Joel’s SL-C Build Thread

Joel K

Now that the body is pretty much located, time to install the seats and the intercooler brackets.

Video on installing the cooler brackets and seat fitment discussion…

The good news is the intercooler brackets mounted with 1/2” clearance to each side of the body and about 3/8” from the rear fender liners. So even if the body needs to be shifted a bit they are mounted for good.

Pic of the cooler brackets installed. Two M6 screws go through the bracket and frame rail. The middle cap screw just screws into to bracket for looks. No need to drill more holes than necessary through the frame. At some point, I’ll fab up a lower sister bracket to the bottom frame rail. Loving the look of the twin rear coolers…


Close up of the cooler bracket…

Now for the not so good news. I’ve invested a lot of hours into fitting the seats in the car with the side impact bars and recently decided to throw in the towel and ordered a pair of Tillett B5 seats.

Turned out I incorrectly assumed the passenger side impact bar had the same orientation as the driver’s side. I removed the bars early in the build and myopically focused on the driver side since that had the wider gentleman’s seat which posed all the fitment issues.

I planned to angle the driver’s side gentleman’s seat toward the center console to line it up with the steering column. Then widen the center console on the passenger side to accommodate the width of the shifter.

Once installed, I now realized the passenger side impact bar is angled in behind where the passenger seat was going to be mounted. Thus not really leaving enough room for a wider center console.

I thought about trimming the seats some more and removing the aprons fully, but felt there would still not be enough room once the seats were upholstered. Here is a pic showing where the side passenger seat needed to be placed, thus crowding the center console…

Here is another pic which shows where I intended to place the seats. Never noticed the passenger seat was right in front of the side impact bar attach point which is a steel tube. I did not want that sitting directly behind the seat…

Sort of disappointed that the seat modifications didn’t work out, but on the bright side I gained some good fiberglass experience which should pay off when I get to a few body mods I have in mind.

Anyway, was excited to receive the Tilletts. Turns out they fit me ok and will work out. Another 1/2” by the hip bones would be ideal, but the height of the seat and width of the bolsters fit fine.

Pic of all the seats. You’ll notice the Tilletts sit 2” taller than the stock seats with the Tillett TB2 Brackets and runners In the lowest position. Going to replace the stock brackets with custom ones like Ken Roberts did to increase the recline…

Next post should cover fabbing up the new seat brackets and install.
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Joel K

This post covers mounting the steering wheel with a quick release to the DCE electronic power steering column.

First component required is a steering boss or short hub. The options are limited for the DCE Motorsports power steering column and safety influenced my decision.

Momo and OMP each make a deformable steering wheel boss and there are also some generic ones on eBay UK which do not appear to be deformable.

Another choice was to use the factory provided slug and weld it to the column, but DCE does not recommend welding anything to the steering column as it may damage the unit. Lastly, could have pinned the slug to the column, but for safety reasons having a deformable steering wheel boss is preferable over a solid steel slug.

Here is a pic of the Momo boss, part number MOMO-7218…

To compliment the steering wheel Boss I wanted to add a quick release and NRG seems to have a great product and large selection. One in particular that appealed to me is the NRG STK-400BK. I spotted this quick release in a post by Walter Williams and decided to purchase it.

The main selling point is that it is only 1” deep vs. 2.5” deep for other NRG quick releases. Unlike an NRG short hub, the Momo boss is about 3” tall so going thin on the quick release keeps the wheel at a comfortable distance.

Here is a pic and dimensions...

Well, things rarely seem to go as planned. I installed the quick release and sure enough it took a tremendous amount of force to turn the collar to lock and unlock. Was going to return it, but after staring at the unit for a while and being the tinkerer that I am I figured out that the rubber pegs were creating too much pressure on the steering wheel plate causing the closing mechanism to be way too tight.

So one more excuse to use the mill and took off just the smallest amount possible where the steering wheel plate touches the rubber pegs and that did the trick. Now it works nice and smooth and still zero play.

The release mechanism on the STK-400BK is not as slick as the dual levers, but now that it works smoothly I really like it. If this was a track car I’d go with some type of disc or paddle release like the Krontec or OMP release. For the street I think this is a good choice.

Pic of the modification…

Moving on to the steering wheel. The RCR supplied steering wheel is really nice but seems to be an odd-ball bolt pattern. It’s close to a Grant-5 hole, but not exactly. So to use the supplied steering wheel it requires a custom adapter which will enable the 5 bolt wheel to attach to a six bolt quick release or hub.

Ultimately I decided to keep it simple and minimize the number of adapters and went with a Sparco flat bottom wheel. The flat bottom wheel provides a bit more knee room when cruising, but I’ll still need to remove the wheel to exit the SLC.

Also, considering I have power steering I went with a 330mm wheel. Not many leather wheels available in that size, but Sparco has a few nice choices and went with the Sparco Leather L360. Going to use either the Freewheel or Raptor wireless push button system so in the pic below you can see how the templates look with each wheel. More on the wireless system in a future post.

Pic of the factory and Sparco wheels with the wireless templates. The Y style steering wheels like the Sparco L360 fit the Raptor button layout best…

It’s listed as a flat dish on Sparco’s web site, but like many “flat dish” wheels there is a slight dish that lines up the spokes with the back rim of the wheel.

Here is a pic of the wheels. You can see the slight dish of the Sparco as compared to the totally flat factory wheel…

Here is the quick release base secured to the boss...

Putting it all together, front view...

Side view, nice and compact with plenty of room to stretch the arms out while driving the SLC...

So in total I have engineered 5.5” of collapsibility into the steering column. The steering shaft can collapse 3” and the deformable boss can collapse about 2.5”.

Here is a good pic of the crushable area in the setup…

At some point I’ll connect the EPAS controller and see how it works and feels.
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Joel K

Time to fit the Tillett B5 seats…

For others buying the Tillett seats I wanted to document a few things I learned so you order the best brackets for your use case and avoid ordering the wrong brackets like I did.

Tillett sells a few different mounting brackets for their B5 seats. The two brackets I considered buying were the TB2 and TB3 which are universal. The TB2 is designed to sit on top of runners and the TB3 is designed to mount directly to the floor or runners.

Considering this will be a street car I figured it would be nice to have the flexibility to dial in the seat distance for me and/or adjust the seat to accommodate another driver. I think it is also easier to install the seats with runners since you can easily expose the mounting holes in the runner while the seats are placed on the chassis.

Here is a pic from the Tillett documentation which shows the difference…

I incorrectly assumed I could use the lowest rear hole on the TB2 bracket to achieve maximum recline. Turns out you can only do that with the TB3, but not the TB2…

After initially placing the seats in the car, they seemed to sit up about an inch too high and if your tall and want the seat all the way back your head will be too close to the door and interior ceiling panel…

In my opinion the TB3 brackets will work well on an SLC when mounted to the floor since the bottom mounting hole is usable thus getting maximum recline. The TB3 might also work with runners but the overall height of the seat may be too high…

With the TB2, the runner mounting hardware interferes with the seat bottom and also the dome of the seat interferes with the bracket base when trying to use the lowest mounting hole. Also, if you trim the bracket to accommodate the dome, the next culprit is the runner actuator lever and it will also foul the dome…

Another alternative is to turn the TB2 brackets around to use the highest hole on the front of the seat. That configuration gives you a nice reclined seating position, but now the base is 3” longer to the rear so the seat cannot be moved all the way back.

So got out the plywood again and mocked up some new seat brackets…

Here is a video on the process…

Traced the pattern onto aluminum then covered the aluminum in clear packing tape and used a jigsaw to cut out the brackets…

Sanded the edges up nice and smooth and drilled the holes. Because of the increased seat angle I had to invert the screws in the rear because the full height locknut and washer pressed up against the bottom of the seat. Should have anticipated that, but what can you do. Also, trimmed the bracket to clear the seat dome…

Took a page from Ken Roberts build and made an almost identical set of brackets with the necessary recline angle. Seats are now 32” off the floor vs. 33” with the stock brackets. The stock RCR seats with a similar recline angle is 31”…

Seats now fit well. With them all the way back they clear the rear bulkhead by 1.75”…

Can finally move forward and mount the seats and the pedals!
i too appreciate the seat research. i baught some different brackets also (sparco, etc). But as experiment Im thinking custom is the way to go.
Its a shame someone doesn't sell brackets like the ones you just made,,,

Joel K

Time to finally mount the seats. I’ve had this on my to do list for months so very glad to finally finish this step.

Howard Jones recommended that it’s best to align the driver’s seat to the steering column, and then the pedals to the seat. I took Howard’s advice seriously and put a lot of effort into doing just that.

As described in prior posts, I purchased the optional side impact bars which triggered a lot of work to try to get the seats to fit between the center console and the side impact bars.

Just for kicks, this is how you can spend 100+ hours on your build with really nothing to show for it…

1)Attach factory brackets to seats
2)Realize there is not enough room and think about an alternative approach
3)Mock up alternate brackets in plywood which bring the seats inboard.
4)Realize the alternate brackets and seats still crowd the center console and side impact bars
5)Cut 1/2” of apron off both seats to get them to fit better
6)Wish they made Tillett seats for bigger people
7)Chop off the sides of the factory seats to further slim them down leaving no way to mount them.
8)Fiberglass up new sides of the seats
9)Use clay to make moulds for revised seat bracket mounting points.
10)Fiberglass up revised seat bracket mounting points
11)Mock up 2nd set of brackets in poster board, then in plywood for the new seat design
12)Make new seat brackets out of aluminum
13)Seats now look great, sit flat, new brackets are super sturdy. Wicked smart!
14)Cut out belt holes
15)Finally go to install the seats and realize the passenger side impact bar is somehow not where you thought it was going to be, thus crowding the center console yet again, but this time on the passenger side. Not so wicked smart!
16)Throw in the towel on the factory seat modifications
17)Order beautiful Tillett seats and realize they fit OK for a larger person after all. Major motivation for a diet!
18)Go to fit the Tillett seats and realize the stock Tillett TB2 brackets with runners cannot recline the seats enough.
19)Mock up a 3rd set of seat brackets from plywood
20)Fabricate the final set of seat brackets out of aluminum

So here we are, super excited to get on with mounting the seats. Finally have the seats positioned so they clear the side impact bars for both driver and passenger as well as have enough room for the upgraded and wider RCR shifter.

Here is a video on the process…

The steering column is angled at 1.5 degrees toward the driver. This roughy centers the wheel to the binnacle when aligning the seat in at 1.5 degrees. The pic below shows a poster board template which places the seat exactly where it needs to be and at the correct angle. Also have a plywood template for the pedal assembly which points the pedals toward the seat…

On the passenger side, made a template to position the seat inboard of the side impact bar mounting point and leave enough room for the shifter…

The runners simplify the mounting of the seats a little bit, but still had to think through how to approach it. Ultimately I decided it would be best to be able to install/remove each seat as an assembly. Thus, assemble the seats, brackets, and runners together and then bolt the whole assembly to the chassis.

To do this, had to expose the front runner track holes and drill them first. After the front holes are drilled, then slide the seat forward to expose the rear runner track holes. Pic of the exposed runner track mounting holes…

There was not enough clearance for a transfer punch to mark the holes. Also since the floor is a bit curved a template may not have located the holes accurately so simply marked each hole one at a time, scribed it then drilled it out. After drilling each hole, I’d attach the seat to the floor and scribe and drill the next hole, etc. This insured the holes lined up perfectly to the runner rails…

Passenger side holes drilled out and aligned with the seat runners perfectly…

Driver’s side holes drilled out and also came out well…

Pic of seats installed with the driver seat moved all the way forward. The runner enables 3.5” of forward travel. Plenty to accommodate a good range of drivers…

Pic of the seat all the way back. The steering wheel and seat line up really well to the driver’s binnacle. Plenty of room for the shifter and side impact bars…

Pic from the passenger side with the console back in. I’ll widen the console to accommodate the shifter and still have plenty of room between the seats…

Next up is to mount the pedal assembly..,
Damnit Joel, now I want to upgrade to Tillett seats!! I thought I had put that extra expenditure to bed long ago.

No, seriously, nice work as always, keep it up!! Good, solid install. I may have just missed it in your video but did you add large fender washers or steel plates on the underside of the floor for your seat mounting to help spread the load? The aluminum floor is not very strong and flexes easily. Fender washers or steel plates are a must for the seat belt anchor bolts and are a good idea for the seat mounts as well.

Joel K

Damnit Joel, now I want to upgrade to Tillett seats!! I thought I had put that extra expenditure to bed long ago.

No, seriously, nice work as always, keep it up!! Good, solid install. I may have just missed it in your video but did you add large fender washers or steel plates on the underside of the floor for your seat mounting to help spread the load? The aluminum floor is not very strong and flexes easily. Fender washers or steel plates are a must for the seat belt anchor bolts and are a good idea for the seat mounts as well.
Hey Kurt, thanks for the comments. I will say the stock gentleman’s seat is far more comfortable, but had to move on and the Tilletts look great for sure.

You didn’t miss anything. I haven’t settled on the mounting HW yet. More than likely I‘ll use 10.9 M8 bolts with fender washers facing up and use high strength lock nuts in the seat runner rails. Hopefully that feels solid and will work out.

Ken Roberts

I made 8 plates that get riveted to the underside of the floor. The rivets stop the plate from spinning and holds it up in place. The bolt head is welded to the plate and the head is shaved slightly so it doesn’t stick down too far. This way you can mount and remove the seats yourself without assistance. It’s best to get them powder coated to help prevent galvanic corrosion.

The identification tags are for when it gets powder coated. I can then replace it to the same position it was drilled for.

I've had good luck marking fabricated metal parts with alphanumeric punches. Shows well through paint, not sure about powder coat.

Joel K

I've had good luck marking fabricated metal parts with alphanumeric punches. Shows well through paint, not sure about powder coat.
Dave, that’s cool. What I typically do is just drill dots to notate a pair or parts that need to line up. Like my passenger side seat brackets have a single dot in each bracket to notate they are a pair. But spelling it out is much better and more professional.
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I agree that the markers look better but I have a devil of a time getting the individual letters & numbers to line up properly. My marking is definitely not professional looking. In fact it reeks of amateurism so I've switched to something similar to drilling holes like you are doing but I simply use a center punch to create a unique dot pattern- quick & easy.
Good point Neil, multiple letters do not line up. So I typically am only doing one letter. R(ight), L(eft) or F(ront),R(ear) or D(river),P(assenger). Or different arbitrary letters with a reference sheet.
And give it one super hard smack, re-hitting the same letter is tough to line up.

Joel K

Now on to mounting the pedal assembly.

Here is a short video on the process and getting to finally sit in the car and check the fitment…

Like the driver’s seat, made a template placing the pedal assembly angled to line up with the seat and steering column…

You can see the slight angle by the gap between the power brake actuator assembly and the pedal assembly confirms the pedals will point toward the driver’s seat…

The pedal assembly mounting plate was designed to be mounted from under the car and thread into the assembly. Used a transfer punch to locate the holes to drill in the chassis floor.

Pic of the mounted pedal assembly. The 1/2” thick pedal plate flattens the curvature in the chassis floor…

Pic from underneath the chassis…

Pic of the secured pedal assembly. The idea behind the multiple mounting holes is to be able to dial in the best for-aft pedal location. It was not designed as a quick adjustable pedal, but rather to provide some adjustability to best set up the car for me, or with some work to accommodate different size drivers…

Pic of the pedal assembly install. In total, have 9” of pedal adjustability. 5.5” with the adjustable pedals and 3.5” with the seat runners…

Finally got to sit in the car to see how everything feels. I really like the way the steering wheel, seats, and pedals all lined up . Thanks again to Howard Jones for the great advice!

Pic of me in the car with the steering column lowered. Line of site and distance from the driver are perfect…

Pic if me in the car with the steering wheel raised…

In the raised position and with the flat bottom wheel I can actually get out of the car without removing the steering wheel. The wheel can be used to boost myself out of the seat which I think really helps.

Next up is to fabricate passenger tub close out panels.
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Joel K

Still focused on the passenger compartment, once finished with the passenger and fuel tank compartments I’ll move on to install the engine and transaxle.

Next up is fabricating the interior tub close out panels. Taking the basic approach of attaching a 1/8” aluminum panel to the side of the chassis and seal it up to the interior tub with weatherstripping. This post shows the fabrication details, I’ll mount them after I’ve finalized the body and tub placement.

The main purpose of the close out panels is to line them with sound and heat shielding to keep noise and heat from entering the passenger compartment from the inside of the side sills. I also wanted to make them sturdy enough to provide some additional support to the side sills in case someone puts a lot of weight on them.

Here is a video on the process…

First step was making a template out of card stock. Fine tuned it with blue masking tape…

Transferred the driver’s side pattern to cardboard…

Since the openings are not quite symmetrical, needed to tweak the pattern for the passenger side. Fine tuned it with blue masking tape and then transferred that pattern to cardboard…

Purchased a 1/8”x24”x45” sheet of aluminum and transferred the cardboard patterns to the aluminum…

Used McMaster Carr part# 12335A53 bulb seal. I like that it is somewhat flexible and has a metal core to maintain a strong base under the bulb…

Pic of the weather stripping mounted on a piece of scrap, attaches securely with no gaps…

Pic of the assembled panels…

Pic of the passenger side panel in place. Looks nice and neat. These will be attached to the chassis once the tub is locked down after the final body fitting. Also, will trim the panels around the weld seams on the chassis so they lay flat…

Driver’s side…

Passenger compartment is done for now and moving on to the fuel tank area…
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Wow, Joel , you have been busy. The steering seats and pedals are perfectly positioned. I could not move the seat enough to the midline so my feet go sideways a bit, but that should not make a big difference driving the car, as Long as the steering wheel is centered to the seat. The trim panels are super nice as well. Great job Joel

Joel K

This post covers the 3rd body fitment. The goal being to finalize the interior tub location so I can install the close out panels fabricated in post #318. Also wanted to adjust the camber to get a better sense for how the stance will look with a real world alignment.

Here is a short video on the process…

First step was to complete the lower front fork adjustment as discussed on post #295. Applied two full turns out on the lower front forks to pivot the front wheels back. Wheels are still at zero camber.

Looks like that did the trick. Good wheel placement front and rear. Pic of right side…

At this point I think I have an acceptable fore-aft position of the body and acceptable wheel base settings on the suspension. Now to center the body left-right.

I simply held a yard stick up against each wheel and measured the distance between the body and the rim and made sure it was centered. The wheels still measured zero camber so thought this was a good approach…

Now that the body is centered, secured the tub with two screws into the rear cross member and one screw in each kick panel. Pic of the rear screws…

Next step was to add some negative camber. Set the front at -1 degrees and rear at -.5 degrees. I planned to do less front camber, but at -.5 degrees it resulted in a little more tire poke than I wanted. Dialing in negative camber is easily accomplished by turning in the upper/outer control arm rod ends.

3/4 view of the car with camber dialed in. I’m quite happy with the stance. I ran out of time, but at some point I want to lower the rear a smidge more and the ride height should be perfect…

Close up pic of the right front after adjustments…

Pic of the right front, a hint of tire poke at the top, but I think it looks ok…

Pic of left front. Had to position the body a bit more forward on the driver’s side to get the wheel centered. Basically, the left side of the tub was moved .25” forward from where the factory put it…

Equal view of tire poke on both fronts. Pic of left front…

Pic of the right rear, confirming the rear ride height needs to be lowered a bit more…

Pic of left rear…

At this point I’m pretty psyched how well the body and wheels line up. Next up is to install the interior tub close out panels…
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