The One Lap Truck

I don't have a truck, I have a tire. A single 325/30-19 Hoosier takeoff from a friend, and this is where it starts.
The plan is acquire a 2007-2010 short box single cab Chevrolet or GMC truck this fall and prep it for One Lap of America 2017 in the truck/SUV class. The tire is to check clearances and make some educated guesses. The first year will be pretty gentle. Get it out there and functioning and learn a bunch about it while still using it as a truck. Eventually we'll add grip, brakes, aero, power, lots of stuff.
I'm sort of calling myself out by starting this thread. It's time to actually build something.

i had a friend who had a crew cab short bed (dont know the exact year but it was the same you are talking) and he dropped it and put some wide wheel/ street tire combo and for a full sized truck it handled like it was on rails, it did surprisingly well in the twisties.

He had the 6.2 and with just HEI and a tune it would mooooove.

One thing to look out for is that they are speed limited to ~100 due to drive shaft issues, so if you plan on going faster then that then its something you will have to look into.

You have more build threads than anyone else on here by a sizeable factor. This is a good thing.

1) Awesome

2) Learn me more about this 325-30-15. Did you mean 19? That hole looks larger than 15"

I think you should turbocharge it. Because why not.

In reply to mazdeuce:

you no good, low down dirty sob. This was MY plan. need a driver?

You know I'm interested. 5.3 all things. Or 6.0 or 4.8.

ProDarwin wrote: 1) Awesome 2) Learn me more about this 325-30-15. Did you mean 19? That hole looks larger than 15"

Yes, 19, I'll fix my post.

The 19 is an issue actually. It's a GREAT wheel size for sticky tires that will fit the trucks but they don't really make 19's in truck bolt patterns because they don't really make truck tires in 19 inch sizes. We're going to need to change to either 5x4.75 which will open up the world of Corvette wheels, or 5x120 which will give us CTS-V and BMW and a lot of other wheels. Before we make that choice we need an actual truck to put on scales. We know 5x120 will work strength wise because the V wagon is heavy and the sporty BMW SUV's are even heavier, but there is some question about Corvette wheels. The scales will help us decide.

Bobzilla wrote: In reply to mazdeuce: you no good, low down dirty sob. This was MY plan. need a driver?

My co-driver from last year in the V is on board rght now, but if a seat opens up you guys will be the first to know.

In reply to edizzle89:

I have a crew cab 5.3 with BIG sway bars on it and it's competent for what it is. Taking out that middle section of doors and lowering it something like four inches should help a lot. These trucks have pretty good suspension geometry in front and enough of them have been lowered that there are a lot of solutions on the shelf.
I know these trucks fairly well and the LS platform means fairly unlimited power potential. The majority of the single cab trucks I'm seeing are 4.8 trucks but that's not a huge deal as we want to go bigger than 5.3 anyway. We'll decide about power later, it's kind of the easiest part of the whole thing.
The speed limiter will be an issue. I need to read up on driveshaft harmonics and see if I can get away with raising it on the short trucks (shorter driveshaft) or exactly how I need to approach it.

yeah my 2008 I had tons of plans to up the mph limiter. until i started finding videos of the driveshafts exploding on dyno's when this was done.

Do you not want crew cab for the extra space? or are you planning on tieing up your codriver and letting him "sleep" in the bed of the truck during transit?

a 5.3 with 4.8 innards with turbo will net some crazy high revving HP btw... (destroked ls look it up...)

If I recall correctly, some of the years had drum rear brakes instead of discs so keep an eye on that.

All of the NNBS 1/2 tons had drums but it's fairly trivial to backdate to factory disks. We'll be moving to bigger brakes on all four corners so it's not a huge deal.
The internet reports that the crew cab is something like 800lbs heavier than a single cab. It also has a much shorter wheelbase at 119 inches. I'm pretty sure we can be comfortable in a single cab without too much trouble. It's not like we sleep that week anyway.

Mad_Ratel wrote: yeah my 2008 I had tons of plans to up the mph limiter. until i started finding videos of the driveshafts exploding on dyno's when this was done. Do you not want crew cab for the extra space? or are you planning on tieing up your codriver and letting him "sleep" in the bed of the truck during transit? a 5.3 with 4.8 innards with turbo will net some crazy high revving HP btw... (destroked ls look it up...) If I recall correctly, some of the years had drum rear brakes instead of discs so keep an eye on that.

Why wouldn't you just start with the 4.8? The difference in the 4.8 and 5.3 is stroke. They have the same bore. Now the 6.0L had the larger bore and longer stroke of the 5.3 so the 4.8 crank with some special rods would make a short stroke, big bore rev monster happy motor.

Also, I'd start with the 2002/2003 GMT800. The were lighter, still had the R&P front end, better aero/less frontal mass and still had the factory discs in the rear.At that point it's just stepping up the size/etc.

As for weight, my 06 CCSB 2wd is 5060lbs without passengers. So take 800-1000lbs off that for the shorter cab, less bed/frame etc and you're in the 4k range pretty fast

I am not sure the short wheelbase trucks have the driveshaft issues. The driveshaft is shorter also.

Just setback the engine and make the shaft even shorter.....

wvumtnbkr wrote: I am not sure the short wheelbase trucks have the driveshaft issues. The driveshaft is shorter also. Just setback the engine and make the shaft even shorter.....

Yeah, the issues are with the EXT cab/CCSB 1-piece driveshafts. IIRC, the two-piece shaft trucks weren't as quirky about the exploding driveshafts.

Bobzilla wrote:

Mad_Ratel wrote: yeah my 2008 I had tons of plans to up the mph limiter. until i started finding videos of the driveshafts exploding on dyno's when this was done. Do you not want crew cab for the extra space? or are you planning on tieing up your codriver and letting him "sleep" in the bed of the truck during transit? a 5.3 with 4.8 innards with turbo will net some crazy high revving HP btw... (destroked ls look it up...) If I recall correctly, some of the years had drum rear brakes instead of discs so keep an eye on that.

Why wouldn't you just start with the 4.8? The difference in the 4.8 and 5.3 is stroke. They have the same bore. Now the 6.0L had the larger bore and longer stroke of the 5.3 so the 4.8 crank with some special rods would make a short stroke, big bore rev monster happy motor. Also, I'd start with the 2002/2003 GMT800. The were lighter, still had the R&P front end, better aero/less frontal mass and still had the factory discs in the rear.At that point it's just stepping up the size/etc. As for weight, my 06 CCSB 2wd is 5060lbs without passengers. So take 800-1000lbs off that for the shorter cab, less bed/frame etc and you're in the 4k range pretty fast

http://www.hotrod.com/how-to/4-8l-crank-ls3-block-how-to-build-an-8000-rpm-ls-stroker/

basically rev to the moon.

I'm super dooper excited to see this because a race truck hits all the right notes to me.

Just checked NADA and the GMT900 is 350lbs heavier than the GMT800. 06 RCSB is 4089lbs, 2008 RCSB is 4418. OK, not a FULL 350lbs.... but close enough.

In reply to Mad_Ratel:

505HP, 432TQ and 8000rpm. God that would have to sound amazeballs.

I know and like the GMT900 trucks. I also prefer the front coils to the torsion bars on the GMT800 trucks. There are a LOT of power options and people have been building LS motors for long enough now that second hand parts are getting sort of cheap. I'll be keeping AC at heat and radio and all of that stuff that makes a vehichicle livible over long road distances.
There is a lot of talk about weights and driveshafts and what not on the internet. It's easy to get lost in other people's opinions of what will and will not work. I'm going to collect ideas and then ground truth them with weights and measures when I have the truck in front of me. For now I have my CCSB that I can poke around and measure and drink coffee and stare at.

You might want to do a search for Ron Adee and Ram Truck.

http://www.caranddriver.com/features/2005-cannonball-one-lap-of-america-the-four-second-factor

Hey mazdeuce, I wonder how hard it'd be to setup a XL sized Syclone with a Trailblazer SS transfer case.

https://youtu.be/a-kysLSIlEI

Ill just leave this here.

Chadeux wrote: Hey mazdeuce, I wonder how hard it'd be to setup a XL sized Syclone with a Trailblazer SS transfer case.

We are looking at splined front hubs to keep that possibility open.

In reply to 1lapdawg:

I talked to some guys about the tube frame Ram this year on the event. As far as they could remember that was the last time a pickup was entered although from what they remembered it was basically a full tube frame car wearing truck clothes. I don't think we're headed quite that far down the path of insanity.