Question about suspension upgrades

[AL Cx5]

Just took a look under mine as winter has subsided for a bit. Apparently one of my corksport adjustable end links pulled out at some point!!!

Crazy.

Bummer! I hope Corksport makes good and replaces it.

How old are those end links?

 

[bTwix]

Approximate [stock] lengths:

Front: 290mm
Rear: 150mm

Tein Adjustable Sway Bar Link Rods

I would get the M10-290 for up to 2" and the M10-335 for a 2-3" drop. For the rear, you want the M10-120 for 2". If lowering more than 2", you'll want the M10-100.

Looks like you can order these ^^ direct from Tein:
Front: M10-290 290-350mm - up to 2" drop
Front: M10-335 335-395mm - 2-3" drop
Rear: M10-120 120-140mm - up to 2" drop
Rear: M10-100 100-120mm - 2-3" drop

Wish the reviews on these https://www.amazon.com/dp/ (commissions earned) weren't so bad
Front: SB-TR-260-10_13 - 310-370mm
Rear: SB-TR-16 - 110-140mm

Think I'll get the Tein links. Any other brands to checkout?

 

[N7turbo]

1.0-2.0" drop

SuperPro TRC10265 M10 320-365mm
SuperPro TRC1045A M10 125-145mm

 

[bTwix]

SuperPro Sway Bar End Links by Size​

SuperPro gets good reviews, ordered these:
SuperPro TRC10265 M10 320-365mm
SuperPro TRC1045A M10 125-145mm

 

[AL Cx5]

SuperPro Sway Bar End Links by Size​

SuperPro gets good reviews, ordered these:
SuperPro TRC10265 M10 320-365mm
SuperPro TRC1045A M10 125-145mm

Those should hold up to some sprited driving!

Nice looking parts.

 

[N7turbo]

I wish I had people to ask. It took me months of research to figure out my ride quality problems and find what I needed to order, including reading BMW forums and spending time under the car to figure it all out. There aren't many options for these cars or detailed discussions on these parts. I hope people find these discussions helpful going forward.

 

[bTwix]

@N7turbo @AL Cx5 agree and really appreciate all the research, experimentation, and willingness to share the knowledge because otherwise everyone would be on their own trying to figure this stuff out.

Feels like I’m one step closer to having my GT-style build complete which like @AL Cx5 includes a tune but also a full audio/acoustic overhaul which added significant weight (fiberglass subs/deadening/mass loaded vinyl). Hoping to shed some of that weight with coilovers, at least up front.

Speaking of coilovers, I’m currently trying to decide between BC racing vs Ceika M1. I’m dealing with some pothole ridden streets and lots of speed bumps which is making me consider Ceika M1 with a Comfort build (rennlist review). It sounds like BC and Ceika may use the same underlying parts and that Ceika are just more customizable.

Currently considering this setup - with comfort dampers dialed on the firmer side. Need to figure out spring rates and if I should get helper springs. Will have Hardrace front/rear ASB likely set to soft on both.

Any suggestions on spring rates and if helper springs are worth it?

 

[N7turbo]

I spoke with them the about the helper springs. The way they describe them is nothing like any other company. Normally "helper springs" just keep load on the main spring so it never comes loose at max extension. So idk if they are fos or if there's something different about them.

For spring rates, I'm eyeing 4K front, 6K rear. If you're doing sway bars, you probably don't want to go stiffer than that if this is a daily on city streets. Their default will be 6K/6K.

The only unknown to me about the rates is making sure it's enough to prevent bottoming out with a 2" drop.

 

[bTwix]

re: spring rates

For spring rates, I'm eyeing 4K front, 6K rear. If you're doing sway bars, you probably don't want to go stiffer than that if this is a daily on city streets. Their default will be 6K/6K.

The only unknown to me about the rates is making sure it's enough to prevent bottoming out with a 2" drop.

OEM spring rates are:
Front 2.94kg/mm
Rear 4.11 kg/mm

Best we can tell is stock for the AWD Turbo is 2.94/4.11 per AutoEXE. CS has different numbers but they seem a bit exaggerated to me so I'm not sure if they're accurate.

If these OE spring rates are correct
- ratio: 0.71 (F/R)

4k front / 6k rear:
- ratio: 0.67 (F/R)

From the Corksport website
- 2.1 inch front & rear drop
- Corksport spring rates were increased 17% & 32% over OE, respectively.
- front: 3.4k
- rear: 5.4k
- ratio: 0.63 (F/R)

Corksport runs iirc 3.4k front and 7k rear. Factory is also higher in the rear. H&R and Eibach drop springs are also quite a bit higher in the rear vs the front.

According to Corksport, the rates for the Turbo AWD car are about 3.0k and 5.2k.

- ratio: 0.58 (F/R)

Sounds like motion ratio may be a key reason rear springs are stiffer. Our suspension setup seems similar to this with a divorced spring in the rear, so the effective spring rates are likely different since the front is a strut and the rear is multi-link. In the hypothetical example they give, the rear springs are effectively 1/3 as effective as their rating. Here's another post from racecompeng that discusses the motion ratio for a BRZ where the rear springs are 3/4 as effective as their rating.

 

[bTwix]

re: Ceika coilovers

I'm using Ceika's comfort coilovers. Id recommend those but with 5k springs on the front instead of the 6k they recommend and with adjustable end links. 6k backs are fine. It's no luxury cruiser but more comfortable than stock while still being stiff. It got rid of the highway front hopping and feeling every crack in the road. If that's not enough, I switched the 19s to 18s that can run thicker tires at a slightly lower psi.

Agree I feel the 6k f/r is a default of sorts. But in emailing Ceika and giving them info they are still stuck on trying to recommend those rates.

Emailing BC now to see what they say as they list their default rates at 6k/6k as well. Seem to be basically the same as Ceika. But Ceika offers a helper spring option for the fronts and BC offers supposedly better Swift springs at a +$320 premium.

@Grey5ive any update on this from Ceika?

 

[bTwix]

re: BC Racing coilovers

@AL Cx5 So BC racing S/N 6248248 for 1.5" front and 2" rear drop?

I dropped my ride 1.5" front and 2" rear. The rear sits a little higher than the front, so I lowered it .5" more

It's lowered 1.5" front and 1.75" rear with BC Racing RC coilovers, Megan front and rear sway bars.

The standard spring package was for a car 1/2" or more lower than our car..

2 to 2.5 inch drop will look so nice. The standard BC Racing kit has the correct rear spring. I would have gone that low but I have to consider the other driver and parking lot curbs...

Full disclosure. My BC Racing front coilovers are not as quiet as stock. They don't clunk but make a slight noise when we hit a pot hole or rough pavement.

The standard spring package was for a car 1/2" or more lower than our car. It rode and handled great. It was too short. BC replaced the springs at no charge for a slightly taller and stiffer spring.

BC-N-37-BR BC Racing BR Series Coilovers (KF2P) 2024 Mazda CX-5 2.5 Turbo AWD Stock 5x4.5,5x114.3. S/N 6248248

I would talk with BC Racing and request the front coilovers used on the above S/N. A way to check is this top does not have camber adjustment. Always refer to your S/N when talking to BC Racing....

Shorter rear spring part #: 97 62 230 006. I have two of these along with a box of other parts that are about to get tossed...

 

[N7turbo]

Now I'm questioning if I should have gotten these front end links:
- SuperPro TRC10245 300-345mm

This is the one I am running.

With a 2.1" drop on Corksport springs, it is the bare minimum length. I can only dial out like 95% of the preload rather than the ideal 100%.

So if you lower no more than 2.1 inches, they will work. But TRC10265 gives you the ability to dial out all preload if you are on CS springs.

I am sure you can't feel the difference, but I still like to do things to the best of my ability.

 

[bTwix]

End links arrive today. Can I zero the preload for one axle on ramps and the other on the ground or does the car need to be level on all 4 corners when zeroing out the preload?

 

[N7turbo]

You can do the front on ramps.

But I couldn't tighten the top jam nut from there. I had to bring the car down, loosen the lug nuts, jack it up (a process when lowered because you can't access the crossmember point anymore), and take the wheels off.

 

[AL Cx5]

End links arrive today. Can I zero the preload for one axle on ramps and the other on the ground or does the car need to be level on all 4 corners when zeroing out the preload?

That was quick ship.

As long as there is no preload with full weight on a level ground you will be okay. Getting each link to match the other side is not needed. On my race car, there is some interference on one side. The link is about 3" shorter than the other side.

I put my car on several 2 x 16 x 3' boards and wheel chalks I keep around for this purpose.

Preload can be tricky. Adding preload to make the car go straight at WOT may make the car turn left when applying the brakes. If you ever watched drag cars crash a the end of the race, they likely had to much preload to make the car go straight at WOT. They hit the brakes and the car goes left into the wall....

 

[N7turbo]

Since these links don't have excessive threads to play with, I recommend getting both sides as close to equal as you can. No, they don't need to be perfect, but there's no reason you can't have them within a thread or two of each other if you take your time.

 

[N7turbo]

My jacking process uses all 6 points (the 4 on the frame plus the front crossmember and rear AWD differential) as follows:

1. Jack rear right, place stand at front right
2. Jack rear left, place stand at front left
3. Jack rear differential, place stands at both rear right and left
4. Jack front crossmember, raise front stands
5. Jack rear differential, raise rear stands if needed

Once you have them installed on one end, then you can bring the car down to connect the other end and adjust.