Drag Racing on IRS Sucks.

[Marc0779]

The gentlemen who is going to set my car up and I had an in depth talk today. They are working on it this week. Does anyone know if taking the camber to one degree more than spec negative without any other adjustments will change the toe? Regardless we are going to see what happens if all four need -1 more, since I have the full set of AAD adjustable arms front and back.

If that is the inside of that tire, what does the other side look like? What did the track look like?

On a demon you want to set the rear camber to 0 the rear is locked solid and does not squat,on a charger or challenger hellcat .5 positive,all 4 upper arms need the same adjustment,set toe in rear a little toe in when it moves foward on launch it will be zero. The front wheels can be put to spec it has very good bump steer from the factory.

 

[Marc0779]

On a demon you want to set the rear camber to 0 the rear is locked solid and does not squat,on a charger or challenger hellcat .5 positive,all 4 upper arms need the same adjustment,set toe in rear a little toe in when it moves foward on launch it will be zero. The front wheels can be put to spec it has very good bump steer from the factory.

top pic is good hellcat,charger setup,bottom demon

 

[Marc0779]

top pic is good hellcat,charger setup,bottom demon

Rt hand pic is demon have driver sit in car,demon spec on rt goes down to .2 positive with driver weight

 

[16GoManGoHC2]

Is that worn in the inside or outside?

Inside

 

[motorhead]

The gentlemen who is going to set my car up and I had an in depth talk today. They are working on it this week. Does anyone know if taking the camber to one degree more than spec negative without any other adjustments will change the toe? Regardless we are going to see what happens if all four need -1 more, since I have the full set of AAD adjustable arms front and back.

If that is the inside of that tire, what does the other side look like? What did the track look like?

For a road race car more static camber is the go-to, but modern suspensions have lots of favourable camber gain built in - so more may not be better. It is the same condition we are fighting here with a drag application. The rear suspension in a non-Demon inherently wants to squat and gain negative camber. As Marc pointed out above, which goes back to the first couple of posts, you have to set your suspension settings in a way that works counter to this effect whereby you program the suspension to be where you need it at the hit under load.

Here are the "off the truck" measurements for my car: https://www.hellcatforum.org/threads/2019-poverty-pak-widebody-challenger.3128/post-13733

-1° camber in the rear and 0.14° total toe isn't a bad starting point. So it is a case of raising and locking out the rear suspension. How? Weight loss is one way (1/4 tank of gas, gut the trunk, pull the back seats) and mechanically raising the car (booster blocks or taller springs) is another.

Once I get done farting around with seasonal prep I can toss my camber gauge on the wheel to see what it takes to get the car closer to zero or even positive camber in the rear.

 

[Jack_Toepfer]

Is it worth looking at the Demon? I imagine it's suspension setup largely consists of compromise for a street car with a sway bar.
If we can trick the BCM into thinking it's got Demon suspension, we should be able to trick it into thinking that it is plugged into "anything" and just buy the best hardware for the job, and I don't know that the hardware best suited for drag racing has any plugs on it. It's been a while since I did any of this stuff though, and none of those cars had BCMs ... but they had their share of demons.

 

[motorhead]

Is it worth looking at the Demon? I imagine it's suspension setup largely consists of compromise for a street car with a sway bar.
If we can trick the BCM into thinking it's got Demon suspension, we should be able to trick it into thinking that it is plugged into "anything" and just buy the best hardware for the job, and I don't know that the hardware best suited for drag racing has any plugs on it. It's been a while since I did any of this stuff though, and none of those cars had BCMs ... but they had their share of demons.

I think the Demon is a great example of a street driven street car that you can drag race. But, as indicated if you are going to start swapping parts it is either go full Demon or get a bunch of aftermarket parts - no need to mix and match. Or a couple easily reversible tweaks to a HC/RE - which is my focus at the moment.

But, if we can get that alfaOBD BCM scan I'll definitely integrate it.