New member here. Kind of long winded but here it goes. So a few questions on 3/5 interchangeability.

I have (my wifes) 2014 Mazda5 which I may inherit shortly and since I need to do all of these items anyway I might as well upgrade as other than the mileage the 5 is in great shape. Collaterally I also need to replace the entire suspension on my 2012 Mazda3 which is completely shot. Right after a bought the car in 2014 I put Biltseins on it and promptly got t-boned trashing the rear shock, but the fronts are still on it. Money is not infinite and considering both cars are over 100K miles I want to cut corners where it make sense by possibly using parts cribbed from a Speed3 or...? The body & drivetrain on the 5 are excellent, on the 3 not so much & rusty too. And I have this weird fantasy about autocrossing the 5 and at least not finishing last.I can't get too carried away as in northeast Ohio we have bad winters creating a plethora of massive chuckholes that I inevitably seem to find.

Questions swirl primarily around the front struts. I want to upgrade springs & shocks. Researching various sites like RockAuto & Shockwarehouse I am getting mixed signals as to strut interchange but the shocks seem to interchange. I would like to use Bilstien B6 or equivalent shocks. Has anyone put M3 shocks on the M5? I have seen posts elsewhere that say H&R can offer some springs that will lower my tippy little friend about 1".

Also want some camber plates & rear camber bars. Some moderate poly bushings for the suspension & swaybars.
The 5 is a real leaner. I compared the swaybars (did not get under the car) and it does not appear the 5 front swaybar will bolt onto the 3 for a cheap upgrade. Wondering if the Speed3 front bar is thicker Or if the aftermarket rear bar for for the M3 from Racing Beat or Progress will fit the 5.

All knowledgeable advice is welcome.!!! TIA, Bill

 

Welcome to the forum

 

NEVER use any parts l; look up except DIRECVTLY from the manufacture's website and their application guide.

As for the suspension upgrade recommendation you are all over the place with what you seem to want to do and what you want to use. It is a poorly mis-match combination that will likely cause the Mazda to ultimately handle worst then stock....... I get it as its great to dream but the reality is your idea will make the Mazda in the end handle like a pig on the street and fighting you on a road track.
Sorry dude but you first need to be realistic on what you are trying to achieve? The other thing is asking what people used would first need to have a same reference point, i.e. miles and generally the same mechanical condition as your Mada as well the same tire and wheel package. So, you can see where this is going.


Mabe take a breath and answer a few of the questions?

 

Thanks. Fair enough. First the desired drive parameters. This vehicle makes regular trips from Northeast Ohio to the east coast along route 76 in Pennsylvania. 76 is a road through the mountains with a number of long climbs and down hills and plenty of high speed curves. Driven near the speed limit the Mazda five is a real dog, and you wind up kicking it in and out of passing gear way too often, makes the drive a hassle. However, take it up a couple of notches and keep your momentum and it is a much better drive overall. So the goal is to dial the suspension in to optimize it for the road trip, which by the way will improve overall road manners.
no company makes aftermarket engineered kits, springs and shocks for this vehicle. So it is a DIY. Been doing a lot of research and by cross referencing sites have determined I can use the Bilstein front struts, which probably means I can use the counties and the other major brands. The problem becomes sorting the springs if I want to lower the car an inch or so. I have found other posts where it was claimed to be successful using H&R springs but no reference part numbers.
with lowering the car, and frankly even without lowering the car something has to be done to get a proper alignment on it as from the factory it is a toe-only adjustment. so I will add camber plates to give it a little negative camber, maybe three-quarter-1° and a little more caster. Have to find the original specs, but my past experiences at speed in other vehicles I’ve set up kind of show a minimum caster of 4°. I believe I have determined that the Mazda three camber plates will fit and if they don’t, they flow downhill to my Mazda three which also needs work.
The 17 inch wheel and tire combination finally works pretty well with the latest Pirelli‘s I’ve mounted. Good sidewall stiffness is essential to controlling the body roll on this vehicle and I have had some tires on it that are downright scary. Unfortunately just because the basic name of the tire is the same year to year does not mean the construction is the same and this vehicle really highlights any changes in the design of the tire regardless of the name. it plows like a pig like most OEM set ups, and I am used to driving cars that oversteer so I would like to fix that a little bit. I don’t see roll bars that are bigger than the stock one for the front but there is a rear bar available that could help.
to summarize, the desire is to lower the center of gravity improve the wheel alignment and reduce the role to enhance handling on mountains highways.

 

PS - I understand the whole sprung, un sprung weight issue etc. with the shock selection but it’s gotta be better than the crappy parts store standard stuff.

 

Ok so don't take this wrong... I am sure you will but you are trying to upgrade for street driving a really bad choice of a vehcle in all respects. Not to mention some of the things you have come to understand having to do with upgrading suspension is just wrong and dangerous. A couple of what you think is short comings in the Mazda is actually your shortcoming in driving abilities. As for [parts while many parts will interchange and can be used on your Mazda that does not mean that they are inferior to what you want to do.I rune rear KYB GAS-Adjust on my Mazda and there is no application guide for that or even for many other Mazda's. However, being somewhat experienced in building Road Track vehicle and suspension parts I looked into the actual specification of the KYB dampener I was wanting to use. This is the same for your thoughts on coil springs. You need to learn the difference between progressive and non-progressive spring and then the spring rates published by the manufacture and then use math to determine if they are the best choice. And lower your Mazda as much as you want is not only ridicules for a non-Track only vehcle but will actually make for sudden unexpected weight transfer in off camber roads dangerous. Ther is no fundamental reason to lower a street vehcle that low except to look "KOOL". Not to mention toss the steering geometry right out the window unless you engineer a way to bring it back to the Mazda engineering specifications. In all your info you failed to even mention anti roll bars and frame strengtheners. If you continue with your thought process and how you describe where you drive you will twist the body, and it will react badly and so fast that you are likely end up off the road.

I could go on, but I can see the responses now coming and frankly while I do appreciate a good project I also hate reading when someone is so far off from build or upgrading something that will in the end just be a waste of money time and likely be an unsafe vehicle. Oh and look at the power to weight ratio,,,, no comment.

Sorry Dude I know this is an unexpected response ................. but someone should and needs to tell you?

 

I appreciate your perspective. But it’s a run what I bring type of thing. I too have built cars for track and auto cross. At tracks like Nelsons Ledges, Mid-Ohio and Watkins Glen. And bikes. Minor lowering with appropriate compensation of spring rates and alignment should not create any issues. 1” Lowering doesn’t hurt anything if you make the appropriate compensations as long as you’re not on the bump stops in the corners. By your logic no one would mod anything as “the factory knows best”. If you are running KYB gas adjust on anything you aren't running very hard or fast. Appreciate your post but is seems i am not going to find the sort of makes specific tech knowledge on this site like i am used to on the other make sites. So ill keep looking.

 

Maybe take my response and show a few professionals in the business .

BTW if you ever in the future actually attend a performance driving school you may learn and understand more of what I said .

Aside from the Mazda having factory struts and springs front and rear that is only because I have not had the time to install what I do have for it. None of my other vehicles are factory suspension, and one I engineered and developed a complete performance suspension and braking system as well a part that correct for steering geometry when lowering the suspension for a BMW . Basically your not likely to find any forums especially a Mazda one useing your model Mazda with and professional experience in upgrading suspension’s.

But good luck finding one. I belong to almost all Mazda forums as well a few other forums the are more or less for sport racing.


One last thing your comment about the bump stop is another indicator you need to learn more about suspension upgrades. And you do realize that lowering also affect the engineering in most top brand gas dampeners. If you don’t get the correct one for your new installed suspension height you also change how the damper was designed to work .


As for the KYB Gas-Adjust on the rear, you should have first asked why that choice.

 

I dont need to justify to you or anyone else what i know and have done. Your posts read like you have no direct knowledge regarding my quest for data points, just “book knowledge” never applied. Probably best not to demean people you dont know. People might think you a know-nothing arrogant blowhard. I actually build (and raced) cars so you are wasting my time unproductively. I will not respond to further posts. Does thissite have a blowhard blocker function?

 

Usually when the name calling starts is when we see the true personality as well what their level of experience is with any topic! LOL
If you don't like what I posted .... well you said it there are places on the internet that will blow smoke up your **** and agree with you.
I suggest you start from basic and learn first how a suspension works. Then move on and learn how to performance drive which is more important than modding any vehcle first. Your post indicates neither of these.
Maybe go re-read everything with an open mind and maybe you might get that I do in fact know what I am talking about. LOL
Otherwise your approach and thoughts about what to do while we all are sharing the road with you are just an accident waiting to happen.
BTW had you taken the time to actually look into any member you question ion this forum you also may learn something about what they know and what you think they don't know.
How about post a picture of this street Mazda with you want to transform on a small budget and using the wrong upgrades? Anyone can see that is is not the best firt choice in what you want to do. refer to your first post on this thread.