RXE16T

"Welcome to Dr Taka's World of Exhaust Science", very technical Taka, but informative nonetheless.
Great to use these tests as a guide to selecting the "right" exhaust, but at the end of the day, nothing beats the aural test.

takahashi

In the RX-8 mag they talked about the quality of sound too: dry vs wet, high note vs low (?deep) note. I wonder what they mean :o They label it in the scale system - very subjective I would say

Here we go again

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Heard HKS, Hymee and Fujitsubo - I think Hymee is high and dry like HKS. If people heard mine will be able to understand what they are saying. Very hard to describe it though.

EDIT: This is my 2600th post. Something useful eventually :D

DCD

Wow awesome Taka. Thanks a lot for the info, I'm sure it will be helpfuil to a lot of people! Uh but nojooc is right at the end of the day theres no substitute for hearing the car yourself.
I am wondering how you say your exhaust got the same rating as the HKS, maybe both of those db figures were done with the car in neutral? From what nojooc says the HKS dosn't really get loud until you are hammering it, so that might be why its rated so similar?
People have been saying that the Apexi is really really loud, so maybe if I want to go for something thats not gonna be too much trouble from police I shouldn't get one that is rated 3 or up?
I know someone has recommended the RE one, I think I remember him saying that he really likes their stuff for rotaries, because they only do rotaries.
And also so the Hymee isn't as loud as HKS?

Hymee

iTrader: (1)

The "Hymee" meets ADR28 for exhaust noise.

I think it stipulates a 90DBa limit at 3/4 RPM of Max. Power, so we did the test at 6000 RPM. It recorded about 88DBa from memory.

I have heard different exhausts hammering along the straight at Wakefield. I know which one I like best

I dunno where Taka gets the "Hymee" rating from? And the tips are 100mm, not 120mm.

For $2000 you could get a stainless hymee exhaust, another hymee stainless exhaust, a grill kit, a ..... :p

Cheers,
Hymee.

PS - DCD - I see your email - I'll respond soon!

DCD

Ah ok, the pity is in New Zealand, there are no hard and fast numbers for exhaust noise laws. Its simply up to the descretion of the guy doing the warrent, or the cop that has decided to pull you over.
If either guy is having a bad day or wants to be a *****, then your nice shiny expensive exhaust becomes about as useful as **** on a bull.
its just such a crappy way of doing it, I wish there was a number then you would know where you stand!
Cool cheers Hymee I look forward to your email.

Hymee

iTrader: (1)

All I can say is I have had not problems from the boys regarding noise. I do a fair amount of suburban/city/highway driving. I'm sure that if I stupid enough to be an idot I'd get pung, but it would be for something other than the exhaust noise, as it is legal. "Driving like a ********" or something similar. The same would happen with a stock exhaust - it all gets down to how "responsible" you are.

BTW - How the hell can a fine stick for something that cannot be "measured" against a yardstick?? Pehaps the coppers over there are OK with being paid whatever the boss feels like paying them each week, and they just have to accept it?? That is about the best analogy I could make!

Cheers,
Hymee.

DCD

Basically the exhaust noise law was a knee jerk reaction to a perceived "boy racer" problem in auckland.
Well I say percieved but there are a lot of young guys over here that do stupid stupid things in their cars. People started complaining so the high ups, decided to crack down on the "boy racers". Heck it was even called the boy racer law!
I think for a few very short weeks, they had actually passed a law banning all cars that didn't have standard exhausts, but that got turned around pretty quick. then it was that a car couldn't have a differnet amount of mufflers from stock, then it was that a car could be modified but only if it was from the factory, so don't worry all the guys that get the expensive euro work done in factory are ok.
Its finally settled to be a car can have its exhaust modified, but the exhaust cannot be "appreciably louder than stock". I bet I could count on one hand the number of warrent shops and cops in NZ who know how loud a stock RX8 is with any real accuracy.
Like I said it all just comes down to how the guy giving you the warrent or the cop driving th eother way feels on the day. I don't care about cops, cause I don't go out and cruise around on weekend nights, when they are out hunting for "boy racers" but I am worried about the warrent shops. Thats why I want something that is reasonably quiet under 5G or so so when they do the ear test in a warrent shop it should pass sweet as.

takahashi

Gomez and Lexic said their tips are larger than that. Maybe their eyes are bigger :p

88dB at 6000rpm... OK up dated. I still stand the rating of 2.5 (Taka rating :p )

Maestro

Exhaust laws have changed DCD.

But the good news is your new exhaust system was factory fitted by Mazda as a factory option so the cop can't do **** since its a factory fitted option.

All it takes is one phone call to my girlfriend and you have that problem out the way.

For Example......

My FD has a 4" Full Exhaust System by Apexi (N1 Race Spec Version) Its pretty damn loud. Sets of car alarms blows 1 meter flames etc But its a factroy option according to Mazda. Oh yeah I work there so I can say what I like :P

Don't tell the cop that though. That can't argue with a company letterhead saying so either - heheeh

Gomez

Ummm, no I didn't......?

DCD

How have they changed exactly? I thought that the "not apprecably louder" rule was still in effect?
Is that a fact? Offical mazda letterhead you say? Well well well DDD:D If that isn't the best news I heard in a while!!! It'll be well worth joining FD Kai just for that letter!!!!
How hard would it be to get a hook up for that offical notice if I decide to go ahead with an exhaust?

lexic

I mentioned that my tips seemed to protrude longer than gomez's and that was the difference between ours (we have different tapered tips). I'm to lazy to measure them to find out how big they are! Besides size doesnt matter its what you do with it that counts!!! And Hymee KNOWS what to do with it!!

RXE16T

Now he does it with mechanical viagra (s/charger)! LOL

takahashi

....... My memory fades. I have an impression when you guys told me and it is certainly was not 100mm. Anyway,

Mechanical viagra - I guess Hymee's s/c is more like a Caverject (alprostadil) - in injectable form - for the RX-8.