H&R Lowering Spring Issue

I recently had a shop put H&R lowering springs in my 2018 CX5 - the front rides fine but the back is super firm - like it has barely any suspension at all back there. I have lowered heaps of cars before and I know this doesn’t feel right - the balance front to rear is way off. Any ideas? My car is front wheel drive and is super light for a CX5 - 1550kg I think - (3417lb) I have checked and they are apparently FWD springs not AWD. The installer said there were no bump stops on the rear shocks at all - not sure if that means anything. Do I need to change shocks maybe? It rides a little better with a bit of weight in the back, but it’s still not tolerable. Thanks for your help!
 

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I believe the bump stop is built into the dust boot. I know h&r didn't list the need to cut the bump stop, but MAYBE it was an oversight and you do need to cut it. That would explain why you feel there's no travel at all.
 
I believe the bump stop is built into the dust boot. I know h&r didn't list the need to cut the bump stop, but MAYBE it was an oversight and you do need to cut it. That would explain why you feel there's no travel at all.
Yes yes yes. The more I think about it, the more I am certain I am riding on the bump stops. H&R said they are only 25% stiffer, so it’s not the springs.
 
Corksport requires about 1.5 inch or so chopped from the bump stop. Might want to look into that
 
I got the bump stops trimmed by 50 mm in the end, it’s ok now. I still think it’s firm in the rear but it’s totally driveable now. I don’t know why H&R springs drop it so far in the back - bizarre. I feel that shock travel is compromised, and it looks stupid. At some point I may get custom rear springs to even it out a bit - 30 mm front and rear would’ve been fine.
 
Get a set of bilstein b6 shocks. They’re super stiff in compression rate and will give you what you’re looking for in the rear. It even lifted the rear a bit after installed.
 
Get a set of bilstein b6 shocks. They’re super stiff in compression rate and will give you what you’re looking for in the rear. It even lifted the rear a bit after installed.
Sweet. Do they work ok in a KF 2018 front wheel drive you reckon?
 
Seems like all suspension parts, FWD/ AWD are interchangeable. So I’d say yes.
 
I am tempted, although it is a sizeable investment putting Bilsteins in - especially front and back - at the moment I don’t feel I’ve really achieved that much with these springs, the car looks tougher, yes, but the back end sitting lower annoys me. It does corner much flatter, but is that really any more fun? Maybe not. Especially when the trade off is such a jarring ride. It handled so brilliantly before - even with a bit of roll. I feel like I’ve ruined the car a bit. Bilsteins might make it the car I hoped I was going to get - with better handling and those tough looks - but am I willing to spend another $1000 or so on that gamble…. Hmmmm. Definitely not right now, that’s for sure!
 
42:50 you can see it's a long bump stop you need to chop half away for Corksport
Can anyone corfirm if we can use the eibach bump stop kit (part # bs770044) Eibach Bump Stop Kit with the corksport lowering springs instead of cutting the oem bump stops?

This way if one decides to revert back to oem setup all the parts are there intact.

I will try to contact my local mazda parts dealer and see if I can get a price on the oem front and rear bump stops.
 
Can anyone corfirm if we can use the eibach bump stop kit (part # bs770044) Eibach Bump Stop Kit with the corksport lowering springs instead of cutting the oem bump stops?

This way if one decides to revert back to oem setup all the parts are there intact.

I will try to contact my local mazda parts dealer and see if I can get a price on the oem front and rear bump stops.
I started worrying about that but then I figured who cares, so what if you have shortened bumps stops and go back to factory height? You will be much less likely to hit the bump stops at factory height anyway. I think if I was selling the car at some point in the future and for some reason it was back at the factory height, I would just tell people it was running lowered springs for a while and the bump stops were shortened. My car has so many mods I think it would mainly be car enthusiasts buying it anyway - most would probably prefer it lowered I think.
 
There is a number on the springs maybe you should verify that they are correct for your vehicle.
In your other thread I believe I sort of suggested to consider all the situations before just lowering your vehicle. Its not always about how low but also what the spring rate is. H&R traditionally have a higher spring rate compared to other manufactures for their kits.
 
I am pleased to report I finally sorted this issue out by getting custom rear springs made to give a 30m drop - making the drop even front to rear now. The custom spring is not progressive like the H&R and rides infinitely better. I can’t tell any difference in the ride from the OEM springs (which were most recently in the car) and it hasn’t bottomed out or hit the bump stops yet either. I can’t believe how easy it was for a local shop to make me the perfect spring, yet a big company like H&R sells something that rides so awfully and looks completely out of balance front to rear. Won’t be buying springs from them again that’s for sure.

8E80AB27-3295-4DC8-870B-9E700488AE9D.jpeg
 
I am curious did you ever and if so, contact H&R spring with your concern. There product line is very high quality for decades as well their experienced technical staff?
The reason I asked if you did get the wrong springs they would have exchanged them or if they needed to adjust the spring specification for your MAZDA they would have I am sure exchanged them out.
While I do prefer none progressive springs on a Track vehicle they are not as forgiving for road condition on the street for creature ride comfort.

I am also curious about the cost of your "custom" springs? My guess is they simply found a stocked spring close to what was needed to achieve your particular ride height. Custom wound springs are not cheap!

I really dislike when someone just blames a reputable and historically long time supplier of a quality product without all the facts. H&R has quality spring sets!!!

I repeat
H&R has quality spring sets!!!
 
I am curious did you ever and if so, contact H&R spring with your concern. There product line is very high quality for decades as well their experienced technical staff?
The reason I asked if you did get the wrong springs they would have exchanged them or if they needed to adjust the spring specification for your MAZDA they would have I am sure exchanged them out.
While I do prefer none progressive springs on a Track vehicle they are not as forgiving for road condition on the street for creature ride comfort.

I am also curious about the cost of your "custom" springs? My guess is they simply found a stocked spring close to what was needed to achieve your particular ride height. Custom wound springs are not cheap!

I really dislike when someone just blames a reputable and historically long time supplier of a quality product without all the facts. H&R has quality spring sets!!!

I repeat
H&R has quality spring sets!!!
Sorry when I say ‘local shop’ I actually mean ‘A local manufacturer of lowering springs for road cars with over 25 years of experience’ so they seem to know what they’re doing. They took detailed ’on car’ and ‘off car’ measurements of both the OEM and H&R spring and made a spring that matched my requirements (30mm drop and 25% firmer ride) exactly - first time! I am actually quite impressed. I think they’ll make a non progressive (linear) front spring for me too just to further improve the ride quality and make the full set available to anyone else who wants a 30mm drop front and rear on their KF CX5.
As to your other points yes I spoke to H&R quite a bit and we did a lot of checks to make sure they were the correct product. Their springs actually gave a 55mm drop in the rear and the perception of a 100% increase in stiffness, which is a lot different to what they advertise - makes my local manufacturers’ effort seem all the more impressive really. The cost was a bit less than the H&R’s - they just put all the numbers into a machine and out came the springs apparently - didn’t sound that hard. The engineer said for this application a linear spring was a better option and progressive springs are quite hard to get right without a lot of R&D. (Research and development) Here’s exactly what he said if you’re interested: “The progressive coils stack up at ride height leaving fewer active coils which creates the increased spring rate and firmer ride. We made the CX5 rear coils linear to improve the ride quality. We generally only make our coils progressive when we are needing to captivate super low coils or build a lot of spring rate over an extended travel. They are tricky to get right and can take a lot of R&D”

I am sure H&R make some great products, but I have read a fair bit of negative feedback on their progressive lowering springs on other forums - for lots of different vehicles. Perhaps they should stick to linear springs if they aren’t going to put in the R&D into getting their progressive springs right.
 
You should post who the company was that you got your springs from. If you were happy as you mention, then promote their service and products. Its what forums like these are for!


Negative comments and reviews on any forum seemingly any topic even none automotive on www out balance people that are satisfied. Humans just like to bit*ch more than praise.

I also prefer linear spring for handling over progressive. The main reason is handling predictability... but most applications using a correct none OEM linear springs to improve the overall handling increase comes at the expense of ride comfort.

Your MAZDA looks good, and your resolve seems to have satisfied you.




Pre ASE proofread none edited version excerpts
.......After contacting several of the most common and a few independent less known spring companies and very few were willing to give me the spring specification or even lb rating of the springs offered. ...................
.........
why this information is not supplied or researchable on their web sites or with contacting them.

......................... The After market and chasses Suspension manufacture have NO standard for height measurement or where the measurements are taken on the vehicles. This means as an example that one brand may use the lower wheel well skirt and another may use the lower bumper to get there installed heights.

............. The Spring production supplies for a specific kit may change, supplied spring specifications change with a different rate spring within the same kit number. This means that the same kit # offered a few years ago may have different rated springs then the one currently offered with that same kit #

.......................... Really Vague definitions of specific application ranges of end user for ride height.


I found that most manufactures seem unwilling almost defensive by nature to even give performance specification other then generalized advertised information or even an approximate percentage spring rate increase over stock oem springs. But apparently after a insistent line of questioning the spring rates supplied from most manufactures range from 10% 25% increase over stock OEM springs.

Almost all used quality material and manufacture process to produce the springs So the price variance was surprising considering this?
Retail kit average price range was from 139.00 to 325.00


My conclusion is that no one Spring Supply Company has the advantage over another.
If I had to suggest a spring company I would see what other’s have used based on like modifications to your own PT to achieve the same results.

..............................................

.............................................The spring constant (stiffness) of a coil spring equals:
k = compression / force = D^4 * G / (64*N*R^3)
where D is the wire diameter, G an elastic material property, N the number of coils in the spring, and R the radius of the spring.
................................So increasing the number of coils decreases the stiffness of the spring. Thus, a progressive spring is progressive because the two parts are compressed equally until the tightly wound part locks up, effectively shortening the spring and reducing its compliance.


.........................................................................

...............................For normal driving, the vehicle uses the upper 3 or 4 'tight' winds to absorb small bumps in the road. For more spirited driving, like cornering , the coil springs are being compressed more, they resist more. The effect helps reduce the suspension travel at the top end resulting in less body roll, and better road-holding. The fact that the springs are progressively wound is what accounts for the lowering factor. The springs are not made shorter just wound differently. .....

Most better known aftermarket springs are generally made from higher grade material than factory specifications.
______________________________________________________________________________________________________

 
You should post who the company was that you got your springs from. If you were happy as you mention, then promote their service and products. Its what forums like these are for!


Negative comments and reviews on any forum seemingly any topic even none automotive on www out balance people that are satisfied. Humans just like to bit*ch more than praise.

I also prefer linear spring for handling over progressive. The main reason is handling predictability... but most applications using a correct none OEM linear springs to improve the overall handling increase comes at the expense of ride comfort.

Your MAZDA looks good, and your resolve seems to have satisfied you.




Pre ASE proofread none edited version excerpts
.......After contacting several of the most common and a few independent less known spring companies and very few were willing to give me the spring specification or even lb rating of the springs offered. ...................
.........
why this information is not supplied or researchable on their web sites or with contacting them.

......................... The After market and chasses Suspension manufacture have NO standard for height measurement or where the measurements are taken on the vehicles. This means as an example that one brand may use the lower wheel well skirt and another may use the lower bumper to get there installed heights.

............. The Spring production supplies for a specific kit may change, supplied spring specifications change with a different rate spring within the same kit number. This means that the same kit # offered a few years ago may have different rated springs then the one currently offered with that same kit #

.......................... Really Vague definitions of specific application ranges of end user for ride height.


I found that most manufactures seem unwilling almost defensive by nature to even give performance specification other then generalized advertised information or even an approximate percentage spring rate increase over stock oem springs. But apparently after a insistent line of questioning the spring rates supplied from most manufactures range from 10% 25% increase over stock OEM springs.

Almost all used quality material and manufacture process to produce the springs So the price variance was surprising considering this?
Retail kit average price range was from 139.00 to 325.00


My conclusion is that no one Spring Supply Company has the advantage over another.
If I had to suggest a spring company I would see what other’s have used based on like modifications to your own PT to achieve the same results.

..............................................

.............................................The spring constant (stiffness) of a coil spring equals:
k = compression / force = D^4 * G / (64*N*R^3)
where D is the wire diameter, G an elastic material property, N the number of coils in the spring, and R the radius of the spring.
................................So increasing the number of coils decreases the stiffness of the spring. Thus, a progressive spring is progressive because the two parts are compressed equally until the tightly wound part locks up, effectively shortening the spring and reducing its compliance.


.........................................................................

...............................For normal driving, the vehicle uses the upper 3 or 4 'tight' winds to absorb small bumps in the road. For more spirited driving, like cornering , the coil springs are being compressed more, they resist more. The effect helps reduce the suspension travel at the top end resulting in less body roll, and better road-holding. The fact that the springs are progressively wound is what accounts for the lowering factor. The springs are not made shorter just wound differently. .....

Most better known aftermarket springs are generally made from higher grade material than factory specifications.
______________________________________________________________________________________________________
Thanks yeah it was Cambridge Auto Springs also known as Cobra Springs NZ cheers. They won’t have a full set of KF springs until my fronts are done though :) Would love to save other people the same hassle I’ve been through if they only want a subtle drop of 30mm. For a bigger drop I would go for Corksport.
 
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