Those were the words of advice from my wise mentor (JWillis) whenever things seemed to get crazy at work. Either the project was in a critical state and things weren’t going right or there were just too many things to do – “just keep kicking the ball”. At the end of the day so long as I kept the ball moving in the forward direction at least some level of progress was being made. Recently, it’s felt a bit like that. Construction Phase 2 has come and gone and we’ve already jumped into Phase 3. I’ve snuck away for a few days here and there to get some wrench time in on the SLC but having both my construction and build shoes on has made it difficult to feel like I’m making any significant progress on the car. Just keep kicking the ball!
Before starting this project I had a (laughably) compressed timeline for building the SLC. I had only planned to take about 3-4 months to build the car so I spent a LOT of time thinking about the build and all the major components before even pulling the trigger on the kit. Once I’d decided I was moving forward I started buying many of the major components figuring if I had everything I needed up front, delays would be avoided and I could keep to my aggressive schedule. HAH! It turns out it’s not the big ticket items that get you bogged down. It’s that M10x1.5 35mm grade 12.9 bolt that (not surprisingly) isn’t in your box of bolts and doesn’t seem to be available anywhere locally that suddenly adds another 2-3 days before you can move forward that really gets you. Perfecting the technique of standing on the brakes and shifting gears into a different area of the car is important if you’re to remain productive and not sit on your thumbs waiting for that ONE bolt to arrive from McMaster – you’ve all been here before.
Since getting back into the SLC I’ve jumped back and forth on:
- Penultimate(?) suspension alignment and body fit check
- Rebuilding the brakes post powdercoat
- Installing the hard and brake lines
- Installing the front hydraulic lift system
- Designing and installing the fuel system
- Bolting in the cage
- Tearing into the crate motor and updating it for the SLC
I struggled to muster up the courage necessary to put that first hole into the chassis so I could bolt a brake line tab to the frame. What if I selected the wrong location and down the road I’d want to use this same real estate for something else more critical? Analysis Paralysis set in and I had a tough time pushing forward DOING something rather than thinking about what I should do, and how it might affect some other portion later in the build. Some days, it seemed like I sat down staring at the car longer than I did any wrenching. These days I’m getting into a better rhythm – still taking that OCD break to overthink things from time to time but telling myself to KICK THE BALL and DO SOMETHING. Eventually I might end up with a completed car!
Looking over my notes from the last time I’d worked on the car, there were a few adjustments left to get the wheelbase and track correctly squared and spaced. Ultimately I had to adjust both rear uprights to get them equally spaced from vehicle centerline. As a starting point I was able to dial in -1deg camber (at each wheel) and 1/16″ toe in (front & rear). I also opted to start with front ride height at 4.5″ and rear at 5″. The front overhang of the SLC is so long that negotiating steep inclines and tall speedbumps is going to be hair raising, even with the front lift system engaged. It’s the front ride height that really dictates how the car’s stance will turn out. Due to the aggressive rear aero package, running equal ride height front to rear may cause front end lift at speed when the rear is pushed down further than the front. For a street car I think a 0.5″ difference front to back is the minimum (it may not be enough) – we’ll have to get the car stitched together for some road tests to see how aero balance affects dynamic ride height. I’m concerned with not having enough downforce at the front, but I didn’t want to add much more rake by lifting the rear even higher as the rear wheel gap starts to get fairly unsightly, even at 5″.
The SLC has an infinite amount of adjustability and it can be a pretty daunting task to get it properly configured and aligned. I haven’t given much thought to corner balancing at this point though it’s considered a necessity if you’re going to drive this with any kind of anger on the track. For the street it’s all about the stance.
One last note about the adjustability aspect – for all the adjustment range the SLC offers, I’m finding that the builder really needs to figure out what they’re going to do with their car and stick with it. If it’s going to be a serious track machine and sustained high speeds and cornering forces are expected, you’re going to have to run higher spring rates and more aggressive ride height/suspension settings. These will push the car too far toward “race”, making it an uncomfortable road car. If the builder’s end goal is a fun road car then you’ll have to set the car up in such a way that driving it near or at the limit won’t be possible due to the aggressive aero (IMHO). Springs will be too soft and you’ll bottom the car out at any real speed. The beauty of this car is you can run it at either end of the spectrum so long as you’re willing to put the work in to make the necessary hardware adjustments. I think it’s unrealistic to expect the car to be a great weekend canyon carver then to set track records the next day. Note this is only my opinion based on what I’ve seen by looking at my own car and taking guesses at what it’ll be like once on the road. My plan is to configure the SLC so it’s a fun canyon car that can be driven to the office. There may be a track day or two in my future but I can’t drive this thing past 6/10ths anyway if I’m being honest.
The brake rebuild was fairly straightforward. Unfortunately I’d torn a boot during the initial disassembly but replacement parts are readily available since these calipers are from a high volume production car. I knew I was really in it when it came time to drill the first mounting hole for the hard lines. I spent about 30 minutes staring at the spot I was to drill and quadruple checked and thought about what else might go there in the future. Once I was sure this was the EXACT spot I wanted to put a mounting tab I pulled out the drill gun and went to town. I had read about the Greenlee DTAP combination drill/tap bits in someone else’s build thread and I have to say these things are amazing. With a single bit you can drill, tap, and deburr a hole in one operation!
Routing the hard lines was fairly basic. When it came to routing and mounting the flex lines I was less sure of what to do. The front brake calipers do not have an anti-rotation feature at the banjo location and I’m concerned without some sort of positive retention at the banjo the flex line is likely to leak at some point in the future. More comments on this in a future update as I plan to install some strain relief tabs to mitigate this issue.
Hydraulic lift system:
The front end of this car is LOW and the overhang is rather long. It’s a bad combination for negotiating things like speed bumps, dips, or just about any normal city street. I purchased the optional RamLift front lift kit. It includes a hydraulic lift pump, a couple of cylinders which fit over the front coil springs, some hoses, and wiring. I hemmed and hawed over where to place the battery for a few days which caused me to hold off on installing the lift pump. I wanted to locate the lift pump near vehicle centerline on the front tray but this is also where the battery would need to be if I positioned it up front. Eventually I decided the battery would definitely/probably be located in the rear and I was able to install the hydraulic lift. Modification and installation of the lift pucks was covered in post 11.
Note the as-supplied plug for one of the hydraulic ports may be too long in your kit. Some kits shipped with insufficient thread depth in the discharge ports; only 1 of which is actually needed with the other being plugged. If your kit’s motor doesn’t have a deep enough threaded body the plug will not fully seat and a leak is guaranteed to occur. Pay careful attention when plugging the unused port and verify you’ve got good seating pressure for the included seal. If there’s any doubt contact RamLift for a replacement (shortened) bung or modify yours by shortening the one included with your kit.
The reason for pushing the battery to the rear of the vehicle was primarily to keep the nose as empty as possible. My plan is to open up the hood vent to aid with radiator air flow/discharge. Keeping the front tray empty allows me to install ducting to keep the air moving as cleanly as possible after exiting the radiator.
The fuel system has taken up most of my time when I’ve been able to work on the car. I’m finding for every component I bolt to the car, I’ve already test fitted it at least twice before. There’s a lot of position, drill, install, measure the next component, find out there’s an interference later, uninstall, adjust, reinstall … this was especially true for the various fuel system components. I have to remind myself it’s OK if things aren’t perfect. Keep kicking the ball.
I positioned my pumps such that the inlets for each are at or below the port they’re being fed from (low pressure fed from tank, high pressure fed from swirl tank). I also wanted to minimize line lengths and unnecessary bends. My prior experience piecing together a fuel system was using Earl’s/Russell stainless braided lines – really nasty to work with and very stiff. For the SLC I opted to use the Starlite line from Aeroquip. These are Nomex covered lines and are MUCH easier to use and assemble than the previous lines I was familiar with. When planning out my build I expected to have to make longer runs due to line stiffness but these Starlite lines are so pliable I was able to get much tighter bends without straining the lines at all. As a result I ended up purchasing almost enough line for two complete fuel systems. I also opted to use more 90-deg hose fittings than necessary; I could have used straight fittings and let the line just bend but using more 90s meant I could keep the packaging tighter and neater looking. The pumps are over-spec’d for the power level I’ll be running so I figured the additional line losses due to the 90s would be OK.
I also fabricated a closeout panel, fully separating the fuel tank from the engine compartment. This meant bulkhead fittings were necessary for any fluids/venting to get past the closeout panel. The bulkhead fittings required more length that I had originally planned for so some last minute redesign led me to an OK solution; the closeout panel wouldn’t be 100% covered at the bulkhead fittings but I guess it’ll be OK.
The cage was another one of those sweating bullets moments. Drilling holes large enough to secure the cage had me on edge as the first hole was being drilled. After completing the first hole and discovering that I hadn’t completely swiss cheesed and destroyed the frame I braved the remaining holes. If I were to do it again I think I would fully drill the rear supports first, then move to the front and do only 2 holes on each side. Once I had 2 holes at each of the front supports complete I would secure them with bolts and use the end plates as drill guides for the remaining 4. I would also HIGHLY recommend installing a full sized backing plate opposite the front attach points. The aluminum at this location isn’t strong enough for the cage to be secured with just nuts and washers unless you’re running some very large fender washers.
I also noted my cage is NOT symmetric. The two overhead bars tying the front to rear hoops are equally spaced from the hoop centerline. At first I constructed a centerline by drawing an imaginary line equally spaced from the inner edges of the top two bars. After positioning the cage something looked odd to me and I had to double-check the cage dimensions. This is when I discovered the true cage centerline should be constructed using the frame attachment points (effectively the hoops themselves). This gave me a much better centered cage and jived with how the factory had originally set it up prior to shipping. As a final sanity check I installed the interior tub and ceiling panels to confirm the overhead bars would not interfere with those pieces.
This is when I also noted the two front attachment points were not fully on the frame. To get the attachment points in their proper position I used a strap to pull the bars forward about 0.5″ so all 4 holes could be positioned.
At long last I was able to pull the engine out of hibernation! I purchased an LS376/525 GM crate motor from Pace Performance. What’s a bit different with the motor I selected is it’s actually an LS376/430 GMPP crate motor that’s had its cam replaced with the 525hp version. This update kills the GM 2 year crate motor warranty however it does have a 1 year warranty. Doesn’t really matter to me (and likely others) as most folks won’t get their cars running before the warranty expires anyway. By going with the Pace version of the 525hp motor a not-insignificant savings can be had (about $1k as of this writing). Apart from the cam, the LS376/430, 480, and 525 motors are identical.
Note this motor did NOT come equipped with the triangular engine mounts needed for engine installation into the SLC chassis (contradicting the SLC wiki). I am not sure if this is because I purchased the Pace crate motor as opposed to an untouched GMPP crate engine direct from GM themselves. The motor mount PNs are 10349964 and 10349965, purchased from GMPartsDirect.com or available at any local GM dealership. 6x M10-1×50 x 35mm bolts will be required to secure these to the engine block.
I elected to purchase the optional LS accessory kit from RCR directly. After staring at the AC compressor and engine for a few minutes and scratching my head, a call to Fran revealed I had not received the AC compressor bracket with the original shipment. Kudos to Kristin for getting the missing bracket and hardware out to me just a few days later. Once the bracket arrived figuring out where things went was fairly straightforward though I did ping PeteB for some information just to be sure (thanks Pete!).
As noted in the SLC wiki, the GMPP crate motors now ship with the Camaro style deep sump oil pans. These are too large to be compatible with the SLC and need to be replaced with a shallower version. I went with the Corvette C6 style pan with an added Improved Racing baffle and crank scraper kit while I had the pan off. Improved Racing offers this system as a kit, PN EGM-414, and they’ve got data on their site showing improved oil pressure over the factory GM configuration – the LS3 motors are fairly notorious for unsteady oil pressure/starvation in long left hand sweepers. The hardware looks and feels the part – precision machined and stout.
In preparation for installing the motor the rear chassis frame brace was removed and the Graziano pulled (installed from the factory as it was purchased with the kit). The Graziano transaxle is the OEM gearbox used on the Audi R8 and Lamborghini Gallardo – both 4WD vehicles. Since this gearbox is to be used in a RWD application it’ll require modification to eliminate the additional forward propulsion section. Slight grinding of the oil pan provides enough clearance for the forward prop shaft so transaxle and engine mating can occur without interference. Details of this modification are covered in the manual and SLC wiki. In my case I opted to cut the forward prop shaft splined section off instead of modifying the oil pan. I intend to have this transaxle updated with the newly available drop gears provided by JBurer and at that time the forward prop shaft will be removed altogether. Since the shaft is going bye-bye I’d rather modify this than the oil pan (on the LS motors the oil pan is a structural load bearing member). More details of the drop gears are available at this thread. The addition of the drop gears will effectively increase the final drive ratio of the transaxle, making it a more appropriate fit for a low revving/high torque V8 as opposed to the higher revving motors it was originally intended for. However, I want to get this car ON THE ROAD before sending the transaxle out for update.
It’s been a lot of planning, doing, stopping, re-doing, stopping, and pressing forward. You really need to have about 4-5 different things you can do at any one time to stay productive on a project like this. Hit a road block? Find another ball and kick it!