Cool bean

In preparing for front end rebuild, I could use your advice. Here's the situation:

• 1974 coupe, L48, stock suspension. Stock sway bar.
• Borgeson upgrade
• 550 pound springs, BilsteinHD shocks, getting spreader bar.
• Complete front end rebuild kit (ball joints, tie rods, stock sway bar busings, etc.
• 15x8 aluminum torque thrust 2 rims.245/60r15 all around
• I have 2 complete sets of control arms, including mounting bars. I also have 2 sets of poly busings. (first set from car, second set from craigslist deal: the plan was/is to practice bushing removal and replacement, use one set, sell the other.) Both sets are media blasted and ready for paint or powder coating and new poly busings installed.
• rear is already rebuilt to stock, (steel spring, stock shocks (but will replace these), poly bushings, rebuilt trailing arms). Getting adjustable strut rods.
• application: funner than fun, spirited driving, good road feel, (not soft, as described by jb78L82)

Question
After researching the advantages of tubular upper control arms (uca), I am considering nexts steps. Based on jb78L82s posts, I had planned to go with stock control arms. I'm not going to do coil overs/sharkbite route. (Too expensive) However, I could finish the one set, sell them, and fund the purchse of uca (vansteel, spc, other?) With all that said, whats your suggestion and why:

• stay with stock control arms. Sell one set.
• sell one set, sell 2nd set of rebuilt ucas. Get new uca to get extra caster. If so, which ucas? (Im staying with 550# springs-cut-one-coil, bilsteinHDs.)
• Which tie rod hole to use?? When i disassembled front end, the outer tie rods were in the 'inner' hole, not the one closest to the end of the bracket. Should i stay with original holes or go with outside holes for outer tie rods.

Crimson Thunder

After spending the afternoon putting back together my front suspension after installing new ball joints and tie rod ends I would go ahead and get the new upper control arms. I like the Van Steel or the Global West arms.

cagotzmann

When looking at after market controls arms usually means you cannot get enough caster set in your alignment. Global west and others help out with this.

If you can set 2.75 degree caster without problems the only other reason to go with aftermarket is track days.

Better design to limit camber changes with different length ball joints.

Something a little stronger.

or you just like the look.

I have SPC race upper control arms. They are completely adjustable to get any caster setup within reason.

The down side to some UCA is they don't have bump stops and your shocks must have travel limiters in them. ( this you need to check if you are using the car mainly for street use )

To be honest I didn't notice much if any change in track days before and after the change from stock control arms vs aftermarket units.

Cool bean

Ok, good advice and things to consider. I'm feeling adventurous and after a bunch of research, I think I'm going try and slot the uca cross shafts. Gkull and others here at cf and other forums have done so with success. I'm going to mill 1/4 inch (yellow section in photo from all 4 holes which will allow sliding uca back, which will allow (results vary) up to 6° castor with stock uca. The objective is to enable stress free straight line driving, or another way of saying 'staying straight with todays wider tires' or 'return to straight' after a turn.
I'll report back with final alignment specs in a few months when everything is back together. In the meantime, please share results if you've taken this approach.

gkull

The most caster I could get on my 79 was about 3.79 Norval who used be on here out of Canada did posts on zero bump steer and modding the cross shaft.............. I have a gusseted frame and a cross bar because I used 295/17 inch slicks with 700# front springs

Now I use about 6.5 caster and-.43 camber for best ware on my my tires

Cool bean

The upper control arm rebuild process continues.




Slotting the upper control arm cross shafts in hopes of getting close to 5 degrees caster with Borgeson steering box upgrade.

Cool bean

Adding to this post to follow up on progress. Here's the slotted cross shafts on uppet control arm during install. To fill in partial hole, I took the grinder/cutoff tool to a galvanized 7/16 carraige bolt. I used the unthreaded part of the shaft and cut it to fit. Shims, trimmed 550 lb springs go in next. I'll post results once its aligned and on the road. Thanks for advice and help!

gkull

That is how mine are done For the less adventurous without a vertical mill. you can buy them from VB&P, but I personally don't know if they are thicker and have the same problem as the global West which it sounds like also induce addition unwanted Camber.

You should probably ask the VB tech before buying.

i use a 1/2 inch drive powerful air hammer to drive the old bushing out of a-arms. Then a hydraulic press to put the new ones in. They just have to end up without end play and snug on the shaft when installed. I've come across a-arms that have been bent in over the years.

I've gotten pretty good at it because i do clients Vettes.

gkull

Cool bean, I was just showing how easy it is to remove the A-arms and paint or powder coat them and reinstall. My slotted upper is covered by the nuts and shims so you can't even tell that it eas machined

cv67

Interesting

imo generally speaking like cargtozmann said unlees you need the ability to do some special adjustment due to a geomoetry problem or needing a different ball joint location dont waste your money

Prefer polygraphite over polyurethane they dont squeak.

Cool bean

Now I got it, Gkull, thanks. Its been a mighty productive few days. A-arms, VBP spreader bar mounts, 550 lb springs (cut a little), borgeson box, Ride-tech brace, , new turn signal switch, are in.
I'm already committed to the poly bushings, but I'll probably progress through the learnjng curve and wish I got the polygraphite and/or the serviceable zerks once I start hearing squeaks. Until then, I was generous with the grease that came with polyurethane bushings.
Its a good feeling getting this far in the project. Thanks for all your help, corvette people!
Control arms, springs, shocks, borgeson box in.

gkull

I've had the morroso solid motor mounts for many years. I think that it uses the block as a cross mount and makes the frame more ridged.

Later after years of racing i added the VB&P cross bar and I never really noticed a difference witht the cross bar installed

Cool bean

Dang! Good point. I went with solid motor mounts too, but already spent the $ on the spreader. Oh well. That's why the neighbors call me over-kill Phil. Thanks for mentioning that. If the spreader interferes with any fitments i know i can remove it.

hugie82

I've heard a few guys say the mount doesn't make much of a difference and solid motor mounts would definitely do the same job but I have to ask how was the vibrations in the car? I've used them in a 67 nova and it was unbearable, I'm wondering if the full frame vette is a better candidate. I also ran a solid mount on the drivers side and rubber on the passenger side in a chevelle, that worked well but the shift kit made for some brutal 2nd gear shifts!!!

gkull

I don't understand this unless you had a horribly unbalanced motor or something as bad a Harley Davidson. Yes I owned a POS stroker HD all hopped up.

If you turn up the idle a little bit motors also run smoother

Günther-C3

Hello Cool Bean!

I´m wondering if you could test drive your Vette with the slotted shafts. I´m really interested because I want to do the same with mines.

Did you notice any performance in straight line stability of your car? How many milimeters or inches did you slot the shafts?

Regards, Günther

Cool bean

No problem...I honestly can't wait to test drive it, but its going to take about two months before I can do so. I think the bigger milestone is once the engine is in and the new suspension settles, the alignment shop will need to confirm that I they could get greater than 2-3 degrees of caster.

After that, you bet I'll report back on the test drive!

Phil

Günther-C3

Thank you!

Blue Juice

gkull:


I have run solid mounts for +10years. Found they really tightened up the feel of the front end when I fitted them.

Now I just fabricated a cross-brace last month and didn't notice any difference to the handling of the car.

However I did notice that when setting the length there was noticeable flex of the frame.
I had the chassis jacked up to take some (but all) or the weight off the front wheels, and adjusted the bar so it was snug but not really tight against the brackets (pushing out).
When I lowered the car the bar was locked tight.
So there is evidently some flex there.

I may investigate this further and measure the change in distance between the brackets when jacked up (wheels off the ground) and sitting down on the wheels.

cagotzmann

What happened to all those that claim this is the best mod they ever done. (Spreader bar)

I also didn't notice any handling difference with it installed.

The only difference I noticed is less interior body rattle noise on certain roads.

Do the towers move, yes they do but enough to effect handling I don't think anyone could feel the difference if they did a blind test where someone else removes or connects the bar and asks the driver to identify what was done.

I am running poly engine mount on the driver side and rubber on the passenger side