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Old 04-04-2012, 08:35 AM   #1
str8shot
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Default Corner weighted coilover adjustment

Quick question that's got a friend and I stumped.

My car is currently corner weighted. I'd like to raise it some, it's a little too low for street use.

If I raised every corner and equal amount (say 1/2 inch), would it need to be re-weighted, or would the corner weighting remain static.

I say as long as each corner is raised the same amount, everything should stay balanced.

My buddy disagrees.

Thoughts?
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Old 04-04-2012, 08:40 AM   #2
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Good question, I've been wondering the answer to this as well.

I was forced to do it for the same reason...
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Old 04-04-2012, 12:27 PM   #3
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If you could raise each corner EXACTLY the same amount you'll probably be fine.
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Old 04-04-2012, 10:32 PM   #4
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Exact definitely being the key word here. It will be hard to keep it perfect but if you are careful it really should be close enough.
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Old 04-06-2012, 07:46 PM   #5
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Use a sharpe and make a line down the threaded portion and on the threaded collars. That way you can bump it up so many turns and line it back up. Should be about as good as it gets.
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Old 04-11-2012, 03:01 AM   #6
MEDUSAzx3
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myself i'd re corner weight it just to be sure. you're already playing with the collars, whats a couple more hours and beers?
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Old 04-11-2012, 12:50 PM   #7
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you should put it back on the scales. I have spent many hours turning the collars on my spec miata measuring corner hights vs weight.

You need to also think about how when you raise your car the camber, caster and sometimes toe can even change a bit.

Also turning each shock collar the same amount does not work, the only way it would work is if you had a car that had 50/50 weight dis. unsprung.
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Old 04-11-2012, 04:18 PM   #8
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^^Michael it has nothing to do with a car being 50/50 weight distribution to determine if this method would work. If you take a car that is 60/40 weight distribution and raise it an identical amount (measured at the wheel, not the shock body) the distribution will be the same. However I would agree spinning all 4 collars the same amount on MOST road cars will result in it still be off a bit from the original setting.

I was just thinking about this again and the reason it does not work perfectly on MOST road cars is the fact that the suspension motion ratio (tire travel/spring travel) is different on most cars front to rear, and normally is not perfectly linear. Therefore .5" on the front collar is not the same movement at the wheel as .5" on the rear collar. I am used to doing set ups like this on Open wheel cars which were designed to have linear, and identical motion ratios front to rear.
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Old 04-11-2012, 10:02 PM   #9
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Dave
Are front and rear springs the same length and same K value?

My point of 50/50 weight is that it will take more turns of the collar on the heavier end of the car..vs To raise the light end of the car it does not require as much preload on the spring so you do not need to spin the collar as much

This is why you could never turn them all the same amount to get an equal increase of ride height at each corner

Also simply measuring that you increase all four corners the same amount will not guarantee that you have the same corner weights that you started with.

Picture this you raise the LF and RR 1 inch each do you think the other 2 corners are still at the original height? (((If they are you have a lot of flex in your frame)))) and on the scales the LF and RR will be the heaviest 2 corners

MY point is you can achieve raising each corner of the car by 1" and have way different corner weights then what you started with.

Last edited by michael85cooper; 04-11-2012 at 10:10 PM.
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Old 04-11-2012, 11:50 PM   #10
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Quote:
Originally Posted by supradjza80
No you can't. If you raise each corner exactly 1" the cross weights and individual wheel weights will be the same. It obviously was not raised 1" at each wheel to achieve the results you have found. I am not saying it is easy to do it perfectly, because it is not, but in an ideal test world It will all be the same.
Quoted fully for accuracy. You would also find that the car will list towards the LR or RF in your example so just raising the two corners would not result in the entire car being the correct 1" higher. It will be off. Cars have these things called CG's which are pretty high off the ground, and normally not perfectly centered front to back or Left to Right to begin with.

The only way for you to possibly get your results is to OVER raise the RR and LF while then adjusting the LR and RF very slightly to make the hieghts measured on the chassis correct. This result is not possible if you adjust all the corners in a similar equal fashion which has been discussed this entire time as we are not trying to screw up the corner weights.

Earlier you brought up spring length and K value, again something that if all 4 corners are adjusted equally does not matter (same weights on each wheel), however in your Adjust only 2 legs/wheels example the springs will be more heavily compressed then they were originally (more weight), and therefore the only way to achieve your result AGAIN is to over adjust the coilover collar on the shock body to achieve said result.

And with that I am out of the conversation.
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Last edited by Supradjza80; 04-12-2012 at 09:46 AM.
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