Kurt H (hoffkm) SL-C build thread

Bummer Kurt. Good luck with the chase. I am really nervous about leaks, since this is my first build. I had my share while doing the brakes, stainless steel lines are tough to work with, then I had a major leak with the traction control unit , had to send it back. I crimped all the AC lines myself, fingers crossed. Thanks for the dye tip Alan, I have a UV light at work I can borrow. But I am not going to need it. Riiiight!!!
 
The UV dye is your friend. You only have to get in about a half can of freon in the system to get enough cycling to find the leak with dye and a UV light. I knew I had a leak and didn't want to charge so I spent days chasing it with soapy water. Once I gave up and put some freon in, I found it under an hour, and it took way less freon than I thought.
Alan,

Thank you for the tip. I have a UV light and glasses to test that way if I do not find my leak by pressure testing. Good to know that the system will pressurize to compressor turn on temp with only a small amount of R134a added.

How much R134a do these systems take? Vintage air states an amount for a typical installation but we have a lot longer line runs due to our mid engine arrangement. I saw on here where someone stated they used 2 lbs in their GTR, is that about right? Do I charge to 20 psi static pressure on the low side?
 
Yay, my AC system held pressure overnight so I do not have any leaks after all. :) The problem was in the quick connect couplings on the gauge setup I am using that connect to the lines on the compressor. Either the Vintage Air connections are a little too loose or the o-rings are worn in the couplings. I am once again moving forward with my build instead of back! Charge the AC this weekend and set the body in place next week for hopefully the final time (before taking it all back apart for paint next fall).
 
Vacuumed down and charged the AC this morning. All is well, I have cold air coming out the vents about 35 degrees below ambient. My pressures are on the low side but it is also not very warm outside and was about 65 in my shop while I was working so I am sure that is affecting the high and low side temps. I do not want to overfill the system (I used about 32 ounces R134a to get a full charge).

I am very happy that my first experience with automotive AC is behind me and successful. That is one of the best things about building this car, learning new things.
 
Kurt, for what’s its worth

I took my system to my local AC shop to fill her up. The old timer there shared some wisdom with me. While running the AC look into the dryer window on top for bubbles. When you stop seeing bubbles and the pressures are right, you got enough refrigerant.
 
Kurt, for what’s its worth

I took my system to my local AC shop to fill her up. The old timer there shared some wisdom with me. While running the AC look into the dryer window on top for bubbles. When you stop seeing bubbles and the pressures are right, you got enough refrigerant.
Dan,

Thank you for the tip, that is good to know. About 3/4s of the way thru my last can the bubbles did stop in the window and it was just a smooth flow of liquid refrigerant so I would say based on your knowledge I should be good!
 

Kyle

Supporter
Hey Kurt you’re using the terminator system right? Any way you can share your tune with me so I can compare? I just cannot get this motor to stay running. It was fine on the stand with the GM harness.
 
Hey Kurt you’re using the terminator system right? Any way you can share your tune with me so I can compare? I just cannot get this motor to stay running. It was fine on the stand with the GM harness.
Kyle,

Certainly, but no guarantees on anything. I am certainly not a tuner and will probably have a professional tune done when I get her on the road. My current tune is derived from the wizard with a custom made timing and afr table, both of which are conservative. Mine did not run very well off the wizard until I changed to these custom tables and got things up to temp for the fuel to do some learning. It made some pretty significant changes to the base table. The attached gcf file includes all this learning. If you have a cable throttle body it is also very important to get the idle screw set for a 3-10% IAC at idle when the coolant is at 160 or higher. Any time you adjust the idle screw you must re run the TPS autoset wizard.

If you use the attached tune you will need to change the settings to match your displacement, injector sizes, input and output setups, etc. This is easiest with the laptop software and I highly suggest downloading and installing it to make adjustments.
 

Attachments

Kyle

Supporter
Appreciate it, I’ve tried several base tunes, even a tune from sloppy mechanics that should work on this motor. Just can’t make it happy. I have the laptop, software, DBW, etc. I’ll try your tune later this evening and see if it holds. I know there is something simple I’m missing.
 

Johan

Supporter
Appreciate it, I’ve tried several base tunes, even a tune from sloppy mechanics that should work on this motor. Just can’t make it happy. I have the laptop, software, DBW, etc. I’ll try your tune later this evening and see if it holds. I know there is something simple I’m missing.
Appreciate it, I’ve tried several base tunes, even a tune from sloppy mechanics that should work on this motor. Just can’t make it happy. I have the laptop, software, DBW, etc. I’ll try your tune later this evening and see if it holds. I know there is something simple I’m missing.
Kyle, I had similar problems a couple of years ago when playing with my Dominator (same with Terminator). Make sure you have the correct sensors entered, especially MAP sensor.(there is quite a number of different sensor calibrations). You can check it by go ”on line” with engine off and check where the cursor sits on the kpa axis. It should be close to athmospheric pressure, ~95-105kpa. Mine was way off reading 85kpa/engine off.
Also, on your video it sounds like it’s running quite lean on idle. Don’t trust the learn function, it will only learn on what inputs you’re giving it.
Like all computers, crap in=crap out. Try to richen it around the idle cells, don’t know what you have now but try to go a whole point or at least .5 A/F lower. (From 14.5 to 13.5)
 
Been about a month since my last update. I had a goal to get the spider fit and set in place before my daughter went back to college (that day was today). Nothing against my wife but our daughter is a better assistant in the shop.

Since charging my AC before Christmas here are some of the highlights of my progress (mostly it has been some wiring, fitting panels, etc.)

Subwoofer box built and installed. My original plan for a 12" Rockford Fosgate sub I had laying around took up too much legroom in the passenger footbox so I purchased an 8" Infinity Kappa Series sub (matches my 6 1/2" component system) and a larger Infinity Reference amp (need more power for this small sub). The sub is in a sealed enclosure I built and only takes up about 6" in depth of the passenger footbox. I am still working on were to mount the amp, it is LARGE. I think it will end up on the back wall between the seats.

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Installed the anchor duct, fit the dash, and worked on some of the wiring under the dash (I am done with adding wiring into the footwells) for relays, etc.

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My lift system has more stroke in the cylinders than what my shocks allowed for at full extension so I built some tapped steel doubler plates for inside the footwells to lower the upper shock mounts 9/16". The tapped plates allow me to remove the brackets without having to have someone crawl inside to hold a wrench on the nuts.

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Tidied up the plumbing on my oil cooler.

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I purchased the mounting plates from Pantera Electronics along with their controller for my Tesla EPB calipers. There are two tapped holes in the rear wheel uprights behind the calipers that are not used. By adding a 1/2" x 2" length of aluminum to the purchased brackets I was able to utilize these mounting holes without having to add any holes to the uprights. This was my first attempt ever at TIG welding aluminum. After much practice my welds are functional but not the artwork of a seasoned welder so I built them up and ground them smooth.

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After that is was spider on. I trial fit my windshield and with a 1/2" of shim under the spider near the door hinges my windshield fit perfectly.
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After much fitting, measuring, shimming, etc. I decided that I need to move the drivers side of my tub another 1/4" forward to get the spider sitting exactly where I wanted it. SHIT. In order to do this I needed to remove the tub to do it right. This would also give me a chance to insulate my floors and knock out some other small tasks that I had planned to save for later. Off came the spider again. My daughter and I set it outside for a couple of days and sure enough we had ice and snow. The cup holders are perfect molds for making ice cube frisbees.
 
While the spider was back off I made all the cutouts for the door hinges and upper roof scoop. Also added a 1/4" thick aluminum doubler plate for the door hinges.

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And then it was time to put the spider on for the last time (at least until I take everything back apart for bodywork and paint).

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The insulation I applied to my floors and the walls of the tub really deadened out the "ringing" and "drumming" sounds when you tap on them. Once I carpet the interior (during the final finishing stage) I am quite confident in a "fairly" quiet ride. Any noise that is left will be drowned out by the 500 watt Infinity amp (that is when I do not want to listen to the V8 Symphony of Cylinders).

Next up is wiring the dash, carbon fiber skinning my dash gage and switch plates, then installing the gages, switches, and dash. After that I will be taking a little break from the SLC to remodel the master bathroom in our house. I have been doing plenty for myself, time for a project to keep the wife happy. Next month is our 30th Wedding Anniversary so I guess it is an anniversary gift.
 

Joel K

Supporter
Nice update Kurt, lot’s of progress. Nice to see the body and windshield fit well. Like you, based on the initial body fitment I did I’ll also need to shift the drivers side of the interior tub forward to align the wheels in the wheel wells better.

I like that bracket for the parking brake you made. I am not looking forward to drilling into the side of the upright to mount the parking brake.
 

Kyle

Supporter
Looks good brother! That’s probably my least favorite part about the build is taking the spider on and off. I can’t wait until I can get the tub locked down and not worry about it anymore. Speaking of, did you anchor the spider to the tub in the door sill area? I don’t know if you went over that....are those maybe some rivnuts on backside of tub with countersunk screws through the sill?
 
Kyle,

Yes, I attached fiberglass rivnuts into the tub, two per door sill to pull the tub up to the spider using stainless FHCS's. It really stiffened up that area, I can no comfortably sit on the sill while getting in and out of the car without feeling like the fiberglass is going to collapse beneath me.
 
Kurt, Does the windshield fit?
Howard,

Yes it does. I think I got "lucky" with my fitment and it was pretty easy to sort out (I did have a lot of help from reading what everyone on here has done before me :) . I did have to shim the body up some as noted above but it fits perfectly. The only issue now is that the shims have raised the lower front portion of the body off of the aluminum side skirts but I will address that issue next. I may just shim the rear of the spider to match the front and then "pull" the sides of the spider down to the side skirts. Have not decided on my final course of action just yet.
 
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