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Author Topic:   cross weight
Rooster08
Dirt Roller

Total posts: 17
posted October 01, 2003 05:14 AM  
What effect will removing a 2" lowering block from the left rear spring have on cross weight? Does it increase it or decrease it?

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 01, 2003 08:29 AM  
Removing it will lower cross-weight and probably make the car a little looser in the corners.

gonfast
Dirt Full Roller

Total posts: 67
posted October 01, 2003 09:35 PM  
I don't know about your cars but if you take a spacer out of the left rear that should tighten the car, and may make it push in the corners

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 02, 2003 09:14 AM  
gonfast,
Not according to the books I have here. Removing it will lower cross-weight and lower cross weight loosens a car up. Book include Pony/MiniStock (Steve Smith) and Race Car Handling (Peter Brock - Australian driver).

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 02, 2003 09:17 AM  
OOOps - embarrasement, red face etc. I mis-read and gonfast was right it does tighten it. I'll now go and hide in shame.

Rooster08
Dirt Roller

Total posts: 17
posted October 02, 2003 06:08 PM  
wouldn't removing the lowering block from the left rear transfer the weight to the right front?

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 03, 2003 08:30 AM  
Re-re-reading I was right the first time and yes it does transfer weight to opposite front that is why it loosens up - weight if removed from the rear.

gonfast
Dirt Full Roller

Total posts: 67
posted October 03, 2003 10:00 PM  
your not losing wieght on the rear by taking the spacer out your gaining weight on that wheel, which transfers weight to the right front and takes it away from the left front, if the car is a leaf , if it is a coil car then it will be the opposite

[This message has been edited by gonfast (edited October 04, 2003).]

[This message has been edited by gonfast (edited October 04, 2003).]

gonfast
Dirt Full Roller

Total posts: 67
posted October 03, 2003 10:04 PM  
if your book says different then its wrong, I set up four different cars at this time and the scales don't lie.

P.S. three cars are track champions at two different tracks

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 04, 2003 09:23 AM  
You dont loose weight but you do transfer weight distribution as I have observed many times in over 20 years of motorsport. Funny that you seem to think every book written on set-up is wrong.
I quote Steve Smith's Pony Stock/Mini Stock page 80 - "More cross weight is desired to tighten a car up. It currently has a 1.5" block in right rear. That block can be replaced with a 2" block. That lowers the right rear and adds weight to left front" So going to a bigger block will tighten a car therefore a smaller one or none at all will loosen the car.

gonfast
Dirt Full Roller

Total posts: 67
posted October 04, 2003 11:15 AM  
Put it on the scales, a leaf car if you put a larger block on the left rear that will force the right rear to carry more wieght, and transfer more wieght to the left front and right rear, its a matter of physics. A coil car if you take a spacer out of the left rear that takes wieght away from the left rear wheel and off the right front and adds it to the left front and right rear

gonfast
Dirt Full Roller

Total posts: 67
posted October 06, 2003 12:39 PM  
Huh, another Feature win last night in two classes, set these up wrong too!!!!

speedyd1
Dirt Maniac

Total posts: 170
posted October 07, 2003 11:04 AM  
dont forget guys - a leaf spring car has blocks on top of the springs which in essence raises the rear end and lowering the car. pulling them out should raise that corner of the car and in turn raise the cross weight.

Deleonracin3
Dirt Newbie

Total posts: 2
posted October 26, 2003 09:09 PM  
where can i find these books yall are talkin about because i have to figure out y my car wants to spin out on the exit of the corners

USAUS Racing
Dirt Full Roller

Total posts: 69
posted October 27, 2003 07:02 PM  
I got the Ministock Pony stock book from Speedwaymotors.com. The other one I bought many years back while racing in Australia..

rocket36
Dirt Freak

Total posts: 209
posted October 28, 2003 04:59 AM  
i too used to think that less cross weight would loosen the car (i have read & re-read most of the steve smith books & can recite them word for word). in the past we would run less than 50% cross (lr/rf) as the books say with the thinking that the rr would need more weight to drive the car around a left turn. our cars were always on the tight side.
then i purchased my current late model which came with a setup manual. in the manual, under the trouble shooting section it says to increase diagonal % to loosen. i didn't believe it and couldn't understand it, but i tried it and it seems to work, i guess thats why rocket are one of the most succesfull chassis builders. i do think that, like any adjustment, you can go too far and you will get the opposite effect.
my understanding (thanks to this forum) is that it will have a more dramatic effect when unloading the lr while turning in and should be used with the softest front spring on the right.
unfortunately i'm not familiar with a full leaf spring car (only mono leaf/coil over) so i can't really help but you should put it on some scales and see the results. i do know that the blocks change the roll centre height so keep that in mind.

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