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When does properly "weighting" each corner become important?
OK, so there have many threads through the years about how many of our cars aren't "level" from passenger to driver side. I didn't own my 88 for too long before I did a full suspensions build, and I noticed after the fact that the driver side was about 3/4 lower in the front, and about 1/2" lower in the back. It might have been that way stock, I don't know. Never checked. Anyhow, I've been doing lots of testing, and trying out different settings on the Koni's, as well as different springs, etc. etc., and I've also been tweaking the weight jacks a little to try and get it level. As of right now, it's all within a 1/4 inch of being visually level all around, and I'm certainly good with that. You can't visually tell. But as I was under the car looking around, I noticed that the weight jacks are nowhere NEAR evenly adjusted. I'm close to an inch different from left to right on both the front and back.
My question. For a weekend warrior that won't likely see any track duty, would anyone be worried that the corners are very likely NOT properly weighted? My guess is that if i were driving competitively this wouldn't be ideal, but for my purposes I'll likely never know the difference.
Re: When does properly "weighting" each corner become important?
For a street car, it makes it drive differently around right-hand vs left-hand curves. Becomes most critical when braking into a sharp curve.
Which is not necessarily "bad", in and of itself; just, if you merely accept whatever it randomly happens to be as it is, then it's ... just ... RANDOM. Not exactly the recipe for a prediction.
On the rear axle, it also makes a significant difference under acceleration. If the right rear is already light, it's gonna have an even greater tendency than usual to spin.
Seems to me, from a strictly theoretical point of view, I'd like to have the RR/LF heavy, and the other 2 light. I would NOT want to have the front equal and the rears not, or vice-versa; that, to me, would indicate a car that isn't level. Not by ALOT mind you; maybe 5% or so. Just a tweeeek. But I have no data to back up my WAG and will gladly listen to anyone who does.
Re: When does properly "weighting" each corner become important?
Yeah, I hear what you're saying. The car feels very good, and that's part of my issue here. I've actually spent a lot of time on it, and like where it's at. I'm hesitant to change anything. To your point though, maybe it could be better and I'm just "accepting" it as what it just randomly is, which is much better than it was, but maybe not "ideal".
...and part of my question here revolves around the idea that I don't know how much more or less weight makes a noticeable difference (on or off the track). Like is 5 horsepower really a lot? Stock numbers not really, and certainly not when you've got 400+, BUT.....everything counts, so you do your best. .....with corner weight though I just don't have any scale of reference, and for that matter if the car wasn't truly straight to begin with.....ugh....maybe ignorance is bliss and I should stop asking questions and just drive the car!
Re: When does properly "weighting" each corner become important?
So I've been reading about this quite a bit, and what I've found kinda makes sense, and is kinda what I figured. ...I'm paraphrasing but....
-First of all, make no mistake, the fastest way around the track is to have the car tuned to the driver, and the track. No two tracks are the same, and every driver has strengths, weaknesses and handling preferences. This isn't really practical for all but the most serious competitive drivers with the resources for hours of track time to really fine tune the car.
-For "most" weekend drivers who track their car, having a generally balanced car will yield the best times, but as long as the car isn't all jacked up and out of balance, you likely never "feel" the difference, even if track times are a little faster. Kinda like Sofa's point about just accepting the car for what it is and never really knowing any different.
-For street driving, again, unless the car is all out of whack and unbalanced, you'll never know the difference. Unless the car "feels" strange, with weird handling characteristics, the time and effort, let alone money to have everything balanced just isn't worth it. You'd have to push the car way beyond legal limits to even begin to find the limitations of being unbalanced.
That's similar to what I thought. I've read countless threads with guys with 500+ horsepower cars arguing about how to get 2 or 3 horsepower at 6000 RPMs. Put the forums down and go DRIVE the car.....because it likely makes no real difference! I am still a little curious about what exactly is going on with my car to cause it being uneven, but at least I don't feel like the car is gonna blow up on me on the way to the grocery store, haha!
Re: When does properly "weighting" each corner become important?
I can't comment on the importance of properly "weighting" each corner (other than maybe drag racing) but I do have 4 corner weights from the more or less stock 86 IROC (RIP).
In the picture below the results are from sans driver and with driver (driver at ~200 lbs).
The 1660 kg across the bottom is the current 86 Coupe with sub-frame connections and an all iron SBC.
Re: When does properly "weighting" each corner become important?
2 cents worth here
We measure tire temperature for each wheel after every track session (inner, centre and outer contact patch). We adjust tire pressure accordingly. Afterword, between track days, we adjust alignment/suspension to get more even tire temperature (even patch contact). But driver's input is the most crucial information. That's for full on race car. On the street, like others said, as long as the car feels and looks good, one would never noticed.
Re: When does properly "weighting" each corner become important?
We measure tire temperature for each wheel after every track session (inner, centre and outer contact patch). We adjust tire pressure accordingly. Afterword, between track days, we adjust alignment/suspension to get more even tire temperature (even patch contact). But driver's input is the most crucial information. That's for full on race car. On the street, like others said, as long as the car feels and looks good, one would never noticed.
I appreciate the input. I took the car out last night for a spirited drive, and if the weights are off (which they probably are) I can't tell. We've got a business park close by with a long sweeping turn, 2 lanes each way and a center turn lane, and after 5 there's NOBODY back there. You can get going WAY too fast and I've been testing back there for many years. All the entrances are smooth too, so you can take BIG turns or sharp small turns, all substantially faster than what would be considered legal, lol. Anyhow, I realize I'm not pushing like you would on the track, but if feels completely balanced. As I mentioned, it probably isn't, but I'm gonna chalk this one up to ignorance being bliss and calling this one closed, at least for me, and am going to move on the next item on the list!
Re: When does properly "weighting" each corner become important?
Originally Posted by Abubaca
I appreciate the input. I took the car out last night for a spirited drive, and if the weights are off (which they probably are) I can't tell. We've got a business park close by with a long sweeping turn, 2 lanes each way and a center turn lane, and after 5 there's NOBODY back there. You can get going WAY too fast and I've been testing back there for many years. All the entrances are smooth too, so you can take BIG turns or sharp small turns, all substantially faster than what would be considered legal, lol. Anyhow, I realize I'm not pushing like you would on the track, but if feels completely balanced. As I mentioned, it probably isn't, but I'm gonna chalk this one up to ignorance being bliss and calling this one closed, at least for me, and am going to move on the next item on the list!
Seems like a lot of fun!!
You probably know that already but here it goes:
Racing vs lapping (time attack) vs autocrossing (slalom) are all different things. Might require different set-up.
When we race, there is a lot more going on. Driver might do the lines differently to defend, avoid, prep for overtake, catch fresh air, etc. Lapping (time attack) is purely technical with you and your car alone. Stress is lower and you can push the car to its limits safely so to speak. You can negotiate your lines (apex) and braking points to the T. No one is going to block you or dive wheels to wheels in a corner even tap your bumper. More predictable is what I am saying.
I know nothing about auto crossing but it seems a lot more different than tracking.
As the day goes by, the car's handling also changes with pavement and air temperature. Hell, it changes a lot just between warm-up and qualification. Heat is a big factor. Also, any change to the drive train, specially HP will make the car handle a lot different. Right now we are struggling to adjust to an increase in HP from the new engine. Drivers have to adjust their "relationship" with the throttle!!! They are in relearning process and suspension retuning is also a challenge. We took the ditch last event due to that. No one was harmed but we lost an hour fixing the front end before getting back out there. Car was a bit slower from losing the front deflector.... and yes, down force plays a big role!!!!!
Our course is 1.6 mile long with 11 corners. Not a lot of speed but very technical. Max speed we reach is 105mph on back stretch. Average speed is 75mph. It's all about handling.
Car might feel good early in the day but not so much later in the day, let alone the next day depending on a lot of factors including driver's fatigue. But it could be the other way around lol.
And here's what they (drivers) tell me as far as order of importance:
Driver's skills, takes lots of seat time, lots of it
Brakes
Suspension
Tires
Make a slow car go fast instead of a fast car go slow!!!!
In the end, on the street, you will never reap the benefit of some of these upgrades. Since I have been lapping, I don't get excited too much on public roads. The track will make you s*** in your pants at times. You push yourself and the car then you readjust what ever needs improvement.
Best way to go is have a very experienced driver track your car. Ride shotgun and enjoy (be scared at times let me tell ya!!!)
Re: When does properly "weighting" each corner become important?
Assuming your car isn't bent up from a crash or something,
don't worry about it.
Basically irrelevant for street cars.
Now road racing or autocross?Makes a difference.My 92 as an example. I have not corner balanced my setup yet, as I'm waiting on Hub stands.Having a 130lb ish passenger makes my car faster (aprox 0.3 sec) due to the heavy driver front. I would have liked to fix the issue before SCCA Autocross Nationals, but alas; I ran out of time.
06-25-2023, 02:16 PM
