Setting ride heights and weight distribution

[Anonymous24]

Im just looking to obtain some feedback. When setting ride heights and setting weight distribution, do you do this with driver in or out of the car? Also I have seen many racers remove the rear lower shock bolts and just let them hang during configuration of weight distribution. I look forward to your input. Also please explain why you prefer to tune in your particular manner. Myself, I have the driver in the car with the rear shocks fully mounted. If tuned with driver out of the car, the ride heights change, weight percentages change, and suspension component angles change.when the driver enters the car. Looking forward to discussing this topic with you all. PSIf you want to complain about me not sharing my credentials publicly, please refrain from posting on this thread. Its my right to withhold that information and I will continue to do so. Your ignorance will be ignored, much like the information you post that is either incorrect or improperly explained. YOU KNOW WHO YOU ARE.

[JHobbs26]

Is there a true right or wrong answer to this? As long as you can establish a good baseline off of how you scale/set up your racecar weekly then keep doing how you do it.

I set my ride heights, bar angles and scale it all 3 shocks unhooked. I would guess most people scale without a driver in the car, as most chassis builders are set to this. I unhook my shocks because with the aggressive split valving we run now and variable rod pressure on each corner it just make the scale process a little quicker.

[Anonymous24]

Is there a true right or wrong answer to this? As long as you can establish a good baseline off of how you scale/set up your racecar weekly then keep doing how you do it.I set my ride heights, bar angles and scale it all 3 shocks unhooked. I would guess most people scale without a driver in the car, as most chassis builders are set to this. I unhook my shocks because with the aggressive split valving we run now and variable rod pressure on each corner it just make the scale process a little quicker.Just looking for feedback from others. My experiense with scaling with the shocks unhooked is that once they are reattached, the ride height changes along with wheel percentages. I am firm believer that driver must be inside the car when scaling. Some chassis builders say driver out of the car but the down side to this is driver A is 6'2" 185lbs. Driver B is 5'6" and 265lbs. That's an awful lot of weight that goes unaccounted for. Especially when trying to achieve a well balanced weight distribution package. Every components that is bolted on the chassis has a center of mass including the driver him/herself. I'm the type of person that has to know every little detail of every component, engine, driver, ballast, battery, fuel cell etc. and their relationship to the handling of the car. I myself may go a bit in depth a little more than the other guy. But, do you think these top teams that are bad fast week in and week out arent going very in-depth in tuning their race cars? In my opinion, that is what it takes to be a Championship caliber team.

[Flyin Iowan]

most chassis builders have it set for a 200lb driver. if driver is heavier then that, say 215, then set 15lbs in seat. if hes less then add more left side % to your scaling. We are on dirt and the car is never set at ride hieghts when racing. like said above, if your base is good then dont try to do it any different. Theres a lot of paths that can lead to winning, everyone does it different. I scale with out driver because i want to be the one that checks ride hieghts and #'s and i cant do that from in the car, and sometimes its just me scaling alone

[charcoal01]

Anonymous, I see what you're saying and I can't say that I disagree with your logic on scaling the car as close to race resu as possible but the reality is most of us are like iowan and are working by ourselves. So sticking with a baseline with the driver or of the car and at least the lr shock unhooked is what tends to work for most of us. If you're lucky enough to have a dedicated crew guy knowledgeable enough to set ride Heights and bite properly then driver in car is probably preferred.

[speedbuggy]

Anonymous, I see what you're saying and I can't say that I disagree with your logic on scaling the car as close to race resu as possible but the reality is most of us are like iowan and are working by ourselves. So sticking with a baseline with the driver or of the car and at least the lr shock unhooked is what tends to work for most of us. If you're lucky enough to have a dedicated crew guy knowledgeable enough to set ride Heights and bite properly then driver in car is probably preferred.

I agree with this. I don't think it really matters if you always have the same driver. Where scaling with the driver would really count, IMO, is if you have different drivers using the same car, or you want to try to duplicate this setup on a different car.

[Mod77L]

I have always put some concrete blocks in the driver's area to simulate my weight. One block by the pedals, and the rest stacked on the seat. Not perfect, but since I usually scale alone, it is the closest I can come to being there myself.

Do your initial setup the way your chassis builder says to do it. After that, get the numbers with the car however you are going to be doing it weekly. Once you have your baseline setup, I don't think the exact method you use is good or bad as long as you use it the same way every time you have the car on the scales.

[MasterSbilt_Racer]

The ride heights should be correct when the car rolls to the lineup chute. That means they need to be correct with the driver in the car. Scale it however it takes to get what the builder wants.

[LM14]

I always scale a car without the driver (since he wasn't there), all shocks hooked up, air in tires as raced and with a pre-determined load of fuel (usually dictated by the chassis builder) and the correct ballast and offset wheels and ride heights. Just as the car will hit the track, minus driver.

We had a driver over 200# and most good chassis builders will give you numbers for that bigger driver. Same for a smaller driver.

Same for bar angles. Set them where the chassis builder tells you to as a baseline. He knows where his chassis settles to when you climb in it, he's already taken all of that into account. If your chassis builder gives you bar angles w/o driver and you put them in with the driver, you are not on his baseline and anything he tells you is wrong at that point. Don't try to overthink it.

Absolutely keep your shocks hooked up if they are gas shocks. Weigh your car then unhook the shocks and see how much different everything is. You can even put different gas shocks on and see a difference. Scale it as you race it (with the exception of the driver for me).

All that said, what it most important is to get a good baseline and be able to go back to it, good scaling practices. Level scales, correct offsets, stager, left and rear weight (only changed by physically moving weight, can't change with weight jacks unless you have a bind in your car someplace) and a good set or procedures. Your car will rise and drop, roll and bounce on the track. You are not simulating racing, you are looking for a good baseline to return to and deviate from as you make changes. Everything you have on a racecar is fluid, it's always in motion and you can't capture that with a Saturday night race team.

My only suggestion is to scale without the driver to simplify things, otherwise scale as you race so you know what your changes will do out on a race track and how to get back to square 1 when it all his the fan.

JMO,
SPark

[roundboy]

When i bought my car, i got it race ready and took it to the guy i got it from, VERY knowledgable builder and racer, he set it up to the builders specs, ride hights, bar angles, indexed the birdcages, squared everything, toe, caster/camber, everything just as it would hit the track and then set it on the scales and it was SPOT on.. now this was all without me in it and im 6 foot 275lbs.. car was little tight in the beginning but after a couple small changes, it was WAY better... this will be my third season in the car and that was the only time it has set on a set of scales since ive owned it.. now im very particular to keeping everything to builder specs on the car, but it is still fast and the easyest car i have ever drove.. the first two seasons of racing it, its won 8 heats, 1 feature and a semi all in about 25 nights of racing.. anyway, this season starts next week, its all right where the builder wants it and it wont see a set of scales... BTW, keeping fresh rubber under it does seem to make a differance...

[oldtrackchamp4x]

I also don't have anyone helping me, and i also do like several others on this subject. Unhook lf, rf and lr shocks. Have tire pressures and fuel level where they should be, set ride heights and then scale. I set my scale control box on a ladder right next to drivers door where i can see it and push the button for %s and weights and climb back out of car to make changes to car as needed according to builders specs. That way i have both sets of numbers with me in and out of car written down. I do it this way a couple times a year just to be sure it is where the chassis builder wants it. The rest of the time i scale with me out of car. I have all the numbers except ride heights when i am in the car but i allow for that also. Before climbing in car I slightly tweak ride heights so they will be on with me in car. I had someone my size sit in car to come up with those measurements. If that makes sense. Works for me JMO

[mudeater18]

- I scale with out driver because i want to be the one that checks ride hieghts and #'s and i cant do that from in the car, and sometimes its just me scaling alone

Same here.