69 Camaro subframe

[Bwheeler287]

Long time reader, first time poster. I have some questions regarding the build up of my 69 Camaro subframe, a topic I know has been best to death but there are still some questions I have after reading this forum for countless hours.

First some background. The car is a 69 Camaro currently in the sheetmetal work stage but it's time to start mocking up suspension components before finishing off the bottom of the car, which leads me here. I have done full floor, trunk, inner and outer rockers, full quarters, mini tubs, outer wheel houses, toe kicks, rear inner valance, tail light panel, decklid, roof structure and roof panel, tourque boxes, door skins, the list goes on....

plans for the car are to be pro touring, coil overs all around, 4 link, ls air conditioning etc...its use will be more towards the "touring" side as I plan to drive it A LOT. Things like the power tour, drive to large scale shows such as good guys, super Chevy and the like. Now once I get there and there happens to be some road course, auto x, braking challenges etc I would like to participate and have fun with the chance of performing well.

i have found myself researching the abundant amount of info about aftermarket subframes vs building up the stock sub. My stock sub mounts are rusted but I'm plenty capable of repairing so that's not an issue.

Reading about stock subs is I mainly find myself hung up on the spindles. I understand with all the control arms of the major manufactures that they offer corrected geometry to improve camber curve, as well as some like global west adding in lots of caster. Which they all seem to be equally competitive with one another

spindles on the other hand are more of a mystery. I understand the goal with a spindle is to raise the upper ball joint location, also to help camber curve, as well as relocating the steering attatchment to reduce bump steer. My past research around this forum shows the ATS afx spindles are the most recommended. They are also the most expensive.

My question lies with, what other spindles are out there? They can't be the only ones offering such improvements. I see pictures of aftermarket subs running spindles the are not those aluminum ats units housing a c5 bearing. So what spindles are they? For my use, the increased cost in an aluminum spindle to save weight (not a huge concern for me) or the cost of running a sealded bearing (also doesn't interest me much) doesn't add up to me needing to spend $1300 on some spindles. So what are my options?

as far as overall cost of building up a stock sub, I only end up a couple hundred short of have a complete heidts or tci unit. Would these subs offer the handling and performance I am after. Dse art Morrison etc are just not in the cards. What are your opinions on these two subs?

ultimatley if it handles and stops like a modern high performance car, like my 09 Srt8 challenger for example, mission accomplished

[dhutton]

Ridetech Tru-turn is another option worth investigating.

Don

[Bwheeler287]

I'll check into that thanks. Any other suggestions out there?

[ra11ysport]

The downside to building up a stock subframe is tire clearance.
For instance my Speedtech subframe(Non Extreme)can fit a 295 tire with 7in backspace without much issue.
Stock subframe your limited to 5.75in backspace and tire rub on the frame and sway bar.
There are alot of advantages to running a Speedtech subframe for instance, you can run stock spindles or ATS. You can also fab a 3 piece sway bar to work with the frame it has alot of flexability, or you can spend 8k on a dse or AME subframe. But if your your gonna run a 255 than by point is mute!

The problem with TCI and Hiedts is the spindles are made for the unit.
I still think this is the best option when DSE or AME is out of the picture
http://www.speedtechperformance.com/index.cfm/page/ptype=product/product_id=8/category_id=23/mode=prod/prd8.htm

[H20cooled]

With the Ridetech front setup and their Tru-turn you can run a lot larger front tires and you can use their 3 piece sway bar. For me I just could not justify spending $8k+ on a new frame when the one I have is still good. I'm sure the aftermarket ones are better and if you have the money then it would be the best I'm sure. But for $8k I did my whole suspension.

[Bwheeler287]

The downside to building up a stock subframe is tire clearance.
For instance my Speedtech subframe(Non Extreme)can fit a 295 tire with 7in backspace without much issue.
Stock subframe your limited to 5.75in backspace and tire rub on the frame and sway bar.
There are alot of advantages to running a Speedtech subframe for instance, you can run stock spindles or ATS. You can also fab a 3 piece sway bar to work with the frame it has alot of flexability, or you can spend 8k on a dse or AME subframe. But if your your gonna run a 255 than by point is mute!

The problem with TCI and Hiedts is the spindles are made for the unit.
I still think this is the best option when DSE or AME is out of the picture
http://www.speedtechperformance.com/index.cfm/page/ptype=product/product_id=8/category_id=23/mode=prod/prd8.htm
This is the subframe I was referring to being pictured without ats spindles. So this speed tech subframe is designded to run a stock type spindle or their ats spindle?
If I were to run this subframe with stock type spindles would i back into more bumpsteer like the stock sub? Or is the bumpsteer engineered out of the equation by the design of the subframe rather than the spindle?

[Bwheeler287]

Are you happy with the performance you got from the tru turn? And did you do a close ratio box as well? I've been reading a lot about the tru turn and it does seem to be a viable option

[ra11ysport]

With the Ridetech front setup and their Tru-turn you can run a lot larger front tires and you can use their 3 piece sway bar. For me I just could not justify spending $8k+ on a new frame when the one I have is still good. I'm sure the aftermarket ones are better and if you have the money then it would be the best I'm sure. But for $8k I did my whole suspension.

Have you installed the tru turn with a 275 tire (i have) prepare to do fender work or run a smaller tire.

[H20cooled]

My car is still being built but I have installed the tru-turn but I cannot comment of the fit of tires or the ride but I have not heard any negative on that setup, from everything I have read it is the best thing you can do with the stock subframe. Regarding close ratio steering, I sent my gear box and pump to Less power steering and they upgraded it to 12:1 with the setup to provide the good road feel and then they dyno tested the pump and gear box and set them to the right flow/pressure for my setup.

[ra11ysport]

This is the subframe I was referring to being pictured without ats spindles. So this speed tech subframe is designded to run a stock type spindle or their ats spindle?
If I were to run this subframe with stock type spindles would i back into more bumpsteer like the stock sub? Or is the bumpsteer engineered out of the equation by the design of the subframe rather than the spindle?

Yes its engineered for both stock and ats spindles.
I would call Speedtech for a more educated answer, but the frame has the g-mod built into it which helps the camber gain and bump steer.
Cantact Jay at Speedtech and he will answer any question you have they are great to deal with.

[Cdog]

Start with your budget. What are you willing to spend? My personal preference is Art Morrison. The majority of the front end is factory GM. 10 years from now parts will be abundant & C6 has tons of aftermarket performance and racing support.

[F-Body International]

Pro-Touring F-Body has a very interesting kit for 1st gen if interested in checking that out. I'm using PTFB for my '79 T/A and I must say, the parts are awesome. Also, my advice would be to stay with leaf springs if you're building a touring/mild-competition car. You don't need coil-overs and expensive link suspension to lower your car.

http://pro-touringf-body.com/control_arms.html

"Tall Spindle Kit"

This new GEN II™ geometry correction kit makes your stock "short" spindles into one
inch taller spindles with this simple bolt on kit without having to buy expensive spindles.
This kit also improves bump steer. (69 Firebirds use n adjustable bumpsteer kit )

67-69 Camaro 1CS-201 $599.00

[ra11ysport]

Start with your budget. What are you willing to spend? My personal preference is Art Morrison. The majority of the front end is factory GM. 10 years from now parts will be abundant & C6 has tons of aftermarket performance and racing support.

I called AME to find out what is actually factory gm parts. The only off the shelf part is the upper and lower control arms. Everything else is designed and built for the package. The spindle is off the shelf but its modified to to work with their steering arms and r&p.

[Bwheeler287]

Looks like maybe running factory spindles aren't as detrimental to a suspension setup as I thought they were. I am gathering that running increased caster will improve bumpsteer by rotating the tie rod attachment down, improving bumpsteer, similar to an aftermarket spindle relocating it down.

Budget wise, aftermarket spindles are a huge expense in decideding to build up a stock sub vs buy an aftermarket unit. If one could get away with running stock spindles with all the other goodies on a stock sub the price gap begins to widen in comparison to a buying a complete aftermarket unit. Where as if you had to buy ats spindles or a ride tech tru turn setup the cost gets pretty close to an aftermarket sub

[Cdog]

The DSE rack & steering arms are the only non GM items. You just need to cut off the factory steering arm on the upright.

Benefits are the extremely light weight forged aluminum factory GM parts that are track proven.




Looks like maybe running factory spindles aren't as detrimental to a suspension setup as I thought they were. I am gathering that running increased caster will improve bumpsteer by rotating the tie rod attachment down, improving bumpsteer, similar to an aftermarket spindle relocating it down.

Budget wise, aftermarket spindles are a huge expense in decideding to build up a stock sub vs buy an aftermarket unit. If one could get away with running stock spindles with all the other goodies on a stock sub the price gap begins to widen in comparison to a buying a complete aftermarket unit. Where as if you had to buy ats spindles or a ride tech tru turn setup the cost gets pretty close to an aftermarket sub

[F-Body International]

Before you start any of these suspension ideas, I would suggest starting off by ordering solid body mounts and addressing those mounting points for the frame like mentioned. 67-81 F-Body subframes literally bolt to the body in 4 spots and this is a major flex point. Solid body mounts will stabilize the foundation all of your suspension operates on. You can have all the suspension goodies and high grip tires but if the foundation is not solid, everything will flex and your suspension will not operate to its fullest potential.

Again, I would suggest contacting Pro-Touring F-Body for the solid mounts. Theirs uses a steel locating sleeve and is 3-way adjustable. Others are not adjustable, more expensive, etc.

Stock vs aftermarket subframe? My vote would be turning wrenches and saving money by using a stock subframe on this thread. You can build a very well handling car with simple suspension upgrades and good tires.

Hopefully this helps. The PTFB "Tall Spindle Kit" and solid body mounts are really well priced for what you get in my opinion.

[Bwheeler287]

Before you start any of these suspension ideas, I would suggest starting off by ordering solid body mounts and addressing those mounting points for the frame like mentioned. 67-81 F-Body subframes literally bolt to the body in 4 spots and this is a major flex point. Solid body mounts will stabilize the foundation all of your suspension operates on. You can have all the suspension goodies and high grip tires but if the foundation is not solid, everything will flex and your suspension will not operate to its fullest potential.

Again, I would suggest contacting Pro-Touring F-Body for the solid mounts. Theirs uses a steel locating sleeve and is 3-way adjustable. Others are not adjustable, more expensive, etc.

Stock vs aftermarket subframe? My vote would be turning wrenches and saving money by using a stock subframe on this thread. You can build a very well handling car with simple suspension upgrades and good tires.

Hopefully this helps. The PTFB "Tall Spindle Kit" and solid body mounts are really well priced for what you get in my opinion.
Thanks for the info, I will check into that link and look at that spindle kit

[dhutton]

Ridetech spindles with Tru-turn is cost effective....

Don

[Bwheeler287]

The DSE rack & steering arms are the only non GM items. You just need to cut off the factory steering arm on the upright.

Benefits are the extremely light weight forged aluminum factory GM parts that are track proven.


Cdog, your in box is full. My email is [email protected]

[Rod]

I saw that someone recommended some tall spindle ball joint kit, I looked at that kit, its priced right but it won't work. the Camaro's bump steer increases BADLY when you add tall bottom ball joints, that kit adds those...no no...then they add tall outer tie rods and that brings the bump steer right back to the camaros stock curve? so I dont understand those to parts in the kit, the tall upper ball joint is what helps the poor camber curve, helps, in no way fixes, but helps..

what do you want out of the car? what is your budget?

[Bwheeler287]

I saw that someone recommended some tall spindle ball joint kit, I looked at that kit, its priced right but it won't work. the Camaro's bump steer increases BADLY when you add tall bottom ball joints, that kit adds those...no no...then they add tall outer tie rods and that brings the bump steer right back to the camaros stock curve? so I dont understand those to parts in the kit, the tall upper ball joint is what helps the poor camber curve, helps, in no way fixes, but helps..

what do you want out of the car? what is your budget?

If it handles as good or better than a modern muscle car then mission accomplished. Such as my 09 srt8 challenger, I'd be perfectly fine with that. I plan to drive it a lot to bigger events and if there happens to be an autocross etc.. there I'd like to be able to run hard in it. Im a long time racer of many different sports so I much prefer high performance over a luxury cruiser.

as far as budget, that is always relative for me. For example, if I can utilize stock type spindles and run normal tapered bearings, as opposed to spending 1300 on ats spindles with a sealed bearing, the bearing type alone is not worth that kind of money to me, but if it really offered that much difference in performance then it would be. This is just an example of how I think. I don't like to spend lots of money for a minor gain, I'd rather spend lots of money on a large gain and small amounts of money on small gains if that makes sense

[JEFFTATE]

If you are gonna use your stock subrame , I would get the Ridetech TruTurn system with their spindles, control arms, and swaybar. Then get a quick ratio steering box . Get their single adjustable coilovers too .. Their products are tried and tested and priced right.

[Bwheeler287]

If you are gonna use your stock subrame , I would get the Ridetech TruTurn system with their spindles, control arms, and swaybar. Then get a quick ratio steering box . Get their single adjustable coilovers too .. Their products are tried and tested and priced right.

Thanks for the suggestion. I have been studying that quite heavily. I noticed their sway bar is quite expensive. Is this because it is splined? If so what are the benefits of a splined vs standard sway bar?

[dhutton]

Thanks for the suggestion. I have been studying that quite heavily. I noticed their sway bar is quite expensive. Is this because it is splined? If so what are the benefits of a splined vs standard sway bar?

More tire clearance....

Don

[ra11ysport]

Thanks for the suggestion. I have been studying that quite heavily. I noticed their sway bar is quite expensive. Is this because it is splined? If so what are the benefits of a splined vs standard sway bar?

It's not a splined sway bar is just a fancy 3 piece setup.

[79T/Aman]

The PTFB tall spindle kit uses a longer outer tie rod to offset the taller lower ball joint, increasing positive caster will also improve bump steer,

The tall lower ball joint helps lower the car 1/2" somewhat like a drop spindle does, this helps lower the car without decreasing the suspension travel, this beneficial on first gens that are fairly tight in the A-arm area with a very short sway bar swing arm.
You have the option of not using a tall lower ball joint if bump steer is a problem.
A + .900" upper ball joint is available but may limit the width/back space of the wheel if less than 18" wheels will be used.
A bump steer kit also may be used if more bump steer adjustment is required.
This system does not require relocating the inner tie rod pivot points that can cause interference with oil pans and headers.

All in all the PTFB kit is an improvement with compromises as are all the other bolt on kits but the PTFB kit is much more affordable.

Dave

[TheJDMan]

The PTFB tall spindle kit uses a longer outer tie rod to offset the taller lower ball joint, increasing positive caster will also improve bump steer,

I get the sense from this statement that PTFB is just applying band aids on top of band aids. As others have said, your best bet is the proven performance of the RideTech TruTurn system. Also, do some research about welding up the seams on your stock subframe to increase its rigidity.

[Chad-1stGen]

A few things. Control arms by themselves don't fix camber gain at all. You have to change the ratio of the height of the control arm mounting point versus the height of the spindle. There are three ways to do this on a stock subframe. In order of cheapest to most expensive 1) Guldstrand mod to lower the upper control arm mount 2) tall upper ball joint to lengthen the effective spindle height or 3) buy a tall spindle like the Ridetech or AFX. Control arms will only help with caster improvements.

Also, as an owner of a TCI equipped Camaro it is a very viable option if you do decide to go aftermarket subframe. In two years I've put over 20k miles on mine with over 20 track days and more than 50 autocross days. I've placed first in a bunch of local autocross events, podiumed twice at Optima ULtimate Street Car as well as 4th overall in GTV and invited to the Invitational at SEMA. I only list those accomplishments to evidence the TCI subframe potential. If your goals are street driving with occasional autocross or track day most of the setups discussed will get you there.

If you do stay stock subframe prepare to spend more money on shocks and good tires if you are truly after autocross and track performance. The camber gain is the easy part...

[79T/Aman]

PTFB has an economical kit to improve the geometry of the 1st gen using bolt on parts that do not affect other major components.

FYI all the other kits out there for the stock frame have their pros and cons, the bottom line is how much do you want to pay for those pro AND cons ?!

[Rod]

I get the sense from this statement that PTFB is just applying band aids on top of band aids. As others have said, your best bet is the proven performance of the RideTech TruTurn system. Also, do some research about welding up the seams on your stock subframe to increase its rigidity.

agree with JD here on both points, I have raced my own car for many years at many levels in this sport and I have tried many suspension combos on the car, I tested the ball joints in varying combos early on I think Pozzi did also and he published pretty much the same results i had, one of the biggest things I did to the stock frame was welded it completely the factory simply stich weleded it 50 years ago, and after the frame was welded I had the frame shot peened blasted with steel shot, that allows the frames steel to relax again, (welding creates tension and twist in the steel) and then I didnt powder coat it I just sprayed it

[F-Body International]

I get the sense that this members on this forum play too well with sponsors rather than providing real tech advice. I've been a part of this forum a little while now and have seen many people say "go with any of the sponsors" or "proof is in the results" as their tech advice in various threads. What results? Who raced who? Just go with a sponsor and your good?

PTFB is not a current sponsor but has been in the past. Dave at the PTFB shop does build some badass parts that are exclusive to the industry. Please, don't take this as a discredit to other vendor designs...especially the ones that sponsor this forum. As we speak, PTFB is actually building my subframe with all the special tricks and modifications you can do. Mine, however, is a 2nd gen frame which apparently has better geometry to start with. Maybe I'm a little bit biased because of this.

[dhutton]

I get the sense that this members on this forum play too well with sponsors rather than providing real tech advice. I've been a part of this forum a little while now and have seen many people say "go with any of the sponsors" or "proof is in the results" as their tech advice in various threads. What results? Who raced who? Just go with a sponsor and your good?

PTFB is not a current sponsor but has been in the past. Dave at the PTFB shop does build some badass parts that are exclusive to the industry. Please, don't take this as a discredit to other vendor designs...especially the ones that sponsor this forum. As we speak, PTFB is actually building my subframe with all the special tricks and modifications you can do. Mine, however, is a 2nd gen frame which apparently has better geometry to start with. Maybe I'm a little bit biased because of this.

How long does it take PTFB to build a subframe because you have been saying this for quite a while?

Don

[79T/Aman]

Again the PTFB kit has options and as I said the tall lower ball joint does not have to be used but is a way to get another 1/2"of drop without causing tie rod interference with the wheel as do drop spindles.
The PTFB kit works well for a typical street car that is not dropped in the weeds, tall lower ball joints allow for a lower stance but put the outer pivot point lower in relation ship to the inner pivot for the same given ride height if only coils were used to lower the car.

Again this is not about patronizing so and so this is about what accomplishes ones needs and budget.

As for David Pozzi's testing, it was done without a longer outer tie rod or bump steer kit and the datum was based on a car that would be fairly low and with stock upper A-arms, and conservative positive caster setting

[Z06vet]

I'm pretty sure Rod & Chad are qualified to provide real tech advise. It sounds like you're building your subframe the way you feel is best, and keeping things within budget. I have a friend I autocross with that used some PTFB parts on his 69 camaro. He & I usually run near identical times. There are a lot of good parts & companies out there building some quality parts. Just because you feel PTFB is the way tot go, it doesn't seem right to discount the valuable expertise Rod & Chad have acquired and shared with this forum. I dont know anything about PTFB, maybe you could document your subframe build, and share pics with this forum. I'm always open to learn about affordable parts, as I like to build and Sell F-bodies.

[Rod]

I get the sense that this members on this forum play too well with sponsors rather than providing real tech advice. I've been a part of this forum a little while now and have seen many people say "go with any of the sponsors" or "proof is in the results" as their tech advice in various threads. What results? Who raced who? Just go with a sponsor and your good?


cool Im being called to the carpet!

OK then i didnt recommend a vendor, I am a vendor and nowhere in my post did I hock my company or my ****, I gave actual tech advice to his question from what I have done, I didn't suck up to a builder or friend and nowhere did I put down a vendor or product, as I stated some componenets do not play well with others and I dont give a damn who puts them in what package, some crap doesnt work together...simple... do i know it all, hell no, but I will give you it straight on what i have done, built, tested, raced, I put my name out there! at the top of my post and my signature, written articles about my industry, raced all over the nation with friends! If you want to know about me...google it.... Im not here to defend myself, Im here to learn from others and pass on what I have done so others can learn

Have a great weekend

so now back to the original posters questions!

[David Pozzi]

Here's my test data for tall balljoints: http://www.pozziracing.com/proforged_first_.htm
I just updated it with the tall outer tie rod data. For about a year I was not able to change my web page. Found out my ISP was repeatedly giving me the wrong link to upload to.

In my test, I started at less caster (3.4 deg) (stock upper A arms) than you would use with tubular upper A arms. More caster would rock the spindle down in the rear slightly and slightly improve the bump steer.

Tall lower ball joints dropped the car .5". in my tests, I started all the .5" LBJ tests at the same ride height as the stock lower ball joint. Camber gain increases as you lower a car so the tall lower ball joints caused the upper A arm to start in a flatter position and there is less camber gain for that combo. There may be travel and roll center height and migration gains or losses, - that wasn't investigated.

The main point of my tests shows the gains in caster and how much bump steer they add. The .5" tall tie rod ends help reduce bump steer on a stock Camaro but when you add a .5" taller UBJ, the tall tie rod ends only bring bump steer back to stock levels. The best bang for the buck is the .5" tall UBJ with tall tie rod ends. The taller UBJ makes bump steer worse than stock, even with the .5" taller outer tie rod ends. In my opinion, you don't want to do that. Another option is doing .5" tall UBJ with the Guldstrand mod. I would predict similar results as doing a .9" tall UBJ, - more bump steer than you'd like. There are bolt on bump steer studs that allow a Rod end to be used in place of the outer tie rod, but those don't allow enough spacers to fix the bump steer with G mod and .5" or the .9" UBJ. I think the outer tie rod end would need to be extended 3/4" to 1" to fix it. Heating and bending the steering arm or making your own Rod end conversion, or drilling out the steering arm taper to 3/4" and using a straight bolt with machined 3/4" to 1" spacer and a Rod end are the three solutions.

A first gen Camaro needs a new subframe as soon as you want to run a bigger tire than a 275x18 up front. Even to run a 275 you are going to have to do some very very careful setup and it will have to include needed wheel spacing at the camber setting you will be running. An aftermarket sub will be 5" narrower over stock and usually stiffer in torsion. Lighter by total car weight, mainly due to the lighter steering components and lighter A arms.

You need Corvette hubs in front and Corvette or Baer type floater rear hubs if you will be using 6 piston fixed calipers. Knock back is too high with stock front hubs and a non-floater rear. Stick with F/R floating calipers if you don't improve your F/R hubs. Manual brake systems are more sensitive to this but even power brake systems suffer knock back problems. I've driven Camaros with so much knock back that the rear brakes stopped working after a hard corner and the pedal had to be pumped to get them to work again.

Rodney has done amazingly well with a stock subframe, so I'd read his posts with care.

[F-Body International]

Don...
It takes about 2-3 weeks for a normal customer. 1 week to wait for the sandblaster and the rest would be getting the work done.

Z06vet....
I've been busy spending money with personal stuff so my '79 subframe was put on hold for a little bit. It hasn't been cheap for me the past couple months. Since September, I gotten married, bought a 4th gen LS1 T/A, and the holiday's have eaten up a little time/money. I, however, just ordered my front wheels for the 2nd gen on Wednesday so PTFB just started working on the subframe again on Thursday. The wheels should be in and the frame should be able to roll within the next two weeks. I will make thread on the build so everyone can comment or make suggestions there rather than continue to interrupt someone else's thread. Once my frame is done, someone else local to the PTFB shop with an '80 Camaro is bringing in their subframe to get done. That one should be a normal process unlike mine.

Rod...
I agree with getting back to original poster's questions. Like I said before, I'm not trying to discredit any other vendor designs...especially not you if you're a sponsoring vendor. Nowhere have I said that the True-Turn kit is a bad design. I apologize and I'll get off this thread now. Keep on wheelin' and have a good weekend as well.

[Bwheeler287]

I appreciate everyone taking the time to lend their knowledge and advice. Especially the honesty, many places one turns to for technical advice turns into someone trying to sell parts. I feel that most here are offering up what they have learned over the years and what does or does not work well. Especially the guys here with many many years of experience.

This has consolidated many of the other threads I have read that always left me with a few more lingering questions. I'm sure this will help many others out as well.

I'm sure there are plenty of guys out there like me looking for a cost conscious solution (note that I do not mean "cheap") that flat out performs without many wasted bells and whistles.

Don't get me wrong, there's always room to spend for a little bit of "cool" factor. Because let's face it, if none of this was cool and exciting, we wouldn't be doing it.

[Bwheeler287]

Here's my test data for tall balljoints: http://www.pozziracing.com/proforged_first_.htm
I just updated it with the tall outer tie rod data. For about a year I was not able to change my web page. Found out my ISP was repeatedly giving me the wrong link to upload to.

In my test, I started at less caster (3.4 deg) (stock upper A arms) than you would use with tubular upper A arms. More caster would rock the spindle down in the rear slightly and slightly improve the bump steer.

Tall lower ball joints dropped the car .5". in my tests, I started all the .5" LBJ tests at the same ride height as the stock lower ball joint. Camber gain increases as you lower a car so the tall lower ball joints caused the upper A arm to start in a flatter position and there is less camber gain for that combo. There may be travel and roll center height and migration gains or losses, - that wasn't investigated.

The main point of my tests shows the gains in caster and how much bump steer they add. The .5" tall tie rod ends help reduce bump steer on a stock Camaro but when you add a .5" taller UBJ, the tall tie rod ends only bring bump steer back to stock levels. The best bang for the buck is the .5" tall UBJ with tall tie rod ends. The taller UBJ makes bump steer worse than stock, even with the .5" taller outer tie rod ends. In my opinion, you don't want to do that. Another option is doing .5" tall UBJ with the Guldstrand mod. I would predict similar results as doing a .9" tall UBJ, - more bump steer than you'd like. There are bolt on bump steer studs that allow a Rod end to be used in place of the outer tie rod, but those don't allow enough spacers to fix the bump steer with G mod and .5" or the .9" UBJ. I think the outer tie rod end would need to be extended 3/4" to 1" to fix it. Heating and bending the steering arm or making your own Rod end conversion, or drilling out the steering arm taper to 3/4" and using a straight bolt with machined 3/4" to 1" spacer and a Rod end are the three solutions.

A first gen Camaro needs a new subframe as soon as you want to run a bigger tire than a 275x18 up front. Even to run a 275 you are going to have to do some very very careful setup and it will have to include needed wheel spacing at the camber setting you will be running. An aftermarket sub will be 5" narrower over stock and usually stiffer in torsion. Lighter by total car weight, mainly due to the lighter steering components and lighter A arms.

You need Corvette hubs in front and Corvette or Baer type floater rear hubs if you will be using 6 piston fixed calipers. Knock back is too high with stock front hubs and a non-floater rear. Stick with F/R floating calipers if you don't improve your F/R hubs. Manual brake systems are more sensitive to this but even power brake systems suffer knock back problems. I've driven Camaros with so much knock back that the rear brakes stopped working after a hard corner and the pedal had to be pumped to get them to work again.

Rodney has done amazingly well with a stock subframe, so I'd read his posts with care.

This is great info that helps tremendously with understanding the modification of the stock geometry. Bump steer is a tough animal to combat it seems, as it appears to be give and take until you get something your happy with

[nats68]

Are you happy with the performance you got from the tru turn? And did you do a close ratio box as well? I've been reading a lot about the tru turn and it does seem to be a viable option

Just chiming in here because I just did the Tru Turn On my 68 Camaro. I did the Tru Turn and dropped spindles. The tire clearance is great but I'm only running 245's on 8" wheels. I'm running 5" of backspace on the wheels.
I also had my factory steering box rebuilt with the close ratio gears. I love how tight the steering is.
I would really look at the Ridetech stuff. Great quality and great customer service.

[Bwheeler287]

Just chiming in here because I just did the Tru Turn On my 68 Camaro. I did the Tru Turn and dropped spindles. The tire clearance is great but I'm only running 245's on 8" wheels. I'm running 5" of backspace on the wheels.
I also had my factory steering box rebuilt with the close ratio gears. I love how tight the steering is.
I would really look at the Ridetech stuff. Great quality and great customer service.

Where did you have the steering box work done?

[David Pozzi]

I deleted the whole discussion on Corvette hub bolt circle dimensions. Lots of the early info was wrong.
To Summarize, C4, C5, C6 uses a 120.65mm bolt circle which is 4.75"
Fifth Gen Camaro uses 120mm, and C7 Corvettes may also be 120mm which is just 4.7211"

[Bwheeler287]

I deleted the whole discussion on Corvette hub bolt circle dimensions. Lots of the early info was wrong.
To Summarize, C4, C5, C6 uses a 120.65mm bolt circle which is 4.75"
Fifth Gen Camaro uses 120mm, and C7 Corvettes may also be 120mm which is just 4.7211"

Thanks for clearing that up.

[Bwheeler287]

If I was to stick with the stock sub and go with the tru turn, a steering box upgrade would be a must. What is everyone's experience with that?

What's good, what's bad and what works well? There seems to be a wide variety of options as well as prices. Most seem to be based on the 600 box, is that correct? I have a factory power box but would be unsure of the series. Research on this site has shown sending it out to Lee and have them build it up is an option.

I have also come across one (cannot remember which) that said it has rack and pinion style construction and valving rather than a recirculating ball type construction. What's the skinny on that?

[David Pozzi]

If I was to stick with the stock sub and go with the tru turn, a steering box upgrade would be a must. What is everyone's experience with that?

What's good, what's bad and what works well? There seems to be a wide variety of options as well as prices. Most seem to be based on the 600 box, is that correct? I have a factory power box but would be unsure of the series. Research on this site has shown sending it out to Lee and have them build it up is an option.

I have also come across one (cannot remember which) that said it has rack and pinion style construction and valving rather than a recirculating ball type construction. What's the skinny on that?

The gears and piston are not much different, the control valving is supposed to be "better" perhaps with less play.

[Rod]

I use these a lot without issue and the price is right at 387 bucks and free ship

Summit AGR 12:1 box (https://www.summitracing.com/parts/agr-492117/overview/)

I have one in my own car also for 10 hard racing years now

[Bwheeler287]

I use these a lot without issue and the price is right at 387 bucks and free ship

Summit AGR 12:1 box (https://www.summitracing.com/parts/agr-492117/overview/)

I have one in my own car also for 10 hard racing years now

I'm glad you have good luck with it, that's good to hear because I have read some pretty old threads about guys having problems with them and always wondered how well they performed currently

Definitely lighter on the wallet than some $700+ dollar ones