Launch problem [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: Launch problem


Strokethis
09-20-2005, 11:05 AM
:rolleyes: I have a 2004.5 CC SB LLY. PPE 175hp Enforcer w/ PPE Xcelerator stacked. I can never 4x4 launch without the front end going crazy, also when I pull at the local truck and tractor pull it wants to go crazy even with the torsion bars all the way down. I have already broke a tierod and when that broke it slit my outer CV axle boot. What can I do to solve this.

Micheal Tomac
09-20-2005, 11:29 AM
For pulling you need to hang weight or strap the centerlink along with lowing the torsen bars. What tires and rims (width & backspacing) are you running?

ratlover
09-20-2005, 11:48 AM
Also for drag racing you need to keep the front end from coming up. You running stock shocks I assume? They suck for racing..........

Slick
09-20-2005, 11:53 AM
Get some aftermarket tie-rods from fabtech, or some Sleeves from Super Diesel. This will solve the breaking tie-rod problem but it won't fix your toe-in.

Strokethis
09-20-2005, 12:08 PM
285/75R16 on 16x10 Mickey Thompsons

How do you strap the centerlink.

ratlover
09-20-2005, 01:14 PM
I'm betting sleeves(or differnt tie rods) and controling how the truck launches will fix your woes at the drag strip.

Buzz
09-20-2005, 02:53 PM
I have the same problem as you. I run 285/75/16 and aftermarket wheels with tie rod sleeves and can not launch 4x4. All over the place on launch and Front tires squeal from the toe in all the way down the strip. I havent had the chance to run with the TB lowered all the way and straped yet. They are still adjusted the same as when i bought the truck new with a recent alignment.
With the stock tire and wheel combination i never had any problems. it must be the backspacing. I should have kept the stockers.:(

ratlover
09-20-2005, 03:22 PM
I bet if you put the nose down and kept it down you would have better results launching;)

Deadeye
09-20-2005, 06:34 PM
I have the same problem as you. I run 285/75/16 and aftermarket wheels with tie rod sleeves and can not launch 4x4. All over the place on launch and Front tires squeal from the toe in all the way down the strip. I havent had the chance to run with the TB lowered all the way and straped yet. They are still adjusted the same as when i bought the truck new with a recent alignment.
With the stock tire and wheel combination i never had any problems. it must be the backspacing. I should have kept the stockers.:(

Your problem is exactly why Super Diesel makes a straight centerlink.

Strokethis
09-20-2005, 08:34 PM
How do you strap the centerlink

ratlover
09-20-2005, 10:12 PM
I have cut 1.6X 60's on street tires and have seen trucks 60' even better with slicks on all 4 corners with just sleeves. At the strip center links ect are uneeded IMO.

Take a look int the truck pulling section.....I think there is some talk and pics of straping.

IdahoRob
09-20-2005, 10:43 PM
Keep lowering air pressure until she bites. I run mine around 32psi and have the bars lowered all the way. I've pulled a 1.7 60' without N2O and just the sleeves.

Buzz
09-21-2005, 10:27 AM
This is what I found on another post. Thanks Tomac!

You're want to take a small 1" or so wide ratchet strap and use it to pull down on the centerlink (the pitman and idler arms are hooked to it). To do this, first take off the plastic skidplate and aluminum front differential skidplate. Then hook one end of the ratchet strap (J-hook or S-hook) to the backside of the crossmember (the one that the lower a-arms hook to) and run the strap on the underside of the crossmember then up and around the centerlink and back down and back under the crossmember then hook the other end of the ratchet strap to the backside of the crossmember. Then ratchet until it's as tight as you can get it. You should see the centerlink move down (toward the ground) as you're tightening the ratchet strap.

Deadeye
09-21-2005, 11:33 AM
ratlover;
not to argue, but every time I have launched the front end jumps up and to the left. Was nerve racking on the strip where there was a concrete wall next to it :(

Since installing a centerlink the truck launches nearly straight and "jumps" less than 1/2 of what it used to (4x4 launch).

Also, I have seen a lot of other trucks jump up and to driver's side at strips when they launch. However, I suppose, for other reasons, some trucks do not have the same problem?

ratlover
09-21-2005, 12:15 PM
a center link may work. I'm not saying it dosnt. But I decided for my application it wasnt the answer. Its a trade off. $$$+less turning radius for tha ability to not have the tires bow if you launch hard with the torsion bars in the air and your truck isnt reacting right. I decided I wanted the torsion bars down regardless and I didnt want to drop the coin and what I was doing works just peachy IMO as an added bonus my turning radius didnt dimnish witch is important to me persoanlly for plowing. Different strokes. Some may find that its the answer for them. Ask anyone that has seen my truck launch when I actually have my spray dialed in and I dont blow the tires off and skate sideways how my truck leaves. I also have 55k on my 100% original factory front end. Only addition is the SD sleeves.

I have no idea what it does at the pulling track. IIRC tomac ran a set up similar to mine with just straping the front and then moved to braceing the center link. Might try and talk to him. He is one of the resident pulling gurus.

If your truck is "jumping" you have a problem in your suspention set up. Tires towing in and the vehicle rising are 2 different things. Now if your nose rises up your more likely to bow in and its effects will be more noticable. Thats were the link will help.

JMO, take it for what its worth.

Slick
09-21-2005, 12:19 PM
It would be worth a shot to at least try it with the bars all the way down. If that doesn't solve the problem(I bet it will) maybe look into a center-link. I would check everything possible though before spending the money on one.

Deadeye
09-21-2005, 12:35 PM
I have read about turning the Tbars down but have never done it as I don't do near the amout of draggin as others. . . . also I have a lift kit and 35" tires and a handshaker so I will never get extremely fast (14.5 best I've done). (Philip you may have seen my truck at IRP) it also has other mods including ranchhand bumpers and weighs about 7700#. Anyhow,

Mine is a daily driver also, and have had the centerlink quit a few months. As far as the turn radius, while I have not measured it before and after, what seems to the the other side of the coin, is that it keeps both tires parallel so on a tight turn both are leaning on there edges. I tends to wear the tire edges pretty fast. So I try to avoid tight turns.

I do like the stability which it gives my truck constantly. Anyhow, next time I will try a launch with the tbars turned down and see how it works for me.

Cheers,

Buzz
09-21-2005, 12:38 PM
Turning radius is very important to me. Its already hard enough to park this thing in a parking lot. I am going with the cheap solution and see if that works for my truck.

BTW when you strap the centerlink you are not taking a risk of it pulling the link off is it?:eek: That would be real bad!!

ratlover
09-21-2005, 01:28 PM
For some the sd link is a perfect fit, seems to be for you deadeye, for some its not. All depends on your application :)

Maxter
09-21-2005, 02:51 PM
I have the same problem with my 305x70x16 on 16x10 pro Comp. I Broke my driveshaft 2 weeks ago while pulling because of the crazy front end. With 265s on stock rim I have no toe-in problem with the front-end strapped.

It seems that the combination of wider/higher tires, 10 inches wheel and a lot of backspacing render the front end uncontrolable with just sleeves and strap.

I had no more success at the dragstrip nor at the pulling track.