Oversteer help

[ReQ]

we have open practice every Thursday at this track, season starts next month

just picked up a pair of SS201A adjustable rear shocks, I this these will be a very big help, getting rid of the crappy gas charged Gabriel rear shocks, these Pros cost 6 times more.. but I suppose they are worth it in the long run, going to swap some tire sizes around to help get a more natural stagger, I think I am running the tire pressure too low to get proper stagger, I have been told on this track you have to keep the street tires pumped up more since the sidewalls are soft, keeps them from rolling over

I will try the chalk marks as well, to see how far they are rolling

 

[pontiacgp]

since you have a tire guy as your sponsor can you get some nitrogen?...if you can fill up the inside tires with nitrogen and the outside with air. The air expands more so if you don't have enough stagger cold you'll gain some out on the track..

 

[UMI Sales]

since you have a tire guy as your sponsor can you get some nitrogen?...if you can fill up the inside tires with nitrogen and the outside with air. The air expands more so if you don't have enough stagger cold you'll gain some out on the track..

Nice one PGP.

What makes me think it would be good to have you on a team?

Here's another one. In street stock, we got weighed before the race. So, we moved our fuel cell right. As the race went on we gained left side. Perfectly legal. Kind of.

 

[pontiacgp]

thanks..there always little tricks that are legal that help and it's fun reading up on the rules to see how you can add your personal interpretation of them..last year one team got busted porting their heads and their excuse was they were just matching the heads to the gaskets...that's taking it way too far.

 

[ReQ]

very nice tricks, we did a lot of "rule bending" running mini-stocks, another reason I really want to find an F-body with an LS/LT1, so much more potential for sneaky stuff with fuel injection, and coilover struts, this metric suspension may as well be voodoo to me... guess I am just not old school enough lol

I can get nitrogen from several places locally, we are not allowed to run it in this class, but I have never seen them check once for this in ANY class

but anyway, some good news... we have scales now!, $500 for a "like new" set of Longacre 72588 computer scales, full setup with case/charger everything, not a bad deal for $1200 scales, picking them up tomorrow afternoon, so hopefully by at least Wednesday I will have some numbers for you guys

 

[pontiacgp]

That is a great deal and just in time. You really can't do much without scales cause your just guessing and iof you have a problem you don't know where to start. Have you got a tire temp guage?

 

[UMI Sales]

Tire temps are important, yes.

Can you get a setup sheet, like from Longacre or Afco or something?

https://www.google.com/search?ix=hcb&so ... etup+sheet

After you have your corner weights, tire temps, springs, shocks, etc. you'll start to get a picture of where things are.

Keep a sheet like this every time the car goes out with as many details as you possibly can.

Do you know your current ride heights? The car should be relatively square. We always ran our street stock a tad lower on the LF and a tad higher on the RR, thinking when it was mid corner the chassis would be level.

How about your thoughts on corner heights PGP?

ramey

 

[ReQ]

I don't have any paper setup sheets, on my modified I used a laptop and Excel to keep track of everything, I use to have a tire probe but now I have an Infrared pyrometer and not one of the cheap ones, it only reads surface temperature but I think that is sufficient for this task

they way I figure it, the only real numbers I need are the differences between each tire, the number at the surface may differ from inside the rubber but they should still be consistent across each tire, I will know if one tire is cooler than the rest, as long as I keep track of every number each time, I will get an ideal of whats going on, the actual numbers don't matter that much, just the fluctuations

at least that is how I do it, no one ever taught me any of this stuff.. so maybe I am doing it wrong lol

on my way to go weigh the car in about 5 minutes, we have almost 700lbs of lead from 5 to 100 pound blocks to play with, any suggestions on front/rear balance?, rules are 54% left side

 

[ReQ]

I have some numbers finally, a bit disappointing to some degree, mainly because I do not have enough lead, I thought we had 700lbs, but forgot we sold most of it on my last car and only have 260 something pounds currently

anyway, here are the numbers as the car sits now

total=3018 must weigh 3400 minimum when I come off the track and go through tech

LF=1015
LR=714
RF=673
RR=610

57.5% left side which is too high
43.9% rear, no rules for that
46% cross LR/RF

its quite a pain to use these scales without any ramps or setup pads, jacking the car up and placing/removing the scales every time you want to do something is annoying, there is also some slight discrepancy in the numbers as they kept changing and we just wrote down the average, not much of a change just 2 or 3lbs they would bounce around

so there we have it, car is way too light and it already has about 110 lbs on lead on it, spread pretty evenly in the rear left and right side, I need to get the total up almost 400lbs and drop the left side weight about 3 or 4 %

PS.

my next question, where on the car do you recommend adding weight? ahead of the rear axle or behind, how about mounting on the rear end itself, is unsprung weight bad for these cars?

 

[pontiacgp]

as for the weight of the car that is with you in the car with your equipment right? When you had it on the scales you were in the car with all your race equipment including the steering wheel I hope. Before you put the car on the scales I hope you checked the wheel alignment and tire pressures cause that will change the weight bias and wedge. I hope you also made sure the floor you used for the sclaes was perfectly level cause that will give you inaccurate readings.

now for the weights they need to stay inside the wheels or you'll end up having to figure out the dynamic effects of having the weight hanging outside. The rear weight is very hard to get in a metric but if you have to add weight make some plates that go on each side right in front of the rear axle that get hung with some rods and welded to the rear fire wall, that is if you don't already have the plates. We put the battery on one of the plates on the left side along with the weights we need to place there. We also place the weights we need on the other side and pass a 1/2 bolt thru them the secure them. We made our own lead weights by melting down wheel weights and using a bread pan to form the weight. Since your sponsor is a tire guy he might have a bunch of old weights to give you

and yes it's a pain in the *ss setting a car up but there is no fast way to do it if you want to do it right. Look at time you gained just with changes you made and now you see how out of wack you set up turned out to be. Now think what it's going to be like with a car that is set up properly. We made boxes about a foot high to put the scales on it so we can get under the car when it's on the scales. Another thing is when you do make any changes when scaling it you need to rock the car as hard as you can to make sure the car is settled or you could get incorrect readings