Ride Height

[Guest Nik]

Hi gents, have fitted gaz coilovers to the front of my car today. Measured lower wishbone height and height to the head light mount (bottom of wishbone 80mm top of head ligjt mount 574mm) with the car sitting level before dismantling. The springs fitted are 325lb the ones that came off were 225lb but for some reason the ride height had dropped 30mm. I have not adjusted the shocks yet so they are on the lowest setting but should that make a difference. I thought the spring would set the ride height. I have wound the spring up but if I go much further it will go spring bound. Any advice would be much appreciated.

[Longboarder]

Next step is to measure the old shocks and the new shocks, eye to eye, open and closed. Then measure the old and new spring lengths with the springs off the shocks and uncompressed. Post the results. You should then see the problem.

 

Nigel

[Guest Nik]

New and old shocks 9'' closed 13" open. New springs 7 " uncompressed 325lb old springs 8" uncompressed 225lb. I would think that the longer spring would need winding more so more chance of going spring bound?? Please correct me if I'm wrong,

[Bob Tucker]

The length of the spring does set the ride height, with a bit of adjustment from the bottom spring seat..

The new spring needs to be the same length as the old spring, regardless of poundage.

Increasing the poundage may raise the ride height a small amount, but not by an inch.

If I read it right, the new one is 7" vs the old one at 8"?

30mm is just about the 1" you have lost in spring length.

Also if the spring is getting coil bound as you wind it up, something is jammed.

Either the shocker is at full extension, or possibly the upper ball joint is jammed at full flex.

Its a common misconception that winding up the spring increases it force.

It doesnt, it just raises the ride height.

HTH Bob

Edited October 11, 2014 by Bob Tucker

[Longboarder]

Put the old springs back on with the new shocks to check ride height. (You haven't given a reason for changing the springs one inch shorter and 100lb harder. Well not in this thread anyway) This would confirm that the spring swap is the problem. Are the figures you give your actual measurements or what you were told the parts measured.

What is the suspension type on your car?

 

Nigel

Edited October 11, 2014 by Longboarder

[Guest Nik]

Morning guys thanks for the replys. I always felt the old springs were too soft and reading a few threads a 2b wishbone with pinto people seem to go between 325-350. I brought the new springs without measuring the old ones uncompressed. The new springs are not yet spring bound but would be to achieve the original ride height. Can't try the old springs as I have gone from 1.9 to 2.25. I appreciate that the spring sets the ride height, but can't understand how a longer spring will increase it. As presently I am effectively shortening the spring to increase the ride height and if I have to do this to a longer spring assuming I will need to have the bottom platform somewhere near where it is now it will become spring bound sooner?? Cheers

[Guest Ian & Carole]

325lb 9"

set to get correct ride height

 

 

350lb 9"

Same ride height

 

HTHs

[Guest Nik]

Cheers Ian, your top mounting looks lower than mine. Mine is tucked up under the head light mount so may make a difference. Your coils look tighter together than my new ones are, how tight together is safe before they will touch under driving conditions? When I was playing with cars years ago it was off roading so needed plenty of suspension travel maybe I'm letting my experience there cloud my judgement of how close the coils are to each other ! Cheers

[agent_zed]

Hey just to check how do you know the springs before were 225lbs. That seems surprisingly light to me. The stock green zimmeride shocks that came with the 2b wishbones were 320lbs. I've just gone to 325lbs on gaz shocks without too much issue although the shock was actually shorter than the zimmeride unit.

 

As bob said above if you wind the spring seat up it shouldn't really change the spring. If your car is sitting on a 300lb spring and compressing it an inch and you move the spring seat up yor car will still be sitting on a 300lb spring compressing it an inch you have just moved the ride height (correct me in I am wrong).

 

Hth

Edited October 12, 2014 by agent_zed

[Guest Ian & Carole]

Cheers Ian, your top mounting looks lower than mine. Mine is tucked up under the head light mount so may make a difference. Your coils look tighter together than my new ones are, how tight together is safe before they will touch under driving conditions? When I was playing with cars years ago it was off roading so needed plenty of suspension travel maybe I'm letting my experience there cloud my judgement of how close the coils are to each other ! Cheers

 

In the 1st pic the car would have been un-drivable with the springs being almost coil bound at rest.

The 2nd pic is the set up now and has been on the road like that for 8 / 9 years including some spirited drives, including a run around the "Ring" back in 2009.

[Guest Nik]

Morning Zed, old springs have a stamp on the top of the coil 225. I understand that no matter how far you compress the spring it won't change the spring rate. What I'm struggling to understand is if I put a spring on that Is an inch longer I will still need to wind the bottom platform up to alter the ride height so will i still risk becoming spring bound? An 8 inch or 9inch spring will still have the same distance between coils I would just end up with the bottom platform an inch lower down the shock. Or Am I having a blonde moment here. I an strawberry blonde after all!!

[Guest Nik]

Thanks again Ian. I'm gonna go up the yard now and re measure everything. And double check what came off. I'll be back!!

[Bob Tucker]

if I put a spring on that Is an inch longer I will still need to wind the bottom platform up to alter the ride height

Ignoring leverage moments, if you put on a similar rate spring an inch longer & dont alter the spring seat, the ride height will go up by (lets say) an inch

If you put on a spring an inch longer but higher poundage, the car will raise by more than an inch.

The car still weighs the same, but doesnt need to compress the spring as far to take its weight.

Ian's picture does paint a thousand words...

Post up some pictures to help us see whats happening

Edited October 12, 2014 by Bob Tucker

[Guest Nik]

Got it now Gents I was being blond after all. Bottom platform height being the same the extra inch wil be upwards!! I have checked old and new, new ones are actually 2" shorter. The originals were 9" and 250lb. There are also 2 sets of holes on the bottom wishbone for the shock mounting. I have used the one that would actually raise the ride height (to help the larger diameter springs clear top wishbone) this I suspect is why I am only 30mm lower with 2" less on the spring. Thanks for your help I will order longer springs and try again.

[Bob Tucker]

Hi Nik,

if you have 2 sets of mounting holes, it is better to use the ones nearer the wheel...

so long as you can fit the bigger shocks.

All to do with leverage forces.....we have had a small number of early & homebuilt

wishbones buckle from the bending forces.