Confusion on RR spring rubbers as night goes on?

[Zkessler16]

as night goes on I will drop right side bars down 1 hole each.Drop j bar on pinion 1. And if really slick take j bar up 1 on frame Change my shocks adjustments for the slick. Some people say pull RR spring rubbers as it gets slick n some say add in as it slicks off? Adding rubbers will make it a progressive rate which would be good in the slick correct?

[grt74]

they are doing other things too, not just rubbers only

[MasterSbilt_Racer]

Just as was the case in 1995, your adjustments will need to take track configuration into account, and what the car is doing.

For example, stiffer lf spring does nothing when that tire doesn't touch the track.

[Jking24]

Very dynamic situation their. As masters said track configuration has alot to do with it. But from the sounds of it all your normal adjustments are based around being out of the fuel(decelerating) during turn in. This narrows the window a little bit. Speaking in reference to the rr While adding rubbers increases rate witch technically creates mechanical grip. It also reduces roll which can inturn reduce grip/ sidebite. So it's a bit of a double edge sword. Their really isn't one correct answer especially with the amount of load that has become common in today's setups

[dirty4life]

Why is it that dirt guys don't use preloaded on RR like on pavement?

[MasterSbilt_Racer]

Why is it that dirt guys don't use preloaded on RR like on pavement?

Who says they don't?

[dirty4life]

just asking because every time I ask people around here, they tell me it won't work. I thought it would make more sense to help control static and dynamic #'s………..

[BNaylor91s]

Some guys I know are going to bumps on the RR with a softer Initial rate. For example a 175 with a 75# bump instead of a 225 with a rubber

[MasterSbilt_Racer]

Some guys I know are going to bumps on the RR with a softer Initial rate. For example a 175 with a 75# bump instead of a 225 with a rubber

There is where a linear bump actually makes sense in my mind. I used to have to remove/add packers on my multi-RSW setup on the 33b car all the time. That rate of a spring would be much more forgiving, but less consistent on dynamic geometry. Keith Masters got me in the ballpark. That yellow 71, with Don driving, was ahead of the game.

[Jking24]

There is where a linear bump actually makes sense in my mind. I used to have to remove/add packers on my multi-RSW setup on the 33b car all the time. That rate of a spring would be much more forgiving, but less consistent on dynamic geometry. Keith Masters got me in the ballpark. That yellow 71, with Don driving, was ahead of the game.

It's ashame they've lost their way currently. Hudson proved that he wasn't the problem this weekend

[CCHIEF]

as night goes on I will drop right side bars down 1 hole each.Drop j bar on pinion 1. And if really slick take j bar up 1 on frame Change my shocks adjustments for the slick. Some people say pull RR spring rubbers as it gets slick n some say add in as it slicks off? Adding rubbers will make it a progressive rate which would be good in the slick correct?

Usually as you add rubber to RR you decrease Ride Height load. Decent initial rule of thumb, keep RR 1.5 or 2" (from ride height) compressed load the same with the increased spring rate. Looking for same travel, just get there easier and stick RR beyond that travel. Typically we don't move any 4 link or panhard mounting points...ever except RR lower for tight corner/high bank tracks. We Only adjust right side wheel loadings, spring rates (rubber from RF to RR), and RR trail. Also LR extended load. Rear spoiler and stagger too if needed.

[King1]

I was with a car at the Lucas race at PRP and we discussed the adjustment for the race and the driver said it was right getting in when he took the mega arc. The owner added spring rubbers to the RR, which I questioned it because I would tighten him up. Then he raised the jbar 1/2 inch and lengthened the left side rods and I just knew they would go backwards. They went from 14th to 4th and had a 3rd place car.
I totally wouldn’t have done it but that’s why I wouldn’t have made the show

[MasterSbilt_Racer]

King,

If I have the car right, he didn't advance at all for the first 18 laps. I'd say tire deteriorating and track came to him.

[smartguy13]

The other thing to consider in this question is the starting point of the car. I think the main question for the thread is rooted in the idea that the car is right to begin with when the track is heavy. Could be that the car in the situation above was not quite right and they took a swing to fix the handling issues AND adjust for the track all in one swoop, seemingly making very odd adjustments just for the track slicking off. Not saying that this is the case, but something to consider.