If so do you have any pics? I have been tossing around the idea for my project. I have done a lot of reasearch on different systems and the upper/lower A arm is deffinately a better design. I have all the fabrication skills and equipment so it would not be a big deal anyways.

Thanks
~Matt

 

Nobody??? Nobody has done this or has anything to share? I know that I am not the first to do this....

~Matt

 

there is one of the people who posts in the apperiance board who has, he basicly took a LS1 front and and attached the 3rdgen body panels to it. i really don't have much more info than that for you.

 

I'm about 49% done- here a quick rundown

With Performance Trends Roll center calculator I took measurments from the car - height of lower bushings and ball joints above ground- distance from centerline of the joints and bushings- track - and maximum distance from the centerline of the upper control bushings

aslo the spindle geometry -height and spindle angle - and with the upper and lower ball joints installed on the spindle I got the distance between the upper and lower pivots which is the theoritical center of the ball in the upper and lower jonts

After adding all the measurements and altering some things I got geometry I like - 0.75 deg camber gain with 1in dive and 0.78deg camber gain with 1in roll - roll center is 1.7in above ground.

I'm keeping the lower control arm bushing position out from centerline stock but lowered it .25 in and had to extend the lower ball joint 2in from stock (16in lwr arm 14in stock)- track is 61in and I'm using a 7in upper control arms- wheel offset is 7.5 in with 9in rim- scrub radius is 0.9- I had to compromise I wanted it to be 0

I;m using spindles from a 94 Caprice 8 inches tall 10deg spindle angle - severly chopped up to reduce weight and I'm working on the caliper brackets now - and using ball joints from a 94 caprice as well

I got upper control arms from AFCO 7 inches long - I got issues with em the pivot shaft has no businngs and the ball joint mount hole wont fit the ball joint - minor things I can take care of

I still have to make the lower control arms - I got the ball joint ring and plan to use bushed rod ends to make them adjustable for camber

The upper control arm will be mounted above the spring pocket on the outer side of the strut tower with welded on backing plate
and angled slightly for brake ant-idive

for the upper spring mount I plan to use a rectangular steel pipe welded through the spring pocket to the top of the frame so the coilover can mount somewhere in the middle of the upper control arm - coil over length is about 11.5in

and I got to make a k-mbr - rack mounts etc- I have the mtr mounts


WHY

I know this sounds like a lot - and the decision wasn't easy to go forward with it but

I needed to loose weight the strut and stock spring combo is still heavier than the upper control arm (3lbs with joint) and coil over (guesing 10-15lbs dont have em yet). The camber gain dive and roll- anti dive, decreaseed scrub radius, lower roll center are positives- hell why not

how far are you Matt?

 

Thanks Kenn for replying. I'm still in the R&D stage, so I have not started fabricating anything yet. I have the car all gutted now, and hope to start welding in the roll bar and subframe soon.

I will be making a whole new front end from scratch, including the crossmember. I will probobly use some coil over springs. Then cut the top off of the wheel wells, and form a new smooth piece of metal over the top, to remove the old strut mounts, thus making for a cleaner look.

Thanks for posting your dimensions, it will be very helpfull.

Did you find the software program helpfull, or would it have been just as easy to make some drawings. How many degrees of anti-dive are you going to run? What steering rack are you using?

Your project sounds very interesting, keep me posted on how it works out for you. Do you have any pictures of what you have done so far?

Thanks.
~Matt

 

The roll center program was about $65 - It was helpful in finding out the best position for the upper control arm to get the right roll center, camber gains and scrub radius - theres a lot more to it - BUT it only shows the layout in 2D so for the lower control arm bushing position I had to do a little calculating since the rear lower control arm bushing is farther away from the centerline of the car than the forward one - also the roll center prgm doesn't calculate caster changes as the suspension travels - I plan to just set that at 10degs

Performance trends offers a Suspension Analyzer (about $175)- a 3D version that has way more capabalities - I tried the demo but for the money the Roll Center prgm works for me -

my main reference is Herbs Chassis Engineering and he explained that 30% antidive was ok for a street car but other things like front end wieght and shock settings also have an affect on brake dive and that too much antidive causes caster changes which makes the car unpredictable - 20% is what I plan but I want to do more research on that- this is something I have to do on paper

I reccommend the program over the paper route for the whole setup - you get the ability to make changes and see immediately how it affects system - one feature real helpful was the wheel rate calculation - based on the coilover position and the spring rate- I did a stock strut layout and found out the wheel rate was about 150 with a 600lb spring since the stock spring is so far away from the tire- I positioned the coilover about 4 in from tire centerline on the SLA setup and with only a 400lb spring the wheel rate is 293 so I can pick a lighter spring and still maintain the wheel rate of the stock setup

I'm using a 4th Gen rack - the program does no accomodate that either - I'll do my best to line up the pivot points with the lwr con arm

I'm still working on the spindle/brake/rotor assb so I don't have much to show yet -

Good luck

 

Plans have changed

I took the strut towers out to mount the upper control arms directly to the frame - and welded in plates to cover holes in the firewall where they were connected - about a 12 x 2in section

I'm using C4 spindles now - the height betwee the wheel center and the lower ball joint center is longer than on the 94 caprice spindle so I had to go back to the program and redesign
- reason bieng I couldn't weld on a caliper bracket - that cast iron spindle wasn't receptive- C4 spindles was about $75 from the Yards and included the bolt on hubs - hubs in good shape too- a $150 replacement part - which is why I started with the other spindles - and a provision to bolt on a caliper bracket

Spindle selection is key

Another thing about the C4 spindles is the steering arms are too high -I would have to position the Rack high - in interference with the oil pan to avoid bump steer - I cut em off - I got a design on paper for replacements


K-mbr is done - RP mounts still needed but thats dependent on steer arms and geometrics

Lower ctrl arms done - sway bar mounts and coil over bracketry needed

Upper control arms - needs mods to accept C4 ball joints -
easy stuff


My concern now is the frame itself - I plan to reinforce the depression area with a welded in brace where the spring was and include mounting for the coilover to be positioned just outside the frame - and plates to mount the upper ctrl arms to

I can show what I got so far- after I take the to other 12 exposures on the film roll - its coming along alright
kenn