SOOOOO close, but not quite there.

[nubuilder]

I wish I could run my truck at a track.

I bet if you got a Black Bear tune, you'd be into 13.8-13.9 most definitely. Airing down the backs gives you more surface area, but what does airing down the fronts give you?

 

[Texas Jim]

I wish I could run my truck at a track.

I bet if you got a Black Bear tune, you'd be into 13.8-13.9 most definitely. Airing down the backs gives you more surface area, but what does airing down the fronts give you?

Dan will verify or not...but I think he has a BB tune.

He uses 4 WD to take off...so letting down the fronts, also gives a little more surface area and makes the tires less HARD, so hopefully he will get better traction.

Thats my opinion, anyway.

 

[Matt_]

Dan, what kinds of springs/shocks are you running?

Might even want to consider some air bags for the rear if you tow anything. You can bump up their pressure to prevent the rear from squating during the launch. You're a mtb guy... its like pedaling effeciency between a full suspension and a hardtail.

Same logic works for the front, you dont want your front to lift up... doing so just means that some torque is being used to raise the front as opposed to moving it forward. This may not be much of an issue though because I think you have your torsion bars cranked... so your suspension probably doesn't have much more movement.

Edit: i also wouldn't air down anymore unless you know that traction was an issue... ideally you want as much psi as you can such that you don't lose traction. Beyond that, you're just adding unnecessary rolling resistance.

 

[DV2000NJ]

I'd be impressed if his truck breaks decently into the 14s but id guess low 15s. I could be wrong though

We should put a trip together for a test & tune night. Think Umberto will run his truck?

Maybe ill get my "winter" wheels and tires early so i can run with them on (im going back to the coopers after the MTs are done and getting the P-rated 275/60/20)

I'm with you there, I'd be surprised to see 14s. Really all he has that makes any difference is a tune, and he's running 35s with 4.10s, which is going to be TERRIBLE off the line. Not to mention a lifted CCSB probably weighs in north of 6k lbs. With stock tires/wheels, I think he could easily be into the 14s, but the 35s/4.10s is going to hurt him big time.

And I doubt Umberto would drive down to Atco, it's about 2 hours from him.

I wish I could run my truck at a track.

I bet if you got a Black Bear tune, you'd be into 13.8-13.9 most definitely. Airing down the backs gives you more surface area, but what does airing down the fronts give you?

Dan will verify or not...but I think he has a BB tune.

He uses 4 WD to take off...so letting down the fronts, also gives a little more surface area and makes the tires less HARD, so hopefully he will get better traction.

Thats my opinion, anyway.

All correct. Thanks for saving me the typing.

Dan, what kinds of springs/shocks are you running?

Might even want to consider some air bags for the rear if you tow anything. You can bump up their pressure to prevent the rear from squating during the launch. You're a mtb guy... its like pedaling effeciency between a full suspension and a hardtail.

Same logic works for the front, you dont want your front to lift up... doing so just means that some torque is being used to raise the front as opposed to moving it forward. This may not be much of an issue though because I think you have your torsion bars cranked... so your suspension probably doesn't have much more movement.

Edit: i also wouldn't air down anymore unless you know that traction was an issue... ideally you want as much psi as you can such that you don't lose traction. Beyond that, you're just adding unnecessary rolling resistance.

Running in 4wd, you're right. Being an ext. cab 4x4, it really doesn't transfer much weight to the rear, you can see that in this video:
[YT]2nh5tbuHzSM[/YT]

If I were running in 2wd though (which I plan to do a few times with a set of slicks if I can get my hands on them), the slight loss of efficiency that comes from that initial weight transfer is more than made up for in additional traction.

You can also see in the above video that I was having traction issues, that's why I aired down this time (I was still running 35psi in the front, and 30 in the rear, I usually run 40 all around).

 

[Matt_]

yeah lookin at that video your truck barely squats so its a non-issue. I've seen trucks where the bed drops down a good 2-3" on launch... it looks cool, but really hurts the time. As with anything there's always an optimal setting.... too stiff doesn't allow enough weight to transfer and requires even lower tire pressures which will hurt once out of the hole whereas too soft transfers too much.

 

[NWSCREW]

LOL, The guy in the black stocking cap, is telling his friend "Dude!!! That truck is beating the crap out of the Camaro!!

Good job, that is fast for a heavy truck....

 

[drperry]

Sixth, and best run:
14.048 @ 95.14 with a 1.944 60'

You should have stripped down naked after this run and maybe chucked the passenger seat. When you get that close I would have gone around and started pulling off all kinds of odds and ends off trying to get 13.99.

I pissed before the run, folded in the mirrors, and pulled the passenger headlight. (both times with the headlight out I seemed to run slower, though ).

If I hadn't put those 14 gallons (~80-90 lbs.) of gas in, I think I would've had 13s easily.

Aerodynamics!