Jump to content
SAU Community

Recommended Posts

the silencer on the xforce barely does anything

i tested it on and off, and i couldnt feel a difference

takes the edge off the noise though. and it would depend on how much power you have as to how much power it takes off. someone pushing 350-400hp would notice a bigger loss than someone on a stock turbo at stock boost.

  • Replies 83
  • Created
  • Last Reply

Top Posters In This Topic

hrmm, so if epa tests an xforce muffler with the silencer and it passes, would this be the valid reading? or would they have to test the exhaust without the silencer?

I was going through some of the regulations in relation to testing procedures and here's what i found:

PROTECTION OF THE ENVIRONMENT OPERATIONS (NOISE CONTROL) REGULATION 2000 - SCHEDULE 2 - Testing Procedures

5 Vehicle operation and noise measurement

(b) If the Engine Speed at Maximum Power (ESMP) for that engine has not been determined by the EPA—the engine is to be brought to and stabilised at a speed as close as the authorised officer can achieve to one of the following speeds:

(i) if the engine has 5 cylinders or less—4000 rpm,

(ii) if the engine has 6 cylinders—3200 rpm,

(iii) if the engine has 8 cylinders—3300 rpm,

(iv) if the engine has more than 8 cylinders—4300 rpm,

(v) if the engine is a rotary engine—4500 rpm.

© If, in the opinion of the authorised officer, the test speed determined by reference to paragraphs (a) and (b) is not attainable by the engine—the engine is to be brought to and stabilised at the maximum speed that the authorised officer believes that the engine can be safely tested.

Hi guys,

It seems the Apexi bomber exhaust has a dB reading of 98. The N1 has a reading of 94! The fujitsubo legalis R has a reading of 94db (@5100 rpm), while the fujitsubo STD exhaust has 92dB (@5100 rpm).

My question now is, will this level reduce once the BATMBL dump/front pip and large cat is installed? The Apexi cat back (bomber or N1) was what i was looking at - but the sound levels seem to be in the illegal range. I know that the different type of mufflers matters to reduce the sound. Any types that you guys recommend?

Thanks in advance.

Hi guys,

It seems the Apexi bomber exhaust has a dB reading of 98. The N1 has a reading of 94! The fujitsubo legalis R has a reading of 94db (@5100 rpm), while the fujitsubo STD exhaust has 92dB (@5100 rpm).

My question now is, will this level reduce once the BATMBL dump/front pip and large cat is installed? The Apexi cat back (bomber or N1) was what i was looking at - but the sound levels seem to be in the illegal range. I know that the different type of mufflers matters to reduce the sound. Any types that you guys recommend?

Thanks in advance.

if you want legal, you should buy my cat back :P

tanabe 3" mild steel, oval muffler (JASMA approved :O)

see sig.

Trust PE2 specs from what I remember shows 90dB. But I'll assume this changes once you put an aftermarket dump/front pipe in with a high flow cat.

From my experience the PE2 is quite quiet compared to other brands of catbacks. Having said that it still shows the nice RB groal when you hammer it :P

ey guyz i just got home from work (im a mechanic)....and i finished fitting my X-force 3inch turbo back on my 32...the exhaust cost me 950 from just jap....i actually thought that it would be much louder...at idle its a little bit louder than the stock one...i jumped inside and gave it a rev....when you get higher in the rev range thats wen it starts to become loud...i havent driven it yet tho i will first thing tomorow....but the xforce i found is really quiet at idle

hrmm, so if epa tests an xforce muffler with the silencer and it passes, would this be the valid reading? or would they have to test the exhaust without the silencer?

I was going through some of the regulations in relation to testing procedures and here's what i found:

PROTECTION OF THE ENVIRONMENT OPERATIONS (NOISE CONTROL) REGULATION 2000 - SCHEDULE 2 - Testing Procedures

5 Vehicle operation and noise measurement

(b) If the Engine Speed at Maximum Power (ESMP) for that engine has not been determined by the EPA—the engine is to be brought to and stabilised at a speed as close as the authorised officer can achieve to one of the following speeds:

(i) if the engine has 5 cylinders or less—4000 rpm,

(ii) if the engine has 6 cylinders—3200 rpm,

(iii) if the engine has 8 cylinders—3300 rpm,

(iv) if the engine has more than 8 cylinders—4300 rpm,

(v) if the engine is a rotary engine—4500 rpm.

© If, in the opinion of the authorised officer, the test speed determined by reference to paragraphs (a) and (b) is not attainable by the engine—the engine is to be brought to and stabilised at the maximum speed that the authorised officer believes that the engine can be safely tested.

And as you said, old stuff...

The are old regulations.

RB25 is 4800rpm

RB26 is 5200rpm

RB20 (i think) is 4500 or 4400rpm

The above supplied is the old regulations that were changed some 18months ago for Vic and are now motor specific, not generalistic

cheers

I heard the testing in brissy is that they check the dB rating at 2/3 of yer maximum rpm? Well i've used a HKS super drager on my previous r33 gts-t and i liked it, never had problems with the cops at all..its pretty silent at low revs but opens up real hard on high revs...I feel the exhausts all give about the same power gain, but its the exhaust notes that differ between japanese catbacks and xforce, and perhaps durability is of another issue..the japanese exhausts seem to keep that same sweet note fer a long time, but other dodgy exhausts kindda give out a different note after a while compared to when its new...but well just my personal opinion..i would stick with japanese exhausts~ :)

Now im running a fully customised 3.5" exhaust system from japan on my gtr, mines stainless dumps, titanium split front pipes, 3.5" metalcat ( the flow on the metal cat surprises me, i practically feel not much difference comparing it to when i was running straight-thru), 3.5" stainless custom welded catback, it flows awesome but its quite loud cuz im running internals as well, but i did test using a silencer on it, brought the dB down by 3dB, but pretty restrictive....Here's how it sounds~

http://www.grouper.com/GlobalMedia/MediaDe...st=-1&s=7&q=gtr

And as you said, old stuff...

The are old regulations.

RB25 is 4800rpm

RB26 is 5200rpm

RB20 (i think) is 4500 or 4400rpm

The above supplied is the old regulations that were changed some 18months ago for Vic and are now motor specific, not generalistic

cheers

Can anyone shed light to the current regulations in NSW in relation to what the RPM RB25's are tested?

I heard the testing in brissy is that they check the dB rating at 2/3 of yer maximum rpm? Well i've used a HKS super drager on my previous r33 gts-t and i liked it, never had problems with the cops at all..its pretty silent at low revs but opens up real hard on high revs..

Awesome ey! :)

I love my super drager!

  • 1 month later...
  • 2 months later...
Thought i'd bump this one - Emsta - noticed you've ended up getting a PEII.. how's it sound.. what else did everyone else end up doing..

My trip to america has prevented me getting a new exhaust :D

Sorry about resurrecting an old thread, was just doing some reading while having a cup of dilmah tea (supposedly the finest ceylon tea)

Couldnt be happier Links - I still have to slap the car on the dyno, will do that next service. But yeah, batmbls products and the trust cat, is fantastic. Its very quiet too, like, as I mentioned above, I liked the growl of the x-force, but the PE2, is very quiet, goes well when Im building up my car in terms of performance. Basically, got RE Customs to install it, and it was a straight bolt on job - the only trouble was a couple of the bolts that were hard to remove it seems.

In time, will get more mods done. Right now, I need a job :D

Edited by emsta2003

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Lucky man, who owns it in the family? Any pics? 
    • The engine stuff is Greg Autism to the Max. I contacted Tony Mamo previously from AFR who went off to make his own company to further refine AFR heads. He is a wizard in US LS world. Pretty much the best person on earth who will sell you things he's done weird wizard magic to. The cam spec is not too different. I have a 232/234 .600/603 lift, 114LSA cam currently. The new one is 227/233 .638 .634. The 1.8 ratio roller rockers will effectively push this cam into the ~.670 range. These also get Mamo'ified to be drilled out and tapped to use a 10mm bolt over an 8mm for better stability. This is what lead to the cam being specced. The plan is to run it to 6800. (6600 currently). The Johnson lifters are to maintain proper lift at heavy use which is something the LS7's supposedly fail at and lose a bit of pressure, robbing you of lift at higher RPM. Hollow stem valves for better, well everything, Valve train control. I dunno. Hollow is better. The valves are also not on a standard valve angle. Compression ratio is going from 10.6 to 11.3. The cam is smaller, but also not really... The cam was specced when I generated a chart where I counted the frames of a lap video I had and noted how much of the time in % I spent at what RPM while on track at Sandown. The current cam/heads are a bit mismatched, the standard LS1 heads are the restriction to power, which is why everyone CNC's them to get a pretty solid improvement. Most of the difference between LS1->LS2->LS3 is really just better stock heads. The current cam is falling over about 600rpm earlier than it 'should' given the rest of my current setup. CNC'ing heads closes the gap with regards to heads. Aftermarket heads eliminate the gap and go further. The MMS heads go even further than that, and the heads I have in the box could quite easily be bolted to a 7.0 427ci or 454 and not be any restriction at all. Tony Mamo previously worked with AFR, designed new heads from scratch then eventually founded his own business. There he takes the AFR items and performs further wizardry, CNC'ing them and then manually porting the result. He also ports the FAST102 composite manifold: Before and after There's also an improved racing crank scraper and windage tray. Helps to keep oil in the pan. Supposedly gains 2% power. Tony also ports Melling oil pumps, so you get more oil pressure down low at idle, and the same as what you want up top thanks to a suitable relief spring. There's also the timing chain kit with a Torrington bearing to make sure the cam doesn't have any thrust. Yes I'll post a before and after when it all eventually goes together. It'll probably make 2kw more than a setup that would be $15,000 cheaper :p
    • Because the cars wheels are on blocks, you slide under the car.   Pretty much all the bolts you touched should have been put in, but not fully torque up.   Back them off a turn or two, and then tighten them up from under the car with the wheels sitting on the blocks holding car up in the air.
    • Yes. Imagine you have the car on the ground, and you mine away all the ground under and around it, except for the area directly under each individual wheel. That's exactly how it'd look, except the ground will be what ever you make the bit under each wheel from
    • Yes, if you set the "height" right so that it's basically where it would be when sitting on the wheel. It's actually exactly how I tighten bolts that need to be done that way. However....urethane bushes do NOT need to be done that way. The bush slides on both the inner and outer. It's only rubber bushes that are bonded to the outer that need to be clamped to the crush tube in the "home" position. And my car is so full of sphericals now that I have very few that I need to do properly and I sometimes forget and have to go back and fix it afterwards!
×
×
  • Create New...