Taking the Duramax to the Drag Strip

[Dannyboy]

I've decided to see what I can get for a 1/4 time Stock before I do any Mods. My Plan is to Pre Load the Turbo on the Launch and Leave the Truck in Tow Haul so the RPM's will stay higher. Any Suggestions?

I hoping to run around 17 seconds? What do u guys think for a time?

[Kennedy]

To get a good launch, you'll need to use 4x4. At stock power levels you may be ok without lowering the front end, but don't get carried away on the launch. We typically lower the torsion bars (count the number of turns so you can return to same point) so the truck launches straight and nothing breaks...

[Dannyboy]

I was planning on doing a 2WD Launch because I really don't wanna take a chance of breaking something.

[BMDMAX]

2WD launches are tough, even at stock power levels. I'd expect 17 to 18 second 1/4 mile runs stock depending on your experience level at the track.

If you lower the t-bars you can do a decent 4WD launch with low risk.

[Dannyboy]

First time going to the strip. I've been playing around with the launch RPM's around town today. I figure i'll launch at 1800 RPM's. That will give me a little bit of wheel spin. I don't know anything about adjusting the T-Bars.

Thanks for the Replys!

[Florey]

Some one can correct me if I'm wrong, but I really don't think that launching in 4x4 would make you much more prone to breaking something in your stock drive train then in 2 wheel drive, and you will like the results a lot better. Lowering the T bars is not a big deal, just make sure to count the turns so you can tighten them back up. I don't bother doing it to mine, but mine is stock height and I run 265 TOYO's. I do have braces and sleeves on my tie rods and ends. Mine launches very straight and I launch much harder than what you are going to do.

[BMDMAX]

Some one can correct me if I'm wrong, but I really don't think that launching in 4x4 would make you much more prone to breaking something in your stock drive train then in 2 wheel drive, and you will like the results a lot better. Lowering the T bars is not a big deal, just make sure to count the turns so you can tighten them back up. I don't bother doing it to mine, but mine is stock height and I run 265 TOYO's. I do have braces and sleeves on my tie rods and ends. Mine launches very straight and I launch much harder than what you are going to do.

Without proper reinforcements on the front end 4x4 high boost launches at stock heights will break things, especially with larger tires. If you are stock, lowering the torsion bars is critical to maintain tie-rod and CV angles.

High boost launches on slicks in 2WD is arguably harder on the rear diff than 4WD since you don't have the extra traction and drivetrain to absorb the load. When I asploaded my Gov-Lok it was cracked in places I never would have believed.

[Buck]

If you spin the tires(2wd) forget it, that costs a lot of time. Like the previous guys said 4x4 launch is the best way to get a solid baseline.

I always remove the torsion bar bolts completely (I put them in the center console, so they don't get lost) when racing or pulling. First, measure the amount of bolt sticking out of each side and WRITE it down for reference. It is best to try to get the tie rods as level as possible, they are the weakest link.

Cognito motorsports makes pitman and idler arm supports they are a very good investment. They will prolong the life of the pitman and idler arms(if they are installed when new or near new) and helps resist rotation of the centerlink.

[Kennedy]

Ubet, we stock the SD sleeves, pitman/idler supports and new pitman/idler assemblies...

[fourtenposi]

I have run my truck(05 gmc 2500hd 4x4 ext cab) in stock form when the race car broke(needed the points) and it ran a 10.80 in the eigth which converts to around 16.80's in the quarter. Does your truck have the LBZ motor? I would expect you to run a little faster if that is the motor you have. I used 4 wheel drive. I only launched at 1400 rpms. I found that the truck was really inconsistant. I didn't run it in tow/haul mode, would it run faster in that mode?

Thanks