coilover choice/advice

[bedoef]

For track I am running:
Bump: 4 clicks F / 5 clicks R (will probably need to be revised as the car is still not balanced
Rebound: 12 clicks F / 12 clicks R

For the street, I used to run like 2-3 clicks bump and 14 clicks rebound to try and stop the car from kangarooing everywhere.

 

[LiamP]

If we call setting 1 the softest. How many click’s clockwise……. Front and rear

I think this depends on the damper but I have always been told to go from fully hard Ie closed, you can then be sure it will be equal left to right.

 

[Big Ben]

Coilovers have arrived, what damper settings are ppl running with this setup. Just to give me a starting point. Otherwise I’ll just start on the middle and adjust accordingly when next at the track in relation to how the car behaves etc.

If we call setting 1 the softest. How many click’s clockwise……. Front and rear

cheers

Four clicks front six clicks rear is what I use on the road. On track I use a base setting of 12 clicks front 18 rear and adjust depending on track, weather etc

 

[adamgas85]

Thanks Ben that sounds reasonable.

Liam - yes I realise that mate, we are talking about GAZ gold as mentioned earlier in the thread.

 

[suj]

I think this depends on the damper but I have always been told to go from fully hard Ie closed, you can then be sure it will be equal left to right.

As long as you go from the same side (both start on soft, or both start on hard on each axle) it doesn't really matter, I always went from soft (that's what she said) and never had a problem.

 

[Beany]

I always go full soft on the road… drive like an old man to and fro circuits and it doesn’t see action aside the circuit

i set off from snetterton once forgetting to change it back… pulled upon the side of the road changing it

 

[av4625]

When you run an inboard spring, it needs to be stiffer than the equivalent outboard spring, so for example I am converting my E36 to true rears and I went from 11kg rear springs inboard to 9kg outboard.

So your inboard 7kg spring (400lb) would be like an equivalent of maybe an outbound 5kg (so what's that a 280lb spring-ish)?

Thought I would just update this again as we talked about it here. Ill put it out there that this isn't my field and take everything below with a pinch of salt.

I did some rough (they were rough as the rear beam pivot is at an angle and I have no lift etc) measurements to work out the effect of the lever on the separate spring. For my measurements I took a true coilover as being 1:1 (no lever effect) as the coilover mounts "exactly" where the wheel/axel mounts to the beam.

Disclaimer: I'm only thinking about linear springs. Progressive springs should be the same principle, but harder to work out exact values as it depends how much they are compressed I think.

I worked out that the mechanical advantage on the inboard spring is "1.278". This means that my inboard 7kg (400lbs) spring is the equivalent of 5.5kg (just over 300lbs) spring on a true coilover. @suj your guess here was almost spot on!

This is likely why I feel my car is pretty safe and not playful enough, especially with my pretty hard front spring (might get a lighter one).

I would need a 10-11kg inboard spring for what I want, to be a bit closer to cup racer but not just as heavy as them.

If anyone has spotted mistakes or knows better than me be sure to correct me!

Now armed with all the info I am going to contact the crowd linked earlier to see if they can make a spring for me

Used this for the conversion from Kg to Lbs: https://garage.redline360.com/spring-rate-conversion-chart-easily-convert-kgmm-to-lbsin

 

[suj]

Thought I would just update this again as we talked about it here. Ill put it out there that this isn't my field and take everything below with a pinch of salt.

I did some rough (they were rough as the rear beam pivot is at an angle and I have no lift etc) measurements to work out the effect of the lever on the separate spring. For my measurements I took a true coilover as being 1:1 (no lever effect) as the coilover mounts "exactly" where the wheel/axel mounts to the beam.

Disclaimer: I'm only thinking about linear springs. Progressive springs should be the same principle, but harder to work out exact values as it depends how much they are compressed I think.

I worked out that the mechanical advantage on the inboard spring is "1.278". This means that my inboard 7kg (400lbs) spring is the equivalent of 5.5kg (just over 300lbs) spring on a true coilover. @suj your guess here was almost spot on!

This is likely why I feel my car is pretty safe and not playful enough, especially with my pretty hard front spring (might get a lighter one).

I would need a 10-11kg inboard spring for what I want, to be a bit closer to cup racer but not just as heavy as them.

If anyone has spotted mistakes or knows better than me be sure to correct me!

Now armed with all the info I am going to contact the crowd linked earlier to see if they can make a spring for me

Used this for the conversion from Kg to Lbs: https://garage.redline360.com/spring-rate-conversion-chart-easily-convert-kgmm-to-lbsin

Great work, I have never looked into the Clio for the actual maths, but I did for the E36 and a mates 350z years ago, I think from what you wrote looks about right. What do Clio Cups run on the front. I know there are many factors like weight loss in the rear (but then of course cage, but that CoG is more central, so still the rear will be lighter) to work out what the optimum spring is. It's going to be a trial and error to get bang on for your preference as Clip Cup isn't the "best" you can do, as they would have had so many limitations for things, so if you are racing in a different series you have even more to play with.

The guys above are mainly running 650/350 so that's 11.6/6.2 (on trues, so using your calculations 11.6/8, but as you're a bit stiffer front at 700 aka 12.5, maybe bump up to a 500lb rear so 8.9kg)?

 

[av4625]

Great work, I have never looked into the Clio for the actual maths, but I did for the E36 and a mates 350z years ago, I think from what you wrote looks about right. What do Clio Cups run on the front. I know there are many factors like weight loss in the rear (but then of course cage, but that CoG is more central, so still the rear will be lighter) to work out what the optimum spring is. It's going to be a trial and error to get bang on for your preference as Clip Cup isn't the "best" you can do, as they would have had so many limitations for things, so if you are racing in a different series you have even more to play with.

The guys above are mainly running 650/350 so that's 11.6/6.2 (on trues, so using your calculations 11.6/8, but as you're a bit stiffer front at 700 aka 12.5, maybe bump up to a 500lb rear so 8.9kg)?

From the standard cup racer setup sheet they run 75N/mm (430lbs) front and 130N/mm (740lbs) rear (true coilover). I used an online converter for N/mm to lbs so hopefully its right.

I know they are able to run lighter front springs as they have a heavier roll bar, lighter cars and the rollcenter correction but it is very different to what people run on the road cars

 

[suj]

From the standard cup racer setup sheet they run 75N/mm (430lbs) front and 130N/mm (740lbs) rear (true coilover). I used an online converter for N/mm to lbs so hopefully its right.

I know they are able to run lighter front springs as they have a heavier roll bar, lighter cars and the rollcenter correction but it is very different to what people run on the road cars

Yeah looks about right 75N/mm = 7.6452...kg/mm (as you just divide by gravity of 9.81m/s^2), 130N/mm = 13.25kg/mm (742lb/in) which is crazy stiff rears!

Yeah definitely so many factors, so you can use the guys in here as a ratio front to back, or using the cup racers, I guess down to your intepretation (and if you want to drive on road without losing your teeth lol).

 

[av4625]

The custom springs are ~£125 + vat each. So pricey enough. Such a nightmare that I can’t just run a true rear coilover

 

[suj]

The custom springs are ~£125 + vat each. So pricey enough. Such a nightmare that I can’t just run a true rear coilover

My E36 runs linear rear separate springs currently, they can be had for very cheap to try (just work out lengths and make sure the droop is set correctly on the damper so spring won't fall out) but again depends on the gaps / angle of spring plate etc (E36 has a spring arm, not a beam)

 

[suj]

Or work out the dimensions of these VS Clio ones, £75 for the pair, they have 9kg ones

HSD BMW Rear Coilover Springs (Pair)

A replacement pair of rear springs for BMW HSD Coilover kits. Whether you're driving on the road or track, changing the springs on your HSD coilovers is a great way to alter your car's handling characteristics. These are the springs supplied with HSD Monopro and Dualtech Kits and are designed to...

www.driftworks.com

 

[av4625]

Or work out the dimensions of these VS Clio ones, £75 for the pair, they have 9kg ones

HSD BMW Rear Coilover Springs (Pair)

A replacement pair of rear springs for BMW HSD Coilover kits. Whether you're driving on the road or track, changing the springs on your HSD coilovers is a great way to alter your car's handling characteristics. These are the springs supplied with HSD Monopro and Dualtech Kits and are designed to...

www.driftworks.com

Legend again! Might send them an email

 

[suj]

Legend again! Might send them an email

They're not far from me and I've went in many times and picked their brains on stuff, give them a call and they'd be happy to help, they sold me bits for my HSDs that they should sell separately (or I'd have to buy full top mounts @ £180, instead bits for £30)

 

[av4625]

They're not far from me and I've went in many times and picked their brains on stuff, give them a call and they'd be happy to help, they sold me bits for my HSDs that they should sell separately (or I'd have to buy full top mounts @ £180, instead bits for £30)

Thats the sort of people that you want to be dealing with. I have watched some of their youtube videos

 

[LiamP]

The custom springs are ~£125 + vat each. So pricey enough. Such a nightmare that I can’t just run a true rear coilover

What do your regulations say? Are they clear on if the original pickup points / spring locations have to be used?

 

[av4625]

What do your regulations say? Are they clear on if the original pickup points / spring locations have to be used?

The rules say: "Springs are free but must retain their original location."

I still have to look into the springs in the drift works link above. But I had a "silly" idea.

I was researching how springs work and I found out that springs that are in parallel is the same as adding the rates together so two 5Kg springs is the same as a 10Kg spring. So with that information, yellow speed do a 4Kg spring, if I used that and a 250lb-300lb Gas spring I would get what I want and then I could just change Gas springs if I wanted to try different rates instead of getting custom ones all the time.

By doing this a spring is still technically in the original location. I'm still trying to decide if this is just a really bad and stupid idea

Edit: I apologise for taking over this thread I just thought some people may be interesting in the calculations I added earlier

 

[suj]

That'll be a massive spring combined lol.

Would a spring on a true coilover and in OEM position work for the rules? Probably drive like shit though lol.

 

[av4625]

That'll be a massive spring combined lol.

Would a spring on a true coilover and in OEM position work for the rules? Probably drive like shit though lol.

not sure if it would be allowed. But if my inboard spring works out like a 300lb spring i could put a 150lb or 200lb coilover spring on and it should be like a 450lb or 500lb coilover spring lol

Edit: I still think this is a bad idea though lol