1995 S10 Build for Endurance Road Racing - Thr3ve Racing

Are you happy with the engine build as it stands now? I started a stock bottom end heads/cam/turbo build on an extra motor I have and I'm considering holding off on the turbo for now, just so I can get it done before I lose interest.

Most definitely. I guess I'll go ahead and breakdown what we've done regarding the engine and quit being lazy. We haven't dyno'd it, but I'm guessing somewhere between 230-250 HP. We did follow a lot of what Hot Rod did in a 4.3 build (http://www.hotrod.com/how-to/engine/113-0208-chevy-43l-262ci-v6-engine-build/) but I'm not sure we have 300 HP, but it's fast and the cam pulls like a mother. Of course, when the truck is at race weight (2750 lbs with fuel and driver) 250 HP at a near 10 lbs/HP ratio makes anything feel pretty quick.

For starters, we had the factory (Z engine code) 4.3 TBI out of a 1995. Factory specs are about 155 horsepower. At Road Atlanta our truck would hold it's own in the twisty bits, however, once we hit the straights, everyone would walk off and leave us. We knew more than anything we needed more power. At the time, we debated an SBC or LS swap. However, that would have necessitated a new transmission and rearend and we didn't have the time nor the funds before our next race (Atlanta Motorsports Park November 2014) to pull all of that off. So we decided as a stop-gap measure we would build our 4.3 and enjoy it for a couple of years while we upgraded the drivetrain and built an LS offline.

So here's what we did:

1. We found some true Vortec heads off of a 1998 Blazer, Casting#: 12556140 at Pull-A-Part for $120 or so.

2. Tore down the engine and had a clean-up bore (0.030") on the block. Of course it was cleaned, balanced, and we had all of the bearings replaced. We decided to use some Icon 0.030" over forged, flat-top pistons to bump up compression. For a cam, we went a Comp 56-430-8 cam with a sweet spot of 3,500 to 5,500 RPM which is perfect for us. We also removed the balance shaft and plugged the oiling holes for it.

3. We had the heads redone by having a triple angle grind performed on the factory valves and had the heads decked to give another tick up in compression and to have everything nice and flat. We used Comp roller rockers and as far as we can tell, there's a trick to making that work as we couldn't find anyone else on the internet that had done it because of rocker stud availability. We've considered patenting our idea so I won't give too many details about it. We also used some Comp beehive springs to deal with high RPM valve float. We bought some cheap valve covers and made those work.

5. We were not interested in using a factory fuel injection system, because well, frankly, we hate wires. An aftermarket fuel injection system would have been fine, but they are too pricey for our tastes. For an intake we used the Edelbrock 2114 performer intake. We topped that off we a Holley 500 CFM 2BBL intake with road race floats in it.

6. For sparks, we went with a stealth DUI distributor designed with a curve to maximize our components and in the RPM range we wanted it. We used DUI LiveWire spark plug wires and gapped our plugs at 0.55".

7. Found some JBA headers on CL for $75 and stole from that poor guy; man what a deal.

8. Used an under-drive pulley to free up a few extra ponies and took advantage of an A/C delete pulley. Other than that, the Front End Accessory Drive (FEAD) remained intact.

Most of that is allowed within the ChumpCar rules but it comes at a penalty within their system. However, we didn't take any penalty laps because our truck's base value is 200 points. You are allowed 504 points before you take 1 penalty lap. We squeaked it all in within 504 points.

Here's a video of it idling:

https://www.youtube.com/watch?v=W4ZR36awS_A

Sounds awesome, thanks for the details. There is a recipe for making the comp rollers work on the vortecs, I have 1.6 pro mags on the heads I have now. I think the info is this thread somewhere:

http://www.s10planet.com/forum/showthread.php?t=14790

I've seen a few other similar builds making 270 hp at the fly wheel so I definitely don't think you're over estimating your power numbers. I'll probably shoot for something like this although it will likely be lower without the bottom end parts. I'm going to stick with the factory-style fuel injection setup.

Sounds awesome, thanks for the details. There is a recipe for making the comp rollers work on the vortecs, I have 1.6 pro mags on the heads I have now. I think the info is this thread somewhere:

http://www.s10planet.com/forum/showthread.php?t=14790

I've seen a few other similar builds making 270 hp at the fly wheel so I definitely don't think you're over estimating your power numbers. I'll probably shoot for something like this although it will likely be lower without the bottom end parts. I'm going to stick with the factory-style fuel injection setup.

Our solution doesn't require any re-drill or tapping, etc.

I'm sure your truck has the CPI instead of the TBI which makes a nice difference. I don't blame you.

I will say it is amazing how many cars in a race weekend end up with ECU failures. I'm not sure if that's because they've done some jam-up, super kung-fu tune and they don't like it. Or because they've hacked their car to bits and something shorts out or their ECU is laying in their floorboard and the sweat, rain, and other bodily fluids destroy it. Who knows, but it happens a lot. It seems to be very prevalent in the BMWs, which makes me happy.

We came back from Road Atlanta in February and worked on the motor as described above. We had a few other issues to address.

One issue was brakes. Our EBC yellow stuff pads only lasted about 10 hours. That was unacceptable. We also noticed a lot of cracks in our rotors with about 15 or 16 hours on them (14 from the race and a couple hours of practice).

Since EBC was sponsoring us, I called them up and explained the situation. They sent us a custom pad just for our S10 of Orange Stuff (a set goes for about $250). We were going to give them a try at AMP in November 2014.

We also had discovered that along the way that our internet research fooled us and we had incorrectly used 75w-90 in our NV3500. We corrected that with the proper Synchromesh.

Also, we had incorrectly used friction modifier in our rear end which housed an Auburn LSD. We checked the breakaway torque (good at 60 ft-lbs), flushed with dino juice and hopes the peg-legging out of T7 and T10b would be better at AMP's similar turn, T6.

AMP actually touts to be a private race facility much like a country club...and considering a membership starts at $40k/year, I was astonished they let such heathens as us on site.

We showed up prepared to race what is dubbed a "D7" which is a "Double 7," or two separately scored 7 hour races. One on Saturday, and one on Sunday.

I'll post more details on the weekends results next week, but below is 45 minutes of my 2 hour stint. The rest of it was lost due to GoPro issues.

Be patient. The first 10 minutes of my stint I was going slow. I had never turned a single lap at that track and I went out as our 2nd driver under green flag conditions, so I took 10 minutes (5 or so laps) to learn turn-ins, track-outs, and braking points. Then I let it fly. Enjoy.

https://youtu.be/MohWYvK_z5g

What brake setup are you using, still single piston?

Actually, we are currently converting over to the C5 setup with Frozen Rotors.

We did use the single piston setup for the first two races and it did amazingly well. We use Amsoil Hi-Temp brake fluid and brake ducting which definitely helps. Funny though, our calipers only last one race because the backing pads usually get welded to the piston and since they were so cheap ($16 at Advance Auto) we didn't waste our time rebuilding them. Usually we have to take a mini-sledge to beat the calipers off the spindles/rotors after a race. One thing the single piston calipers are absolutely horrible for is allowing the pads to "wedge." Literally, the leading edge of our pad would be to the backing plate and the trailing edge of the pad would look only 1/4 worn. I'm hoping the dual piston calipers completely alleviate that issue.

One of the areas where we seem to get beat is in braking, so I'm hoping the new setup will help us buy back some time. Also, we are currently swapping to a Ford Explorer 8.8" rearend that uses disc brakes. So we are adding in a brake bias valve and will be doing some track testing in October to help dial that in.

Note the stress/heat cracks in the rotor. These were with our old EBC brakes. We are upgrading to Frozen Rotors because nearly everyone we race against really speak highly of the ability of Frozen Rotors to last through endurance events. i've heard of some teams with over 12 races on a set! Literally, we were having to replace our EBCs after every event. The guys at Frozen Rotors said once the cracks reach 3/4" in length, throw them out. At our last event (not the picture below) our rotor cracked from the very edge of the rotor all the way to the hat in about 10 hours.

Gotcha, yeah you were definitely overworking the single piston brakes. They weren't too good for street driving when I had them, I can't even imagine road racing on them lol. I have C5 brakes now. They worked well on the track day I just did last week. I have some cheapy pads and rotors which took some abuse, but I plan on upgrading them down the road. I can't tell by the pictures but does your truck have ABS? With the C5 brakes my ABS kicks in very soon and can make stopping very jittery. I only used about 3/4 of the pedal to slow down from over 100mph to keep it under control. Under full braking the truck would want to dart left and right, it was pretty sketchy.

I have the C5's now with Carbotech auto-X compound pads - they're very strong. Even with high temp fluid I would occasionally get serious fade at auto-x events so I can imagine the stock brakes would be a problem in an endurance race!

Gotcha, yeah you were definitely overworking the single piston brakes. They weren't too good for street driving when I had them, I can't even imagine road racing on them lol. I have C5 brakes now. They worked well on the track day I just did last week. I have some cheapy pads and rotors which took some abuse, but I plan on upgrading them down the road. I can't tell by the pictures but does your truck have ABS? With the C5 brakes my ABS kicks in very soon and can make stopping very jittery. I only used about 3/4 of the pedal to slow down from over 100mph to keep it under control. Under full braking the truck would want to dart left and right, it was pretty sketchy.

ABS is gone.

You'll be much happier with the C5 brakes. With good rotors and the brake ducting you have I doubt you'll run into the cracking issue again.

There is so much awesome going on in this build.  I'm loving it!  You guys have done a great job building a competive truck and you also seem to be driving it quite well.  Looking forward to more updates!   Now you've got me wanting to spend money I don't have with a couple friends to build one of our own team trucks!

X 2     I am loving this build & would enjoy hearing more about it. 

I love endurance racing & have always wondered where I could do that with a S10 pickup.   The thought of racing a LS powered S10 has me all goofy inside  LOL

Thanks guys.

I promise more details soon. Our plans for 2016 are:

-Road Atlanta - February
-Barber - August
-VIR - December

As we get closer, I'll post dates. If you guys are semi-close, come hang out in our pits and check the truck out. One thing is, the body is getting rougher. There is way more contact than I anticipated or prefer, but when you are racing wheel-to-wheel with 50-100 other lunatics, it's gonna happen.

I don't want to get the build chronology too out of order, but spoiler alert, we almost have the C5 conversion done, a Ford 8.8 in it and a Richmond Super T-10 in it. We just got our custom driveshaft today.

Pics or it didn't happen! 

Give me a week or so. We just pulled the ST10 back out to rebuild it. I promse, pics coming.

I'm skipping ahead a little, but we got the C5 setup on our truck with Frozen Rotors and Raybestos ST43 pads. The pads were pricey ($198), but I'm hoping we get 2 events out of them. I'm not real thrilled about the lack of compliance with our factory hoses, so we'll probably spring from some stainless braided lines.

We did something a little different on the hub. We drilled it out with a 39/64 drill bit and used 1/2-20X3" ARP bullet-nose studs. Since our wheels fit the Chevy and Ford bolt pattern, and since we are running a Ford 8.8" it just makes sense.

Looking good.  It looks like you still have the bars bracing the sides of your bumper in front of your front tires - there's another pound or 2 of weight loss - I ditched mine 

im not familiar with the rules but do you even need the stock bumper?
tubular beam would be lighter

We could ditch the bumper and go tubular, and could ditch the brackets, however the bumper gets used, a lot. As in, multiple times per race. We've had to straighten it after each event, necessitating the need for the supports. It is amazing how much contact happens and how much they "allow."

Also, our our cooling duct intake is in the front bumper, and the bumper also retains our ability to use the front air dam (think aero). We are getting ready to add more plastic below the front factory air dam for more aero. Since we use the front bumper a lot, it saves us time in not customizing everything, especially parts we can cheaply and easily replace at Pull-A-Part.