Balance & weight

[doggydoo2000]

Just had loads of work done (will update my build post with all this soon) including cage fitting - had the car weighed up, looking good. What does everyone think about the weight distribution?

Not bad but not quite the illusive 50/50

Total: 1061 kg
Front: 55%
Rear: 45%

Front Left 287kg
Front Right 297kg

Rear Left 235kg
Rear Right 241kg


I suppose changing the battery & moving the tank will help. Without exerience I feel its good as is but anyone got any views on this? (in relation to the e30 that is)

[shorty73]

Are those weights taken with you in the car?

Also agreen who used to be on here a lot has a varley redtop 30 for sale. You'll save about 10kgs over a standard battery and my car has started on the button every time.

[doggydoo2000]

no, not in the car. Just been simply stripped & fibreglass bonnet, 2 race seats - no reduction from the bumpers.
I thought it was quite good tho (will look at the battery thanks)
What about the balance of weight?

[handpaper]

50/50 on a stripped e30 is next to impossible for a number of reasons, not least that the original weight distribution is 53/47. Add to this the fact that most of the easily removed stuff is behind the A-pillar and it gets harder still
60/40 is about the limit to retain reasonable handling on a FR car, so you're still OK there.
You don't mention what car it is - if it's a 320i or 318i(s), moving the battery to the boot will help; the fuel tank is actually pretty well situated as standard - low down and near to the car's CofG.

[shorty73]

Get it corner weighted with you (or a bag of sand that weighs the same) in it. The biggest lump of weight that you can play with will be you (lowering the seat/moving it further back).

When you corner weight it, you want the diagonal weights to be equal or near as you can. I've worked out the ideal corner weights for the car with out anyone in it and they should be

LF 285kg
RF 298kg
LR 233kg
RR 243kg

So it's not too far out but as soon as you shove 80kg's of driver in it'll go way out. Add a passenger and you'll make matters worse.

[doggydoo2000]

325i 4 door '87
Yep I realise 50/50 is out unless you want to add weight (i'll skip that) - battery is a good idea - will even things up.

[fuzzy]

managed 52/48 in my cossied touring. cant remember what it was corner to corner though.

[handpaper]

Interesting stuff on the corner weights there, shorty - adds weight to the legend that BMWs are built to be perfectly balanced with just a driver.
Problem is, the driver should be on the left

Fuzzy, Tourings have heavy arses! Can give better balance when stripped though - at least one guy in PBMW runs a Touring....

[JimmyC]

Interesting stuff on the corner weights there, shorty - adds weight to the legend that BMWs are built to be perfectly balanced with just a driver.
Problem is, the driver should be on the left

Fuzzy, Tourings have heavy arses! Can give better balance when stripped though - at least one guy in PBMW runs a Touring....

and someone else has just started building one ;)

[shorty73]

If you want to work out what your corner weight should be it goes like this;

work out total car weight (with Driver)

work out front and rear %'s

work out L and R %'s

convert %'s to decimal ie 40% = 0.4

Then do the maths.

LF = total mass x F% x L%
RF= total mass x F% xR%
LR= total mass x R% x L%
RR=total mass x R% x R%

Then take off a shed load of weight, forget to corner weight it again and then wonder why the back comes round quicker than a pikey on a waltzer!

[doggydoo2000]

Interesting - cheers Shorty. I'll look back at this once I've finished any mods/lightening