Questions about corner-weighting?

I have noticed regular questions about corner-weighting cars. Did you know that we have an article on that very subject?

http://grassrootsmotorsports.com/articles/understanding-corner-weights/

Thank you kindly sir.

But I'm still going to let a well-known shop in the Dallas area take care of it once my fancy coilovers are on.

Even if you have a shop do it, at least now you'll better understand the process. Plus learning stuff is fun, right?

David S. Wallens wrote: Even if you have a shop do it, at least now you'll better understand the process. Plus learning stuff is fun, right?

And useful. I was struggling to find pace to run with class leaders a few weeks ago at the Glen. I was questioning the driver, the dampers, the alignment, etc.

I came home put the car on the hub stands and scales... and found a 4% cross-weight descrepancy. Seems like a small amount. A 4% chance of rain is damn good odds you don't start on wets, right? In the case of balance... it's a berkeleyload. A little understeer one way and a little oversteer the other can cripple your pace at a fast track like the Glen.

To put that in terms of time - yesterday at the Glen I found the extra ~1.5 seconds PER LAP to put me on pace with the class leader from the race in June where I got owned. Simply tuning the ride height on two corners let me confidently get more power down earlier in fast sweepers. That is all it took. (well, that and adjusting my nutsack to take advantage of the extra grip) Who knew? Details matter!

That is awesome to hear. Yeah, 1.5 seconds per lap for basically free? Sign me up.

As usual, "^what GPS said^".

I'm literally about to go to the garage and check cross weights before putting the #51 Radical on the trailer to go to Summit Point. I shoot for less than 1%.

David S. Wallens wrote: Even if you have a shop do it, at least now you'll better understand the process. Plus learning stuff is fun, right?

Very true.

I figure learning beats forgetting stuff. I mean, I do plenty of that, too.

49.8 / 50.2 on the diagonals, 50/50 side-side.

I've always been fascinated by how much you can change the percentages just by leaning one way or the other in the seat.A friend of mine can change the side to side weight by over a percnt when he leans over to look at the readout- IT Sentra, 240 lb guy.

Belted in (or in that position) hands on the wheel. Let somebody else read the numbers.

One question has always hounded me with the corner weighting. I have read in several places that "you can't move the car's CG without physically moving/removing/adding components in the car" which makes sense to me. Tilting the chassis with minor tweaks of the spring perches can't be moving the CG around, but then what are we reading on the scales when the values change after the spring perch changes? It can't be the weight versus mass concept because the force of gravity doesn't change as we make adjustments.

On a similar note, do you try for the best cross/F-R/L-R balance you can get regardless of any minor ride height irregularities that may create, or is it better to set the ride heights where the rules limit them and then make the minimum change for getting cross weights equalized?

Obviously formula cars have to deal with spring rates/ride heights/bottoming the chassis on the track issues as well as corner weights, but the idea is the same (they just don't have as much inherent L-R imbalance as production based cars or even sports racers).

Streetwiseguy wrote: I've always been fascinated by how much you can change the percentages just by leaning one way or the other in the seat.

Exactly. I used to fret getting numbers absolutely bang-on. The OCD in me wants perfection.

But you can change the numbers even if your race-day clothes are different. Or if your body is shifting to one side due to the cornering.

I try not to fret it, and believe "close enough" is going to work out just fine.