Upgrading springs?

[BrianG]

Hello,

I have a lot of weight in the hatch (stereo gear) and the back end sags about 1/2"-1" lower than the front. I never had any problems with bottoming out with the stock tire setup (once the TSB for the plastic thing in the fender was done). But now, I have some 225/40R18 wheels and it seems I bottom out when turning hard around corners with less than even pavement or just hitting a decent bump.

I'm not interested in lowering the car or installing a body kit. I just want something stiffer to compensate for the added hatch weight. I know there are Eibach Sportline or Pro-kit springs, but is that what I need since I don't want to lower the car?

 

[bbrich57]

Brian,
I sometimes carry weight in my hatch too, and I tow with this vehicle and have noticed a lot of sag as well. This had led me to wonder the same thing, but all I have found are lowering springs on the market. I don't need to lower my car either.
My 3 reminds me of some of the old Austin Healeys which had an unbreakable drivetrain and a tough front suspension, but were often caught sagging in the rear. It seems the weak link in it all.
My only suggestion, though I haven't yet looked myself, is to find a "spring" shop and have a new set of rears wound of thicker or more dense steel.

 

[BrianG]

Hmmm. That wasn't what I wanted to hear.

I stopped by a tire place today and explained the situation and they didn't know either. I don't even need stiffer springs, just something that will return the rear to the stock height. If it happens to be stiffer, then fine, but it's not specifically what I'm after - it would just be a collateral benefit. Getting a pro kit or whatever would lower the car even more than it is. The guy at the tire shop is going to do some research and call some people, so I might have more information on Thursday.

I figure I can do one of five things: get taller springs, install a 1" spacer on the springs, maybe get an adjustable shock, remove the weight, and re-install the stock tires. The taller springs seem to be difficult to come by. The spacer is not a great idea because if they are too tall, the lip that holds the spring in won't do its job. I don't see how an adjustable shock would work since they just dampen the movement, but it was something suggested to me. Removing the weight is simply not an acceptable alternative. Re-installing the stock tires does not really solve the problem as the sag is still present - it's just not causing a problem because they are so small.

I was hoping for a relatively easy and inexpensive fix (around $200-$300), but custom making some springs doesn't sound like it would be neither inexpensive nor easy. What about using springs from a different and heavier Mazda vehicle? Any Mazda mechanics in here know the size and spring rates who can offer some advice on a suitable replacement?

There must be other people with aftermarket tires with the same type of problem (aside from you bbrich57).

 

[goldwing2000]

What offset did you get on the wheels? That could be part of the problem.

Since the Mazda3 doesn't use struts in the rear, you might be able to put in a set of air shocks. If they don't make any for the specific application, you could look at the specs and find a set that would work with only minor modifications.

That way you could "air up" when you're loaded and "air down" when you're empty.

Alternately, you could go with air springs. It would probably cost more than a couple hundred dollars but it would be a good fix.

 

[BrianG]

Thanks for responding GoldWing. I'm not sure right off what offset I'm using, but I can find out tomorrow. All I know so far is that I'm using ICW wheels, which are 18". So, according to that link, they are either 37mm or 45mm (but I think 45mm is the right one). And I'm using Kumho tires. The tire size is 225/40R18. I've heard of others with similar sized tires but no reports of what I'm seeing - and I imagine others have audio equipment in the hatch as well.

So, using springs from say, the heavier MZ6 won't work (or similar idea)?

Out of the two suggestions you offered, air shocks sound the most feasible in my budget (I think). I thought shocks were simply dampeners to keep the springs from bouncing and had no effect on ride-height? So, they do have some sort of ride height adjusting feature. Interesting. I won't have to adjust them often - just once to offset the weight from what is in the hatch, which is constant with small variations for groceries or whatnot.

 

[goldwing2000]

45mm sounds about like the right offset for ya.

I have no idea if MS6 springs would work or not. It's conceivable, since they use a similar suspension setup but you would have to acquire a set and measure them to be sure. Even if they did physically fit, the spring rate could be all wrong and make your car look like a cat in heat.

You're absolutely right. Normal shocks don't do anything for ride height. Air shocks do. Think of it as a shock absorber and air bag all in one. Add air, ride height and load carrying capacity goes up. It's like a coil-over, except easier to adjust.

Here:

http://www.monroe.com/products/mp_detail.asp?cat=0&detail=Max Air

I don't see a direct application but this page has links to the dimensional sheets.

I used a similar method to find a pair of air shocks to put on the front of my old Chevette.

Oh, and speaking of coil-overs, a set of rear adjusters from a pair of coilovers would work, too. I don't know if the companies who make them would sell you the adjusters separately, though.

 

[BrianG]

Thanks goldwing. I looked at those links you sent and am lost. There was nothing for the MZ3 and those other application charts are too much for me. I have no idea where to look or what to look for. All I know is I'd like to have something relatively inexpensive that would increase my rear height back to stock settings.

I guess I'll have to leave it up to the experts and trust they won't rake me over the coals. Some of those places can sense when someone walks in who has no clue and will recommend items they don't need just to make a few more $$$. Time to start hunting the Yellow Pages for suspension shops...

 

[goldwing2000]

Yeah, I said there were no direct applications. What you'd have to do is get dimensions from the stock shocks and find something in the "other guide" that comes close to those dimensions.

I can just about guarantee that a shop isn't going to want to do that for you. It would be too much liability to install non-recommended parts. They would probably to make something completely custom.

You'd be further ahead calling one of the companies that are already making air suspension kits for this car and asking about buying just the rears. Do a yahoo search and you should be able to find a few people to call.

 

[Solo2Protege]

To take some simple technology from Nascar, what about spring rubbers?

they are like discs (or similar) you insert into the coils. This does 2 things, A) does not allow the spring to fully compress and B) it will stiffen up the rate some.

I have seen some at Autozone, Pepboys etc.

This would be by far the easiest and cheapest fix, not sure how effective they'd be longterm, but worth a try.

 

[bbrich57]

To take some simple technology from Nascar, what about spring rubbers?
This would be by far the easiest and cheapest fix, not sure how effective they'd be longterm, but worth a try.

Yes, thanks for the reply and the suggestion Solo2.
I have thought of this too but wonder what other problems could be caused by these in the long(er) term.
I used to hear that they can fall out at inconvenient times, but I don't have any direct experience, or know anyone who has, with them. Does anyone here have any experience with these donuts?
If not, I may just try them and see if it solves my problem.

 

[Solo2Protege]

drill a hole through the rubber and secure to the coil(s) with zip ties.

they'd be just like adding stiffer springs, when used with OEM shocks, they'd tend to wear em out a little faster.

 

[bbrich57]

drill a hole through the rubber and secure to the coil(s) with zip ties.
they'd be just like adding stiffer springs, when used with OEM shocks, they'd tend to wear em out a little faster.

Excellent suggestion!! I'll try that.
Thanks again, Solo2! (cheers)

 

[BrianG]

I talked to the tire shop guys some more about this and they don't really recommend going with those rubber spacers - but I didn't really understand since I know little about suspensions.

They did come up with something that sounds promising and not too expensive though. For right just under $200 (is this a good price?), they can install airbags inside the coil springs. At first they were going to go all out and add a compressor with a switch so I can raise or lower at whim, but I told them I wouldn't be changing it often, if at all, once the height gets back to normal. Instead, they are going to add a valve (like a tire valve stem) inside the trunk so I can manually release air or add air using a regular tire pump. The only time I may need to adjust it is to add some air in winter and remove some in the summer due to temperature of the air (expansion/contracting). They said these should also stiffen the back end a little as well, so handling should improve. This should solve all my issues if it works as advertised. :fingers crossed:

At first, I was a little leary about using airbags because I thought they replaced the springs. If that were the case, I'd be in trouble in the unlikely event of a "blowout". But since they go inside the springs, the springs would take over until the bag(s) are fixed.

bbrich57, I'll let you know how they work. If they seem to do a decent job, you may want to try something like that, except you might want to go for the compressor and cabin switch so you can adjust it on-the-fly when you tow something. My weight is pretty constant, so I don't need to go that far.

 

[bbrich57]

...bbrich57, I'll let you know how they work. If they seem to do a decent job, you may want to try something like that, except you might want to go for the compressor and cabin switch so you can adjust it on-the-fly when you tow something. My weight is pretty constant, so I don't need to go that far.

Cool Beans, BG!! That is exactly what I was hoping/looking for, only I couldn't find a supplier for a "3". 'Guess I didn't search HARD enough.
I found air springs too, but they are different (and much more expensive) than supplimental air bags.
So y'all don't get the wrong idea, I only tow a small trailer once in a while. But since my car is a grocery getter, a sports car and a pick-up truck in one, it has to be flexible. I didn't want a pick up truck although living in out in the country, it would come in handy on a pretty regualr basis.
I would appreciate anything you can tell me, Brian! Thanks! You made my day.

 

[BrianG]

Well, I have some bad news and some good news:

Bad news:The shop thought they had an airbag supplier, but turns out they don't have anything that will fit.

Good news: Despite the reservations they told me about before, they installed some spacers in the center of each coil (the widest gapped one). The spacers look like a strip of thick rubber that sits between the coils and goes all the way around one rotation of the coil. They certainly did the trick and now the rear end sits where it is supposed to.
Yay! (cabpatch)
The ride seems a bit stiffer now (which is OK by me) and I have less body roll on corners. I guess time will tell if there will be any negative side effects from the installation. Best part is that they are CHEAP at $10 each ($20 total)! But they didn't charge me yet because they want to see how they will work. They told me to come back after a while to see if everything is holding up.

On a side note: I will have to say this shop has the best customer service I have ever seen in any shop! They have spent a lot of their time at no charge to me to research the issue and work with me to make me happy. When they say they will contact me the next day, they do. Most places don't care once the sale is made. As a matter of fact, when they installed the spacers today, I had asked them to do an oil change and they forgot when I got back. Because I had to wait a while (other customers in front of me) they didn't charge me for the oil change because I had to wait longer due to their error. So, if anyone is in the Des Moines area, do me a favor and take your business to Big-O Tire in Altoona (next to Wal-Mart) and you won't be disappointed (and no, I won't get any kickbacks or special deals). They deal with their customers right! Their prices are competitive too, but even if they were higher, service like this is worth a few extra bucks IMO.

[Edit]:
I almost forgot: While the car was on the lift, I noticed a smudged area where the bump stops (on the lower arms) must have come up against the top of the coil spring area. That means the car must be bottoming out. The clunking sound I hear is probably the rubber stops hitting when cornering. Hopefully this will go away as well...

 

[bbrich57]

Bad news:The shop thought they had an airbag supplier, but turns out they don't have anything that will fit.

Hey Brain, 'Glad for the update. Thanks!
Boo! (burn) Too bad, but chances are there won't be a supplier for these cars. There only seems to be two of us here that have this problem and are worried about it. It wouldn't be worth it to a supplier for the number of takers... you and me. (cheers)

Good news: Despite the reservations they told me about before, they installed some spacers in the center of each coil (the widest gapped one)... ...They certainly did the trick and now the rear end sits where it is supposed to. Yay! (cabpatch)
The ride seems a bit stiffer now (which is OK by me) and I have less body roll on corners. I guess time will tell if there will be any negative side effects from the installation.

I figure we are both going to have to settle on this fix. Since you have effectively eliminated the use of one complete coil, the ride will be stiffer (and roll rate reduced.) It's only the center of gravity that hasn't changed. Often, this is how companies that produce lowered springs tout increased rates, not that they necessarily increase the diameter or the type of steel used. And it will put more stain on the additional coils that are still in service. A long term affect, IMO. I had heard this about donuts before, many years ago, but hopefully the sping steel producers have improved their processes and QC is up from then.

On a side note: I will have to say this shop has the best customer service I have ever seen in any shop!

It sounds like you found a shop you feel you can trust! That's GREAT, and hard to do. It almost makes me wanna move to Des Moines.... NAH!! (poke)
Thanks again for the update!! I was hoping that air bags could be had, but am not surprised either.
Happy Motoring, Brian! And remember... Drive Fast, Drive Crazy!!

 

[BrianG]

I initially thought they were going to put a spacer at the top or bottom of the spring (like a rubber washer type of thing), which increases the risk of the spring popping out of the "cup" that it sits in. That type is one that I've seen some very bad stories with. Obviously, this is different so I feel confident all will be well.

About long term effects; the more I think about it, the more I wonder why there would be any at all. The rubber "donut" simply goes inside the coil with the weakest tension (and most travel) keeping it from compressing. The top and bottom parts of the coils (where they are stiffer and offer less travel) aren't seeing any more weight or use then they were before, right? The worst case scenario that my limited intelligence can think of is if the rubber donut were to fall out. OK, so it falls out and the suspension returns to stock. The car will be a little uneven until both sides are the same, but I don't think it is cause for serious concern, unless I'm doing 118mph at the time, which will never happen in the foreseeable future.

However, if anyone can explain how or why this will cause long-term effects, please let me know.

 

[BrianG]

It's been a long while since the last entry in this thread, but I wanted to post an update, and yet another question.

After running with the rubber spacer for a while now (over 2 years), it seems I need new springs in the rear. The spacers aren't keeping the back end from bottoming out anymore (when I say "bottom out", I mean the rubber stops hitting the frame). So, removing one of the coils did place more stress on the other ones. Poo. Oh well.

Anyway, since this car has been out for a while now, does anyone know of a stiffer spring set that will keep the same ride-height? Every solution I see stiffens the rear, but also drops it as well. The car is already low enough in stock form for my uses (and the ruts/potholes/weather in this state). I'll probably update the dampeners too to compensate while I'm at it.

 

[goldwing2000]

I think finding a set of air bags is still going to be your best solution.

 

[bbrich57]

Yes. I agree. I know of no one that makes a stronger rear spring that does not lower the car.
With air bags becoming more and more popular I'm sure someone could install a set for you. I do not think it would be your average w/e DIY though.

I have a friend/coworker now who's second job is doing just that. They chop, channel and bag all kinds of vehicles, new and old, but also they only do (or have done) American iron. I'm sure somebody out there would tackle a rice-burner though.
I also know of one other here in Austin that bag thfront of his 3 sedan. He talked about doing the rear too, but I don't know. We have lost contact w/each other.