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Discussion Starter #1
How much weight is the rear lighter than the front?

How realistic is it getting a fox to 50/50 weight distribution ?

I will install MM forward offset arms some time this summer, and set the engine 1 inch back, on top of tubular front bumper and gutted fox. Also the Torque arm/panhard bar add weight to the rear and most of the cage is in the back half of the car, im interested to see how far off from 50/50 iam. Any one use scales and dial in their track cars? What are sitting at ?
 

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My car weighs 3,200 without me. I am 54% on the front with a 130 lb aluminum 9.5 inch block and fiberglass hood. Engine is set back with a Griggs K member and the AC is still in place. Battery is in the rear. Full interior except for the rear seat delete. A six point roll bar, TQ arm, and subframe connectors add weight to the rear mostly I would think. The T56 is heavy and does not help. Except for the AC and bumper support I am not sure how much more there is to extract from the front without getting silly.

Edit: Smog pump, charcoal canister, wiper fluid reservoir are long gone. The horn and wiper motor still exist.
 

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Discussion Starter #4
Ive gutted the stock hood, Tubular front bumper, no horn, no cruise control, no ac/heat/emissions/charcoal canister. Smaller MM swaybar, tubular GT40 intake, aluminum PS/Alt brackets, coilovers, MM k member
Battery is behind passenger seat, stock motor and tranny

Anyone have scales and lives in CT or NY/NJ ?


Id really love to see how close to 50/50 i can get before i need to add weight to the rear.

Aluminum heads to would help a ton! ( i know)
 

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It should not be that hard. My drag car is at 50/50 with a Dart Iron Eagle block, 2.8 LQ Kenne Bell S/C sitting over the engine with a custom air/water I/C as well. With me in the car the weight (per the rules I race under) is 3,150 lbs. This is with an oversize aluminum radiator, S/C coolant pump, hoses/radiator/reservoir as well. Car still has power windows.
 

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It should not be that hard. My drag car is at 50/50 with a Dart Iron Eagle block, 2.8 LQ Kenne Bell S/C sitting over the engine with a custom air/water I/C as well. With me in the car the weight (per the rules I race under) is 3,150 lbs. This is with an oversize aluminum radiator, S/C coolant pump, hoses/radiator/reservoir as well. Car still has power windows.
Can you give some details on how you got to 50/50 with all that engine and blower out front? That sounds very impressive.
 

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Can you give some details on how you got to 50/50 with all that engine and blower out front? That sounds very impressive.
No A/C, No P/S, QA1 tubular K-member, coil overs, lightweight springs, no sway bar, no front bumper inner structure, Battery in right rear, 8 Gallons of water in rear I/C tank, full tank of gas, playing with the ride height front/rear. Lots of little things moved around add up.

 

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To be fair, when a car is at 50/50 or close to it, a little bit of weight makes the number jump a lot. Here is a picture of the scale with just 5 gallons of fuel taken out of the tank.


 

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5 gallons is 40 pounds give or take and about 1.25% of your total weight. Perhaps that is the wrong pic? Corner weighting changes can affect the cross weight but I don't think it will change the front to rear percentage.
 

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Curious...how come the total weight went up by 1 pound? :nerd:
I will have to check my notes. Maybe I ate a big lunch...lol
 

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5 gallons is 40 pounds give or take and about 1.25% of your total weight. Perhaps that is the wrong pic? Corner weighting changes can affect the cross weight but I don't think it will change the front to rear percentage.
1.25% of total weight that is located about as far rearward as you can get. It does effect the front/rear more than you think. It is the leverage that makes the change more than 1.25% of the front/rear bias. If it was dead center of the rear wheels, you would have a point, but it is a good 12+ inches or more behind the rear wheels.
 

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You did not take out 8 gallons and only change the static weight by 1 pound. No amount of corner weighting changes will change the static weight although that would be nice. That was the main point I was trying to make. I will go look for corner weighting effects on front to back. I am fairly certain I have read that corner weighting will not materially change that relationship either.

Edit: I found an article by GRM on the subject. See second sentence under Setting Cross Weights.

http://grassrootsmotorsports.com/articles/understanding-corner-weights/

But to your point. Yes a change like we are discussing can have a fairly profound impact.
 

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I suggest attending a NASA race weekend and politely asking the scales people if you can do a quick weighing. Odds are, they won't mind as long as you aren't mucking up the queue (i.e., do it when there is no queue, when a session like CMC or AI is on track). Alternatively, attend a national-level SCCA auto-x, they always have the scales there.
 

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Discussion Starter #18
No worries man, this is why iam here to discuss.

Yes i have 1 pic of the skinned hood (granted theres more i plan on removing but yes) Its on my instagram account, scrool down a bit and you will find it.


Not to hijack the thread or anything, but, I'm looking into doing this on a junk hood I have...do you have any pics and/or a write up of what you did?

Thanks,
Mark
 

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Discussion Starter #19
Ive read/heard that racecars are actually or preferr to be rear heavy, so when your hard on the brakes it shifts to 50/50. Love this stuff
 
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