Wheel alignment, should I use ballast?

SKYHI · Postby **SKYHI** » Tue May 20, 2008 4:08 pm

Hey guys,

I'm getting a wheel alignment on my race car Thursday.

I've read before about people being in the car for both corner weighting and wheel alignments and I wondered whether anyone has had experience with this sort of thing.

Is it necessary for me to have ballast in the drivers seat to compensate for my weight whilst the wheel alignment is being done? Given that the MX5 is a relatively light car, does it actually make much difference?

Paul.

Charlie Brown · Postby **Charlie Brown** » Tue May 20, 2008 4:55 pm

Ballasting with me sitting in my NC made 0.2 degrees difference to the camber on the drivers side.
Where possible I sit in the car for an alignment but I've never done corner weighting, that would take a lot longer. I'd use my other trick of 3 x 25kg bags of pebbles placed on the drivers seat/floor to match driver weight.

Damo · Postby **Damo** » Tue May 20, 2008 9:42 pm

TCR wrote:Given that the MX5 is a relatively light car, does it actually make much difference?
Paul.

Given that the MX-5 is a relatively light car it'll make more difference than with most cars because you'll add around 6-12% to the weight, depending on how much pudding you've been eating recently.

You may as well sit in the car or add ballast if you don't have time.

wun911 · Postby **wun911** » Wed May 21, 2008 10:24 pm

Does the amout of fuel in the car make a differnce?

If it does I would rather do the alignment with an empty tank...

Fatty · Postby **Fatty** » Wed May 21, 2008 10:26 pm

wun911 wrote:Does the amout of fuel in the car make a differnce?

If it does I would rather do the alignment with an empty tank...

that's an interesting point of view.... you often drive on an empty tank, do you ?

Damo · Postby **Damo** » Wed May 21, 2008 11:02 pm

Fatty wrote:you often drive on an empty tank, do you ?

I wouldn't be surprised if he fills the empty space with hydrogen gas, too.

Fatty · Postby **Fatty** » Wed May 21, 2008 11:03 pm

d.ethakada wrote:
Fatty wrote:you often drive on an empty tank, do you ?

I wouldn't be surprised if he fills the empty space with hydrogen gas, too.

LOL, or helium balloons! :lol:

Postby **Okibi** » Thu May 22, 2008 1:15 am

Given it's a race car I would; you want your optimum setup with you driving.

Damo · Postby **Damo** » Thu May 22, 2008 3:47 am

Fatty wrote:LOL, or helium balloons!

Nup, H, He, Li, Be,... if I remember correctly. Hydrogen's lighter.

SKYHI · Postby **SKYHI** » Thu May 22, 2008 9:27 am

wun911 wrote:Does the amout of fuel in the car make a differnce?

If it does I would rather do the alignment with an empty tank...

Well I normally run the car with half a tank to start so I have as close as possible to that for the alignment. Even if you had a full tank (ie: another 24 litres) it's probably about another 18 kg so it might make a slight difference but nothing I'd be too concerned about.

I've dropped the car off today for the alignment and have left ballast for them to put in the drivers seat. If I had the time and money I'd like to get them to take readings with and without the ballast to really see what difference it made.

Paul.