Scaling F-Body GM

67champ · 03-27-2009, 10:36 AM

Can someone explain to me what the purpose is in what I think they call "scaling" a drag car? I am asking about the process of weighing each four "corners" of the car, and making each "corner" a certain weight or percentage.

Is this something that a person would do to a leaf spring camaro or firebird? If so, what would be the proper percentage of weight per corner, etc.?

THANKS!

63corvette · 03-27-2009, 02:40 PM

Scaling a car is to setup the suspension to plant the rear tires and go straight on the launch.
It can be done with the four link or ladder bar suspension. It also allows you to keep the front end square with the front wheel equally loaded on the launch which will keep the car straight.
I am not sure how anyone would do it with a stock suspension.
With a good set of scales you can setup a car in the garage and have it ready to race as far as the suspension is concerned before every taking it down the track.
My 2 Cents

Bob Pagano · 03-27-2009, 03:08 PM

Yep, Stocker's do it too. done with you in car, balance weight and move as much to the rear as possible.

Tony Curcio · 03-27-2009, 06:10 PM

Scaling is very helpful if you just built a new car, or it has been in storage a long time, or in a crash. It can save a lot of time if it pulls to one side as well.

If you install a stiffer spring in the left front, the wheel weight of the right rear will increase. The opposite corners effect each other, no matter what type of suspension.

Also, the preload adjustment on Caltracs have an effect as well.

I had King Race Cars scale my 69 Camaro a couple years ago. He heated and bent one front coil to get the rear wheel weights about equalized. I'm sure that I recorded the corner weights in that year's log book. If you are interested in knowing the numbers, send a PM, and I'll dig out the books and try to find the info.

bob gonier · 03-28-2009, 07:49 AM

Quote:

Originally Posted by Tony Curcio

Also, the preload adjustment on Caltracs have an effect as well.

Yes It will/does but Calvert doesn't recommend doing so.

bob

67champ · 03-30-2009, 04:24 AM

Thanks for the replies everyone!

dt

Tony Curcio · 04-02-2009, 09:36 PM

Off the trailer the corner weights were as follows:

LF- 956 RF- 910
LR- 811 RR- 706

After raising the LF spring rate 50 lbs, the rear wheel weights were about equal, then the Cal-Tracs were re-set according to mfr instructions:

LF- 1006 RF- 863
LR- 756 RR- 772*
*16 lbs preload

Pistol Pete · 08-13-2013, 09:54 PM

Quote:

Originally Posted by Tony Curcio

Off the trailer the corner weights were as follows:

LF- 956 RF- 910
LR- 811 RR- 706

After raising the LF spring rate 50 lbs, the rear wheel weights were about equal, then the Cal-Tracs were re-set according to mfr instructions:

LF- 1006 RF- 863
LR- 756 RR- 772*
*16 lbs preload

Why would you want 143lb. difference between LF & RF ????
I'm guessing the driver is in the car with these wt. numbers ??

Tony Curcio · 08-13-2013, 11:43 PM

Yes, 220 lbs in the driver's seat. The front weights are not critical on a drag car. The object was to get some balance on the drive tires.

Pistol Pete · 08-14-2013, 02:12 AM

OK Thanks Tony.

03-27-2009, 10:36 AM	#1
67champ Junior Member Join Date: Feb 2002 Location: Ohio Posts: 48 Likes: 7 Liked 4 Times in 2 Posts	Scaling F-Body GM Can someone explain to me what the purpose is in what I think they call "scaling" a drag car? I am asking about the process of weighing each four "corners" of the car, and making each "corner" a certain weight or percentage. Is this something that a person would do to a leaf spring camaro or firebird? If so, what would be the proper percentage of weight per corner, etc.? THANKS!

03-27-2009, 02:40 PM	#2
63corvette Senior Member Join Date: Mar 2007 Location: Canyon, Tx Posts: 551 Likes: 127 Liked 353 Times in 102 Posts	Re: Scaling F-Body GM Scaling a car is to setup the suspension to plant the rear tires and go straight on the launch. It can be done with the four link or ladder bar suspension. It also allows you to keep the front end square with the front wheel equally loaded on the launch which will keep the car straight. I am not sure how anyone would do it with a stock suspension. With a good set of scales you can setup a car in the garage and have it ready to race as far as the suspension is concerned before every taking it down the track. My 2 Cents

03-27-2009, 03:08 PM	#3
Bob Pagano VIP Member Join Date: Jun 2002 Location: New Holland, PA Mooresville,NC Posts: 1,163 Likes: 240 Liked 16 Times in 11 Posts	Re: Scaling F-Body GM Yep, Stocker's do it too. done with you in car, balance weight and move as much to the rear as possible. __________________ Bob Pagano A/SA

03-27-2009, 06:10 PM	#4
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: Scaling F-Body GM Scaling is very helpful if you just built a new car, or it has been in storage a long time, or in a crash. It can save a lot of time if it pulls to one side as well. If you install a stiffer spring in the left front, the wheel weight of the right rear will increase. The opposite corners effect each other, no matter what type of suspension. Also, the preload adjustment on Caltracs have an effect as well. I had King Race Cars scale my 69 Camaro a couple years ago. He heated and bent one front coil to get the rear wheel weights about equalized. I'm sure that I recorded the corner weights in that year's log book. If you are interested in knowing the numbers, send a PM, and I'll dig out the books and try to find the info. __________________ Tony Curcio 1860 STK Last edited by Tony Curcio; 03-27-2009 at 06:12 PM.

03-30-2009, 04:24 AM	#6
67champ Junior Member Join Date: Feb 2002 Location: Ohio Posts: 48 Likes: 7 Liked 4 Times in 2 Posts	Re: Scaling F-Body GM Thanks for the replies everyone! dt

04-02-2009, 09:36 PM	#7
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: Scaling F-Body GM Off the trailer the corner weights were as follows: LF- 956 RF- 910 LR- 811 RR- 706 After raising the LF spring rate 50 lbs, the rear wheel weights were about equal, then the Cal-Tracs were re-set according to mfr instructions: LF- 1006 RF- 863 LR- 756 RR- 772* *16 lbs preload __________________ Tony Curcio 1860 STK

08-13-2013, 11:43 PM	#9
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: Scaling F-Body GM Yes, 220 lbs in the driver's seat. The front weights are not critical on a drag car. The object was to get some balance on the drive tires. __________________ Tony Curcio 1860 STK

08-14-2013, 02:12 AM	#10
Pistol Pete VIP Member Join Date: Oct 2003 Location: Punta Gorda Isles, Fl. Posts: 1,626 Likes: 3,402 Liked 779 Times in 209 Posts	Re: Scaling F-Body GM OK Thanks Tony. __________________ "Pistol" Pete Dutko