If you ask Racing Beat the only intake they know of that makes more HP than theirs is the K&N.

I don't think Mazda ever claimed 271. They claimed 248hp vs the real 238hp.

Regarding the springs - you say potato and I say potato (this doesn't really get conveyed well in text). The spring rate info that Mazda claims is pretty buried and non-existent on any Mazda N America site. They aren't exactly looking to make a killing on these things based on price and lack of info. They must have concluded those numbers somehow. I don't care how, I like mine and we should let those that don't believe Speed's compressor to piss off and believe whatever they want. He's not going to bankrupt Mazda by making everyone look elsewhere. He's also not promoting anyone else's product, just providing a public service. Knowing is half the battle!

http://pic9.picturetrail.com/VOL268/...9/94116161.jpg

^^^ well thats just an RX-8 for you.

and yes, You can not trust manafacture numbers. I belive K&N claimed 10 h.p. realistically its more like 2. ;) this comming from a guy that LOVES his K&N.... but untill someone does REAL test, both the numbers 10 and 2 in my book are worthless.

Mazda changed their minds on what the RX-8 could produce more then once. I have a magazine artical (well several accually) that say Mazdas RX-8 will be 255 h.p. then after the big hype of it not producing that they lowered their claim to 238. not trying to diss mazda here, but more proof you cant trust their numbers. :tear:

I bought the MS setup because it was the only setup out here that was matched up to each other and to the car, not because of some numbers. You are right about #'s being marketing ploys. Testing by more then one user is what I would count as credible, though his testing does raise questions. I would be interested in seeing two other users testing the springs. To many variables to take one test as the right #, bad spring tester, or bad set of springs. If three tests come in around the same # then I'll be convinced. As far as clutch, flywheel, and pulleys, your right that the performance gains may not be all that worth it but for some people the process of working on their car makes it worth it. The pulley I added probably freed up 1HP, do I feel it? Well No, but it was fun installing it and stripping 2 of the bolts:(

The magazine wrote 255, not Mazda. Once released they always claimed 247... until they claimed 238... and then 232...

232 was due to revised SAE testing procedures, not Mazda's fault on that one.

I know.

hp, parts, and dynos......what a big frustration. We had a local dyno day down here in So cal..with about 20 RX8's with varying level of modifications...even had a couple of ATs showing up. I had one of more heavily modified 8's and I had one of the lowest dyno results. It was very dissapointing.

We don't want to get off track though, as we are talking about springs. I am pleased with the MS setup as it fits my needs, and works well with my bodykit and wheels. It is perfect for me, I wouldn't change it for anything (as a daily driver...which mine is....Im at 77k miles now)....but as for autocross, which I also do....I think there are better setups.

wow.. 5 pages of nonsense.......

i personally know speeddemon and his entire family.... his father was a professional racecar driver for damn near all of speeddemons life... speeddemon was part of his father pit crew for years. take what i say with a grain fo salt, but if he says the spring rates are what they are.. then thats what they are!

and after reading all of this, ive noticed that the ONLY one who has ACTUALLY done any testing is speeddemon... but numerous people are chiming in with their "butt dyno" results like they are concrete evidence! obviously those poeple are just making fools of themselves....

lionzoo.... im much like you in the fact that its really hard to believe anything thats put on the internet.. and i tend to go as far as you in finding out exactly what i need to know... but in this situation, and with me personally knowing speeddemon and his testing methods, i'd take his results as the answer you were looking for! becuase if you notice, nobody else has actually tested them on a spring rate tester, they only have their "butt dyno" to chime in with:)



kwescott.... as for your comment about never installing a aftermarket flywheel or clutch on any car again.... the rx8 seems to be one of the worst mod friendly vehicles in the world... but there are MANY cars that these mods really do make a big difference... take my evo for example.... the factory clutch is very spongy and weak... just about any aftermarket clutch out is better than mitsubishis... and lightened flywheels are great for some cars, but not all.... same goes for underdrive pullies... some cars show major power increases when pullies are installed.. the evo in that case isnt one of them.. they are a waste of money much like they are on the rx8... but i just had to comment because your taking the headaches youve acuired from your rx8 and trasferring them to all cars in general

speeddemon.... take what was said in this thread and shrub it off.. you know your right, and your the only one who actually took the time to do these tests...

ghost.... your a very smart person, which is why its suprising that you are taking your buttdyno results and trusting them more that a tried and true method of testing spring rates.... casey knows how to test progressive spring rates, so you should trust the results given, even if they dont truly agree with what you thought you felt when driving...:) but in any case, you got smart and got jic flt-a2's just like me:) we're so cool:):)

that does not help your case much. ;)

I agree, I would LOVE for a couple more people to test a set. I DO NOT agree with your bad spring tester idea though as I tested the 500 and 700 pound springs and they came back as they should. (and the stockers). but maybe I did have a bum set of MS springs. I cant deny that. my ONLY form of backup on that is when I called Mazda and they said they are not advertised as stiffer. but again, maybe they were a bum set. by all means someone please test a set of MS springs to see what the rates are. it really is the only way to confirm my results. (just make sure you have a couple controll test to verify the test is working as it should..... you know.... kinda like I DID! ) :)

THATS WHAT I KEEP SAYING!!! :)
I REALLY REALLY want someone else to test springs to... I just dont know anyone that has the ability.
but thanks!

So here is the deal ;


If everyone here pitches in a few bucks, We can go rent 3 spring compressors/testers. We use at least 2 "control" springs. And then the mazdaspeed springs. ( and any others we want to try out.) And whoever is right gets to say "neener neener neener" to the others.


Now we already KNOW how the tests are going to turn out. But if we really need to do it, I will organize the $$ and the rentals. I will also find a non biased person to do the tests.

***raises hand***

It's funny this topic was discussed in the same way over at vwvortex (used to have a GTI before it was ripped off.) Anyway one guy decided to test every spring he could get his hands on and the results shocked everyone there. As for me that is why I am very sceptical on changing springs. Unless the manufacture can provide you with exact rates and not one of these % stiffer #'s I would not trust it. It is amazing that we have someone here that has a tester and can give us actual rates.

I have to agree that the increase in stiffness is mostly due to the improved struts or to the fact that the car when lowered runs out of travel and rides on the bumpstops which are as stiff as hell (not sure if this applies to the RX8). Maybe someone can let me know how much suspension travel the 8 has at stock ride height before it gets down to the bumpstops.

I was running stock springs w/koni sport yellows on my GTI and the ride was much stiffer then stock even at full soft.

There is also another issue to consider when you change springs. If your new springs don't keep the same ratio front to back your car's handling will change, more understeer if the front spring rate is higher in relation to the rear and more oversteer if the rear spring rate is higher in relation to the front. This also applies to sway bars. I feel many of these manufactures tend to increase the front spring rate more then the rears to make the car understeer more in a way to make the cars more forgiving in the hands of everyday drivers.

Keep up the good work speeddemon32

ok what??? :squint: :squint: :squint:

Did you post the info as you claimed or not? :dunno:

sounds like a good idea! though I doubt anyone will step up. most people are willing to piss and moan, but not willing to acctually do something about it. anywhoo, if you need my help with anything, just let me know. I obviously will not be the person doing the test, nore will it be my spring rate tester (just incase my tester is biased to anything other then RX-8 springs, except for the stock ones of course, because it said they were what they were supposed to be).

for your/their test I would assume you would want the following.

Spring rate tester
2 front stock springs
2 rear stock springs
a KNOWN spring and its rate (like I had the 500 pounder)
maybe a second one. (like I had the 700 pounder) (the above 6 springs will establish that the spring rate tester is functioning, and the person doing the test knows what he/she is doing)
a set Mazdaspeed springs, maybe 2 or 3 since those seem to be the most in question.
any other springs in question
and a witness...... or ten.
maybe a Notary or two.


ok ok, the end of that was a little smart assish, but seriously, that is what you would need to validate any results. (not the notary). also make sure the person notes EVERY SINGLE INCH not just mentally, but on the forum or else they will hear about it. ( I guess this was my mistake? )

again, good idea, and good luck. I hope to hear results!

hahaha. you give me more credit then i deserve.

but in any case, its a dyno. i cant really argue with that especially given speeds background.

;)

thanks Ghost... and you are a smart guy, you know what your talking about. just dont trust your butt dyno all the time. I know I cant trust mine. mine seems to be broken. (I think we have talked about this before. :) )

its not really the backround I am trying to have as my support here. rather the numbers that speak for them selves. I stand by my self and I know the test was done right.... its not rocket science.

the only argument that I am seeing (now) is that I did not type more then 3 inches of travel.... I think "these people" have agreed (now) that I know how to test springs, and that the rates are right. their complaint or argument is that I did not type the rest of the inches. I dont know why this got blown up like it did. I am telling everyone that I saw the entire range and it never did anything special. next time I will be sure to type up every single inch. then hopefully they cant complain. :)

anywhoo, see you next week? :)

speeddemon, i would like to contribute to some tried and tested research into this spring. i currently bought a set of RB springs. installed the fronts and not even noticed a hair in drop. the rears are not installed yet. i was wondering if its not too much trouble to have the rears tested for its spring rate.

i also have a formula to follow under measurements to determine a set of spring rates for a given spring by measuring its dimensions. i bought a digital caliper and would like to do some testing using simple formula's to get a given number. i have a very handy book by fred puhn called "how to make ur car handle" and would like to see their formula's if they work or not.

is there something we can work out? i know a stock spring to test is useless. but in RB's catalog it claims 174/122 and not whatever someone else posted that has not been revised with something like 187/136???

i like to find REAL proof and help give REAL proof that manufacturers numbers are indeed marketing strategy. but i'd also like to use simple formula's that don't need any machine's to also help determine spring rates and exploit the use of that as well, as i've noticed RB's set has 8 coils to the stock 7 coils on its springs.
this way, if its really proven on the machine( ur compressor tester) and proven with the recommended formula, we can all pretty much be educated buyers in the science of vehicle dynamics rather than just falling into advertising BS.

i feel u on this project. and so far...its a given. to test a spring is to compress 1 inch and find the lbs. and u end up with the given #. wouldn't it be nice to also verify the accuracy of a formula with the help of a cheap measuring tool so we can simply walk into a speed shop and know exactly what springs with what # of coils with what diameter wire and etc. would equate to what spring rate?

i just want to help. let me know if u wanna help make this worthwhile.
and to say the truth... i would only like to spend any $$$ on performance. and i'd like to know if i'm getting ripped off. so i'm very eager to accomodate in this research.

magic. absolutly!
come on over, I will test it for you. (hell I'll even let you do it if you want) and we will be sure to document every inch. :)
contact me over PM if your intrested, I'll give you directions. :)

Ohh... sounds good!

TrochoidMagic, what is your formula for calculating spring rate? I have a formula that does the same thing and I'd like to compare yours to mine.

eeeeewwwww. :) he he he. :)

W(4th pwr) G
_____________
K =
8ND(3rd pwr)

K=stiffness of spring in lbs. per inch
W=diameter of the spring wire (in inches)
G= 12,000,000 for steel springs
N=number of active coils (# of free coils+1/2)
D=diameter of the coils (measured to the centers of wire, in inches)
note: an easy way to find coil diameter D is to measure the O.D. of the coil minus wire diameter.

this info is gathered from "how to make ur car handle" by fred puhn.
this book seems very informative and very knowledgeable, however, i use it for an "easy" way to find things. it is not a mechanics training textbook, so the info may or may not be very accurate to modern standards if its off. there are specific formulas i've learned in suspension dynamics and etc. but the textbook formula hardly stays with me as its only practiced occasionally to see if the students can comprehend the formula and its function and to prepare for ASE testings and such.

i'm only stating the above info to inform everyone "no way in hell am i goin back to my parents house to dig up a textbook and research long chapters for one specific application". this should be reasonable enough to start as a foundation formula to test on.

^^typo. separate the K so that its K= blah blah blah over blah...