compaddict

Somewhere an engineer is crying..

Probably the one or two that designed the intake system on the RX-8 I'm guessing.

Look at our problem this way, Mazda designed our cars to have about 250HP.

Our cars really put out (in NA trim) around 220HP.

If the car is 30HP shy of the design and something other than the intake or exhaust has been changed to loose the 30 HP changing the intake or exhaust isn't going to bring it back.

The higher the bullshit HP claim the more I despise the company making it.

That's all I have to say about that.

Vince

Lock & Load

VINCE

MAZDA has certainly lost in the reputation stake for honesty , but they are partly owned by FORD (FOUND IN RUBBISH DUMP)

Before i buy another mazda i will be more cautious in their power output claims , they have lost their credibility imho.

michael

syntrix

What's the stock intake size anyway.... 3" or just a bit more



And it's not that long of an intake anyway!!

edit: arrow points to emissions crap, not the intake

Gord96BRG

I don't think Vince's particular point here is Mazda - he's complaining about the vendors of aftermarket air intakes and exhausts that make ridiculous claims like 14 hp for a replacement intake (*cough*K&N*cough*).

Regards,
Gordon

Lock & Load

OOH OK

Thanks

syntrix

He's talkin' Mazda all up in his post there.

Gord96BRG

Sigh - let me translate:

Thread title: Mazda makes no intake or exhaust HP claims. It's aftermarket vendors who make claims of improved power for their replacement components.

Translation: Mazda designed the stock intake and exhaust systems to easily handle engine output of 250 hp. For various emissions-related reasons, the ECU has been detuned so the engine is only putting out around 220 HP (238 claimed by Mazda). Therefore, the stock intake and exhaust are capable of supporting significantly more power than is being generated stock. The intake and exhaust systems are not the restriction on power output.

Therefore, changing the intake and exhaust systems for aftermarket components will not show any more power, especially if the ECU is unchanged.

Translation: aftermarket intake/exhaust vendors claiming BS HP increases from just the installation of their components are despicable. NOT MAZDA. Aftermarket vendors.

Got it now?

Regards,
Gordon

compaddict

Gordon,

You are so well spoken!

Vince

O.R.A.

Well, if the ECU is making the car run very rich in open loop and you make the car breathe better, it would lean out the open loop mixture and produce more power, right?

Intakes and exhausts are really not designed for "X" amount of power, but for "Y" amount of airflow (and then noise, packaging, cost, etc. enter the equation).

I'm not saying that any aftermarket company's claim is correct or not, but there is some logic behind an improvement.

I know it's kind of like using a wrench to hammer a nail, but it does go in eventually.

Chrisbert

FIRD?

wakeech

the problem is that aftermarket replacement parts which are suppost to change the optimization of the comprimise more toward power making, don't. the problem is that the engine isn't breathing more effectively, and that "more air" isn't going in.

not to mention that the sensors the ECU uses to estimate the amount of fuel to add would simply adapt to this higher rate of ingestion appropriately, ending you up with similiarly related fuel curves anyway.

ON TOP of that, most aftermarket bullshit is built to conform to market tastes and desires, not to what actualy will perform better. take exhausts for example: no one will buy anything less than a 3" internal diameter exhaust, with no less than a 4" tip or some stupid thing on the back of their fart can muffler. does this actually help your engine breathe better?? i've got many an arguement which says no (the resonance changes with the diameter and length change, velocity isn't optimized meaning that the pressures are wrong), and heard only one voice contending it, who's still not produced any sort of theory to back up what he's said. and this "one size fits all" application nonsense is just as bad on the intake side.

"paint it pretty colours, and retard kids will buy them".

i like this thread.

bureau13

Well, that's why its important that testing, be it dyno, G-Tech, whatever, be done on these products. That serves a two-fold purpose, rewarding those companies who have intelligently designed components that do what they say they'll do, and trashing those who do not.

jds

Lock & Load

GORDON

Thanks for your clear conscise , accurate translation .

Speaking 3 languages makes life sometimes difficult , tend to think in spanish and hungarian and try and wriite in ENGLISH or should i say Australiana , and interpred in all 3 languages ,hey no wonder i get confused .

michael

Gord96BRG

No problem!

Speaking of Hungarian - Well, I can't speak it, but I do have a Hungarian dog - a Puli! Extremely cool dogs!

Regards,
Gordon

Lock & Load

GORDON

YEAH i can just picture you with your cool dog cruising the roads , hey how can the women resist.

The puli not you , just kidding

I resently lost my boxer ( claudia to cancer ) she used to travel with me most of the time sitting upright in the passenger seat , i really miss her .

Women come and go but a good faithfull dog or car stay forever .

michael

deadrx7conv

Dynos don't lie.
If you install an intake/, exhaust or both, and you do before/after runs that verify power increase or decrease, then that is what is happening.

There are engine pumping losses through the intake and exhaust even when air/fuel ratios aren't even considered.

Rotaries respond well to intake/exhaust mods.

rabinabo

Well, the dynos don't lie, but they can be used in such a way as to bias the results. You don't believe the "dyno" results that you see in the commercials for products like the Tornado, do you? Just think about it, there are any number of things that you can do, like pump up the A/C in the building or running the base run while the engine isn't warmed up etc.

It might not even be a completely stock car. For an intake they could put in an exhaust with less backpressure (or not cat etc.), then by adding a intake you get even more gains than you would with just an intake. Or vice versa.

There are enough BS "dyno" results published that I'm usually skeptical unless the company has a good reputation.

wakeech

this is of course not what we're saying. if a real observable increase in power is evident, of course we're not going to say that it isn't... but this is the problem: we aren't observing the kinds of gains claimed by manufacturers for many reasons, all which we find reprehensible.

no mechancial process can be done with perfect efficiency. using comprimises to the effect of sound produced, fuel efficiency, drivability etc we can find more speed, but seldom do the replacement parts do this to the extent that we desire or intend (this is why the guys with the fastest cars do it themselves).

saying that rotaries respond well is of course true, as it's not entirely different from piston engines: it still ingests and exhausts itself of the same gasses, combusts them in the same manner, and transfers power the same way. they use almost universally the same hardware and "support" systems (cooling, lube, etc)... they're really not all that different, other than in fundamental archetecture.

deadrx7conv

Which aftermarket manufacturers for the RX8 have made HP claims that were proven false?

I also think that everyone assumes that an HP increase must always occur at peak. Most of the time, this is not the case. I've seen aftermarket components add 10hp without changing the peak HP. Toss in ricer math and everyone gets pissed.

And, like I said, YOU DO THE DYNO run for your own verification.

Anyone who believes any marketing/advertising dept is an idiot.

wakeech

i think everyone agrees with this

Tamas

iTrader: (1)

I AM Hungarian :D
(so I can speak the language of course)
Pulis are cool dogs... a good friend of mine has a "vizsla" which is also a Hungarian dog.

And, to keep this post car-related, I can't wait for my RX-8. End of October is here but the car isn't - yet...

canzoomer

I completely agree with his post.
The original intake is VERY well designed, flows well, pulls in fresh cold air, and is resonance tuned.

There are some HP to be gained in the exhaust.
Mainly in the midpipe, by installing one with no, or at least a less restrictive catalytic converter.

Of course these solutins involve possibly not passing emission tests in at least some jurisdictions.

Wakeech also hit an important point dead on the money:
If your ECU is controlling the flowo and fuel, then adding more airflow WILL cause it to add even more fuel at the high range of 6,000rpm and up.
The way the ECU decides how much fuel to inject is based on the readings it gets from the MAF sensor in the intake. More air WILL result in more fuel.

That is the LAST thing you need at higher rpm ranges.

As we are already WAY too rich here ( like 10:1 air fuel ratio at WOT at 6500rpm, when it should be around 12-13:1) you stand a good chance of making even less power with stock ECU AF maps.

IF you want more power, you have to:
1) Deal with the air/fuel control
2) deal with ignition advance settings
3) Open up the midpipe resistance.

I sincerley doubt any cat-back, by itself, will yield any significant amount of power, and i suspect that changing the intake will LOSE you some power.

Don't get me wrong, there is a LOT of power available in the RX-8, but it can ONLY be had with a complete solution, and touvhing the intake or exhaust by them selves will gain you jack all.

wakeech

*wanted to highlight the most pertinant part of the post*

MrWigggles

If you do get more air and thus more fuel, won't the ratio be the same?

100 CFM at 12:1 is going to make more power than 80 CFM at 12:1 (I am just making up the cubic feet per minute numbers)

Anyway, the biggest problem I see with aftermarket products is that it is so easy to cheat. Turn the A/C on and you lose 5HP or more right there. So as an example, they do a before run with the A/C on and they get 100hp, then put on their 2hp mod, turn the A/C off and do a test at 107hp. Wow the 2hp mod made 7hp!!

That's just an example. The dyno has to be third party.

I recommend buying a Gtech or Gtimer and do your own dyno work. If a device claims "10% more power" then at some point in the RPM band it should be making 10% more torque and thus 10% more g's. If it don't they are lying.

-Mr. Wigggles

bureau13

These comments on the intkae are all very interesting to me, especially now that Rortary Extreme has just put up dyno charts of their new intake that appear to show a pretty clear increase in both torque and power across the rev range. Yes, the dyno was done by the manufacturer, however he makes a pretty good point in that why would he have waited until now to fake the dyno...he could have had the intake on the market a long time ago if he was going to do that. Sooooo...who's going to jump first and get one of these things to test independently???

jds