The 4-link is usually set to ge tthe front tires off the ground and "transfew weight". To me, it seems like maybe you have something wrong in your shock setup.
The first motion is for the rear shock to extend, once this happens, you want the wieght to transfer, but then to "stay up on the tire". If you have adjustable shocks in the rear, tighten up the compression, and try more air in the tires. Looks like your squashing the crap out of the sidewall.
Kyle

 

Send your pdf to Bill@Gilsbachracecraft.com much did you lower the car and did you plot it out before or after you lowered it.Lowering the car substantially will move your instant center down quite a bit and with the power you have you will need to hit the tire fairly hard,raising the bars on the chassis will bring it back up,but I would like to see your plot.Where are your shocks set?Rear spring rates and length?Tire?Any info helps.

 

Send your pdf to Bill@Gilsbachracecraft.com.How much did you lower the car and did you plot it out before or after you lowered it.Lowering the car substantially will move your instant center down quite a bit and with the power you have you will need to hit the tire fairly hard,raising the bars on the chassis will bring it back up,but I would like to see your plot.Where are your shocks set?Rear spring rates and length?Tire?Any info helps.

Pdf sent. Lowered the car almost 2". Strange single adj.'s set on full soft. I tried bringing this up, but it seemed the 60's were falling off? They are qa1 springs at 150lbs. 14" long. Never scaled the car, but I do know it weighs 3350 with me in it. Front shocks are qa1 single adj.'s at full soft. 31x18.5-15 quick time pros, that I run around 10 lbs. in. Boy there sure is alot more to this than I really realized. I got alot to learn to say the least. I sure appreciate all of this help!!

 

X2 on more info needed.
For one, rear tire air pressure.

 

It seems you are under the assumption that your 4 link IC settings control weight transfer. This is only 1/3rd right. The three things that control weight transfer are Center of gravity, Power and Traction. While your IC may have effects on traction, it don't control weight transfer. It's a three way equation and you may get results from juggling any or all the parts. There is always a different way to skin the cat. Don't make them right or wrong.

To your problem. 1 You was ok with your launch before? 2You lowered the center of gravity. This probably lowered your IC. Guessing by the body roll you picked up after lowering, you was close to zero anti squat before dropping COG and front mounting points of 4 link. If you have no resistance to compression, you are likely to get body roll (twist). anti squat provides resistance to compression. It seems like you lowered COG with out compensating your two other parts of the equation. You now need more power and traction. While power stayed the same you may have gave up some traction from lack of transfer and lack of resistance to compress your rear. It's a matter of balance.You think your changing one thing but you are changing three.

 

To your problem. 1 You was ok with your launch before? 2You lowered the center of gravity. This probably lowered your IC. Guessing by the body roll you picked up after lowering, you was close to zero anti squat before dropping COG and front mounting points of 4 link. If you have no resistance to compression, you are likely to get body roll (twist). anti squat provides resistance to compression. It seems like you lowered COG with out compensating your two other parts of the equation. You now need more power and traction. While power stayed the same you may have gave up some traction from lack of transfer and lack of resistance to compress your rear. It's a matter of balance.You think your changing one thing but you are changing three.

Yea, I really liked the way it launched befor. It seemed to carry the wheels out a ways, not just pop them up and it ran it's best 60 ft's EVER at around 1.46. Now they are around 1.52. Boy you are pretty much right on the money! Before no antisquat, and no body roll. While I would LOVE to add more power, that probably won't happen for a little while again. baby on the way in 2 months. So the third thing is traction. That sounds EXACTLY right. I could actually pull the wheels a little on the street before, now I have had trouble hooking on the track! So now i just need to get the traction back? Now i just have to figure out how. You guys are really helping! This all makes ALOT of sense! (and no that is NOT sarcastic LOL)

 

Dropping the car 2" (lowering the 4link frame brackets) with a 54" instant center could drop as much as 40% A/S. Where before you may have been at 110% and the rear separating it may now be as low as 70% squatting hard. Measure everything accurately, plot it out and you will find the problem.

 

billyshope. Good webpage! I will take a look at the dimensions tonight when I go home and plot these out.

gilsbachracecraft, I sent a pdf. But I did not measure for the c/l of the cam. I will do that tonight. Thanks much guys!!

 

...and plot these out.

This not necessary. Just plug the numbers in the spreadsheet and let it do the "plotting."

 

gilsbachracecraft. Just wondering if you ever got that pdf?? Just curious.

 

Yes sir,I will get back to ya tonite.