I have 150 lbs of steel bar stock hanging from the rear frame rails (tucked in behind the rear roll pan) on my S10. I did it to get the front to rear weight more reasonable but not sure it was a good decision.
I had a few racers say to remove the 150 lbs and put 75 lbs in "above the rear axle", as high as I can mount it under the bed cover.
**** Lahea once did a segment about this. Weight above the rear axle or below is just weight. Above behind is weight transfer. So depending on what you are trying to accomplish. If you just want weight moved to balance truck then above would be right,If you want to make it more a weight transfer then sounds like you made the correct move. If wheel standing issue than I would move to above rearend.
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Gotta agree with Wide on this I currently have no ballast in the vette but have used 80 lbs. over the rear axle to help slow the car for a E.T. finals when they had an E.T. break a little slower than I was running
The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
Posts: 428 | Location: des moines iowa | Registered: January 10, 2020
I had a 79 Malibu way back, ladder bars and a BBC motor, just a back halfed car. It was nose heavy for sure which I was able to remove some nose weight but it needed more help. I made two 80 lbs weight bars, mounted one above the rear end about the height of the rear window deck lid, made a world of difference! I tried the other one right behind the bumper, made no difference in consistency at all.
When you add or move weight further out from the CG of the car you are increasing the polar moment of inertia which means it's harder to start weight transfer but also harder to stop it once it's in motion. Moving weight higher above the CG increases the weight transfer forces as it raises the CG of the car, same for adding more weight above the CG.
My combo needed to get the weight transfer going at the hit due to the front end weight,,, your combo could be similar due to the wheel base,,, I would try it above the rear first.
I do not have access to 4-wheel scales but I did roll it on some track scales. 1640 lbs on front and 1350 on rear. S&W Back half with 4-link and 140-lb springs. I felt my issue was it would hook, pull the wheels maybe a foot and then drop them down and pull them off the ground again. I added 150 to the rear of the frame rails and it almost cured the "double wheelie" issue but I am wondering if I could use less weight and accomplish the same. I will try 75 over the rear end housing, as high as I can get it and see what happens.
Appreciate the ideas, I also will have a new converter in it that should be better; right Marco? ;-)
Originally posted by Toad1: I do not have access to 4-wheel scales but I did roll it on some track scales. 1640 lbs on front and 1350 on rear. S&W Back half with 4-link and 140-lb springs. I felt my issue was it would hook, pull the wheels maybe a foot and then drop them down and pull them off the ground again. I added 150 to the rear of the frame rails and it almost cured the "double wheelie" issue but I am wondering if I could use less weight and accomplish the same. I will try 75 over the rear end housing, as high as I can get it and see what happens.
Appreciate the ideas, I also will have a new converter in it that should be better; right Marco? ;-)
See ya at the stripe,
Jok
Can you determine why it drops after the first wheelie, not enough power to keep it going or tire spinning,,,, tire spin can occur when you run out of front end travel and there's not enough sack to hold it up. If it separates to fast up front, this is usually an issue that can cause the rear tires to unload and spin.
Originally posted by Toad1: I have 150 lbs of steel bar stock hanging from the rear frame rails (tucked in behind the rear roll pan) on my S10. I did it to get the front to rear weight more reasonable but not sure it was a good decision.
I had a few racers say to remove the 150 lbs and put 75 lbs in "above the rear axle", as high as I can mount it under the bed cover.
Anyone done this with ballast?
Thanks in advance for your replies.
Jok
My Nova is 50/50 no balast. Currently I'm running 300 lbs a foot and a half behind the axle centerline as close to the bottom of the rear deck lid as can be, centered in the trunk.
I've run as much as 475 lbs on the same weight bar in the trunk.
For bracket racing I run a down hill ladder bar, low ride height.
For fast 60ft index racing, I run a nearly level ladder bar, higher ride height.
Put the ballast high & behind the axle. Run the ladder slightly down to the pickup point. Then use the compression clicker to time the amount tire rap. Tight setting on compression will wind the tire as soon as the damper shaft changes directions from extension to compression. A loose compression setting will delay the tire grabbing traction (tire windup). Take some video, it'll guide clicker adjustments, to perfect it.
Originally posted by Toad1: I do not have access to 4-wheel scales but I did roll it on some track scales. 1640 lbs on front and 1350 on rear. S&W Back half with 4-link and 140-lb springs. I felt my issue was it would hook, pull the wheels maybe a foot and then drop them down and pull them off the ground again. I added 150 to the rear of the frame rails and it almost cured the "double wheelie" issue but I am wondering if I could use less weight and accomplish the same. I will try 75 over the rear end housing, as high as I can get it and see what happens.
Appreciate the ideas, I also will have a new converter in it that should be better; right Marco? ;-)
See ya at the stripe,
Jok
needs better shocks, not weight and must be 4 corner scaled.
Posts: 13522 | Location: NJ | Registered: August 20, 2000
A video (if link works) that shows what a good front shock setup can look like. No bouncing after that huge wheelie
If you are picking up the front tires, putting them down and then picking them back up. The problem is suspension and suspension related setup most likely. There is a minor chance convertor and tires could play into it, but I would start with proper shocks and car setup
As Ed has already said, get a weight on 4 corner scales. Link us some videos of the car if you can, post a few tickets as well. More info the better. Even if I don’t have the knowledge to tell you the problem, the above info will help others help you
Posts: 866 | Location: Georgia | Registered: May 09, 2008
I have some work to do for sure. Going to try to find a stock car guy with some scales, if anyone around Cedar Falls/Waterloo, IA knows of a set I would be glad to rent them for a couple days. I am getting a little more convinced the front QA1 double adjustables aren't up to the task of controlling 1700 lbs dropping back to the track. Going to get the ballast out for the fist weekend and see what it does. Probably too many band-aid fixes. With one time run for every three day race, testing is about impossible. Thanks for the ideas, I will get to work on it in a few weeks.
Any tips on how to upload a video or picture would be helpful, I haven't got that figured out at all.
Just taking the weight out will probably make things worse as the weight is a band aid fix. Again, need to scale it, if you can’t borrow or rent scales then get it to a chassis shop who will record the weights as is, then remove the weight, neutral the suspension and work from there. Your shocks are part of your problem and your rear springs are too stiff. For reference, mine are 125lb.
Posts: 13522 | Location: NJ | Registered: August 20, 2000
Originally posted by Toad1: I have some work to do for sure. Going to try to find a stock car guy with some scales, if anyone around Cedar Falls/Waterloo, IA knows of a set I would be glad to rent them for a couple days. I am getting a little more convinced the front QA1 double adjustables aren't up to the task of controlling 1700 lbs dropping back to the track. Going to get the ballast out for the fist weekend and see what it does. Probably too many band-aid fixes. With one time run for every three day race, testing is about impossible. Thanks for the ideas, I will get to work on it in a few weeks.
Any tips on how to upload a video or picture would be helpful, I haven't got that figured out at all.
Jok
Video you may want to use YouTube
Images you want to google search for a “bb code generator” you will upload your photo into it and then copy and paste the code here
Posts: 866 | Location: Georgia | Registered: May 09, 2008
If you run a low technology damper made in indonesia, you may indeed be better off with a light spring, and the damper might even be able to keep up.
If you run high end damper/shock, have a look sometime at Jerry Bickels spring chart.
It's the recommended spring rates I use. I've been told for years I have too much spring., yet the first time I tried to go fast, I ended up in a handful of runs, with the fastest 60ft on the planet 3200 lbs , 10 x 28 tire, n/a 23 sbc.
Most of the perspectives given on the net in regards to springs, is meaningless and useless in the real world.
talk about what you know, not what you think you know! I'll put my knowledge and skills setting up a race car chassis against yours anyday of the week!
Posts: 13522 | Location: NJ | Registered: August 20, 2000
Originally posted by 1320racer: Just taking the weight out will probably make things worse as the weight is a band aid fix. Again, need to scale it, if you can’t borrow or rent scales then get it to a chassis shop who will record the weights as is, then remove the weight, neutral the suspension and work from there. Your shocks are part of your problem and your rear springs are too stiff. For reference, mine are 125lb.
If your lost I agree with Ed's statements regarding the weight and suspension. Either way I also agree that the rear springs are too stiff unless the springs/shocks are mounted in front of the rear end but for your typical rear mounted shock/spring setup, you may even need to be closer to 110 lbs/in, especially if the 1350 rear weight includes the 150 lb weight bar!!!
This message has been edited. Last edited by: 1320racer, 
