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Ive been on a long journey of changers with my car which is now coming close to an end (thank God!) I was going for 350rwkw but have fallen a little short with 338rwkw on tap.

I'm running dash 5s with a forged engine but pretty much of standard configuration, I have Tomei manifolds and dumps, apexi GT front pipe, Matrix 3.5" cat and a 3.1/2" exhaust which tapers down to a 3" Nizmo cannon muffler.(loud)

I was thinking by the time the exhaust gases cool down to the rear muffler that this would not be much of a restriction, maybe I was wrong?.

After searching the Net Ive come across a Magnaflow 3/12 muffler, Ive been epa'd before and running 285 RE55 tyre's on all paws so I'm becoming a police magnet in the current climate, I'm pretty handy with the Tig so maybe I could kill two birds with one stone and install two of these mufflers, have my 350rwkw and a quiet car, or am I just chasing my tail, Just after some opinions from people with a greater knowledge than myself. Thanks

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3.5" can be made legal, 4" would come close. However you need decent mufflers. Magnaflow are cheap, will not do the job.

-5's are capable of 380-440rwkw, you ideally want a 4" exhaust for such a turbo selection.

3.5" can be made legal, 4" would come close. However you need decent mufflers. Magnaflow are cheap, will not do the job.

-5's are capable of 380-440rwkw, you ideally want a 4" exhaust for such a turbo selection.

Shit!, that really surprises me, I thought Bozods was just playing around, I had a theory that when the exhaust gases cooled down it would shrink slightly making it less restrictive at the muffler, has given me something to think about. Thanks

my advice is dont worry about dyno figures so much :)

I'm being a bit of a fussy bastard that's all, the car still pulls really hard and runs better than ever, its just seems a shame not to get the full potential out of the car that I have been denied for so long due to bad advice and workmanship of the past, thanks for your comment it has merit.

you can tell a restrictive exhaust by the shape of your power curve... ignoring the final number as long as the power/boost curve aren't flattening off too early or nosing over then you should be fine

that said, as Ash has mentioned a 3" exhaust isn't really big enough to push 350+rwkw

does boost fall off higher in the rpm range?

best way to tell if its the exhaust is to drop it for a dyno run and compare

I've got a 4" Apexi exhaust, flows great but not going to help you with the whole 'police magnet' issue

Having trouble with my scanner so can't print the Dyno sheet, at 2500rpm shows 50kw's, 5000rpm shows 275kw's, 5500rpm shows 315kw's, 7000rpm shows 338kw's, then the graph disappears at 7100rpm.

I'm sick of spending cash on this car but I'm so close now' I might have to buy one of $700 fabricated 3.1/2" mufflers with the twin tips and maybe a cheaper one in the center and take my chances, Cops did a u turn and came after me the other night so I hide down a side street, bloody shame really since I drive it like a pensioner, have never lost my licence or caused an accident, I just love my car.

What do you think of the Dyno figures. cheers Nick

you can tell a restrictive exhaust by the shape of your power curve... ignoring the final number as long as the power/boost curve aren't flattening off too early or nosing over then you should be fine

that said, as Ash has mentioned a 3" exhaust isn't really big enough to push 350+rwkw

It just goes to show what I missed out on with my past set up, car was pushing out 350kw at all fours using the same 3" muffler.

Damn it !!!!!!!

Edited by Ziller

If you spend the money, get the exhaust down to a near legal level... you shouldn't have a problem at all.

If you get pulled over then with lowmounts etc etc, who cares? :)

Combine it with a stock airbox etc etc, no issues should be your end result

If you spend the money, get the exhaust down to a near legal level... you shouldn't have a problem at all.

If you get pulled over then with lowmounts etc etc, who cares? :)

Combine it with a stock airbox etc etc, no issues should be your end result

Ive got the stock airbox in and going back to a standard gearbox, I have a PPG in at the moment, the triple plate clutch is coming out and and Ive settled on a coppermix twin (standard spec) clutch which will arrive from Japan soon, I have GZILLER number plates which will remain on my wall at home, Im finished with calder and any track work I had planned ' I intend on keeping this car for years to come so I'm having a real crack at this, the car is becoming a pleasure to drive again.

Ash you may know this car from the past, one of Ice Performance's last client, Tim's old GTR if that ring's a bell. Cheers

Ive got the stock airbox in and going back to a standard gearbox, I have a PPG in at the moment, the triple plate clutch is coming out and and Ive settled on a coppermix twin (standard spec) clutch which will arrive from Japan soon, I have GZILLER number plates which will remain on my wall at home, Im finished with calder and any track work I had planned ' I intend on keeping this car for years to come so I'm having a real crack at this, the car is becoming a pleasure to drive again.

Ash you may know this car from the past, one of Ice Performance's last client, Tim's old GTR if that ring's a bell. Cheers

lol ye im 99% i know who you're talking about. Used to see a fair bit of him. Silver or white i was ye?

I ain't seen him around for a long time, but then i don't talk to certain people anymore and he was an associate friend

You've since put the -5s etc on yourself?

Nismo coppermix, such a nice clutch... no plate "rattle" though :)

lol ye im 99% i know who you're talking about. Used to see a fair bit of him. Silver or white i was ye?

I ain't seen him around for a long time, but then i don't talk to certain people anymore and he was an associate friend

You've since put the -5s etc on yourself?

Nismo coppermix, such a nice clutch... no plate "rattle" though :down:

Silver, I think a lot of people don't speak to certain people any more! (he had a white one) I spoke to Mick from Micolor a couple of weeks ago and I seen a nice R31 in for a paint job, I seem to remember a guy fitting an exhaust to it a few years ago, I think that guy may have been you! that same guy told me not to go to far with my car and save some dollars and to keep the standard cams in it, God I wish I had listened :P Simon from Nizpro has done the latest engine build and all work on my car, Ben from Racepace has also been helpful' he may tell you an interesting story about my car. Cheers

hehe, ye you ended up with the Silver one - i think it was resprayed/touched up just before you would have purchased it (would be at a stab 3-3.5yrs ago?)

Ah, ye if you were down @ Mick's you would have seen a certain car there :down:

lol - hindsight is a wonderful thing, i go down that road probably once a week, i wouldn't worry about it!

Interesting story hey? Don't tell me there is yet another one (probably not a good story, but nothing unsuprising) :P

hehe, ye you ended up with the Silver one - i think it was resprayed/touched up just before you would have purchased it (would be at a stab 3-3.5yrs ago?)

Ah, ye if you were down @ Mick's you would have seen a certain car there :teehee:

lol - hindsight is a wonderful thing, i go down that road probably once a week, i wouldn't worry about it!

Interesting story hey? Don't tell me there is yet another one (probably not a good story, but nothing unsuprising) :P

Correct a Moundo!!!, the only story I have from down that end of Town is that I purchased a set of brand new Dash-5 Turbo,s, it took me 3 years to find out they were 2871-7s which were supplied by Raceline or Racingline Performance?, as for the other story, I think a man in your position should know hopefully for the sake of others (its a bad one a real bad one!!!). :P

lol... well at least you know you weren't the only person!

Oh dear... I'm already cringing @ the thought, although to be a real bad one it'll have to be pretty bad haha...

If Nick is refering to the one he told me, you are in for a story to remember for a long time, one of the worst I have heard of personally.

I also saw a certain r31 the other week at Micks when I went to book my car in, will be a mint car when finished.

Nick, mate what's going on you just can't stop spending money lol.

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