Upgrade on 2006 rear suspension to 2012

Davicho · Mar 22, 2013

So I finally decided to bite the bullet and be the guinea pig for this upgrade. After numerous hours of research the verdict was that the 2012+ Mazda5 has an updated and reinforced rear suspension that mainly revolves around two main components: the rear springs with higher spring rate and the rear sway bar which is also thicker and higher spring rate as well. So I just ordered the following parts to do this upgrade to my 2006 Mazda5 and stiffen up the rear suspension without having to lower the height with lowering springs.

#CG37-28-011 Rear springs (2)
#CG16-28-151 Rear sway bar
#BP4K-28-156E Rear sway bar bushings (2)
#C273-28-012C Upper spring rubber mount (2)

The end links, lower control arms and cross-members are identical for all generation Mazda5 (2006-2013)

I just installed brand new KYB GR-2 shocks and I already have the two plates that hold the bushings to the cross-member (#BBM4-28-155)
I will update once I get the parts and get them installed.

Wishmaster · Mar 22, 2013

How much did the parts cost and where did you buy them?

Secondtyme · Mar 22, 2013

For those who are joining the party late, this is to address which issue? The springs would logically give you a more firm ride in the rear, especially when loaded heavily. The thicker rear sway bar will give you flatter cornering and less potential for understeer. Or is this to deal with the camber thing?

Davicho · Mar 22, 2013

It is to provide a firmer ride and flatter cornering. Also to prolong (hopefully) the life of the rear shocks. Mine has camber as well as all other Mazda5 but I love the looks of it and it doesn't seem to be an issue as far as tire wear.

Davicho · Mar 22, 2013

I bought them from Romero Mazda in Ontario, CA. I have a good friend that works there and since I also work for a car dealer network of course I got the "employee" hook up. $202.85 including tax for all those items listed above.

Premacy5 · Mar 23, 2013

How much thicker is the 2012 rear sway bar? Usually people upgrade to speed3 RSB which are sligthy more than 100% stiffer.

I have 32mm Tripoint Engineering RSB set at the softest setting and it still about 400% stiffer. It's prett rough with OEM shock. I have KONI sport now and its much comfier.

Davicho · Mar 23, 2013

I don't know any measurements yet but I will get specs once I get them next week. Visually the RSB is thicker on the 2012+ Mazda5 then those on the first gen Mazda5. So since I am running OE Spec KYB shocks I wanted to upgrade my rear suspension to a bit stiffer without having to lower the height and keeping OEM parts. I consider it a simple, easy and affordable upgrade.

Davicho · Mar 25, 2013

UPDATE:

Decided to ax the 2012+ rear sway bar since I confirmed that both first gen and second gen Mazda5 have identical 20mm rear sway bars. 2012+ has beefier bushings but that's it. So I am still doing the stiffer (higher spring rate) 2012+ rear OEM coil springs but I am doing a first generation Mazdaspeed3 rear sway bar (26mm) as soon as I get confirmation from Silentnoise or someone that knows or has done this already whether it is a direct bolt on swap and if I can use my stock Mazda5 end links with the bar.

Premacy5 · Mar 25, 2013

I am not sure about the first generation Mazdaspeed3. The Tri-Point engineering swaybar on my car came from second generation Mazdaspeed3 and its drilled for 12 mm end link stud. My Mazda5 came with 10 mm end link stud. Luckily its only drilled larger in the middle setting so I just the softest setting.

Davicho · Mar 25, 2013

Thanks for your input on the Tri Point. However, I need confirmation on the OEM first gen rear sway bar. Thanks!

Robotazky · Mar 26, 2013

(popcorn)

tech_az · Mar 27, 2013

I really hope this works out for you Davicho.

Maybe, my suspension issues are clouding my judgment, I'm being pessimistic, jumping the gun or I didn't listen/pay attention carefully enough but... the suspension combination I have in the rear now doesn't sound or feel that much different than what I had before with the KYB's. My brother, who recently borrowed it, acknowledged this as well . I know this contradicts what I said earlier in the other thread. I just thought I would throw it out there. Hopefully my take on this will change after I put the right size bushings back on. If my perception doesn't change, perhaps a stiffer spring and thicker sway bar in addition to what I already have would help.

I know Robotaz and many others changed to Koni shocks only and noticed a significant difference. I think it was because their shocks were actually "shot". I don't mean to mislead anyone... just my 0.02.

Davicho · Mar 27, 2013

Nah your good tech. I'm mainly doing this not because my rear suspension was feeling or sounding bad. I have read and confirmed through lots of research that the new gen 2012+ rear springs are of a higher spring rate then those on our first gen. So since they were fairly cheap to buy new I bought them. I am also waiting for a first gen Mazdaspeed3 rear sway bar to arrive just to get a better and more firm cornering feel from the thicker 26mm bar. KYB feel good btw.

Davicho · Mar 30, 2013

UPDATE:

I finally got around to installing the new gen (2012+) MZ5 rear springs and upper rubber mounts. I did a before and after measurement with old springs and new springs without a load and with a 200lbs load behind the third row. To my surprise they both measured exactly the same. ~27" (from floor to the bottom of the wheel-well) and ~26.25" with a 200lbs load. The feel can be subjective but to me it felt a lot firmer, not harsh and stiff but firm nonetheless. I have not installed my RSB that is in transit that came off a 2009 MS3. I will do that as soon as I get it. So for now, as far as measurements it seems like the old gen and new gen provide the same height with or without a load. However.....the old spring has a total of 9 complete coil and the new gen spring has only 8 coils that are spread out further apart, also, both new and old gen springs measure the same as far as coil thickness ~12.5mm thick. This could be why they also feel firmer do to their progressive rate. The upper rubber mount is also a lot more substantial compared to the old gen rubber mount. Here are a couple of pics.

This was the measurement without a load with old and new gen coil springs

This was the measurement with a 200lbs load with old and new gen coil springs

The 200lbs load

Old and new springs

Top rubber mount old and new

Overall I am happy I did this because to me my rear suspension does feel a bit more firmer, at the very least I got a new set of rear springs and any sagging or weakness the old ones had is now replaced with this new set up. I will report once again when the MS3 RSB goes on.

Secondtyme · Mar 31, 2013

Liking the looks of the more substantial rubber for the spring mount! I wonder if that is the fix for some (not all) of the rear end clunking I hear...

Davicho · Mar 31, 2013

Today I drove 50 miles loaded as I normally do in the weekend (wife, toddler, baby, myself) plus gear and what not. I can definitely confirm that the rear suspension feel a lot more substantial, smooth, and firm then my old set up. I am definitely happy and satisfied with the upgrade. It seems to absorb road imperfections a lot smoother and without breaking a sweat.

rodslinger · Apr 1, 2013

Davicho said:
Today I drove 50 miles loaded as I normally do in the weekend (wife, toddler, baby, myself) plus gear and what not. I can definitely confirm that the rear suspension feel a lot more substantial, smooth, and firm then my old set up. I am definitely happy and satisfied with the upgrade. It seems to absorb road imperfections a lot smoother and without breaking a sweat.

Can you check the spring tubing diameter of each? In the picture they look the same but it is hard to tell from a pic if one if a few thousandths thicker than the other. Looks like the 06-10 coil has 8.5 turns while the 12+ coil has 7.5 turns with about the same free length. If the rod diameter is the same I can see how it would be a little stiffer.

Davicho · Apr 2, 2013

I will get some precise measurements on both old and new spring coil tubing. The coils are definitely spaced out further apart I will also get a measurement on that and post it.

I installed MS3 rear sway bar yesterday and OMG what a difference. That rear sway bar should have been the one from factory. Way better handling. Thanks to the combination of 2012+ MZ5 rear springs, upper rubber mounts, 1st gen MS3 RSB, 1st gen MS3 end links and combined with new KYBs the entire suspension feels firm, responsive, smooth and substantial. If anyone out there with 1st gen MZ5s want to dramatically improve their rear suspension without having to lower height you can't go wrong with the set up I did. On 2012+ MZ5s please upgrade your RSB to one from an MS3. To both MZ5 gens please use a 1st gen MS3 RSB because 2nd gen MS3 RSB will not fit.

njaremka · Apr 4, 2013

excellent thread. thanks!

Davicho · Apr 14, 2013

I axed the OEM rubber bushings (there was nothing wrong with them, just wanted to go with Polyurethane bushings instead) and in came Prothane (#19-1142BL) 26mm rear sway bar bushings and brackets.

Upgrade on 2006 rear suspension to 2012

Member

Member

Member

Member

Member

Member

Member

Member

Member

Lover of 5's

Member

Member

Member

Member

Member

Member

Wiggity-Wack-O-Tack

Member

Similar threads