Coilover Adjustment

Author
Discussion

Calza

Original Poster:

1,994 posts

115 months

Friday 6th October 2017
quotequote all
Apologies for the photo quality.



I'm reading about different types of coilovers going in opposite directions to adjust. Am I correct that the type I have here need to screw up to increase the ride height? But this will also reduce the amount of spring travel available (which seems bad) ?

If so, is there any issue taking them all the way the top of the available thread?

E36GUY

5,906 posts

218 months

Friday 6th October 2017
quotequote all
Dont do it yourself. The set up will be awful.

Get it taken to a place that can do proper corner-weighting and have them do it. So many people fit coilovers without doing the CW but the difference it makes is unreal

Boosted LS1

21,187 posts

260 months

Friday 6th October 2017
quotequote all
Yes, loosen the locking ring and then screw upwards. You'll increase the spring tension slightly as you compress it. I wouldn't go to the very end of the thread, leave a few mm's. Oh, if you oil the threads before doing adjustments you'll find it easier.

CraigyMc

16,405 posts

236 months

Friday 6th October 2017
quotequote all
E36GUY said:
Dont do it yourself. The set up will be awful.

Get it taken to a place that can do proper corner-weighting and have them do it. So many people fit coilovers without doing the CW but the difference it makes is unreal
This all day long.

Boosted LS1

21,187 posts

260 months

Friday 6th October 2017
quotequote all
^ I wouldn't be overly concerned with corner weighting unless it's a light weight race car. A road car has to cope with all sorts of different loads in the vehicle. Full tank, empty tank, just the driver or 3 passengers plus luggage etc.

Calza

Original Poster:

1,994 posts

115 months

Friday 6th October 2017
quotequote all
Thanks for the replies.

It's not lightweight and it's not a track car. The reason I bought these is that the standard ride is awful, and the lowering springs which were meant to improve ride quality dropped it much further than I wanted.

These are now fitted with the adjuster fairly near the top, but the ride hide is even lower than before. For some reason my car seems to ride lower than it should (was fine as stock), and I just wanted to make sure the coilovers weren't wound the wrong way. I also think it could be bottoming out over larger bumps in the road, perhaps due to lack of spring travel.

I've read about / am interested in corner weighting but the issue is the only adjustment is lower which would make it fairly intolerable!

Edited by Calza on Friday 6th October 10:43

Boosted LS1

21,187 posts

260 months

Friday 6th October 2017
quotequote all
Sometimes the manufacturer gets it right. Stock ride height but with firmer suspension can be a good solution for day to day driving on our crap roads.

HedgeyGedgey

1,282 posts

94 months

Friday 6th October 2017
quotequote all
Agreed, no need to corner weight even on a semi-track car. You'll sometimes have a passenger, sometimes be on your own. Have different amounts of fuel in the car, bit pointless to corner weight it unless its a very serious track car chasing 2 seconds round the lap. You can grease the threads to make it easier for future adjustments

227bhp

10,203 posts

128 months

Friday 6th October 2017
quotequote all
You'll need longer springs if you want much of a change in ride height.
They are an old outdated design which has been superseded by much cleverer stuff these days.

e30m3Mark

16,205 posts

173 months

Friday 6th October 2017
quotequote all
Buy some new springs from somewhere like Faulkner. It seems lots of people buy coilovers and assume whatever spring comes with them will be the best for the car. More often than not they're just not ideal. I would do some research on your specific car and the best spring rates for whatever use you need.

Calza

Original Poster:

1,994 posts

115 months

Friday 6th October 2017
quotequote all
This is how it is set now, (i.e. at the top):




And this is how low the car is:




Something just doesn't seem right.

227bhp

10,203 posts

128 months

Friday 6th October 2017
quotequote all
Yes your springs are too short for you, see my post above.

Calza

Original Poster:

1,994 posts

115 months

Friday 6th October 2017
quotequote all
e30m3Mark said:
Buy some new springs from somewhere like Faulkner. It seems lots of people buy coilovers and assume whatever spring comes with them will be the best for the car. More often than not they're just not ideal. I would do some research on your specific car and the best spring rates for whatever use you need.
How does that work, can I put non H&R springs on?

You're right, I totally did assume that. They advertised it for the car so I assumed it would go from anywhere near stock to fairly low. Not fairly low to scraping.

Edited by Calza on Friday 6th October 18:52

E-bmw

9,219 posts

152 months

Friday 6th October 2017
quotequote all
I initially suspected they should have "helper" springs on & they have been removed, as the springs on there look way too short for the car.

However a quick look on ebay comes up with these, which look like yours.

http://www.ebay.co.uk/itm/H-R-Street-Performance-C...

Then when you read the blurb it says front ride height adjustment -30 to 70mm, that is a lot & I suspect way too much.

Unfortunately the shocks look very short because of this, so all you will do is to reduce the suspension travel even further by taking the adjusters to the top as I bet there is virtually no additional compression when the car is dropped off the jack now.

Calza

Original Poster:

1,994 posts

115 months

Friday 6th October 2017
quotequote all
Thing is, 30mm would be absolutely fine I think (this is stock):



But I feel I'm already way lower than that, despite being at the top the thread basically You are right though, there is no room for the spring to do it's thing like this, it's already very compressed, but I simply can't go any lower to free it up. The ride actually isn't that bad even like this, certainly better than stock or the lowering springs I had on before.

Lose lose! mad

E-bmw

9,219 posts

152 months

Saturday 7th October 2017
quotequote all
Previously, when I had different issues with coilover springs I did a few measurements with them on & set up & took the springs to (I used Springcoil in Sheffield) a manufacturer & for the princely sum of £55/spring had exactly what I wanted manufactured.

Calza

Original Poster:

1,994 posts

115 months

Saturday 7th October 2017
quotequote all
Going to contact them and Faulkner as listed above, cheers!

e30m3Mark

16,205 posts

173 months

Saturday 7th October 2017
quotequote all
Give those threads a good clean and waxing too. I appreciate you'll probably find a ride height and stick with it but it's worth keeping those units in good condition.

GreenV8S

30,194 posts

284 months

Saturday 7th October 2017
quotequote all
Ignore the spring at first. The damper bump and droop stops limits the total range that the damper can travel. Typical dampers have about 100mm range and for a strut that gives you roughly the same distance total vertical travel in the suspension. The vehicle has to stay within this range of heights under all circumstances. You should already know the fully extended length so this defines the maximum vehicle height the car can have with those dampers. You can either unload the springs and collapse the damper, or estimate the amount of compression before the damper hits the bump stop rubber and how much compression the rubber will have (maybe 25mm) to find the fully compressed length. This defines the minimum vehicle height with those dampers.

If those upper and lower height limits are acceptable for you, you need to decide where you want the normal ride height within that range. Typically you will want it to be in the middle of the range to give you maximum travel up and down. If you want it higher or lower, bear in mind you will be limiting the available travel in that direction so you will need to increase the damper and spring rates to reduce the travel used. From the spring rate and vehicle weight distribution you can estimate the spring deflection at rest. You can then go ahead and choose the spring length and spring seat position which puts the vehicle at your desired ride height at rest.

TL;DR Sort out whether the damper dimensions fit your needs before you worry about springs, because if the damper length is wrong you can't fix that by changing the springs.

Calza

Original Poster:

1,994 posts

115 months

Tuesday 10th October 2017
quotequote all
e30m3Mark said:
Give those threads a good clean and waxing too. I appreciate you'll probably find a ride height and stick with it but it's worth keeping those units in good condition.
What do you suggest using?

GreenV8S said:
Ignore the spring at first. The damper bump and droop stops limits the total range that the damper can travel. Typical dampers have about 100mm range and for a strut that gives you roughly the same distance total vertical travel in the suspension. The vehicle has to stay within this range of heights under all circumstances. You should already know the fully extended length so this defines the maximum vehicle height the car can have with those dampers. You can either unload the springs and collapse the damper, or estimate the amount of compression before the damper hits the bump stop rubber and how much compression the rubber will have (maybe 25mm) to find the fully compressed length. This defines the minimum vehicle height with those dampers.

If those upper and lower height limits are acceptable for you, you need to decide where you want the normal ride height within that range. Typically you will want it to be in the middle of the range to give you maximum travel up and down. If you want it higher or lower, bear in mind you will be limiting the available travel in that direction so you will need to increase the damper and spring rates to reduce the travel used. From the spring rate and vehicle weight distribution you can estimate the spring deflection at rest. You can then go ahead and choose the spring length and spring seat position which puts the vehicle at your desired ride height at rest.

TL;DR Sort out whether the damper dimensions fit your needs before you worry about springs, because if the damper length is wrong you can't fix that by changing the springs.
I appreciate the more detailed explanation. The thing is it's not that expensive a car, and nor is it a track car or b-road blaster. I was honestly just hoping to achieve a half decent ride in terms of comfort and height.