Car weight and distribution

[Blue MK3]

Couple of questions related to car weight/distribution. First question is what does your car weigh? I had my MK3 in a performance alignment shop a week ago and as part of the service, they weighed the car. Mine came out to be 2280 lbs. with 47.5% on the front wheels. Engine is a 347 stroker (small block) with aluminum heads, intake manifold, and oil pan with the battery located in front of the front x-member. There was about 12 gallons of fuel in the tank. Second, on the FFR web site, there is a video clip about setting up a FFR car (MK3?) to go head to head against an original 427 Cobra. As part of the modifications made (brakes, rear end, engine tweaks), they set the ride height. Then they set the F/R weight distribution to 50:50 by simply adjusting the front shocks, or so it appears. How can adjusting the coil-over affect F/R weight distribution? Did the video leave something out?

[Wayne Presley]

Couple of questions related to car weight/distribution. First question is what does your car weigh? I had my MK3 in a performance alignment shop a week ago and as part of the service, they weighed the car. Mine came out to be 2280 lbs. with 47.5% on the front wheels. Engine is a 347 stroker (small block) with aluminum heads, intake manifold, and oil pan with the battery located in front of the front x-member. There was about 12 gallons of fuel in the tank. Second, on the FFR web site, there is a video clip about setting up a FFR car (MK3?) to go head to head against an original 427 Cobra. As part of the modifications made (brakes, rear end, engine tweaks), they set the ride height. Then they set the F/R weight distribution to 50:50 by simply adjusting the front shocks, or so it appears. How can adjusting the coil-over affect F/R weight distribution? Did the video leave something out?

The FFR's are rear weight biased and work really well. 50/50 is fine for a low HP car but everything really fast is tail heavy.

[Bob Cowan]

My car weighs 2450#, 49% front, 51% rear. 1/2 a tank of fuel, a my weight in the driver's seat.

[Ray]

Here is what ours weighs (used the CHP's scales)

Weight 2460 lbs. (302 with iron heads, live axle, full tank, steel wheels and me in the car)

Weight Distribution (%) F/R 46.9-53.1

Ray

[Someday I Suppose]

As other noted you probably don't want true 50/50 weight, but to answer the other part of the question, adjusting the springs has a major effect on effective weight at the corners. While your not physically moving the weight around you are transfering weight by changing the heights. Think about a wheelbarrow, when you lift the handles, you didn't move weight, but you are putting more of the weight onto the front tire.

HTH's

Scott


Couple of questions related to car weight/distribution. First question is what does your car weigh? I had my MK3 in a performance alignment shop a week ago and as part of the service, they weighed the car. Mine came out to be 2280 lbs. with 47.5% on the front wheels. Engine is a 347 stroker (small block) with aluminum heads, intake manifold, and oil pan with the battery located in front of the front x-member. There was about 12 gallons of fuel in the tank. Second, on the FFR web site, there is a video clip about setting up a FFR car (MK3?) to go head to head against an original 427 Cobra. As part of the modifications made (brakes, rear end, engine tweaks), they set the ride height. Then they set the F/R weight distribution to 50:50 by simply adjusting the front shocks, or so it appears. How can adjusting the coil-over affect F/R weight distribution? Did the video leave something out?

[Blue MK3]

Scott, let me think about the wheelbarrow analogy. Thanks for the post.

[Ray]

How about this. Lets say that you weigh 220lbs. Get down on your hands and knees with your weight evenly distributed between the hands/knees. That's 55lbs for each point of contact with the ground. If you lift one hand off the ground, you don't weigh any less, but have transfered that 55lbs to one of the other points of contact. Which one and how much depends on how you adjust for the missing point of support.

Ray

[Blue MK3]

Ray, why wouldn't the hand now remaining on the ground weigh 110lbs, assuming that I didn't shift my body forward or back?

[Blue MK3]

I think I just figured it out. If I have 110lbs on my hands and bend my elbows a little, there's now more weight on my hands and less on my knees. But in the video clip I mentioned, the weight distribution adjustment was done AFTER the ride height was set. Seems like the ride height would have been changed from the 4 1/2" setting they dialed in. Thanks, guys.

[CraigS]

Within any normal amount of available change ride height has no effect on front to rear weight distribution. What they may have been doing was balancing the left to right distribution to make sure the braking was good w/o locking up one of the wheels prematurely. Do some google searches on corner balancing for more detail.

[Mark Dougherty]

Blue
I think you were thinking Jim was adjusting the front to rear on the scales. He was not
It was the diagonal corners he was after. Jim was going for 50/50 left front to right rear, VS. right front to left rear.
Not front to rear.
It is fairly simple on a car with coil over shocks to adjust the diagonal corner weights.
As stated earier in this thread front to rear and left to right weight is built into the car.
where the batt is, the engine, and the meat sack in the drivers seat.

[Blue MK3]

Well, I'm not sure I understand the details of how it works, but I'll take your word.

[Tad]

Well, I'm not sure I understand the details of how it works, but I'll take your word.

Think of a 4 legged table where 1 leg is too short - every restaurant has one of those. The majority of the weight is shared diagonally across the table on 2 legs as it teeters back and forth. The idea is to get all 4 legs (wheels / coilovers) to balance the load - but you've got to do it on the diagonals. Not much you can do side to side or front to rear without "moving" heavy stuff around. But you can balance the diagonals to stabilize the table.

[Blue MK3]

Thanks Tad, now I get it. I guess I was thinking the F/R weight distribution was being reset. Best, Blue.