RR load numbers

[shadowj38]

Rocket sent me their recommended load numbers for a blue front. They said their RR numbers can vary anywhere from 300-700. Can someone explain what track conditions you would want a lighter load like 300 and what conditions you would want 700? Thanks in advance

[Jking24]

300 is standard 700 would be for a fast track. But it's alot deeper than that

[shadowj38]

I appreciate your reply. I was hoping to get into a good discussion about this. I’m trying my best to learn this stuff but it doesn’t seem like many people will discuss it.

[RaceEngineer]

RR load is RR drive. More you run, more the rr drives the car forward. This makes it looser on throttle, typically. But, can tighten off throttle entry, typically.

[RaceEngineer]

The difficulty in giving absolute answers to most questions about these cars is that all adjustments have the possibility of effecting wheel load, steer, cg height, and lateral location of he rear track.An adjustment that effects wheel load and steer dynamically can yield different end results at different tracks. This can be because the car is driven differently or because the suspension travel is different at the same point on the track for the two tracks in question.

[shadowj38]

Race engineer I understand 100% what you’re saying. I was just asking about load numbers specifically. Given that everything else would stay the same, how does the load number effect the car, was mainly what I was asking. I guess I should have clarified that a little better. Thanks for your reply.

[RaceEngineer]

That's just it, everything else does not stay the same. Your ride heights will change when you change that load number.

[RaceEngineer]

Then, once you hit the corner and the chassis gets to it's roll angle, the RR and RF have gained a different amount of the weight transfer compared to when you had a lower RR pin to pin. This is assuming you have a simple 1 spring system on the RR and kept the same spring.

[Jking24]

On paper rr load at ride height may tighten off throttle (entry) but it generally does not because the added static ride height reduces weight transfer so the effect is generally overall looser not just on throttle

[RaceEngineer]

On paper rr load at ride height may tighten off throttle (entry) but it generally does not because the added static ride height reduces weight transfer so the effect is generally overall looser not just on throttle

Is weight transfer not a function of CG height and lateral acceleration? I agree it doesn't seem to be as noticable as the acceleration change, but physics say it should tighten.

[Jking24]

Is weight transfer not a function of CG height and lateral acceleration? I agree it doesn't seem to be as noticable as the acceleration change, but physics say it should tighten.

i guess i shouldn't have said reduces because while I'm not a very educated man i understand and agree with your point. I don't know how to say this correctly but it creates what i would refer to as a timming change in when the weight is beginning to be transferred and what direction. The only thing i know to compare it to in layman's terms is it's very similar to stiffening right side compression to slow the transfer of weight to the right sides ie. Creating a overall looser effect on entry. Maybe billet or someone a little more educated could explain it correctly. Now im not trying to pick any fights here but what i can say is spin your rr adjuster nut down a inch and a half and run hot laps

[billetbirdcage]

what i can say is spin your rr adjuster nut down a inch and a half and run hot laps

Just my opinion (worth nothing):

Doing that will loosen the car on the gas (usually for most people) and the argument/disagreement will come on entry. I find it does tighten off gas entry, however it's not noticeable to most people do to the fact that most are gonna do that when it's really heavy and they need loosened up. Part of this is because you are driving very aggressively and you're not out of the gas long enough (or may not be lifting at all) for it to be noticeable or register to the driver. Now if you did that and drove in and stayed out of the gas for a while (more like slick track racing), I think most would find that they are in fact tighter on off gas entry's.

[fastford]

its amazing how things have changed , 10 years or so ago , we were on a slick track and could not get any forward drive , the train of thought then was keep adding left rear bite and you would gain forward drive , which we did but didnt get good results , so i decided to try reverse wedge and made the rt rear 100lbs heavy , had to lower gear a little , but that thing would come off the corner like a bullet , that was with a 10 year old set up , man how things have changed........

[Austin34471]

Is weight transfer not a function of CG height and lateral acceleration?

and track width 8-)

[TwistedFrame21]

So would a guy want to start the night out with a 300 rr load number, and if the track gets slick later in night move toward the 700 number?

[RaceEngineer]

So would a guy want to start the night out with a 300 rr load number, and if the track gets slick later in night move toward the 700 number?

The dominant factor in that adjustment is on gas handling. So I would not.

[CCHIEF]

No, the other way.

[Matt49]

So would a guy want to start the night out with a 300 rr load number, and if the track gets slick later in night move toward the 700 number?

If you do that, it may help you a little getting into the corner but it is going to really hurt you coming off.

[TwistedFrame21]

Thanks, didn’t me to hijack just wanted to clarify

[billetbirdcage]

300 to 700 is a pretty big swing at one time. 100# change is pretty noticeable to most people and their cars, then again I've swung 300# and have people say did you do anything, lol.