Digital Scales: "The Final Thread"

Mark Vitacco · **Posted:** Wed Apr 13, 2005 9:05 am

I just purchased a set of Longacre #72583 digital scales. They should
be here next week. The pads are rated at #1100 per pad so it will
weight up to a 3600lb vehicle (Viper with driver). No trucks or anything
larger.

I will be "renting" them out charing $65 per 2 hour set up "session"
and give you hard copy of the set up sheet. Will be working out of
the garage at the house. The usual "going" rate is between $75-$100
per hour. If you don't have adjustable suspension and just want to
know the weight and corner weights fee will be $25.

Details to follow when they arrive. I found them on Corvette Forum
yesterday like new supposed to be used only 5 times. You can go
to the Longacreracing.com web site and read their technical paper
on setting corner weights and look up the model number and see
an example of the various read outs.

Please contact me if anyone is interested.
THus far I have Eric Hardcastle and Craig Gelston booked.

Thanks
Mark V

Chris Brown · **Posted:** Wed Apr 13, 2005 9:47 am

mark, were these the scales bought with club funds? i know there was talk about it at one time.

Keith Quistorff · **Posted:** Wed Apr 13, 2005 9:57 am

Mark,

Thanks for the great news. A few questions I and probably others are interested in knowing:

Will each session include leveling the four scales to ensure they're all at the same height after they are positioned for the car's wheelbase and track, or will it be assumed the floor is level?

Is it up to the car owner to handle the entire process of cornerweighting, or will an experienced person be available to assist?

Will the scales have ramps also, or is the car to be jacked up to put each scale under a tire? If a jack, will one be provided or should the car owner plan to bring one?

AndersGreen · **Posted:** Wed Apr 13, 2005 12:38 pm

Mark Vitacco wrote:

The pads are rated at #1100 per pad so it willweight up to a 3600lb vehicle (Viper with driver).

(Four wheels) * (1100 pounds per pad) = 4400 pounds... I'm guessing that there is a 19% safety factor then, so that the cells don't get overloaded?

(Just curious how these set ups are rated.)

Anders

Richard Casto · **Posted:** Wed Apr 13, 2005 12:54 pm

AndersGreen wrote:

Mark Vitacco wrote:

The pads are rated at #1100 per pad so it willweight up to a 3600lb vehicle (Viper with driver).

(Four wheels) * (1100 pounds per pad) = 4400 pounds... I'm guessing that there is a 19% safety factor then, so that the cells don't get overloaded?

(Just curious how these set ups are rated.)

Anders

Your assuming 50/50 front/rear left/right. In addition to safety factor they allow for non-ideal weight distribution.

AndersGreen · **Posted:** Wed Apr 13, 2005 1:16 pm

Richard Casto wrote:

Your assuming 50/50 front/rear left/right. In addition to safety factor they allow for non-ideal weight distribution.

Ahhh, that makes perfect sense. I forgot all about that.

So, bottom line... I can't go corner weight my one ton van? :twisted:

Anders

Mark Vitacco · **Posted:** Wed Apr 13, 2005 2:23 pm

Setup would, of course include, making as level as surface as possible
else it would be a waist of time. let alone $ I have been able to
repeat readings within 2 lbs using a long carpenters level, streight
edge, and floring tiles for shims.

This is all explaned in the scaling article on Longacre's web site.

Keith Quistorff · **Posted:** Wed Apr 13, 2005 4:14 pm

Cool.

I figured you'd do it the right way but just wanted to make sure. I once had the opportunity to corner-weigh my M3 at a shop that had scales but apparently didn't use them often. When I asked if they had a level, the answer was no. When I asked if they knew for sure if their floor was level, the answer was, "it looks level, it should be pretty close". Needless to say, I wasn't real confident in the accuracy of the corner weights.

Mark Vitacco · **Posted:** Wed Apr 13, 2005 4:44 pm

I purchesed the scales myself. This is independant of the club.

Mark Vitacco · **Posted:** Tue Apr 19, 2005 1:12 pm

Seller advised my scales shipped today. As soon as they get
here and I have the change to get the process sorted I will start
contacting folks who are interested with details individtually.

Mark Vitacco · **Posted:** Tue Apr 19, 2005 1:21 pm

FYI: You do need to be on a level surface. I would not include that
in the setup time. What I do at K&E when I use Peter's scales is take
a long carpenters level and use a 8' piece of heavy angle iron or box
tubing as a streight edge and shim the scales level. Then lift the car
onto them one side at a time. When working by yourself its easier to
make sure they are cented and the ramps dont slide around. For now
2x8's will suffice for platforms. One person can do it, I typcially do my
cars by myself, but it's a lot faster & easier with two people

Mark Vitacco · **Posted:** Thu Apr 21, 2005 9:45 pm

Scales Arrived today!
They are like brand new, calibrated and ready to go.
Will also have weights on hand to simulate the driver as well as
ramps to make it as convient as possible.

I am ready to start making bookings. Will be placing an advert
in the H&T.

Mark Vitacco · **Posted:** Wed Apr 27, 2005 9:49 am

Did the Corvette and Scirocco last weekend (found a bad shock on
the Vette in the process).

Flat patch is marked out on garage floor.

Have weights to simulate driver weight. (you don't need to jump in/out
of the car to take measurements).

The ramps do want to slide on the garage floor. We will want to
jack up the side and place the car on the ramps then push on/off
the scales. I stacked two 2x12's make roll on /roll off easy.

Craig Gelston has signed up and I'm waiting for Keith to get his
aligment done first.

Camber & Caster does effect wheel weight. I was playing with the
Scirocco and changes as little as 1/2 degree did alter the wheel rate
(suspect tire size comes into play here as well). So you want to
do aligment first. Following the Longacre guidelines scaleing should
be the last thing you do before going on track.

DickRasmussen · **Posted:** Wed Apr 27, 2005 10:13 am

Mark,

In regard to alignment effecting corner weights. Was this due to "tire tilt" from different camber angles raising/lowering a corner? Assuming equal left/right camber and castor settings I would "assume" the changes were front/back as you raised/lowered the relative front/rear ride heights via alignment changes. Are my assumptions correct?

Thanks!

Mark Vitacco · **Posted:** Thu May 05, 2005 3:19 pm

Yes, Tire tilt will effect cross weights so it is higly recomended to
set Camber BEFORE you scale a car. Fluids full or at the level
you normally run including fuel, etc.

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Digital Scales: "The Final Thread"

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