Launch Help Please

[grandville455]

Guys , I had my converter restalled to 4200 was 3600 before, before i could bring it to barely 2000 then it would slowly flash to 35-3600 car left hard ,but was 60 fting at 1.78 in the heat, 1.70 was best in spring. Now I Can bring it up to 2500 and it flashes very quickly to 4200 then the car launches and about 4 feet out its spinning almost everytime, Same settings as before rear shocks at 8 on QA1's drivers air bag at 5 psi, pass at 12, tires at 19..26x10x15 M'T et drags still. have tried various things, The front is slowed to 60/40 now nothing has really helped. I did pull a 1.68 sunday morning, that was with shocks at 9 and tires at 16.5, but after that run right back to spinning and the car has picked up 3 tenths and two mph with the converter change, Do U think my shocks are wornout? My brother runs a camaro and his are set at 3 and its stiff as hell, mine u can still push a little at 9 even. Really don't want to go to a taller tire cause it will bring down my gear ratio. Only have a 3.42 and thats all i can get with this rearend, hence using the smaller tires and low gear set in trans to get it out of the gate which it is now, running high 11's in 90 degree heat with a spinning 1.75 60 ft! I don't have any close up video yet, will get some next race to help me se what its doing.

[John_Heard]

4' out does tend to sound like the shocks are either too loose, out of travel, or both.

Video would be helpful.

Do you have a way to see what kind of travel the car has on the shock? How far can you lift the rear end from rest to where the shock runs out of travel?

[grandville455]

John
U mean if I jack up one side to see where the shock is topped out and tire is coming off ground?

[John_Heard]

Basically yes - how much shock travel do you have in extension from setting at rest. If it's stock setup, you probably have plenty but it wouldn't hurt to check. The problem you're describing "might" be due to running out of shock travel (extension) - just something to check.

For example, if you find out you only have 2" of travel, then that might very well be an issue.

[grandville455]

John I took them off last night, but i can put one back on to check it, as i ordered the longer 2720 shocks again. I tried them before, but i took them out for some reason or another? I just think its hitting so hard now it has no extention . Here is a PIC of before and u can clearly see the C/E ones are longer.

[grandville455]

Here is a pic from sunday.. Launch is good at the hit, its after that it goes down,lol

[John_Heard]

Sorry - neither the pic of the shocks or the launch pic tells us if you're running out of travel. Like I said, if it's happening that far out (4') it tends to mean something is upsetting the car. Running out of travel in the rear, running out in the front too quickly (shocks too loose or not enough front end travel).... etc. If you watch it on video closely you might be able to get an idea.

[grandville455]

I know was just showing you as a reference of the difference in lengths etc.. I will post a video tonight of it when the shocks were at 80/20 and u could see it was coming up way to quick then it would top off and come down, now at 60/40.. I will watch video tonight to see if i se anything with them at that settings and post it also ok..

[grandville455]

John
I went out tonight and put the shock back on the pasenger side and let the car down at ride height, and with the air bag at 15 psi like i run I measured the shock, then i slowly jacked it up till the tire just started come off , and remeasured exactly 1" is all!I would say thats not good at all!.. Here is a couple of videos the first one is the 22nd and with front shocks at 80/20 back at 8 clicks , tires at 18 3/4... second video is the 29th tires at 16, shocks at 60/40 and the rear shocks at 9 clicks.. it definately looks better on the second one ,doesn't rise as quick, but it was still spinning, but after seeing only 1" of travel I would guess that isn't good! The 3rd video was back when it was running high 12 to low 13's, and thats with the C/E30/70 back and 80/20 front,hooked good then,but also was leaving at only 3-3200! The C/E shocks I am getting I will set at loosest ext and stiffest comp 30/70 again , and they will give me another 2" of travel. I will be getting a much better video of the car next race too see whats going on after the shock change, these are not that good to see. I talked to my gf and told her what i wanted next race :).. She didnt slap me ,lol

http://smg.photobucket.com/albums/v209/ ... 104307.mp4


http://smg.photobucket.com/albums/v209/ ... 165236.mp4


http://smg.photobucket.com/albums/v209/ ... 094631.flv

[John_Heard]

Can't see shit in the 1st two videos, last one is ok. On the last one, you can see it compress the rear shocks when the front end comes up - so you weren't getting the benefit of that weight transfer. Best I can tell it didn't do that in the first two vids but hard to tell?

No, 1" isn't enough travel. You might be getting by with that travel as the compression is so soft it can't deal with the weight transfer dropping the rear instead of planting the tire.

Sounds like you have some things to play with, get some more travel like you're planning.. Oh & be nice to your GF, you don't want to have to go to the track alone! but good video would help.

[grandville455]

Yea Those first two do suck!, lol.. I will get good video next sunday and repost them, also I will see what it does after i get these other shocks installed. Tis all came about after i restalled it to 4200.. its hitting alot harder now!

[sc racing]

It looks to me like your rear suspension is not working at all, its not separating its compressing I would start looking at the angle of your rear control arms uppers and lowers. Ill bet they all point up in the front. Plot out your IC and your anti squat and you will see the IC is way too long and the antisquat % is very low.Thats my guess

[grandville455]

It looks to me like your rear suspension is not working at all, its not separating its compressing I would start looking at the angle of your rear control arms uppers and lowers. Ill bet they all point up in the front. Plot out your IC and your anti squat and you will see the IC is way too long and the antisquat % is very low.Thats my guess

Question's for you,
1. My rear sway bar is tight against the bottom of the carrier could that have a effect?
2. How do u plot out the IC and anti squat?
3. Or is it squatting in back cause i only have 1" of travel on my rear shocks?

[sc racing]

sent you a pm

[grandville455]

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