Joel’s SL-C Build Thread

Scott

Lifetime Supporter
Joel,

The DCE unit isn't collapsible. Are you going to use a collapsible column between the rack and the DCE unit? Agile Automotive is making a custom one for me. I don't have it in hand yet, but I assume that it will be as well engineered and machined as the other items I've bought from them.
  • 9” of possible collapsibility (exact measurement will depend on longitudinal position of the EPAS motor relative to the rack)
  • 20 spline ¾” shaft and receiver for ultimate strength
  • Tight tolerance spline minimizes steering play often found with other sleeved collapsible linkages
  • Telescoping rubber boot to keep dirt and debris out
  • They will assist in providing the correct universal joints for each end based on application
 

Joel K

Supporter
Joel,

The DCE unit isn't collapsible. Are you going to use a collapsible column between the rack and the DCE unit? Agile Automotive is making a custom one for me. I don't have it in hand yet, but I assume that it will be as well engineered and machined as the other items I've bought from them.
  • 9” of possible collapsibility (exact measurement will depend on longitudinal position of the EPAS motor relative to the rack)
  • 20 spline ¾” shaft and receiver for ultimate strength
  • Tight tolerance spline minimizes steering play often found with other sleeved collapsible linkages
  • Telescoping rubber boot to keep dirt and debris out
  • They will assist in providing the correct universal joints for each end based on application

Hi Scott,

Thanks for sharing.

I have not given it any additional thought since I believed it was collapsible. Considering this I may use a collapsible steering wheel boss made by MOMO which will provide some protection. As far as a collapsible linkage, I am curious what your source comes up with and maybe I’ll order it as well.
 
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Joel K

Supporter
Time for the next update. Getting started on installing the suspension. Considering I received the chassis crated, I’ve had to look at a ton of pics to figure out what goes where. Thanks to Cam T and Scott Swartz for posting many detailed suspension pics in their threads and blogs. Also, a special thanks to Ken Roberts who has answered many of my questions off-line.

I figure this post may be useful to other beginner builders by providing some additional detail in assembling the SL-C suspension.

Here is an overview video of the SL-C suspension components....

Here is a video describing mounting the cross brace and suspension pickup points...

Here is a video of squaring up the suspension pickup points...

Here is a video installing the front lower control arm mounting blocks...

First thing I did was mount the rear chassis cross brace, I’ll probably change the color at some point but for now it’s nice to see some components going on the chassis...
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Next I ground the excess tig chassis welds to allow the suspension control arm brackets to lay flat against the stantions...
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Just used a Dremel with a grinding disk and small sanding drum which worked out well...
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Brackets were torqued to 30 ft-lbs. All backing plates, washers and bolt shoulders were treated with anti seize. Locknuts on the rear by the exhaust were distorted locknuts with blue threadlock. I did not want to use the nylon lock nuts near the exhaust....
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Next was to attach the front suspension pickup brackets. I had clearance issues with the backing plates/doubler plates which go behind the front most suspension pickup brackets on the inside of the foot box. I decided to simply shorten them instead of grinding away the inside weld. Not sure if this was the best approach but was concerned to weaken the weld into the joint where the suspension would be mounted. Seems to me the washer is firmly pressed into the weld and the top of the bracket and should be ok. I’d be interested to know what others front inside backing plates look like and if it was done differently...
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When I torqued the brackets some of them spread slightly and I wanted to square them up. You can see the bracket on the right is square and the one in the middle is slightly spread. I used a 3/8” bolt to squeeze/pinch the brackets so the ears would be square and allow the bolts to slide in and out freely. This should come in handy when removing the bolts to adjust camber....
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Had to cut down the front suspension bolts to fit.....
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Last step was to attach the aluminum front lower control arm mounting boxes. Also torqued them to 30 ft-lbs and applied anti seize on the washers and blue threadlock on the screws..
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Lastly, I made sure all the bolts installed had shoulders long enough to span the ears on the pickup brackets. In some cases I needed bolts with longer shoulders. Thanks to Cam T for documenting this in his blog...

Here you see suspension mount brackets squared up, cut front bolts with ample shoulder length, and the lower mounting block installed....
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Next up is assembling the uprights and installing the steering rack....
 
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Joel K

Supporter
Got a chance to install the steering rack. It did not go too smoothly, and would appreciate some advice if I should weld the top holes closed and re-drill them.

Here is a video of the process and end result...

Since my car was delivered as a crate the holes on the chassis were marked with small pilot holes where I needed to drill...
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First step was to drill out the 2.25” hole for the steering gear. I was running the drill too fast and snapped the pilot drill and Put some nice gashes in the outer footbox...
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Sanded out the mishap and drilled the first 3/8” hole on the upper right side...
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Drilled the other 3 holes and got the rack perfectly level. I drilled the top two holes too far apart and to get the rack to install I wound up enlarging them to 1/2”.
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My issue is the top holes are now larger than they need to be and since the pillow blocks are only 1/2” wide wondering if I have compromised the clamping force.
Here is a pic showing the size difference of the top vs. the bottom hole...
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Here is a pic of the left side top hole from behind the rack..
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Here is a pic of the right side top hole behind the rack..
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Your feedback is appreciated, thanks!
 
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Scott

Lifetime Supporter
1/4" seems a little overkill. I installed 1/8" cold rolled. It's my understanding that the Raver/Thunderhill car uses 1/8" chromoly.
 

Joel K

Supporter
Thanks Ken/Scott, appreciate the feedback. The standard backing plates from RCR for the suspension are 3/16”. So maybe I’ll split the difference.
 

Joel K

Supporter
The second part of the steering rack install went a bit smoother. That is to fabricate a mounting plate for the steering gear.

Machined down a 1/4” aluminum plate slightly to fit between the steering gear box and the top of the foot-box. I may have this welded on at some point.....
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Trimmed the weld on the top of the foot-box so I could get the plate fully under the steering gear box....
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Drilled the front two holes...
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Came out well and and level...
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Here is a pic from the underside. I may add a backing plate here as well....
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Nice to see some more components get mounted on the chassis....
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Ken Roberts

Supporter
There is a horizontal loading on the steering rack. The backing brackets and pillow blocks are narrow. I would compensate for this short fall with thicker backing plates. Just my thinking.
 
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Neil

Supporter
As Ken pointed out there are horizontal loads on that bracket. In the photos I can't tell what bolts you have installed; make sure they are good shear bolts.
 

Joel K

Supporter
As Ken pointed out there are horizontal loads on that bracket. In the photos I can't tell what bolts you have installed; make sure they are good shear bolts.

Thanks for your feedback Neil, I am not familiar with the term “shear bolts” you are using. They are 3/8”-16 grade 8 bolts fully threaded. That is what came with the kit. I also bought Same size grade 8 with a flanged head which I believe spread the clamping force a bit better than a standard hex bolt.
 

Brian Kissel

Staff member
Admin
Lifetime Supporter
Just my opinion, but I definitely would ditch the fully threaded bolts out for some with a unthreaded shank, and then threads. The shank should go through the entire piece. Little I said, just my opinion. That’s how we have done it on our race cars for the last 45 years.

Regards Brian
 

Joel K

Supporter
Just my opinion, but I definitely would ditch the fully threaded bolts out for some with a unthreaded shank, and then threads. The shank should go through the entire piece. Little I said, just my opinion. That’s how we have done it on our race cars for the last 45 years.

Regards Brian

Thanks Brian, that’s what I did for all the suspension pickup point brackets. I went with partially threaded 3/8” bolts.

As to Ken and Scott’s suggestion, I’ll make some backing plates and to your suggestion get partially threaded bolts.
 

Joel K

Supporter
Thanks again Guys for the help, This forum just so valuable with the great people and Information available.

I re-read Scott’s thread on his steering rack upgrade and he is going to re-drill his pillow block holes since they became oversized with the hardware for the new rack. That sounds like a good approach and will Have the top holes welded closed and re-drill them correctly. At this point I don’t have the interest in learning how to weld, so will batch up a bunch of work and before I apply sound deadening I’ll have the welder take care of this.
 

Neil

Supporter
Thanks for your feedback Neil, I am not familiar with the term “shear bolts” you are using. They are 3/8”-16 grade 8 bolts fully threaded. That is what came with the kit. I also bought Same size grade 8 with a flanged head which I believe spread the clamping force a bit better than a standard hex bolt.
Joel, The latest issue of "Hot Rod Magazine" has a very good article on fasteners. I recommend it for anyone building a vehicle. Aircraft bolts are not threaded fully because you never want the threads bearing on the hole that the bolt is in. They are available in different "grip lengths", the length of the unthreaded shank. The grip lengths are usually specified in sixteenths. A 2" grip length bolt specification would end with a -32. Similarly, the bolt diameter is also in sixteenths. A 1/2" x 2" bolt would be its type number followed by -8-32. Shear bolts are designed to optimize shear rather than tension forces.
 

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Joel K

Supporter
Joel, The latest issue of "Hot Rod Magazine" has a very good article on fasteners. I recommend it for anyone building a vehicle. Aircraft bolts are not threaded fully because you never want the threads bearing on the hole that the bolt is in. They are available in different "grip lengths", the length of the unthreaded shank. The grip lengths are usually specified in sixteenths. A 2" grip length bolt specification would end with a -32. Similarly, the bolt diameter is also in sixteenths. A 1/2" x 2" bolt would be its type number followed by -8-32. Shear bolts are designed to optimize shear rather than tension forces.

Thank you Neil, this is very helpful.
 

Joel K

Supporter
Happy New Year everyone, here is the final build update of 2019. It was a fun year getting started on the SL-C. Learned a lot and made some good progress.

Had a chance to install the ball joints. On the first pass, I installed the front ones incorrectly so posting some pics of the proper orientation of the ball joints and bolts.

Here is a video of installing them...

I coated the washers and bolt shoulders with anti-seize. Also coated the top of the ball joint plate as well with anti-seize....
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The rubber bellows on the ball joints are a tight fit when being pushed through the control arms so applied some silicone grease which worked well...
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Pushed the ball joint through making sure both large bellows clear the hole...
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Torqued the bolts to 22 ft-lbs. Here are the rear control arms with bolt heads on the bottom.
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Here are the front control arms with bolt heads on the top...
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Joel K

Supporter
Completed some more basic assembly and finished putting together the front and rear uprights. I decided to use red threadlock on all the bolts. I like the 3M Scotch Weld brand red threadlock since it is easier to remove than Loctite Red, but is still a heavy duty threadlock. I think it also does a good job of sealing the threads so they don’t gall the aluminum.

Here is a video describing the details of assembling the uprights....

When assembling the top and bottom plates onto the uprights I wanted to make sure there was enough thread in all the upright holes so the bolts torqued the plates instead of hitting the bottom of the threaded area in the upright. I saw one instance on the front upright where the bolt was bottoming out.
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Here is the rear upright ready to be tapped...
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I used a flat bottom tap and added 2 full turns in each hole to insure the bolts were not hitting bottom. You can see the two turns made a big difference...
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I applied anti seize on the bottom of the upright where it attaches to the steel ball joint plate...
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Applied the red threadlock.....
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Torqued the top and bottom 7/16” bolts to 40 ft-lbs....
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Next up was installing the bottom toe link bracket. I also used red threadlock, mil-spec washer machined to fit. Applied anti seize to the washers and torqued the 5/16” bolts to 22 ft-lbs.
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Here are the fully assembled rear uprights....
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Last step was to attach the tie rod bracket to the upright. I decided to upgrade the standard 3/8” cap screw and used a longer shoulder cap screw and locknut to better secure the assembly. I noticed this approach in Scott Swartz’s build thread. Since he has the Brembo GT brake package, RCR provides the longer bolts for this purpose. I figured I would take this approach for an added margin of saftey.
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The 3/8” cap screws have anti seize applied to the mil-spec washer and screw shoulder, red thread lock applied to both the threads and the distorted locknut. These Screws and nuts were torqued to 30 ft-lbs. Here are the fully assembled front uprights.
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Next up is mounting the suspension, going to be a fun weekend!
 
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Joel K

Supporter
Over the last couple weeks I was able to install the control arms and uprights. It’s a lot of fun bolting parts to the chassis. As I got familiar with the components and how they go on the car I made a few changes based on what I’ve seen on some other builds and some feedback on the forum.

Here is a video detailing the control arm install...

Here is a video detailing the upright install...

Based on Alex’s recommendation and an upgrade Cam T and and Ken Roberts did, I decided to use zinc plated steel safety washers on the suspension rod ends. Eliminating the likelihood bolts would seize if and when I need to adjust or replace the rod-ends is a good thing.

I paid close attention to the washer configuration so when I tightened the brackets they clamped down squarely on the rod ends. After getting the washer configs right I coated the bolt shoulders with anti seize and hand tightened all the pickup bracket bolts. Here is a pic of the upper front control arm install....
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Since the lower front fork is located in an aluminum square tube and not a more bendable pickup bracket I wanted to make sure I eliminated all slack between the tube walls and safety washers. First I tightened up the lower rear fork which fixes the position of the front fork. I found some thin 5/8” AN washers and they fill the gap very nicely....
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Next up was to attach the uprights. I coated all the suspension with Ballistol to preserve the finish of the beautiful Superlite suspension..
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For now I followed how Cam T and some others secured the bottom ball joints. That is to use a single washer and grade 8 locknut and cotter pin on top of the nut. Considering the rest of the suspension is secured with locknuts I think this should work. As always I’d like to know what others think about this approach.....
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I used Scott Swartz’s recommended Zero Camber settings for now...
1)Bottom front and rear rod ends all in.
2)Top front rod ends 5 turns out both upright side and chassis side.
3)Top rear rod-end 2 Turns out upright side and all in chassis side.

The fronts are close to zero, but had to add two more turns out on the Top rears to get close to zero. I’ll mess with this more once I set ride height etc.

To address bump steer, added a couple washers to get the angle of the steering tie rod to match the angle of the bottom control arm. I’ll mess with this more once I set ride height etc..
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Attached toe adjustment rod....
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I ran into an issue installing the toe rod spacers. Most builders seem to fit two standard 1/2” washers between the bottom toe link bracket and the tall toe link spacer. I was not able to do this, there was just not enough clearance to assemble the stack of the short toe link spacer, toe link rod end, Long toe link spacer and two 1/2” washers between the top and bottom toe link brackets on the rear uprights.

I wound up using 3 AN washers, 2 placed between the toe link rod end and small spacer and 1 placed between the toe link rod end and large spacer. The tall bolts and washers were all coated with anti seize....
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This seemed to work out well. It was still a tight fit and the bottom 1/2” washer needed to be tapped in, there is no slack in the assembly...
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All in all I think this part of the build went well....
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Next up is to replace the wheel studs with longer ones...
 
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