speeddemon32

I tested the stock front spring which we ALL KNOW is 156#'s

I tested the stock rear spring which we ALL KNOW is 113#'s

I tested a 500# spring I have laying around the garage.

I tested a 700# spring I have laying around the garage.

ALL 4 CONTROLL SPRINGS CAME BACK WITH WHAT WAS EXPECTED.

So when I test the Mazdaspeed spring, the sprint spring, the what ever spring you want, I dont know how you can dispute the rates I get back!?!?!?

Yes the perch on the spring rate checker is curved to match the springs. yes I tested more then 1"., in fact on the Mazdaspeed springs I beleive I even posted 3" of measuments.... if I rememember right it progressivly got stiffer by 10#'s per inch.


anyone else not belive the rates...... sorry, your on your own.



EDIT: ah yes, here is the Mazdaspeed spring test (ALL 3 Inches) https://www.rx8club.com/showpost.php...&postcount=100

and here are 3" worth for the sprint springs. https://www.rx8club.com/showpost.php...&postcount=130

so yes, I did test the progresivness of the springs.

Juice

iTrader: (1)

I believe you, which is why I don't have Mazdaspeed.

speeddemon32

Thanks
he he he.

I just dont see why there is even doubt, thats all.

Thanks though!

speeddemon32

oh yeah, just for Sh*#ts and giggles I tested the springs on both my flat perch, and my curved purch, they came back with t;he same results. its just a matter of what keeps the spring in the tester better.

LionZoo

It's not about not believing your testing methods. I do believe your numbers are obtained accurately. However, car suspensions are designed with several inches of droop and in a situation like the Mazdaspeed sport springs where there are no tender springs, the portion of the suspension that is designed as droop needs to be close to stock rate or else you sacrifice droop travel, which is bad for rough roads. That is why I asked how much travel is in the spring; generally a suspension will have similar amounts of droop and compression travel.

Think about it this way, if you up the spring rate by a factor of 2, you only need half as much travel as what you did to support the weight of the vehicle. If you're shooting for a ride height close to stock, that would mean losing about half your droop travel, a bad situation! Coilovers partially avoid this problem by having a low rate tender spring, but the Mazdaspeed sport spring is a standalone which means the only solution to keeping the needed droop is an aggressive progressive rate, linear or otherwise.

Considering what I've seen of the RX-8's front suspension and assuming a stock rate, there's probably something like 4 inches of droop from static in that setup.

speeddemon32

... ummmm ..... ok.

I have no idea what you are getting at.

I measured the entire spring range (with the exception of the first inch, witch is useless information anyways) and all I am trying to say here is that the spring rates I came up with are legit. the Mazdaspeed spring IS progressive, and it is progressive by 10 pounds per inch. (wooptie doooo) meaning if it was a 170 pound spring at the first inch, it was a 180 pound spring at the second inch, and a 190 pound spring at the third inch. nothing close to the 280 pound (or whatever) spring we all thought it was.

when I was looking for a new spring to go with I was looking for the stiffest spring I could find. (quadruple the spring rates would have been nice) with 285 R compound tires and the Koni struts, a super stiff spring would have been nice. but unless you go with a coil over where you can put a real stiff spring on, your just not going to get a stiff replacement spring for the struts on an RX-8.... they just dont exist for this car at this point. (Disclaimer:... none that I know of). they are all very close to the stock rates.

all the replacement lowering springs are exactly that.... lowering springs. which is not a bad thing, it makes the car look good and lowers the center of gravity... just dont expect it to be a stiffer spring by more then just a couple of pounds.



the point of my reply to this thread was to backup my test numbers. I was under the impression there were concerns my method was not valid. (though I cant see why if they read my thread) I was simply trying to prove my numbers. sorry if I took that wrong.

to answer your main question, When I called Mazdaspeed about the numbers I tested I wanted a replacment set because mine were faulty. Mazdaspeed Motorsports Developments responce was "we do not advertise these springs to be any stiffer then factory, we advertise them as lowering springs" they do not know how we came up with the 280/190 numbers on this forum. I could return them if I want, but they were not faulty springs.

take this info how ever you want it. but I have come to the conclussion going off of what Mazdaspeed said and my own, what I consider 100% valid test results, and you have yourself a Mazdaspeed lowering spring..... LOWERING SPRING.

LionZoo

There's only 4 inches of travel in the spring?

speeddemon32

realistically... yes.

when I tested the springs I had the suckers collapsed way further then it would ever be on the car. the coils were damn near touching each other.

I dont know how to be more clear then I have been. when I test a 500 pound spring, it comes back 500 pounds. when I test a 700 pound spring, it comes back 700 pounds. when I test a 140 pound spring, it comes back 140 pounds. when I test a progressive spring and it comes back progressivly 10 pounds stiffer. when I said I tested the full range, I really could not do another inch. I just dont know how to be more valid or clear then that.

I stand by my claim that my Mazdaspeed springs were as follows:

Front Spring 1
170 lb for the first measurable inch
180 lb for the second inch
180 lb for the third inch

Front Spring 2
170 lb for the first measurable inch
180 lb for the second inch
190 lb for the third inch

Rear spring 1
70 lb for the first measurable inch
100 lb for the second inch
90 lb for the third inch

Rear spring 2
70 lb for the first measurable inch
100 lb for the second inch
90 lb for the third inch

And I stand by my claim that there was nothing more I could have done to ensure I get a more accurate result. I could not have tested another inch, I could not have the stars align better then they were that night.


if anyone still thinks they are stiffer then that with all the info I have given, by all means buy yourself a set of Mazdaspeed springs (or any other spring you might think is stiffer) and enjoy them. or have them tested by someone else.

r0tor

iTrader: (1)

I might have drank too much last night (and i did... damn eagles were suppose to get blown out quickly), but last i checked there is roughly 750lbs of weight sitting on the front tires. If the front MS springs are ~170 lbs/in they would need a little over 4 inches of compression to hold the static weight... and if they have a usable range of 4" of travel they would be basically in coil bind with the car sitting on the floor

...let me look at that again when i'm more sober...

speeddemon32

and again... I didnt even bother testing the first inch or so, for one my tester wil not even measure accurately that low (it takes a 100 pounds or so to get started) and 2 do you really care what the spring rate is at inch number one? its going to be weaker then any other inch.

If you would like your springs tested from the moment the spring touches the perch, to the moment the spring coils collide then fine. send me your spring, I will run the test (which I have already done myself and got the same spring rates) and I will give you every inch. even if its a stupid test....

or you are welcome to send your springs off to someone else and let them give you the same results.

are you magically expecting the first inch or two to be way strong? cause they are not. I have to pass inch one and two just to get to the starting point of the test, I get to see the dial move up... trust me, its not stiffer, if anything its weaker.


in my eyes, some of you are disputing undisputable data. I am all for scrutinizing how test are done. I dynoed my RX-8 once and even claim that my results are somewhat inconclusive. (this is another story) but there is nothing in the spring test that is disputable. I think I have shown that time and time again already.
.

kwescott

If the purpose of this thread, as the title implies, is to get a consensus....I would go with believing the numbers found by Speeddemon32. He and I have done plenty of installs on "lowering" springs on the 8. I agree with his phrasing, and it was supported by Mazdaspeed. Most aftermarket springs are just lowering springs. In general, a review of the available options will demonstrate that most companies are producing springs that lower the car, but maintain a stock ride feel. Most people who lower their vehicle are doing it for cosmetic reasons.

I too fell into the initial trap of the numbers posted on the forum. I thought I was getting the stiffest spring out there for the 8. I was autocrossing my car, and I wanted something stiff. Not wanting to go with a Koni yellow/assorted spring combo...I thought, why not go with the MS setup of matched spring and strut.

Butt dyno results told me the setup was very similar to stock. The strut is slightly stiffer, but the spring rates, as measured...are much like stock.

So, from my own 2 cents....in an effort to add to a consensus.....pick up a stiff strut, and then match it with a spring that gets you the desired ride height....because the spring rates are much the same.

Best bang for the buck appears to be a Tein spring....match that up with a Koni yellow....? or, go coilovers.....

Ghost, who was second to post in this thread had a stiff spring/strut setup with Koni's and Vaughtland springs. He recently removed that setup in favor of a set of JIC coilovers. He asked that Speeddemon32 test the Vaughtland spring....they came back much the same as all the other "lowering" springs...rates very comparable with stock. Conclusion.....the struts was the main reason for the ride "stiffness" (for lack of better word).

When I reported the results to Ghost, his initial reaction was, that the results must be wrong. Take results for what they are worth.....at least they are more reliable than butt dynos.

speeddemon32

couldnt have said it better myself.

LionZoo

r0tor, what you're forgetting is installation ratio. Though the shock mount on the A-arm on the front is really far out and tends to suggest an IR close to 1, it is also going up at an angle. I'm trying to get a good estimate of what the IR actually is, but I haven't had a chance to get the car on a rack to study the geometry in detail.

kwescott

...funny, now....given our recent conversation about the spring rates on the Vaughtlands....

gh0st

the reasoning behind my conclusion is because i have done several comparisons myself. my car on full soft with the konis is WAY stiffer then s techs with konis 1 turn up from full soft. same with sprints (unsure what the konis were set to. the only way i see this happening is if my preload got messed up somehow.

speeddemon32

... I dont know what to tell you buddy. if your one of the ones that feels I must be wrong, then take it how you want it. your welcome to belive what ever you want. your also welcome to listen to your butt dyno all you want.

I will stick with hard evidence. :P

TeamRX8

iTrader: (25)

RX-8 motion ratios:

front = 0.752

rear = 0.855


I'm sure that Mazda Motorsports can confirm the exact rates for the springs. I was simply curious to know how the information was obtained.

speeddemon32

^^^ good info.


now you know

TeamRX8

iTrader: (25)

I just read your note in the other thread about MMS not knowing the rates

seems odd, they always had the spec info on anything I ever called for

LionZoo

Maybe you should call Team, you might have special clout!

speeddemon32

thats what I was going to say,... give em a call. i still dont see why everyone insist they are stiff springs when they are not. the rumor numbers on this thread seem to have magically appeared. but by all means, give em a call again and see if they know exactly what the spring rates are. (hopefully you get a different guy then I did.)

thecow135

Do It!

speeddemon32

do it.... Do It!..... DO IT! ;-)

gh0st

lol i LOVE the sig speed

LionZoo

Is that spring on the right the stockers?