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Author Topic:   % question
Dirt Freak

Total posts: 268
posted April 11, 2004 09:35 PM  
I'm 228 lbs over weight at 3428. I'm 54% left and 51% cross and 48.5% rear. I've lost as much weight in the front as I can and have added 220 lbs to rear, moved the motor back about 2.5 inches to get those numbers. Havent tried the car yet but I'm about 60 pounds lighter than last year and 4% better in rear % than last year. I'm woundering at what point do you quit adding rear weight to incress rear %. I know those last year rear %'s suck but I'm still a rookie in my book and didnt have axcess to scales. Made my own after last year was over.

Dirt Forum Champ
Total posts: 968
posted April 12, 2004 08:28 AM  
You have to get more weight off the front! You didn't say what make car it is, but I have to believe that you will be able to get better front numbers than that. The art of knowing when to quit adding weight is a formula which says= add rear weight till you can get off the corner without spinning the tires. LOL Oh yeah, leave the idea of the "pendulum effect" to Edgar Allen Poe. Put the weight as far back as possible.

Dirt Freak

Total posts: 374
posted April 12, 2004 08:50 AM  
Yeah what he said.

Dirt Forum Champ
Total posts: 635
posted April 12, 2004 11:53 AM  
Hack the guts outta the front fenders, hood, doors and right side heater box/rocker panel if possible.

Let us know what kind of car it is and I'm sure some of us here can help with places to lose weight. Let us know what you've tried too. I run a metric @3050 w/o driver and get 48% rear with about 150 lbs of added weight. Once I can afford a 22 gal fuel cell I'll be a tick over 49% rear and still under 3100 lbs.

And you might find it works good right where it's at. Shocks and springs have much more to do with how it hooks than 2% - 3%. Now if you're way off (say like 42% rear) that doesn't apply. But within reason shocks and springs can take care of a couple % of weight variation.

Dirt Freak

Total posts: 268
posted April 12, 2004 09:07 PM  
Ok here it all is I think. 78 olds metric. 3428 with driver in, 54 left, 51 cross, 48.5 rear. 220 lbs added to rear. Hood is gutted, fenders are gutted, removed radiator support, plastic nose with a performance bumper. Motors moved back and drivers seat moved back. Havent gutted roof or front pillars. Doors are gutted except the outer ring and hinges are removed as well as latches and rockers. I have used bigger round tubing then usual and plan to change all the roll cage out next year. I could get a aluminum water pump and lighter starter but I dont think that would put me over 50 %. Unless my scales are off(tool box scales) and the total weight is less than it shows I dont know what else I can do. I am going to try it this weekend and unless you guys point something that I can do to help this week It will stay untill I see if it works.

x factor
Dirt Full Roller

Total posts: 34
posted April 13, 2004 05:02 AM  
I've only put together one metric (i like the bigger cars) but by gutting everything you should be able to get at least 54% with the engine set back at 3200#. I had got 53% rear at 3200# with the engine in the stock location. A fire wall should be left as only the fire wall, cut off everything but the front face. The door mount pillars, dash, roof,rocker panels any structural metal for the body should go. You will have to make new supports for the body but if you make the supports before cutting the structure completely out it isn't as bad as it may sound. The part of the firewall that the brake pedal mounts to should be reinforced to the cage so the firewall won't flex under hard braking.


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