HiPer strut (GNB suspension code) & coil-over conversion

Something made me want to go all in and do this conversion. I haven't seen it done before so I can't say if it's going to work out but from my eyes, it looks doable.
Basically I'm taking the original steering knuckle out and replacing it with the very different knuckle assembly that comes as an option on some much newer GM FWD cars.
HiPer strut info here

"HiPer Strut utilizes premium, technologically advanced engineering to improve ride, handling, and steering in the front-wheel drive vehicles. Specifically, the technology delivers the following benefits:

Reduces torque steer
Boosts vehicle response to tire variation and imbalanced wheels
Provides more linear steering
Enhances driver communication
Improves isolating impact from bumps and rough surfaces"

While i'm going through the effort, I'll go ahead and do a coil over build too. In some ways, it should actually make it easier.
Original coil-over thread

I'll just post about it as I go and make discoveries but I'm in planning & research stages now. I'm actually more concerned about the coil-over parts than anything because I don't have a lot of experience with it.

the primary things I know I need to make
top strut mount plates for coil overs
simple adapter sleeve to connect coil over body to hi-per strut
round joint to replace the ball joint on the original control arm to connect to bottom of hi-per strut

parts needed for hi-per strut
complete hi-per knuckle/yoke assembly
outer tie rod ends for hi-per strut


strut,knuckle,control arm for a 99 on the right - HiPer knuckle on the left


you can kinda see the need for a different outer tie rod end. The connection point is in a different location and it has to arc around to clear the yoke during turning


just eyeballing it, looks like the barrel joint I need to make is going to be positioned right over the 3 bolt holes for the stock ball joint. If that holds to be the case, it'll be a nice neat compact billet piece.


The top of the hiper knuckle just has a diameter machined in there for a body to go in and clamp tight - super easy


back of stock knuckle


back of bare hiper knuckle
Thankfully it looks like the wheel bearings can be swapped which is necessary because they have different splines and speed sensors - that would have been real trouble if they couldn't swap


top 1998+ top mount
bottom 1997- top mount
I figured they'd at least have the same bolt pattern but nope. Oh well
Originally I was thinkin of setting this up on my green 97 riv so I can go nuts with it right off the batt but instead I'll probably just do it up on the currently stock 99 since that's where it'll eventually end up. I do plan to make the top mounts with at least camber adjustment but I refuse to cut the strut tower opening more so it'll probably only be a small adjustment range.

Always improving/innovating!

Jbird

Another impressive mod!

I've started buying shiny coilover parts

Koni 8611-1259race $344.99 each    I thought it was a pair - i'm gonna be in the poor house pretty soon with this
2-way adjustable damper

QA1 12CS450 $54.52 each
12" long 450lb springs

Allstar performance 64146 - i don't know if I'm going to use these or not but I needed something to start mocking with
sleeve kit


There's a lot of loose ends I'm gonna need to tie up with fitting the parts. I'll need to make split sleeves to fit the shock body down into the knuckle. I'll need some elegant rings so the height adjuster sleeve has a nice full-contact perch to sit on right on top of the knuckle. I might try to integrate a new sway bar mount in that area too since the stock link location conflicts with the new yoke. What else..? I need to make tight toleranced bushings to fit the Koni rods to the pillow balls and I'll likely make my own upper spring seats instead of using what's in the kit because nothing I've seen looks ideal. I'm 90% done designing some sexy caster/camber plates.

James actually helped me get the ball joints off the brand new stock 98-99 control arms. Jesus*** Those rivets suck to get out!

Other things I've looked at
The brake caliper bolt pattern and bolt size is the same as stock. Since this is going on the 99 riv and i'll be running 18" vette wheels on it, i'm just gonna go ahead and put the 13" brakes I accidentally bought a long time ago on it when I install the suspension.

Codith,
Man, your up to some serious shit on these Riv's. Never give up. It's all a learning experience.
Might be an expensive one but you have to be learning a shitload.
Good on you and I'll be keeping my good eye open for this thread. Thanks for posting.
Rick

Update please?

No updates on this for a while because the equal length exhaust stole all of my attention. I've been obsessing over that since last october pretty much. I'm also workin on a few other smaller but more urgent projects like the fuel system upgrade for the green car and getting the corvette wheels to fit better on the white car.
I will get back to this sometime but it's on 'want' status, not 'need'

What are your thoughts on making the Vette rims fit better?

I like the 95 ZR1 rims but they're also 5X120.65.

Jack the R wrote:

What are your thoughts on making the Vette rims fit better?  

I like the 95 ZR1 rims but they're also 5X120.65.

I don't know if I posted about it specifically but my initial test fit of the vette wheels mostly went ok. The only issue was that the outside edge of the tire would rub the inside of the rear fender trim with hard bump or hard cornering situation. That's with using 1.25" thick adapters to mount the wheels. The fronts were totally fine and that's great because the adapters actually bring the theoretical scrub radius near stock - you kinda want the extra spacing there. The back rubbing is obviously a problem so I ended up replacing my rear hub assemblies with ones from the front of a camaro. Basically the only thing you need to do to fit those hubs is drill the 4 flange bolt threads to be through holes like the stock riv hubs and add a ~1/8" spacer to the caliper bracket to put the brakes into alignment with the slightly different offset of the camaro hub. It might seem like a lot but it's not bad. Downside being I can't put my stock spare on the back anymore. You can get a GTO spare for around $100 on ebay i think.

The other thing I did't actually try is just get a narrower adapter. I'd say 1.0" would be as tight as the adapter width could get while fitting all the hardware in it. The 1/4" might be enough to make the rears clear - plus you can play with the exact tire/wheel size. Mine are 18x9.5 275/40/18 for reference.

turtleman wrote:

Jack the R wrote:

What are your thoughts on making the Vette rims fit better?  

I like the 95 ZR1 rims but they're also 5X120.65.

I don't know if I posted about it specifically but my initial test fit of the vette wheels mostly went ok. The only issue was that the outside edge of the tire would rub the inside of the rear fender trim with hard bump or hard cornering situation. That's with using 1.25" thick adapters to mount the wheels. The fronts were totally fine and that's great because the adapters actually bring the theoretical scrub radius near stock - you kinda want the extra spacing there. The back rubbing is obviously a problem so I ended up replacing my rear hub assemblies with ones from the front of a camaro. Basically the only thing you need to do to fit those hubs is drill the 4 flange bolt threads to be through holes like the stock riv hubs and add a ~1/8" spacer to the caliper bracket to put the brakes into alignment with the slightly different offset of the camaro hub. It might seem like a lot but it's not bad. Downside being I can't put my stock spare on the back anymore. You can get a GTO spare for around $100 on ebay i think.

The other thing I did't actually try is just get a narrower adapter. I'd say 1.0" would be as tight as the adapter width could get while fitting all the hardware in it. The 1/4" might be enough to make the rears clear - plus you can play with the exact tire/wheel size. Mine are 18x9.5 275/40/18 for reference.

where can i but the spacers for the calipers? i got 18x8.5 for front and 19x10 for the back. think they will fit?

bbyshrk

It's hard to say on anything other than exactly what i have since it's pretty close on fitment. The smaller fronts I'm sure will be fine. The 19x10 at the back would be really close. The extra inch would help clear the rear tie rod stem coming through the control arm towards the inside of the rim (which i had to grind down a little bit) The 285/35/19 tire would be closer to the shocks and stuff so that's what I'm not certain about.

For spacing the calipers, i just used 1/8" thick washers. I think what i had laying around were the black oxide hardened 1/2" ones but you could double up on the typical narrower washers and be fine. With the caliper being able to float, you don't have to be super precise