PDA

View Full Version : rack&pinion upgrade for second gen camaro



jamesinark
11-08-2011, 12:25 PM
Iposted once about upgrading to a r/p steering system for my 71 camaro.I have storage shed full of parts and will be starting to work on it soon,but as everyone knows the economy has put a bit of a squeeze on the average DIY guy let alone the buy it and have someone else install it crowd.Anyways I saw a post the other day about aftermarket r/p vs the salvage route.I know a few guys from all over that say you can use the racing style rack such as sweet,too name one.As I am getting around to asking,one of the answers to the post I refered to was that the main isssue was getting the dimension from one lower control arm pivot point to the other and matching the tie rod pickup points on the rack.How close would the tolerance need to be ?Any info would be appreciated.

SRDzuess4u
11-08-2011, 12:33 PM
James,

if you had a 1st gen or 2nd gen Nova, we have a bolt in kit I would show you, front steer. One of the vendors we deal with is Unisteer. I would call them on this question. Just ask for the tech dept, let them know what your trying to do then ask them about the dimensions. Pretty good people to work with. I have one of their old kits on my 1st gen...no issues.

Thanks Bob

Bryce
11-08-2011, 01:45 PM
woodward steering will make the rack any width you want.

astroracer
11-08-2011, 03:38 PM
James,
This "swap" can get very ugly, with little to gain. I would suggest going to a quicker ratio steering "box" that will bolt in and forget the R&P thing. You will be much farther ahead.
Mark

exwestracer
11-08-2011, 04:38 PM
C'mon Mark...they're not THAT bad...:)

To answer the OPs question about how wide the rack needs to be, you have to look at the relative location of the steering arms to the lower ball joints. The tie rods should be parallel to the lower control arm pivot line. The inner tie rod end pivot should be the same distance above the lower control arm mounting bolt as the outer end is above the ball joint. Once you establish the height, measure the distances between the lower ball joints, and the outer tie rod ends. Let's say the tie rod ends are 60" apart, and the ball joints are 58". The tie rod on each side is operating 1" outside the ball joint.

Now it gets tricky... You will need to establish your control arm mounting lines (between the upper and lower control arm pivots). These lines will get closer together as they gets closer to the ground. Wherever this line crosses the height that you need to mount the rack, measure the width between the left and right side lines. The tie rods need to be 1" wider than the distance between the CA mounting lines (to match the extra width of the steering arms over the lower ball joints).

Hope that made sense...no simple drawing app on my Mac...:fingersx:

astroracer
11-08-2011, 05:39 PM
Hey Ray,
Well they can be if there is no real design work done. I just hate these threads because guys expect to build an out of this world handling car by swapping a "rack & pinion" into a recirc ball designed suspension. They have to realize this IS rocket science when it comes down to GETTING IT RIGHT! Putting in the wrong rack, in the wrong spot, will not make a world beater... you will hate it.
I always point them to the longacre site. Lots of good info here, AND if they pay attention to it AND understand what it is telling them they will realize it is much better to stick with the "as designed" system and upgrade to a better box.
http://www.longacreracing.com/articles/art.asp?ARTID=13

exwestracer
11-08-2011, 06:17 PM
Yeah, it will just make it a plain "beater"... but then that applies to everything, really...

MrQuick
11-08-2011, 06:41 PM
Im with Mark on this one, since the release of the 600 box there is no real need for a rack.

If anyone can build a rack system that improves bumpsteer, allows the use of a stock oil pan, doesn't require engine relocation and actually works for under $700 then I'd say yes its worth it.
Trust me we have looked into it.


Vince

astroracer
11-09-2011, 03:31 AM
James,
I hope you understand what you will be getting yourself into trying to do this. It really requires a clean sheet of paper when it comes to your suspension design. It is next to impossible to add a R&P to an existing suspension without opening up a can of worms concerning bumpsteer, turn radius, ackerman and a bunch of other issues.
Please take this for what it is. We are simply trying to save you a lot of money and headaches. Don't jump on the Rack & Pinion bandwagon simply because "everybody else" is doing it... just because they are doing it, doesn't mean it's right...
Mark

exwestracer
11-09-2011, 04:17 AM
Im with Mark on this one, since the release of the 600 box there is no real need for a rack.

If anyone can build a rack system that improves bumpsteer, allows the use of a stock oil pan, doesn't require engine relocation and actually works for under $700 then I'd say yes its worth it.
Trust me we have looked into it.


Vince

We've converted Camaro stubs to R&P on a regualr basis using racing racks and off the shelf brackets. You are correct about possible clearance issues, and we typically incorporate bumpsteer kits to allow more flexibility in mounting the rack; so wheel clearance can also be a problem. I was referring more to the fabrication side of it.

I also agree that there are some VERY good boxes out there now, but I will eliminate that center link and idler arm every time if I have the choice...

SLO_Z28
11-09-2011, 05:04 AM
James,
I hope you understand what you will be getting yourself into trying to do this. It really requires a clean sheet of paper when it comes to your suspension design. It is next to impossible to add a R&P to an existing suspension without opening up a can of worms concerning bumpsteer, turn radius, ackerman and a bunch of other issues.
Please take this for what it is. We are simply trying to save you a lot of money and headaches. Don't jump on the Rack & Pinion bandwagon simply because "everybody else" is doing it... just because they are doing it, doesn't mean it's right...
Mark

^Dead on. As someone that has looked into this extensively, this isn't something that is worth doing.

jamesinark
11-15-2011, 10:31 AM
As Mr. Kaufmann stated it is done all the time and he gave me most if not all the info I'd need to place the thing in the right place.I agree with him about that centerlink and Idler arm as well.I don't want nor do I intend to have a beater as one of you so aptly stated.I already intend to place the engine in a non stock location to better distribute weight , unless you think for some reason moving around my LS6 is going to far and i might think I have a world beater or some such animal.I think if you hate these type of threads and have nothing positive to offer,then why bother with such a long post.I won't make a comment on someone trying to make an Astro van a handling machine.I just say different strokes for different folks.I personally would rather start with the car I've had for 24 years and use some newer technology to make a good thing better.Thanks to guys like Ray (and Bryce as well) for their time and input.Rays info and his insight was and is invaluable to people like me who lack all the knowledge someone like he has to offer.I'd like to say thanks again for your time and input.

MrQuick
11-15-2011, 10:42 AM
Its all about both sides of the coin, you asked for an opinion and I hope on a well versed site such as this you would appreciate an honest opinion from both sides and not a padded answer from a vendor looking to make some cash, people that have been on both sides or a guy with experience that has successfully done it. Try to keep an open mind and a level head as people are trying to help you. If not then maybe someone else can gain an education.

By blowing off an answer if its what you wanna hear or not undermines the whole purpose of having a public forum and the opinions of others.

I will note, new technology may not always be the best choice but it is a choice.

John Wright
11-15-2011, 11:30 AM
A 2gen has an advantage over the 1st gen in the steering department, no need to re-invent the wheel when a steering box swap will give you a R&P feel without the headaches.

What ever route you choose to take...I'll wish you well. You may hit upon something worth while that the rest of us may have overlooked.

astroracer
11-15-2011, 01:05 PM
I'm not a hater, I was simply responding to a post, giving my opinion and backing that opinion up with fact. For the life of me I can't understand why somebody, openly asking for knowledge, would turn around and bash the responder, his knowledge AND his project for an honest opinion HE solicited... which, by the way, was heartily agreed to by more than one responder.
Good luck with your project man. I hope it all works out for you.
Mark

exwestracer
11-15-2011, 01:06 PM
As Mr. Kaufmann stated it is done all the time and he gave me most if not all the info I'd need to place the thing in the right place.I agree with him about that centerlink and Idler arm as well.I don't want nor do I intend to have a beater as one of you so aptly stated.I already intend to place the engine in a non stock location to better distribute weight , unless you think for some reason moving around my LS6 is going to far and i might think I have a world beater or some such animal.I think if you hate these type of threads and have nothing positive to offer,then why bother with such a long post.I won't make a comment on someone trying to make an Astro van a handling machine.I just say different strokes for different folks.I personally would rather start with the car I've had for 24 years and use some newer technology to make a good thing better.Thanks to guys like Ray (and Bryce as well) for their time and input.Rays info and his insight was and is invaluable to people like me who lack all the knowledge someone like he has to offer.I'd like to say thanks again for your time and input.

Ummm, that WAS me...lol But the point was that with a little planning (which by your comments I think you will do) you can do things that many people make a mess out of. Glad to help.

jamesinark
11-15-2011, 10:39 PM
That was my whole point is that I need to know as many variables and some of the possible pitfalls as well as some solutions to the usual problems.I've been planning this build for 19 years.I've already went the 1/4 miler route and had some fun and some success with it,but it never quite satisfied me as to the cars natural capabilities versus 1st gen handling issues.I am sorry if I came across as bashing anyone or their opinion,but saying you hate these kinds of threads and some of the other things written came across as a rather narrow point of view.I believe anytime you can improve something with modern technology and or some type of racing technology that wasn't in use when the original car was made then I want to go for it.I wasn't planning on one component by itself alone to make my car better.I have to use longer control arms and reposition many of the original mounting points as well as components to make the whole car work together.I've seen some amazing work done on some you guys cars,many with no more experience than I.I've been a machinist and fabricator for many years as well airframe and aircraft mechanic for some time,so I know things have to work as a system and everything has to work together for things to perform as they were designed.I really appreciate those of you who took the time to reply (pro or con) and I appreciate anymore technical input you can offer.Thanks again.

MrQuick
11-15-2011, 10:47 PM
why didn't you just say that?







LOL just kidding.


there's more than one way to skin a cat. some ways are better than others. Your like 99% of us here, we'd rather build than buy.

jamesinark
11-15-2011, 11:20 PM
I think maybe I owe an apology to astroracer(don't know your name)and maybe Mark (MrQuick) as well.I can see that you have some valid points.If I were to be using factory control arms and spindles(was thinking later model Impala or similar, they're supposed to be stronger and lighter) maybe that part is true But there are brake diameter factors as well.I'd really like to commend (not bash)Astroracer on his apparent success and skill at doing what he has done with the van.Anyone who can make a vehicle no matter it original intended use perform then I should show some respect for their opinion.I've breached this subject before and was met with rather fervent and somewhat strong opinions with some matching language.I believe that even circle track,stock car,and some other types of parts can be used and be adapted too our particular discipline of the auto industry.I know this much though you have to buy quality parts and use high quality planning as well as execution too obtain something safe and more fun than headache.Thanks for your patience and hope too becoming friends.

SLO_Z28
11-15-2011, 11:26 PM
You say you want to improve it with modern technology, but how exactly is a rack and pinion an improvement over a parallelogram steering? You can get the same feel from a good steering box, and you don't save much weight. I think this is a case of fixing something that isn't broken.

jamesinark
11-16-2011, 12:15 AM
I would consider that the centerlink (cast iron mind you) would contribute some of its weight to unsprung weight and that is not taking into consideration that with each connecting point of this type of suspension that there is a tolerance that each and every moving part adds to the original point where motion is initiated and after each you add up each points given tolerance you have a stacking up of tolerances and clearance grows to the point that I feel the more components removed from the equation that the more true feel you have and that you have less potential points of failure.If a parallelogram steering system was the best then there would have never been the movement to rack and pinion in the first place.When DP,GT,and Indy car etc. revert back to using a centerlink and idler arm I will be the first to congratulate you on being the one with the true answer to my needs.Till then why fear something different?I also will probably using longer than stock control arms so there is one reason the rack is looking to me like the answer to some issues that have come up so far.

exwestracer
11-16-2011, 03:19 AM
I would consider that the centerlink (cast iron mind you) would contribute some of its weight to unsprung weight and that is not taking into consideration that with each connecting point of this type of suspension that there is a tolerance that each and every moving part adds to the original point where motion is initiated and after each you add up each points given tolerance you have a stacking up of tolerances and clearance grows to the point that I feel the more components removed from the equation that the more true feel you have and that you have less potential points of failure.If a parallelogram steering system was the best then there would have never been the movement to rack and pinion in the first place.When DP,GT,and Indy car etc. revert back to using a centerlink and idler arm I will be the first to congratulate you on being the one with the true answer to my needs.Till then why fear something different?I also will probably using longer than stock control arms so there is one reason the rack is looking to me like the answer to some issues that have come up so far.

The center link is actually sprung weight (attached directly to chassis), but I agree 100% about the compounding of tolerances and the increased difficulty in optimizing the steering geometry.

The biggest issue you will (fabrication-wise)face is getting the steering shaft clear of the front crossmember. Every project we do is slightly different, so I don't have any set drawing or dimensions for you. I ususally use a lower u-joint with splines on both ends, and cut a tunnel through the crossmember just large enough for the shaft. Again, it depends on your choice of rack.

MrQuick
11-17-2011, 12:02 AM
I think maybe I owe an apology to astroracer(don't know your name)and maybe Mark (MrQuick) as well.I can see that you have some valid points.If I were to be using factory control arms and spindles(was thinking later model Impala or similar, they're supposed to be stronger and lighter) maybe that part is true But there are brake diameter factors as well.I'd really like to commend (not bash)Astroracer on his apparent success and skill at doing what he has done with the van.Anyone who can make a vehicle no matter it original intended use perform then I should show some respect for their opinion.I've breached this subject before and was met with rather fervent and somewhat strong opinions with some matching language.I believe that even circle track,stock car,and some other types of parts can be used and be adapted too our particular discipline of the auto industry.I know this much though you have to buy quality parts and use high quality planning as well as execution too obtain something safe and more fun than headache.Thanks for your patience and hope too becoming friends.

no apology required.

Looking forward to seeing what you come up with. I'll try to help you out as much a we can.

jamesinark
11-17-2011, 06:00 AM
Thanks for the idea about going through the frame with steering shaft.most solutions for the problems encountered revolve around using extra u-joints and an extra os rod end (heim joint or whatever term you prefer),but you usually end up with one or more intermediate shaft at quite an extreme angle.Your suggestion would be an possible answer to the wear and angularity issues.I will do some research and narrow down some choices for a rack.Any Suggestions on which brand of u-joints that you might be inclined to use ?Thanks for your help again.Mark I really do hope to get to know better as the more minds you have working on potential problems the better.

exwestracer
11-17-2011, 09:51 AM
Mark,
I don't recommend brands very often, just designs that I think work. Stay away form the huge "billet" u-joints. We use Borgesen or Flaming River on the race cars. I like them for the smaller body size.

BTW, punching a hole and sleeving that crossmember isn't going to be easy. I recommend drilling small holes and running a welding rod through to verify location, then drill or cut the larger holes. Pretty easy to make a mess on this one, and much harder to clean it up.

MrQuick
11-17-2011, 11:49 PM
Mark,
I don't recommend brands very often, just designs that I think work. Stay away form the huge "billet" u-joints. We use Borgesen or Flaming River on the race cars. I like them for the smaller body size.

BTW, punching a hole and sleeving that crossmember isn't going to be easy. I recommend drilling small holes and running a welding rod through to verify location, then drill or cut the larger holes. Pretty easy to make a mess on this one, and much harder to clean it up.

don't forget about the lower control arm pocket.

jamesinark
11-18-2011, 08:50 PM
Right now I need to decide on which brand of rack I can get with the the least amount of Custom work to be done to fit my application.I have seen some fixes for these types of conversions using double u-joints(borgesen by the way)for the very same reason Ray mentioned.They include more supports and some interesting angles,but they were not using as much engine setback as I would like to use.I'm still measuring for wheel dimensions too see what i can do to use the type of wheels and the offset as well as diameter to allow for bumpsteer adjustment kit.I like the idea of possibly running through the subframe as it has the merit of having less moving parts as well as less steep angles.Simpler means less parts to possibly cause a failure of some sort.Thanks for the reminder about lower control arm pocket.I'd like to box or maybe gusset the rear mount to increase the load capacity.any Ideas on which would be better?

exwestracer
11-19-2011, 06:12 AM
Some of them incorporated a tie bar from the frame to the crossmember.
https://static1.pt-content.com/images/pt/2011/11/subframes-1.jpg
IMO, your best bet would be to make a beefier version of that out of round tubing and weld it to the back of the rear mount. Trying to box or plate it in is going to add a lot of material for not much gain in strength. Just remember the exhaust!

If you are looking for a good deal on steering racks, the late model stock car stuff is all pretty much the same. Be sure to get a pavement rack, as the ones built for dirt cars will be way too fast for your application. I would think something in the range of 2" per turn would be fast enough. There are generic rack mount plates available from many sources. That is what we always start with. If you are using power steering, getting a remote servo valve will save a LOT of space down at the crossmember.

exwestracer
11-19-2011, 06:26 AM
Another thing that can help a lot with clearance is going to a pad style motor mount.
https://static1.pt-content.com/images/noimg.gif
You can buy these anywhere for about $10! (and up). This allows you to build a tower or triangle, and cut away the old mount surface for shaft clearance. I don't remember you saying how much setback you are planning, but you can build pretty much whatever you need to get up to it.
https://static1.pt-content.com/images/noimg.gif
If you don't want solid mounts, I've used these with a "Jelly donut" isolator before, with good results.

jamesinark
11-22-2011, 09:18 AM
I've been looking at racks from all the manufacturers I can find and still am no further on making a decision,but the remote servo is not something I had considered.As far as motor mounts I will probably use a Street&Performance kit as their shop is only ten miles or maybe less and I can get a little hands on with some of my components by buying through them.Also their kit allows you to flip the frame mounts upside down and bring the engine down 1" and back by at least 2"(I may also move the frame mounts back a little).That may not give me the room I would like,but I'll mock up something temporarily and maybe end up using a pad style mount or possibly a tower type mount I found in Speedway Motors.I also have to allow for oil lines I'd have to use if I use Pace Performance's dry sump adapter kit.Also as you so wisely pointed out my headers are going to possibly an issue, especially if I reenforce the rear control arm mount.As you can see it can rapidly get out of hand.Is the lower control arm reenforcement a really big issue in your opinion Ray?

exwestracer
11-22-2011, 09:39 AM
James,
It can't hurt. I would see where you are at with the exhaust first, then see what you can do to brace up that mount.

Do you have an idea on rack eye to eye width yet? Until you get that, selecting the rack you want will be tough.

jamesinark
11-22-2011, 10:38 AM
about that.The lines you are talking about (from upper&lower control arm mounting points).Where are they supposed to converge at?Sorry you already said that.What I mean is in which direction are they at?Are you supposed to measure in the direction of the spindle,lower ball joint,Tie rod end or vertically?I didn't quite get that part.As far as that goes ,Flaming River has a bolt in crossmember with rack mounted already.It uses a bar to mount on what I'm guessing is a corvette rack and the tie rod ends are mounted inboard of rack tie rod ends using a somewhat flimsy steel mount.I'm guessing it would be more pro street or drag oriented.It doesn't look up to road race activities.I'd think the lateral loads would be somewhat high.Are you familiar with that type of conversion?