Visit The Dirt Forum for More Information

Author Topic:   Help with weight setup
posted July 01, 2002 03:30 PM we go...our car is an 85 Monte Carlo, running racing springs (like 1050 and 1150 on lf and rf and 250 and 200 on lr and rr) with pro shocks all around. We run in a 3400 lb class, and have about 400 lbs of lead, like 150 in lr, 100 in rr, 100 under drivers seat, and 50 on passenger floor pan. Here are our weights:

lf 872
rf 867
lr 1041
rr 782

left 53.7%
cross 53.6%
rear 51.2%

(these weights were taken after hot laps with some mud on the car...normally car weighs in about 3475 with 8 gallons of fuel)

Here are our tire roll outs:

lf 81 7/8
rf 82.5
lr 84
rr 84.5

and tire pressures:

lf 17
rf 20
lr 16
rr 19.5

This has been our best setup to date, though I still think it could be better. seems to be slower in the corners than some of the other cars. We seem to do fine on the straights. The driver isn't the greatest on giving feedback, but I can obviously tell on film that he is a little slower in the corners than the others. I know this is kinda generic, but any advice would be appreciated. Oh, no weight jacks or anything, so no adjustment there. Thanks.


posted July 01, 2002 07:24 PM
i would try more rearweight in the 53-55 range

posted July 01, 2002 10:57 PM           
What are the track conditions? wet/sloppy? dry/slick? Do you adjust your percetages for track conditions? or just run the same no matter what the track conditions are?

Is the car loose or tight in the middle of the turns? Even if the driver can't tell you, you should be able to study the tapes and see what it appears to be doing. Need a little more info about what is going on than just numbers to be able to help.

posted July 03, 2002 08:44 AM
Well, the track conditions tend to go from wet/sloppy in the hot laps and heat (depending on where we run in the schedule as the first couple of heats are usually a little sloppy still) and the track gets better as the night goes on. By the time the B feature rolls around, the track is in very good shape and is pretty tacky, and it starts to get a little dry slick as the A feature rolls around. As for our handling, we tend to handle the best in the B feature, when the track is pretty tacky. He does get a little loose once in a while, generally toward the middle and exit of the corner.

Well, we are, at least for right now, a little stuck as far as weight placement goes. We aren't really able to move much weight around at the track because of the size (about 50 lbs) and shape (probably 5" round cylinder) of the weights. We had to come up with 400 lbs in a hurry, so this is what we got. I am working on trying to be able to move them around easier so we can adjust at the track. This is our first season, so we are just trying to get a feel for things.

The rear percent thing is what I was looking at as well. If we add more weight in the rear, where should we move it from? There is about 75 lbs under the drivers seat, and 50 where the passenger seat would be. Should we move one or both of those to the back? If so, which side should we move, and where in the rear should we move it to? Thanks for your advice. You guys have been a huge help.


posted July 03, 2002 08:34 PM
Try to get only the rear weight percentage up
and only go as fas as above the rear end.any after that will tend to make the car looser.

Tim Weiss
posted July 04, 2002 12:04 PM
We run our weight between fuel cell and bumper this gives yu better rear per cent

Tim Weiss
posted July 04, 2002 12:09 PM
I would take it from your seat and passenger side and put it in the back

posted July 05, 2002 12:13 AM
you can put the weight between the fuel cell and the bumper as lont as you dont go overboard. 200-250# seems to be the limit. after that it makes the car loose in the middle(tried it). just moving 125# from the middle of the car to the trunk will help alot. right in front of the fuel cell or on either side seems to work well.

just how exactly do you get the car to turn with 53.6 cross and 259# of rear split? i run around 50.5 with 165#. more than that and it gets pushy. my advice is to go as high as youi can with the rear weight without putting it all on the rear bumper. then if it wont turn or is too tight, take some cross out of it. less rear with more cross might work on a tacky track, but the high rearweight will help you out in the mud and the loose stuff.

posted July 05, 2002 02:57 PM           
What size track do you run?
The reason you run better during the B is cross percentage. The wetter/sloppy the track, the lower the percetage needs to be-tacky and then to dry slick requires a tighter car. 53% is pretty tight to be running a heat race with. The driver is compensating for too tight a car i.e. (off the gas in because it's pushing and can't get the car to set in the corner and then gets on the gas and it wants to come around.)
This takes experimentation on the scales. We had a different set-up (using tires & RR springs mostly)for 46% cross-weight to 57%. This allowed us a set-up for all kinds of conditions for EVERY race and different size tracks. It required a few nights on the scales and quite a few nights on the track to get it fine tuned.

posted July 07, 2002 11:09 PM
Sorry, that should say LR springs in that last post. Guess I was being a little upside down. I was in a hurry.

Back to the Archives