Changing BC Gold Springs

[GlanzaAtHeart]

Hey there guys,

Just a question regarding BC Gold Coilovers - It is possible to change the spring rates?

The dampening changes, but the problem is they still are VERY stiff for daily driving, mainly just effecting the pre-load of the shocks.

If I changed my springs, it would be a lot more accomodative. I presume these are the stock 5kg front and 8kg rear.

Is this possible, and where would I get such springs? Autolign or such? Any information would be helpful.

Otherwise I might look into selling these and getting a nice set of lowering springs and shocks.

Cheers guys

[Jabeo]

Hey there guys,

Just a question regarding BC Gold Coilovers - It is possible to change the spring rates?

I could be wrong but i am pretty sure that 5kg and 8kg springs out of the box are one the lower spring rates that bc offers. Aside from riding at the lowest damping setting you could go for a swift spring replacement which are coil over springs that are designed to improve the quality of your ride and the characteristics of your handling. I am unsure where to source some in NZ though, but BC Australia has a good catalog and they may have lower rate springs if you have a nosey through there. edit: just had a look and they have 2kg and 4kg springs, idk if you can get in nz though

Personally i thought it was a bit stiff at first but i continued to drive on them and are now completely used to it, and thats with driving on the dampers set to 30

[GlanzaAtHeart]

Hey there guys,

Just a question regarding BC Gold Coilovers - It is possible to change the spring rates?

I could be wrong but i am pretty sure that 5kg and 8kg springs out of the box are one the lower spring rates that bc offers. Aside from riding at the lowest damping setting you could go for a swift spring replacement which are coil over springs that are designed to improve the quality of your ride and the characteristics of your handling. I am unsure where to source some in NZ though, but BC Australia has a good catalog and they may have lower rate springs if you have a nosey through there. edit: just had a look and they have 2kg and 4kg springs, idk if you can get in nz though

Personally i thought it was a bit stiff at first but i continued to drive on them and are now completely used to it, and thats with driving on the dampers set to 30

Madman on 30! Haha.

Thanks for the Swift Springs, I'll take a look. Was thinking maybe into getting either progressive springs, or something around the 3-4kg for the front, and 5-6kg for the rear.

It's too stiff for daily, I don't know how you do it.

Guess bad backs just run in my family haha.

Cheers Jabeo, will look into it.

[mickeyduck]

If they feel too stiff you might have way too much preload on them? When you first dial the rings onto the spring you get them finger tight (only just) and then tighten them by 4mm, no more. That's the thickness of a BC coilover spanner. And that's with no load on the thing, like either with the coilover out of the car or with the car on stands.

BC have a number of very useful videos online. Google them and watch them. Makes dealing with their coilovers a breeze.
I put links to them on my Rides thread on this page someplace: https://mr2.org.nz/forum/viewtopic.php? ... start=1695

5 and 8 are standard and pretty soft in my estimation. I ordered harder springs through an NZ agent and BC in the USA them made for me as they were a non-standard rate, and sent them over. Not expensive.

Also if the shocks (the central component) crap out the things won't be at all nice (or safe) to get around on. Stuffed shocks will make the car kick up real bad on bad bumps. Dangerous. Again, shocks are readily available, not overly expensive and real easy to do.

Agents in Auckland are Redline Performance in Mt Roskill.
https://www.redlineperformance.co.nz

[GlanzaAtHeart]

If they feel too stiff you might have way too much preload on them? When you first dial the rings onto the spring you get them finger tight (only just) and then tighten them by 4mm, no more. That's the thickness of a BC coilover spanner. And that's with no load on the thing, like either with the coilover out of the car or with the car on stands.

BC have a number of very useful videos online. Google them and watch them. Makes dealing with their coilovers a breeze.
I put links to them on my Rides thread on this page someplace: https://mr2.org.nz/forum/viewtopic.php? ... start=1695

5 and 8 are standard and pretty soft in my estimation. I ordered harder springs through an NZ agent and BC in the USA them made for me as they were a non-standard rate, and sent them over. Not expensive.

Also if the shocks (the central component) crap out the things won't be at all nice (or safe) to get around on. Stuffed shocks will make the car kick up real bad on bad bumps. Dangerous. Again, shocks are readily available, not overly expensive and real easy to do.

Agents in Auckland are Redline Performance in Mt Roskill.
https://www.redlineperformance.co.nz

Oosh might have to check out Redline once the lockdown is over. Didn't know they were there! I live in that suburb and have never noticed them!

Went for a drive yesterday to test it out after a couple of weeks driving the dog in Mum's Mazda Verisa. Conclusion: Maybe I am speaking a bit too harsh, and that this isn't too bad. But they're a bit stiff and I don't like it. Maybe checking out the prelod is a given.

The coilovers themselves are less than a year old, certed in October last year, thanks to Chris. Speaking to GDII, I'm unsure weather keeping them, upgrading, or what is the plan of action so far.

Jabeo, I talked to BC in Australia, they told me no Swift springs, but can get in custom BC Springs. MR2 Heaven says that BC Springs are prone to stiffening under load (Turning a 5kg spring into 9-11kg spring under an inch of travel), so maybe I just got a bad batch? I have heaps of Speedbumps where I am so it's killing me.

Will update if I can get a set of Swift springs or what, maybe will have to settle for turning down the shock stiffness for now.

[Benckj]

This probably won’t solve your issue but might be worth lowering the pressure in your tyres. The sidewalks absorb quite a bit of energy which is why I like to use my 16” wheels on long journeys.

[GlanzaAtHeart]

This probably won’t solve your issue but might be worth lowering the pressure in your tyres. The sidewalks absorb quite a bit of energy which is why I like to use my 16” wheels on long journeys.

Hmm maybe that's worth a shot. Unsure how my Nankangs are in terms of ride quality... Surprised how good they hold traction though. Maybe it's an MR2 thing though...

[mickeyduck]

Jim has a good point there mate. My SW rides on 18" rims with low profile tyres and ideally I would stick with my extra-hard springs to keep the car handling flat and tight, but run 17" rims with higher sidewalls on the tyres to get a softer ride. My problem is finding a decent set of 17" rims that will fit over the Brembo front calipers and over-sized rotors. Anyway Jim has a very valid point. Don't know what rims and tyres you're running but the sidewall height makes a huge difference to the ride comfort. Don't over-inflate them either of course cos that won't help.

[GDII]

Jim has a good point there mate. My SW rides on 18" rims with low profile tyres and ideally I would stick with my extra-hard springs to keep the car handling flat and tight, but run 17" rims with higher sidewalls on the tyres to get a softer ride. My problem is finding a decent set of 17" rims that will fit over the Brembo front calipers and over-sized rotors. Anyway Jim has a very valid point. Don't know what rims and tyres you're running but the sidewall height makes a huge difference to the ride comfort. Don't over-inflate them either of course cos that won't help.

Advan RG-D? Actually specifically designed to clear large calipers.

[mknz]

Advan RG-D? Actually specifically designed to clear large calipers.

I said the same thing too

[GDII]

Advan RG-D? Actually specifically designed to clear large calipers.

I said the same thing too

I might be biased but.... They are very light too and flow formed so have the flex needed to deal with our crappy roads.

[85AW20v]

..... My problem is finding a decent set of 17" rims that will fit over the Brembo front calipers and over-sized rotors. Anyway Jim has a very valid point. ......

It might even be easier/cheaper to check out some other brake setups. You might only need to change the disc and the caliper bracket to move the calipers in enough to clear a 17" rim. As you've said before Charlie, it was built as a show car so on 18's it looked good. I doubt you hardly ever, if at all, get anywhere near the braking limit of what you've got so you probably wouldn't even notice the difference if you went down in disc size.

Just a thought anyway......

[GlanzaAtHeart]

Howdy everyone,

Just thought I'd give an update on what happened for future users deciding the same thing.

Through Redline Performance NZ (Great guys FYI), BC Gold springs are $129 incl GST per pair. They DO NOT carry Swift Springs, but am looking through my options at the moment.

The fronts are 62mm ID (2.5"), and 150mm long. The lowest spring rate they have is 4KG

The rears are 62mm ID (2.5"), but 200mm long. Again, lowest spring rate is 4KG.

This is important to note if purchasing springs elsewhere. I asked Autolign what they can do and they said they'd give me a call back regarding their pricing but they can definitely source some.

[GDII]

Don't forget that the rears should generally be stiffer than the fronts due to the engine weight. So 4kg front and 6kg rear is a noraml standard. Not saying it's best or even good but if you look at TRD springs, the rates are, as spec'd by TRD themselves.

Soft Kit 48130-SW220
Front 48231-SW212 29.4N/mm 2.9kgf/mm
Rear 48132-SW213 53.9N/mm 5.5kgf/mm
2.6kgf/mm difference

Soft Kit 48130-SW230
Front 48231-SW212 29.4N/mm 2.9kgf/mm
Rear 48132-SW200 60.8N/mm 6.2kgf/mm
http://trdparts.jp/english/parts_spring.html
3.3kgf/mm difference.

Stiffer rear also helps it turn in better along with all the other variables like ride height (front vs rear), damper rates, swaybar stiffness and car weight distribution and how you drive the car. One suspension setup might work for you but it might not work for someone else.

[GlanzaAtHeart]

Don't forget that the rears should generally be stiffer than the fronts due to the engine weight. So 4kg front and 6kg rear is a noraml standard. Not saying it's best or even good but if you look at TRD springs, the rates are, as spec'd by TRD themselves.

Soft Kit 48130-SW220
Front 48231-SW212 29.4N/mm 2.9kgf/mm
Rear 48132-SW213 53.9N/mm 5.5kgf/mm
2.6kgf/mm difference

Soft Kit 48130-SW230
Front 48231-SW212 29.4N/mm 2.9kgf/mm
Rear 48132-SW200 60.8N/mm 6.2kgf/mm
http://trdparts.jp/english/parts_spring.html
3.3kgf/mm difference.

Stiffer rear also helps it turn in better along with all the other variables like ride height (front vs rear), damper rates, swaybar stiffness and car weight distribution and how you drive the car. One suspension setup might work for you but it might not work for someone else.

That's correct! Thanks for the advice, currently I'm looking at dropping to a 4kg and 6kg setup. Just waiting on BNT to get back to me, as Redline is an 8 week leadtime.

Might take my car in to the guys at Autolign and have them align and adjust everything for me. Will see how we go.

Thanks Phil!