vette pump (on a 1980 with the steeroids kit) and it turns like a tank at slow speeds.
 
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