IMSA GTU vintage racer build

[clarkspeed]

Yes, not so much the transducers, but the entire firewall. On the 1000 pics I have viewed when planning this thing, I realized a sandblasting of the area behind the tires is expected. So I have a guard planned for the front and a full fender liner for the rear. Will probably fab both in the next few weeks.

[clarkspeed]

Got a little behind due to work travels. I'm really lucky when I do travel it is to some nice places. It almost makes up for the endless time spent in airports and rushing to the next place. Last 2 weeks were Portsmouth Great Brittian, Berlin, and Piza Italy. 

 

Anyway fuel cell finally installed and brakes leak checked. This is an older cell I re-foamed and replaced gaskets.

Edited April 11, 2023 by clarkspeed

[tube80z]

That's a large cell.  Is it set up for longer enduro style events or are the images misleading on size?

[clarkspeed]

On 4/11/2023 at 4:59 PM, tube80z said:

That's a large cell.  Is it set up for longer enduro style events or are the images misleading on size?

15 gallon. Yea, needed for longer races of 50-55 minutes. There is a mandatory 5 min pitstop, but I don't want to deal with refueling. I usually see little over 5 gal burn in 20 minutes and fuel to level needed.

[clarkspeed]

Wish I had more to show. Started with some of the electrical and plumbing. Changed a set of 20" truck tires on the tire machine Cleaned out the Accusump I had. Those things get really nasty over time, but no metal chips seen. Will pick up the motor Friday. AND I installed the rear tow hook!

 

 

[AydinZ71]

Pretty sweet Clark. Just as an FYI, Canton Racing will rebuild your unit for ~$60 (plus shipping). Pretty affordable! If you have any used oil in the gas-side of your unit, its time to rebuild. I bought a 3qt unit used and had it rebuilt last year. Apologies in advance if you are already aware of all this. 

 

OH, they also have a remote actuator cable, and even an auto-actuate servo. Honestly, i think its worth keeping the heat and mess (engine oil fittings all leak to some extent) in the engine bay. 

[clarkspeed]

I just disassemble them, clean, and reassemble. As long as the o-rings look OK and no metal inside. They tend to get gummy in the inside. Also replaced all the fittings and gauge. Dont remember pedigree of this one but may have bought used. Currently building my own cable remote valve. But it will be mounted in passenger floorboard. I usually wrap with some header insulation to keep heat down. Never had any leaks.

 

Another milestone complete.

 

 

[AydinZ71]

Congrats Clark! Do you have a detail write-up on the motor? Would love to geek-out on the specs. 

[clarkspeed]

Diesel crank, .060 over, 3.0L, 13:1 compression, 33cc chambers, forged flat top pistons, 0.58 lift, 304 duration cam, blah, blah blah.

 

2 days of pulling wire. And a slightly blurry sample of my wiring diagram.

[clarkspeed]

Well this is how you wire a race car. Or any car for that matter. 

 

1. All splices lineman wrapped, soldered,  and sealed with glue lined shrink.

2. All terminals crimped perfect with glue lined shrink. Use a good stripping and crimping tool. Does not mean expensive. Look under a magnifying glass that the strip is clean with no wires cut. Crimp based on wire gauge. Pull test after crimp.

3. Use the correct size terminals. Red, blue, yellow for the correct wire gauge. Do not use a larger terminal for a small wire.

4. A few weather-tite connectors thrown in for removable components. Most everything is wired point to point. No break connectors at firewall.  No relays currently.

5. All data cables ran with 3 wire shielded cable and aerospace connectors. Very careful with any splices and solder the shields. Terminate shield at only 1 end with a ground pigtail.

6. 3 separate harnesses formed. Power, EFI, and data.

7. Buy a ton of wire all from the same source with same insulation. Limit the gauges to what you need based on amperage. Makes stripping and crimping more consistent. 

8. use only glue lined shrink tubing.

9. Buy a wire label shrink tube marker machine. Label all wire ends. I bought a cheap label printer from China and a few cartridges of 5.3 and 8.8mm white tube. Works great.

10. Plan in 3 trips through your harnesses and leave 1 or both ends loose until you get the harness figured out. Then start terminating from 1 end and temp form the harness as you go. Form the harness where it needs to be before terminating the final end. Do not final tywrap until you are sure you have everything included and in the desired route. 

11. As I mentioned before, plan everything out before you start. List every electrical component and plan a rough wiring diagram. 

[AydinZ71]

Wow look at that! Nice wiring job! what kind of wire did you buy? I bought some tezfel Mil-spec wire to try out. The insulation appears to be lighter and it withstands higher temps for the engine bay. Looking great Clark.

 

What fuel do you plan to run? Leaded? 

[Ben280]

I used Tefzel in my build, it's phenomenal stuff. Lighter and higher current capacity, but needs special tools for stripping. 

 

@clarkspeedlooking very very nice!

[AydinZ71]

@Ben280 yeah I had not heard of it until I did a bunch of online research. If it’s good enough for a military aircraft, it’s gotta be good for a race car!

 

@clarkspeed

This time around, I had time to read your full list. Do you mind sharing the make/model of some of your tools? Stripper, crimper, etc? There are soooo many options it’s a bit overwhelming. 

[JMortensen]

All that electrical makes me feel functionally retarded. Nice job.

[clarkspeed]

8 hours ago, JMortensen said:

All that electrical makes me feel functionally retarded. Nice job.

After wiring 3 cars i finally got the hang of it. Probably a year of planning up front.  Read alot of materials and looked at alot of race car photos. At this point, i think it may be my best skill when building/restoring race cars.

[clarkspeed]

On 5/26/2023 at 11:03 AM, AydinZ71 said:

Wow look at that! Nice wiring job! what kind of wire did you buy? I bought some tezfel Mil-spec wire to try out. The insulation appears to be lighter and it withstands higher temps for the engine bay. Looking great Clark.

 

What fuel do you plan to run? Leaded? 

Yea the tezfel is good stuff. It is not easy to strip. Waytec is a good source if unsure of what to use..

 

I used standard cheap wire for power/grounds. Bought a ton of colors and gauges off eBay. Diameters were very consistent. I only race this thing 3-4 times a year and it lives in a garage. If it gets shabby 10-15 years from now, you can pull out the harness and build another. I was a little more careful with data wiring. I do plan to protect the wires running near the engine.

 

In my summary i listed the all things I thought werw important. Some stuff I spend the extra $ on, some stuff I dont think is worth it. Just my opinion.

Edited May 30, 2023 by clarkspeed

[clarkspeed]

On 5/26/2023 at 11:03 AM, AydinZ71 said:

Wow look at that! Nice wiring job! what kind of wire did you buy? I bought some tezfel Mil-spec wire to try out. The insulation appears to be lighter and it withstands higher temps for the engine bay. Looking great Clark.

 

What fuel do you plan to run? Leaded? 

This engine is built at 13:1 compression. I will run 108 octane or better. Yes leaded.

[clarkspeed]

On 5/26/2023 at 5:45 PM, AydinZ71 said:

@Ben280 yeah I had not heard of it until I did a bunch of online research. If it’s good enough for a military aircraft, it’s gotta be good for a race car!

 

@clarkspeed

This time around, I had time to read your full list. Do you mind sharing the make/model of some of your tools? Stripper, crimper, etc? There are soooo many options it’s a bit overwhelming. 

The damn name is worn off handle of my crimper. It has a blue handle and does crimping and stripping near the handle end. It has a cutter on the forward tip and strips down to a very high gauge #. I think i purchased at Lowes. I have high end ratcheting crimpers and multiple all in 1 crimpers, but nothing works as good as this one. Makes perfect crimps every time.  Many of the strip only tools i have  work fine. I think consistent (standard) copper diameter and soft insulation made the stripping easy.

 

It looks just like the Ideal 45-778

 

Edited May 30, 2023 by clarkspeed

[AydinZ71]

11 hours ago, clarkspeed said:

Yea the tezfel is good stuff. It is not easy to strip. Waytec is a good source if unsure of what to use..

 

I used standard cheap wire for power/grounds. Bought a ton of colors and gauges off eBay. Diameters were very consistent. I only race this thing 3-4 times a year and it lives in a garage. If it gets shabby 10-15 years from now, you can pull out the harness and build another. I was a little more careful with data wiring. I do plan to protect the wires running near the engine.

 

In my summary i listed the all things I thought werw important. Some stuff I spend the extra $ on, some stuff I dont think is worth it. Just my opinion.

 

Appreciate it Clark! Hey, do you mind taking a photo of that crimper/stripper you like? Since the brand is worn-off, I can at least look for one in the same "style" Since this is the first time I'm doing wiring beyond the amateur twist and tape, the materials themselves and where to get them is a little lost on me. I already started my wire sizing chart, and will likely make a crude sketch of the point-to-point. 

 

Where did you get your 3-wire shielded? Any specific spec's I should look for? How about the shrink tube label maker, and the shrink tubes themselves? Sorry, so many questions. 

[clarkspeed]

Yea i planned all of the wiring based on how many amps eaxh thing needs. In previous projects I kind of guessed and went oversize on most.

 

Here is a photo of my label printer and the 2 size shrink labels i used. Works great. I purchased all off Ali-express and shipped from China.  Maybe Amazon has something similar by now. 

 

Here is my favorite crimper. And decent for stripping.

 

Edited May 31, 2023 by clarkspeed