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It's not 75%

It's a set RPM determined by the EPA - which is more than that.

Either way, you need to be 89dB @ 4900rpm - that includes on back off/rundown. Which is usually what trips the meter.

Unless you have a stock exhaust, you'll fail.

My memory is hazy on this, but I thought it was around 60% of peak RPM (based on the factory limit) at 500mm at around 45 degree off axis with minimal reflective surfaces during the measurement (the meter must be away from reflective surfaces.)

Can't remember where I had this information though, so not 100% sure it's right...

EDIT: actually I thought it was 50% of max rpm...

Gotta find the EPA doc...

Edited by wht510

Well.. If he said you'll get it in the mail - guess what? You'll get it in the mail :merli:

You really need to have a read of this thread. It'll give you a fair idea of what you need to change.

You'll only need to change the things that can be picked up. ECU is obvious, you already know that. So what else does the ECU control? Injectors, AFMs etc. Only stock items can run on a stock ECU etc.

It's not 75%

It's a set RPM determined by the EPA - which is more than that.

Either way, you need to be 89dB @ 4900rpm - that includes on back off/rundown. Which is usually what trips the meter.

Unless you have a stock exhaust, you'll fail.

Unless you own a gtr which when it rolled out of the factory in japan was over the 90db limit for Australia ... go figure that one out.

A while ago i read there was specific areas that are exempt from height rules, from what i read it was a meter either side of the axles, downloaded the mod guide from vic roads to check and there is nothing in there any more, it is a new one too, october 2011 is the date on it now.

Last time i looked at it exhaust manifolds were free as long as all the original fittings were retro fitted, now you need to have documents from the manufacturer to say that the manifold you are using is suitable for that car/engine, im glad my chinese stainless manifold cracked and i went back to standard.

seems things are getting worse

Edited by W0rp3D

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