Power rack and pinion conversion ?

[POWERBRAKEBOB]

12.7-1 quick steer box

Well, O.K., I have had drag race cars, and even removed the front brakes to drop weight. It was no longer a street car. Maybe? 5% of G.N.s are now pure drag cars only. Racks still need tie rod ends, and with or without a p/s pump, the car still needs steering parts. Most of the guys on this forum are running street only, or occasional drag use. They still need reliable steering and braking. If you cannot put in enough caster to make the car go straight with a rack, then it is too miserable to drive in daily use. Worm gears will not allow tires dropping into pot holes and lane irregularities to kick back the steering wheel. Racks have nothing to stop kick back from the tires falling into grooves or other road irregularities. Racks need more caster built into the a frames to return to center than a worm gear. It's just my opinion that a 12-1 steering box, with a 1.250" sway bar, and the hydrobooost will make an outstanding, all around great handling car. Drag race is anything you can live with.

 

[RAMAIR1]

We sell a 12.7 gear ratio new steering box, that makes the car handle incredible, and is a bolt-in.

Bob, I need info on the 12.7 box. My stocker is SLLLLLLOPPY! The link to your page seems to be bad.
Thanks,
Aaron

 

[POWERBRAKEBOB]

12.7-1 quick steer box

It Should Be At Powerbrakesonline.com Or You Can Call Or P.m. Me

 

[RAMAIR1]

Bob, your PM box is full

How much do you get for the steering boxes. I couldn't find them on your site.

 

[craggar]

I am just finishing my conversion to R&P along with tubular upper and lower control arms. I haven't reweighed the car yet but from weighing some of the parts I don't think it will be much more the 60lbs lighter. Going to aftermarket brakes and rotors may save another 20lbs.

 

[GDNF2ET]

I am just finishing my conversion to R&P along with tubular upper and lower control arms. I haven't reweighed the car yet but from weighing some of the parts I don't think it will be much more the 60lbs lighter. Going to aftermarket brakes and rotors may save another 20lbs.

Which rack did you use ? Any pics ?

 

[craggar]

Everything came from TRZ. No pictures yet.

 

[MAP]

Hi Folks,

I can confirm a weight of 28.5lb for a Saginaw 800 box (the kind with the square top cover with four bolts, and not the 605 box which came with most of the base-model A/G bodies,) including Pitman arm. (The 605 box with Pitman arm is 23.8lb.)

I never did weigh the rest of the componentry, but my guess is that the weight of the tie rods, centerlink, steering box, Pitman arm, idler arm, steering hoses, and steering pump with reservoir, and all associated bracketry, is probably in the vicinity of 60-80lb.

Craggar: aftermarket brakes are more likely to increase rather than decrease, the weight of the spindle assembly. The weight of the OEM spindle, rotor, and brake assembly is 39.5lb. Even the lightest Baer racing street brake conversion will save only 4lb per wheel.

But I continued to be intrigued about your observation of twitchiness, PowerBrakeBob. Even with the matter of Ackerman correction, scrub radius, and reduced steering moving mass, I still can't account for a big increase in twitchiness over the OEM front end. To everyone rading: we have to remember we're dealing with terms that aren't necessarily equivalent. Twitchiness occurs only over a bumpy surface, and relates to how the front-end self-steers over fore-aft upsetting forces on each wheel created by road irregularities. Self-centering, however, is a "zeroeth-order" effect manifested over perfectly smooth surfaces as well as bumpy surfaces.

But maybe something else is rearing its ugly head here, PBB, that may be masquerading as twitchiness, and that's bump steer. Again, only very short racks can work with A/G bodies because of the OEM front end design (at which point, I believe, only manaul racks are viable, and even those will have a limited stroke.) Therefore, any R&P conversion that's not specifically designed for the A/G body front end to eliminate bump steer, will probably manifest copious amounts of the same.

Anything that will increase the front end's tendency to self-center will also help to reduce the perception of twitchiness and bump-steering - and increasing positive caster will certainly do that - but this is like using a leg brace to cure a headache: far better to adjust the fix to target the problem directly.

Best,
MAP

 

[MAP]

Bump to top: this is much too interesting to let fade away from the thread list. PBB, or anyone else, any observations about the bump steer issue?

Thanks,
MAP

 

[GDNF2ET]

Craggar: aftermarket brakes are more likely to increase rather than decrease, the weight of the spindle assembly. The weight of the OEM spindle, rotor, and brake assembly is 39.5lb. Even the lightest Baer racing street brake conversion will save only 4lb per wheel.

As far as lighter brakes are concerned, Strange, Aerospace and Willwood are much lighter than stock..Then theres aluminum hubs, 69 Camaro spindles with TRZ bumpsteer arms and tie rod ends, coilover shocks...Plenty of places to take off weight on the front suspension, not cheap though..You have to have a plan so you don't spend twice..
Which rack is used in G-bodies , pinto or mustang II version ?

 

[Trbobuick]

As far as lighter brakes are concerned, Strange, Aerospace and Willwood are much lighter than stock..Then theres aluminum hubs, 69 Camaro spindles with TRZ bumpsteer arms and tie rod ends, coilover shocks...Plenty of places to take off weight on the front suspension, not cheap though..You have to have a plan so you don't spend twice..
Which rack is used in G-bodies , pinto or mustang II version ?

Pinto i think....

 

[novaderrik]

putting a rack in a car designd for a regular steering box just seems like a good way to spend a lot of money to make the car jump around every time you hit a pebble or small hole in the pavement.
but, hey, you can brag about how much cooler the rack looks than a regular steering box- and you did take 20 pounds off the front of the car.
personally, if i was to upgrade my steering box (which i'm not looking to do), i'd be getting one of those new Remy boxes that weigh about 10 pounds less, have better feel, and bolt right in. i think the "street price" at whatever local parts store you go to is about $500. they are the same box that GM used in millions of pickups starting in '99, i think, so they are tested to be good for more abuse than a puny little 3800 pound G body will ever put them thru.

 

[MAP]

Hi Novaderrik,

"...new Remy boxes... weigh about 10 pounds less, have better feel, and bolt right in." Interesting. This is new to me. Could you please give further details?

About the jumpiness/twichiness issue, this is still puzzling. I can understand some theoretical reasons why an R&P conversion would be *somewhat* twitchier than an OEM front end, but fundamentally, provided the R&P unit is correctly engineered for the A/G body suspension, then all should be well. I spoke earlier of reducing scrub radius to reduce "road feel" with lower steering mass, but beyond this, I strongly suspect that the reason why most people have had bad experiences making an R&P swap into A/G body cars, is that it's difficult to find/make a rack for these cars that won't exhibit a ton of bump steer. I also suspect that some R&P units may afford a considerably faster steering ratio than the original OEM design, and that too would make control over the car's direction less precise.

In short, I think the problem with an R&P conversion for our cars isn't R&P steering per se, but rather the fact the OEM front end design makes a poor match for most available R&P units. This is the fundamental reason why I'd re-design the entire front end before considering such a swap.

Best,
MAP

 

[novaderrik]

Hi Novaderrik,

"...new Remy boxes... weigh about 10 pounds less, have better feel, and bolt right in." Interesting. This is new to me. Could you please give further details?

Remy- of Delco/Remy fame- makes all the steering boxes for the new trucks. they sell them in various ratios for older cars going back to the A bodies of the mid 60's. they are a sort of hybrid rack and pinion/worn gear steering box that bolts in place of a regular old Saginaw steering box using the stock rag joint, PS lines, and Pitman arm. all the geometry stays the same, but with the feel and responsiveness of a newer car with a rack and pinion setup.

 

[MAP]

Hi Novaderrik,

Even more interesting. Would you happen to have a web link with more information?

Thanks,
MAP

 

[novaderrik]

i tried a google search, but the closest i could find was a Super Chevy article where they put one in a 68 Chevelle. in typical Super Chevy fashion, they were low on tech info and high on "buy this becasue our sponsor says it's the best thing going".
the remy site for the boxes- Remy racing shop - seems to be down for "upgrades".

 

[GDNF2ET]

I just talked to Remy racing and invited them to comment on their steering boxes in this thread..
Their box would be a direct bolt in..Use your; G-body pitman arm, hoses, pump, ragjoint...Comes in
12.7-1, recomended for streetcars
14-1, street and strip cars
16-1 for ??

 

[OldElky]

Hello All,

First I would like to thank GDNF2ET for giving me a call and asking me to join Turbo Buick. So far I have really enjoyed reading everything on this topic. I can only comment on what I have heard and seen around the industry. I will try to answer any questions to the best of my knowledge. From what I have read, MAP sounds like he has a very exstensive knowledge of suspension systems. MAP, beside a motor head like the rest of us, what is your occupation? I know Power Brake Bob. He is a great guy and is an originator of using Hydro boost in muscle cars. Bob knows what he is talking about and is willing to help guys like us that have questions. Again, he is a real originator the industry.

I sell the Delphi 600 series power steering gear that is made in America and the GM 525 Manual Steering gear which is made in Canada. Both of these steering gears are direct bolt in's for A/G body 1964-1988, F-Body 1967-1981, B-body 1965-1995, and the X-Body 1968-1979.

The Delphi box is a brand new unit and has three ratios to chose from, 12.7:1 (2 1/2 turns from lock to lock) , 14:1 (3 to 3 1/2 turns lock to lock), 16:1 (4 turns lock to lock). All Delphi 600 gears are Straight Ratio boxes. The Delphi 600 gear is also used on every Sprint Cup NASCAR on the track. If it's durable enough for them it is plenty good for all of us. A version of this gear was also used in the 1999-2006 GMC/Chevy Silverado, Tahoe, and Suburbans. This version will not fit on our cars (different bolt pattern). The 600 gear uses a rack & pinion style hydraulic valve in it as opposed to the standard valve used in the 700/800 gear that came originally in all of the GM rear wheel drive platform passenger vehicles from the early 60's up until the mid 1990's.

The Delphi 600 series Power Steering Gear utilizes the latest in steering technology including a rack and pinion style hydraulic valveing. The valving is the “power” in the power steering gear and is one of the key elements in determining how the steering gear is going to feel in your car. By converting over to the 600 series steering from your original, older & worn out 700/800 series steering gear that your vehicle came with, you will eliminate any “slop” or “slush” that older cars are known for. How and why can it do this you ask, the 600 gear is BRAND NEW!!! Not rebuilt. Many if not all of the older 700 series steering gears used valving that was “over boosted” or very light like grandma or a baby could turn the wheel. The 600 gear feels “heavier” in your hands and more responsive like a modern day vehicle giving you better driver feed back. The 600 will also eliminate the “wandering” “floating” feeling of the steering wheel that the older are also known for. You will not have to constantly correct yourself while driving down the highway. The 600 gear will use your original pitman arm from your old steering gear and use your original steering linkage keeping the OE steering geometry.

People have gotten use to the tighter feel of modern day vechicles and the 600 gear has the same charateristics of todays cars. A lot of people today are coming in to the hobby remember how much they loved their old car from the 1960’s, 1970’s & 1980's. Those same people most likely have not been behind the wheel of those cars they loved so much for 25 or 30 years and have forgotten how they stop & steer. There is no reason to settle for 40 year old technology any more. The 600 gear fits right in with the trend of install modern day convience in to your muscle car.

The conversion is simple to do. Hand tools, a jack, jack stand, wheel chocks, and pitman arm puller (available at any auto parts store for under $20) are needed to install the 600 gear. You need a power steering pump, but do not need a special or a modified pump like you would if you were to use one of the many rack & pinion conversions for your car. Your stock pump that is on your car will work perfectly. The 600 gear weighs 23 pounds. The steering gear kit retails for $579.99 for a plated gear and $559.99 for a non plated box. This about half the price of a rebuilt R&P kit.


Is a rack & Pinion conversion better??? Unfortunatly I have never driven any car that has been converted to R&P from a Steering Gear. Everything I have heard goes along with what MAP and PBB have said. Power R&P that are from another car and used in a different application then what they were intended for tend to sometimes be "twitchy". The origin or cause of this condition are from a variety of places like MAP stated previously about the manual R&P. When you convert to you are changing the geometry of the steering system. I have had people tell me they have actually added problems to the system by changing to R&P. I have also spoke to people at cars shows that have done the R&P conversion and said they like it.

The use of a power R&P requires you to change the pump valve to lower the pressure. If you do not change the valve this will amplify the "twitchyness" of the R&P causing it to be dynamicly unstable.

I have however changed out my old Saginaw 700/800 gear out for a new Delphi 600 in my 84 El Camino. So I can obviously tell you about my experience with that.

If you are drag racing and are looking to save weight and horsepower. We sell the GM 525 manual steering gear. These are made in Canada using the OE tool that made these gears back in the 60's and 70's. The gear weighs 18 pounds. We sell it as a kit that includes a steering gear with your choice of ratio, and new OEM rag joint and pinch bolt. Now, none of our A/G bodied cars came originally from the factory with a manual box right?!?!? Some did come with a horrible "605" box. I have been told that the pitman arm off of a 605 box will fit the GM 525 manual gear. If you can find one or have one please let me know. This makes the swap to manual steering a piece of cake. No one has mentioned that buy dropping the P/S pump will also save weight but you get between 3-5 horsepower back!

 

[novaderrik]

actually, there were some 78 and newer A and G bodies built with manual steering. but they are a rare bird, indeed, and the few i've seen also had manual brakes and a standard heater without AC. i think i've seen maybe 3
"stripped" models like that, 2 were El Caminos and one was a Malibu.
as for the Remy boxes- since i mentioned them here, can i get one for my 74 Monte as sort of a "thank you" for exposing several thousand potential customers to your product?

nope? well, you can't blame a guy for trying, eh?

 

[MAP]

Hi OldElky, Novaderrik, and everyone,

Elky: thanks for that detailed response. I can easily believe that changing the steering box on a 20(+)-year old car can make a huge difference: back in 1998, I swapped my old 605 PS box for a Guldstrand Engineering 800 box with a high-pressure valve (it was ether 30 or 35 PSI; my recollection is indistinct.)

The 1978 Malibu in which the swap was made, went from doing spontaneous and unannounced lane-changes (and yes, the top pre-load was set correctly,) to a track-on-rails precision that reviled the best in R&P I had driven.

Question: does the new Delphi 600 box share many of the same parts as the old 800 Saginaw box? I just had a chance to make a very close examination of a Ford Fusion Roush-prep'd (Nextel cup??) race car, and was surprised to see what I was sure was a Saginaw 800 box for the steering.

Aside from the appearance, I know that speaking for myself, I prefer the higher effort steering of modern cars, which you suggest is what the valving in the 600 box is designed to emulate. About the steering box weight of 23 lb: this is a small reduction in weight with respect to the 800 box, so presumably this swap wouldn't be viewed as viable by most on a weight-basis alone.

I do, however, stick by the opinion that the right way to do an R&P swap into these A/G body cars, is to redesign the front end entirely. I think I can share an idea that Mark Savitske at SC&C Customs shared with me a while ago: try to use a 4th-gen F-body front-end whole! The two biggest challenges there, however, are 1.) how to adapt that front-end into the roughly 3-4" narrrower A/G body width, and 2.) how to tie the spring load, which supports the car's front weight at a location that's virtually identical with a Macpherson strut arrangement, into the A/G body chassis.

About myself, Elky, I'm just a car hobbyist that picked-up ideas here and there, and who occasionally enjoys reading through parts of Milliken's Race Car Vehicle Dynamics. My occupation is not in the automotive field, although I design parts used in many GM vehicles by a GM tier-one supplier.

Happy Easter to all,
MAP