C10CJ: A Pro-touring '71 Stepside on a No Limit Pro-C10 Chassis

[1971_c10]

Originally Posted by crakarjax

Sounds like a blast, can't wait until I actually get to do some racing with mine!

Are you running the trans cooler lines through the radiator as well, or just the derale cooler?

Just the derale cooler. I wanted the trans fluid out of the radiator. The trans and engine were fighting as I suspected. The trans wants to run 180-190 and the engine wants to run 195-210. So the engine would heat up the trans fluid and then combined with the high stall, once the fluid gets hot it keeps getting hot. So I'd routinely see trans temps over 220 and then that would heat the engine coolant up. So far, this little Derale has not had any major issues keeping up and I put at least 75 miles per day on it over the three days driving back and forth to Loveland for the show, one of those days stuck in horrible traffic. I have yet to take it to the mountains and torture test it though. So far I'm liking the setup.

[Advanced Design]

Nice work on those lines! And that had to be some fun changing the suspension settings and evaluating the results...so many variables.

[1971_c10]

Originally Posted by Advanced Design

Nice work on those lines! And that had to be some fun changing the suspension settings and evaluating the results...so many variables.

Thanks Doug! It was a blast. I got super pumped when I would make a change and shave a second off. I was about 6 seconds behind the pro 'pack' (there was one pro just shredding the course so he's not lumped in the 'pack'). I can tell you I'm pretty sure 5 of my 6 seconds were in the hairpins. My lack of experience on those tight of turns was worth a second per turn I'm sure. The rest was probably just in start line traction and hitting the apexes just right. I'm pretty sure if I had handed the keys to one of the pros the truck would have been right there in the fast group of the day (34-36 seconds).

Oh, and I forgot to mention, I did officially place 2nd in the truck class for the event.

[1971_c10]

Hey guys, I'm starting a new video series to help those out running Holley EFI. Over the course of several videos I'll show you guys how I did the setup for the cooling fans and A/C integration along with some other custom options. The first one shows how to use the data overlay feature in the Holley EFI software which greatly helps when tuning, either on the street or on the dyno.

C10CJ Holley EFI Tips: Datalog Overlay - YouTube

[1971_c10]

If you are following me over on social media, than this may be old news, but wanted to let you guys know I tested the 'touring' part of pro-touring. I put around 800 miles on C10CJ this past weekend. Truck drove very well. Cruises down the highway at 75 mph with ease and got around 17 mpg overall across the 800 miles. The only issues I had were interior related and the interior is still something I need to tackle. The issues were basically too much wind noise due to leaking windows. I really need to replace the vent window seals and all the other window seals. I did the door seals earlier and that just showed me where the next problem was (which I expected). So here's a little photo journal of the trip.

The trip was to my Dad's place in the black hills. The route was 380 miles each way, straight up I-25 from Denver then cutting across Wyoming on US 18/20 to US 85, then on US 18 again into SD over to SD Hwy 79 up to Hermosa then towards Keystone no SD Hwy 40. Fairly easy drive with elevation reaching as high as 6100 ft then down to ~3500 ft at Dad's place.

Shot on the drive up, somewhere on I-25


Parked in my Dad's buddy's shop. That dark grey C10 got some updates I installed over the weekend.


The upgrades were installing a new throttle/TV cable setup. He's been having trouble getting his truck to shift in to OD and one thing I found was the TV cable wasn't quite right.


So I fab'd a bracket to bolt to the non-standard throttle on that giant Holley Ultra XP carb (950 cfm feeding a 555 cu in BBC built by Pat Musi)


The final setup.

[1971_c10]

Spent a chunk of Saturday at the drag strip in Sturgis watching a friend run his alcohol burning beast of a '34 drag car. He hasn't had this thing running long so he was doing some test and tune. As I helped him do a couple jet changes he made sure to jab me some on carb vs EFI (all in fun of course). But after spending a bunch of time on his knees working in a cramped engine bay, he did admit EFI wasn't sounding so bad as he could just be making a tweak on a laptop and done in 5 min vs the 30 mins to do a 4 corner jet swap on his 1050 dominator (setup for alcohol). Good times.



Interior shot of the '34


Heading back home. Had some very heavy winds, sometimes a cross wind, then a head wind in Wy. If you zoom in to the vehicle in front of me, that's a motor home with a little lean to the right not due to bad shocks, but due to the wind blowing that hard. He wasn't going very fast due to that.


Wound up doing some night driving.


Truck got really dirty on this trip.

[aggie91]

Great to see you driving this one. That '34 looks bad a$$.

What kind of floor is that in your shop?

[1971_c10]

Originally Posted by aggie91

Great to see you driving this one. That '34 looks bad a$$.

What kind of floor is that in your shop?

Hey Karl, thanks! I built this thing to drive and have the rock chips to prove it!

The '34 is definitely a bad a$$ beast. He got into the high 5's in the 1/8 mile and engine was still rich so there was more power to be had. This is all naturally aspirated. No nitrous, no turbos, no blower. Good stuff!

The coating on the floor is from Epoxy Coat (http://www.epoxy-coat.com). They allow you to choose the colors you want. I have the "premium" package which includes a clear epoxy to put over the colored epoxy and acts as a clear coat. It is more expensive, but much thicker. I have abused my floor pretty hard and do have a few spots where the coating has chipped, but that may be due to a poor bond to the concrete usually a product of bad prep. I used the chemical method vs a diamond sander since my floor was new, but I'd probably do the sanding thing next time to ensure there is a good profile on the surface for good adhesion.

[Advanced Design]

Looks like you had a great trip! Appreciate you sharing it with us.

The night picture shows a decent headlamp spread...was the lighting good?

[1971_c10]

Originally Posted by Advanced Design

Looks like you had a great trip! Appreciate you sharing it with us.

The night picture shows a decent headlamp spread...was the lighting good?

Hey Doug, Trip was awesome. Glad to get some good highway driving and even a little inclement weather driving. I was actually impressed with the lighting during the night driving. What I did with this build is simply got the headlights off the headlight switch and on relays. Those lights are just some ~10 yr old Sylvania's (halogens) from one of the local autoparts store. So just changing to the relays they are way brighter than they were before. I do have some tweaking to do to the aiming. They are a little short for rolling down the highway at 75-80 if there weren't any other cars (just slightly overdriving the lights). I haven't set them yet after the stance changes. I do worry they don't have the beam focus though (once I do adjust them) since when I bought them 75 mph speed limits weren't the norm like they are today, and 80 mph in WY.

For those curious on the headlight relays, what I did was use the existing feed from the headlight switch to drive two relays, one low beam and one high beam. Since the headlight switch puts out 12v, I just wired them straight to a resistor style relay (to make sure the current pulled through the headlight switch was minimal now). The relays are in those littelfuse blocks I added on the radiator support. So the headlights have a much more direct path to the battery and can pull the current they need. The headlight switch in our trucks winds up acting like a resistor so it restricts current to a degree, resulting in the sub-par light performance. One reason why those super bright headlight upgrades all include relays.

[1971_c10]

Hey guys, tossed together another video showing how I setup my cooling fans using the Holley software since I'm running a Holley ECU. I've got the ECU controlling the fans and it is setup to turn the fans off above 50 mph. Posted over on youtube ...

C10CJ Holley EFI Tips: Dual Fan Config - YouTube

[HellaciousA]

I was curious which rear brake setup do you have from no limit? I have the floater rear end and the wilwood caliper no limit gave me is a single piston unit with an integrated parking brake. I have 6 piston calipers up front and I'm worried about brake bias issues given the large difference is piston sizes.

[1971_c10]

Originally Posted by HellaciousA

I was curious which rear brake setup do you have from no limit? I have the floater rear end and the wilwood caliper no limit gave me is a single piston unit with an integrated parking brake. I have 6 piston calipers up front and I'm worried about brake bias issues given the large difference is piston sizes.

Hey man, I've got the 12.88" rotors and 4 piston calipers. Most likely your rear brake setup is just fine. Don't get too hung up on the 4 piston rears vs a single piston rear. Couple things ... the front still does most of the braking and the difference in piston area from the 4 piston to the singe piston probably isn't as big as it sounds. The 4 pistons in the back are pretty small. I went that route as for the non-floater rear end, it was either an 11" rotor/single piston or a 12.88" (or 14") rotor with the 4 piston caliper. The 11" setup was probably enough, but I wanted the rotor to fill the wheel a little more with my 18s so I went with the 12.88" for aesthetics.

And since I haven't been around in a while, here's a recent shot from my instagram account @c10cj

[hotrod1]

Hey Chris - So a lot of time has gone by and I was wondering if you have any suggestions, regrets, or whatever with your truck.

Thanks

[1971_c10]

Originally Posted by hotrod1

Hey Chris - So a lot of time has gone by and I was wondering if you have any suggestions, regrets, or whatever with your truck.

Thanks

Hey man, I got no excuses for the lack of reply ... So far so good on the build. Everything runs quite well. My main things are not replacing the 90's glass and I still have to sort out the bed floor. Otherwise, I haven't come across anything the annoys me or drives me nuts.

I do have some updates I need to add to the build thread. After a great season in 2019 I qualified for the Goodguys Duel in the Desert final autocross in Scottsdale, AZ and made a few changes for that event since I would be racing the pros. I did change tires from the Nitto 555 G2s to BFG Rival S 1.5 which made a huge difference on the autocross track but I actually like the Nitto better on the street.

Main things I changed other than tires was moved the battery and trans cooler to the bed and changed the front springs to a stiffer spring rate. The stiffer spring rate (from 450 lb/in to 550 lb/in) was great for autocross but definitely makes the bumps in road driving a bit worse. So the usual tradeoff for a stiffer spring. Now after 1.5 years of no racing due to you know, time to get back at it next weekend with GG Colorado.

[hotrod1]

That's great. Any pics would be great also.

[crakarjax]

Originally Posted by kxmotox247

Do you remember what your overall rear end width was with your brakes? I ordered mine a little more narrow than stock to get maximum backspace.

Out of curiosity, why would you want maximum backspace? I know on the front you'd want a backspace that minimized scrub radius if possible but I've never given the rear much thought.

[knomadd]

Originally Posted by 1971_c10

Ok Guys! It's Official!! C10CJ is signed up for the C10 Nationals May 4-5 @ Texas Motor Speedway. The first major goal has been set!

Congratulations Chris! That's a great milestone achievement!

Originally Posted by crakarjax

Out of curiosity, why would you want maximum backspace? I know on the front you'd want a backspace that minimized scrub radius if possible but I've never given the rear much thought.

I'm guessing here, but since he said he ordered a slightly narrower than stock rearend, I think he meant minimum backspacing to get a bigger wheel lip.

[kxmotox247]

Originally Posted by knomadd

I'm guessing here, but since he said he ordered a slightly narrower than stock rearend, I think he meant minimum backspacing to get a bigger wheel lip.

Yep. Wrong choice of words. Trying to maximize wheel lip. This thread has a ton of good info in it for those building a truck with a No-Limit chassis. Just figured I would ask him what rear end width he ordered. I'll start my own build thread for my truck but it'll be pathetic in details compared to this one.

[1971_c10]

Originally Posted by kxmotox247

Yep. Wrong choice of words. Trying to maximize wheel lip. This thread has a ton of good info in it for those building a truck with a No-Limit chassis. Just figured I would ask him what rear end width he ordered. I'll start my own build thread for my truck but it'll be pathetic in details compared to this one.

Hey guys, sorry for the lack of attention. The end of January was a nightmare for me at work. Been recovering since ...

And thanks for the compliments on the thread content!

My rear axle is 61" wheel mount surface to wheel mount surface (so rotor installed yes). 61" is the standard width Rob installs in the chassis. It's a good balance of getting a decent lip on the wheel but not narrowing your track to drag race specs. That's 2.5" more narrow than the stock '71 rear axle, but keep in mind the 67-70 had a different width than the 71-72.

[1971_c10]

Didn't realize until today I didn't post anything on the mods I did to the OEM trans tube to fit an LS. Recall I'm running a fairly built 700R4 as I had that from a prior upgrade. I was using the factory style trans tube and dip stick. So when I went LS, a problem came up. The hole where the dip stick mounted doesn't exist. Yep, it's the one hole in the bell housing that got deleted on the LS blocks. So I went about fabricating a simple bracket that attached the tube to the back of the passenger side cylinder head. And darn if I forgot to take a shot before I cut off the factory bracket.

Here's the bracket I came up with. I actually used a scrap piece of 16 ga steel and from start to finish painting this thing only took me 2 hours.


The curve was hand hammered to match the tube diameter. The small holes are for the plug welds I used to attach it to the tube in addition to some perimeter welds.


The original bracket was brazed on one end and welded on the other. This one is just welded since I don't have any gear to braze.


All painted up. That small square piece below is the remainder of the OEM bracket that was welded on. I didn't feel like trying to remove it so I cut it and benched the edge.


And here's a shot showing the tube installed. Also got a nice new air cleaner to finish off the look I was going for.