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Pinto steering rack in a C4, pictures

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Old 01-28-2015, 11:00 PM
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383vett
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Default Pinto steering rack in a C4, pictures

Last week I had my fabricator friend install a Pinto manual steering rack in my 84. On my last race, I removed the power steering assembly and ran the Z51 rack with no pump or belt. I gained a tenth but you don't want to do this for long unless you are Charles Armstrong. The Z51 rack was 2 turns lock to lock. The Pinto is almost 4 turns. Obviously the steering effort is a lot less than the Corvette rack with no power assist. The weight difference of the racks is about 4.5 lbs. I weighed the stock rack at about 14 lbs. The Pinto was 9.5 lbs. The pump and bracketry was 7 lbs. The total weight savings is approximately 15 lbs. That doesn't include the chromemoly steering shaft. Along with the less engine drag and lighter weight, I think a tenth or more quicker in the quarter is a good estimate. My fabricator is very meticulous in his work and fabricated my 12 bolt rearend install years ago and I trust him 100%. I wouldn't have anyone do this work who didn't have a lot of experience. You've got to be able steer these things at 130+mph. A perch had to be welded on the crossmember on the passenger side to mount the rack. He was able to use the existing mount, with some fabrication, along with notching the crossmember on the drivers side. You can see how much lower the heim joints are below the control arm. This bump steer spacing allowed at most 1/8" of toe change from full compression to full extension. This should provide good control of the car when it settles back on the ground. The shocks are revalved double adjustable Afco shocks. I had 90-10 Lakewood shocks for years and my friend thought controlling the extension of the front shocks would keep the front end down and the car would be quicker. Here are some pictures...











Old 01-29-2015, 08:57 AM
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rklessdriver
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Looks really good.

Are you saying he built 1/8" additional bump steer into it or that by lowering the tie rods he reduced the 1/8" of factory toe change?
Will
Old 01-29-2015, 11:44 AM
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383vett
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Originally Posted by rklessdriver
Looks really good.

Are you saying he built 1/8" additional bump steer into it or that by lowering the tie rods he reduced the 1/8" of factory toe change?
Will
Hi Will. As you know, most factory cars have built in bump steer or toe change throughout the suspension cycle. My car's front suspension is designed to have very minimal toe change throughout the range so as not to affect handling with a toe out situation or scrub off speed with excessive toe in.
Old 01-29-2015, 12:21 PM
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rklessdriver
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I totally understand now. I was misreading your bumpsteer amount....

I've never measured the factory bump steer, so I had no idea if 1/8" toe change was more or less than whatever the factory design produced.

Your install looks really good.

When I went to double adjustable shocks on the front of mine it was totally night and day difference. Those new shocks should allow you to make a huge change in the how the car leaves. I see you bought threaded body shocks so you have the option to go to coilovers later if you want as well.

Nice stuff! I hope it gets the car where you want it.
Will
Old 01-29-2015, 01:31 PM
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383vett
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Thanks for the encouragement

Last edited by 383vett; 01-29-2015 at 01:43 PM.
Old 01-29-2015, 02:57 PM
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desertmike1
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That's a pretty slick set up.. curious how it fairs out..
Old 01-29-2015, 11:16 PM
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Rockcrushervette
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Have built a few rods here and there! My uncle hooked me up on this! Run tranny cooler lines throught rack n pinion before cooler ! Use tranny power to run rack! Have done this on 2 pre 30'z rodz helps keep engine clean of pump and drives good! If your an auto tranny!

Just saying !
Cliff
Old 01-30-2015, 10:14 AM
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Originally Posted by Rockcrushervette
Have built a few rods here and there! My uncle hooked me up on this! Run tranny cooler lines throught rack n pinion before cooler ! Use tranny power to run rack! Have done this on 2 pre 30'z rodz helps keep engine clean of pump and drives good! If your an auto tranny!

Just saying !
Cliff
Interesting concept. Too late for me, the Pinto rack is a manual unit. I'd like to see someone try your idea, though.
Old 01-30-2015, 12:18 PM
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project C4
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Originally Posted by 383vett
Interesting concept. Too late for me, the Pinto rack is a manual unit. I'd like to see someone try your idea, though.
It does sound good. I didnt know there was any pressure there at the cooler lines.
Old 01-30-2015, 07:05 PM
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Originally Posted by project C4
It does sound good. I didnt know there was any pressure there at the cooler lines.
I have done it on 2 builds there is enough flow to run the rack! i never checked pressure just hooked them up and it made a big change ! Works good on old rodz gets rid of needing a power steering pump! but never on a Vette I have always cruzed old cars last Rod was a 29 chevy sedan! Dropped a 350/350 !
Old 01-31-2015, 05:16 AM
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Great info, Thank you Cliff
Old 01-31-2015, 05:58 PM
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Nice job Willie
Old 01-31-2015, 08:07 PM
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Looks good, how hard is it to steer?
Old 01-31-2015, 11:29 PM
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cudamax
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Great Job but u want Zero Bump otherwise ur car can get potentially dangerous if ur able to lift the wheels of the ground or close to it with enough lift. When ur car comes back down it can go the the left or right REAL HARD.I've seen cars totaled/hit the wall and roll. You want the tie-rod ends perfectly level with the knuckle's. Also have it put on an Alignment rack and raised an Inch at a time until the wheels come off the ground, measuring toe. You want ZERO TOE CHANGE
Old 02-01-2015, 12:00 AM
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Originally Posted by cudamax
Great Job but u want Zero Bump otherwise ur car can get potentially dangerous if ur able to lift the wheels of the ground or close to it with enough lift. When ur car comes back down it can go the the left or right REAL HARD.I've seen cars totaled/hit the wall and roll. You want the tie-rod ends perfectly level with the knuckle's. Also have it put on an Alignment rack and raised an Inch at a time until the wheels come off the ground, measuring toe. You want ZERO TOE CHANGE
Ideally, zero toe change is the goal. The car is aligned at 1/8" toe in in at track altitude. There is a maximum of 1/8" toe change, that is at most 1/16" at either direction or 1/32' at each side which is near negligable, certainly not a toe out condition which would result in instability. Bushing deflection will give more than 1/16" toe change.

Last edited by 383vett; 02-01-2015 at 11:45 AM.
Old 02-02-2015, 11:52 PM
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Menscer Motorsports shocks .. I should have went to dental school .. haha
Old 02-02-2015, 11:54 PM
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Originally Posted by Rockcrushervette
Have built a few rods here and there! My uncle hooked me up on this! Run tranny cooler lines throught rack n pinion before cooler ! Use tranny power to run rack! Have done this on 2 pre 30'z rodz helps keep engine clean of pump and drives good! If your an auto tranny!

Just saying !
Cliff

Can you please further explain this ?

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