Help, No forward drive center off.

[Smitty84]

We have a 08 Larry Shaw, the car just lights up the tires center off. We are debating using straight bar vs. j-bar, as we are currently running a j-bar. The track is 3/8 mile. Any suggestion? Thanks.

[TALON75]

What are you running for fifth coil shock and spring? Also check everything for binding

[Smitty84]

A 400 lbs spring

[FlatTire]

I'd stick with the j-bar. Those straight bars can make a car pretty erratic and when there is any moisture in the track you will have your hands full.

The best way to create "forward bite" is to maintain momentum. The way you maintain momentum is thru good side bite which in turn helps promote forward bite. A lot of times when you are
lacking forward bite on exit, its due to the driver being loose in the middle and he had to get out of the gas to keep from spinning. Getting in/out of the gas unloads/upsets the chassis and kills forward bite and
all the momentum you had.

So with that in mind are you lacking side bite in the middle? Whats the attitude of the car? Pretty flat, not up on the bars? Whats the rf doing? How do the rear tire temps compare to each other?

I'm assuming you are on the slick when you are lacking forward bite?

Here's what I usually do:
-As the track slicks off I like to move my 5th coil forward. It helps keep the car from tailing out as much from the middle on out and will aid with forward bite. I think the torque arms
on the Shaw cars are all the same. For the slick I run the 5th coil in the 3rd hole back.

-Also you can shorten up your right side 4-bars 2 turns.

-You can also put some more angle in the 4-bar links. The trade off is more 4bar angle produces more roll steer.

-Drop tire pressure 2lbs on the back tires.

Let us know the shocks/springs you are running.

[stevo]

Straight bar will make more foward drive to answer your question,but there is a trade off as stated above.

[Smitty84]

The car is just spinning on top of the ground. I will check and see what springs are on it. During hot laps when the track is tacky, the car is good. when the track rubbers up the car just lights the tires up. we are running bilstein shocks. We're gonna try something on the right front with stacker springs... but thanks for all these suggestions.

[TALON75]

400 is pretty stiff, specially if your on hard tires, might want to try 350 or even 325.

[dualdj1]

think they're right with dropping your 5th coil. sounds pretty heavy to me.

If you want to run straight bar, key is rake. Too much rake and it gets real erratic as stated, too little and you won't get much drive. It'll take you some testing to find out what works right for your car. When you find the rake you're comfortable with, then keeping rake constant and dropping bar on chassis and pinion will add more drive. It can work very well, we used it extensively (even in wet) for quite a while. It also likes a gas comp (traction) shock on LR, with a good amount of pressure (100-250 range).

[Matt49]

I agree with softer 5th coil. Harder the track, softer the spring. Harder the tires, softer the spring.

Also, too soft of a RF (a popular setup) can really kill forward bite because the car doesn't get enough dynamic wedge. You have to compensate for that somewhere. Something to consider and think about.

[JustAddDirt]

Also if they are a non-canister, no gas bulb Bilstein, they have a good bit of rod pressure from the gas.
I think 15-25lbs of rod pressure depending on gas pressure, witch also can kill side bite and forward bite. Been threw this on a modified. Sounds like you have the same problem a lot of people do on the mods in the slick. They have a new base valve shock for this.

[lindsey97]

I'm having similar problem on my car. I believe my trouble to be the car is rolling over too far on the right front. I know when i get to center of corner it is bottoming out on right front shock and I think it is unloading the chassis causing it to be loose out. I can "pat" the accellerator and get it hooked back up and its fast down the straight. Make sure your not bottoming out the right front, I'm running a '10 Shaw, it has two motor mounting positons and i have been on the high spot, just lowered it down to see if that helps stop some of the weight transfer, but looks like mother nature is going to delay the outcome for another week here. I have also increased my left side about .5 percent, that made some difference also. I believe stiffen right front and softening left rear can help with this also.