Ballast Location

[sackracing]

Some of the builds I have looked at on Yellowbullet use steel containers full of shot. I have a metal rack full of steel plates in our maint. shop, I'm going to cut some 25 lb. plates and stack them. I'll drill and tap them for the stack and use flathead 1/2" socket head bolts.

 

[sackracing]

What I have going on shock-wise is the front is rising fast and falling fast.

 

[Mike E]

Does it spin before the front end comes back down or after?

 

[sackracing]

last time out was the only time it spun, and it was after, like the suspension unloaded

 

[sackracing]

 

[Mike E]

That's tough to make a guess at without seeing some datalogs. It could be from a lack of power, but at 10lbs. I doubt that's it. Because you said you loosened the compression on the rears, I would look to see about tightening them back up. You could be bottoming the shocks and springs and then unloading them quicker than the rear shock can control. What rate rear spring did you put in it?

 

[sackracing]

The above pass was with everything at nominal. All settings in the middle.

 

[sackracing]

I do not remember the spring rate, but it's on the spring. I'll have a look when I get home.

 

[johnplogii]

What RPM do you launch at?

4200-4300 works good for my car.

 

[forcefed3.8's]

I am running 17psi in my 325 hoosiers 1.32 60' off 5 psi, 1.35 off 3 psi footbraking. I am using cheapo comp engineering drag shocks 60/40front, 50/50 rear.

 

[sackracing]

The rear springs are 12-130 QA1s.

When are you going to get to BG, John?

 

[johnplogii]

I'll be there sunday night for the whole week.

 

[johnplogii]

Looks like you could add some droop travel up front too until you get the thing to hook well. Just be real careful launching it that hard cause it may go right on the bumper. You must have limiters on it?

 

[sackracing]

It has limiters, about 4 inches of travel right now. I might pick your brain some at BG if you don't mind.

 

[johnplogii]

I don't mind at all. The car must sit pretty low then, 4 inches should be plenty. I'll be down along the river where I'm at every year.

 

[sackracing]

I'll be by

 

[Dusty Bradford]

If it hooks initially and then spins after launch the front shocks are too loose. Run compression on full tight and extension may need to be full tight as well depending on how quickly it rises. What it's doing is bouncing off the travel limiters. More travel and a slower rise will help keep the nose up and the rear planted. It sounds like you did go backwards on the rear shocks as well. Rear shock settings aren't the same for every car. Settings are opposite depending on whether the car squats or seperates on launch.

 

[sackracing]

Should I set it for full travel?

 

[sackracing]

Before I put it back on the ground I set the front rebound two clicks from full tight, the rear compression is at full tight and the rear rebound is at two clicks up from middle.

 

[Dusty Bradford]

Never take any travel out of it unless it's trying to wheelstand. If you have extension on front shocks full tight and it's still doing a wheelstand, that's when you take travel out. I run my compression on the rear at 50% and extension at 50-70% depending on track conditions. That's why every car is different. If my car spins at the hit, I can soften the compression a couple clicks on the rear and it will go down the track. On a slick track I may run my compression 2 out of 8.