Exhaust Help

[Tangles]

Ok,

With a list of mods, I had 160awkw at 12psi with standard turbo, but am now running the highflow turbo..... R&R cuts in at 1bar but at 13.5psi the car seems very quick.... with a tune I expect close to 200awkw.

I say close, as my muffler seems quite restrictive. 3inches from turbo back, including cat, to the muffler where it goes into 2inch and inside the muffler would be a S-type setup. So, the exhaust gasses dont flow out the exit all that well.

Im thinking about adding a $100 cannon muffler. 3inch inlet and outlet and 4inch barrel. Cut the current muffler off and weld on a cannon. Im sure this could weild a lazy 5awkw or more. I want a tune done over the xmas break so I need to take action now, if Im going to change the muffler. (lol at tune, currently used half a tank for 130kms!)

Those with cannon mufflers, how loud can they be when the foot is mashed against the accelerator? Do they make a horrible drone sound? Should I be looking for a brand name from Japan, or a cheapie no-name unit? Any tips, tricks or ideas are welcome.

Brendan

[munchstagea]

Hi Brendan,

Do you read HPI? They did a comparison of a big, fat, loud exhaust on an R32GTR against the stock (GTR) system on the dyno and the stock system made more power and was much easier to live with.

As the gas cools it reduces in volume the further down the pipe it travels and thus flow and restriction at the far end are less of an issue.

Adding a cannon will make it louder and that might make it feel faster (cause it's louder) but on the dyno I don't think you will see much improvement, it could actually be worse.

Maybe look at a split dump or just a 3" muffler for the rear?

Cheers

Luke

[Tangles]

Cheers Luke,

Got a straight 3inch dump pipe, not split, and wont be upgrading that particular part. This is something I want to quickly do at home with the donkey-leg (ie jack up car, unbolt from cat, cut, weld, rebolt up) and on a $100 budget.

But yeah, a 3inch muffler might be the way to go. Hence my query about the cannon style mufflers, whatever I go for I want 3 inch internals I guess - thats if I change it at all.

Currently toying with buying a PowerFc, auto valve body and 500cc injectors when the bike sells, and flogging off the tuned safc/sitc piggybacks.......................... no hurry for that I guess, but if Im doing a retune (and I need to) to the piggybacks then I figured I might as well have a free-flowing exhaust.

Thanks for the info re- cooling exhaust gasses. No, I havent bought HPI since issue 30-odd (very repetitive).

[Tangles]

Im thinking buy 3 x 3inch exhaust flanges

Weld one to the cat-back system one to a new 3inch straight thru muffler, and one to the current S-shaped restrictive (ie it is VERY quiet) internal muffler.

That way I could bolt on the muffler to suit my mood and noise tolerance

Thinking of this sort of thing:

http://cgi.ebay.com/ebaymotors/3-INLET-UNI...057837141QQrdZ1

Dunno, not a huge concern I guess. But there is no doubt that my current muffler would be a restriction, and by changing it I reckon I could net a couple of kws.

[munchstagea]

That would be good,

Then it would be easy to test on the dyno, the difference that is.

[GorGasm]

I just got my exhaust done on my car.

I got full 3" system from dump pipe back with 2 resonators and 1 semi straight through 3" in/out muffler.

The noise was intolerable. It was pretty raw and aggressive when on full throttle and sounded kinda cool but for everday driving below 3000rpm the drone was actually painful to the ears!

I got the muffler switched to a 3" in/out with an sbend type arrangement in it and its heaps better. Doesnt feel any different either.

Perhaps hunt down a higher flow muffler?

[Tangles]

Yeah I dont want an awful drone, but yet want least restriction as possible.

I guess the hunt begins!

Im thinking the current muffler must be decent flowing for me to achieve 160awkw @ 12psi on stnd turbo, but things can always be improved upon

Probably something I'll have to leave (budget restraints) until mid-year 2007, when I may switch to a stand alone full ECU replacement.

(although a cheapie $80 3" cannon muffler with welded on adapter flanges might just happen - if I dont like the sound it can easily be replaced with the current muffler)

[fcruz3r]

i had a jap (unknown brand with a jasma stamp) cannon which was really2 loud...so i swapped that for an apexi megaphone which was supposed to be a tad bit quieter with possibly better flow...cant say i feel the difference in power and it still drones around 2000-3000 rpm (i.e: city drive rev range)

Think i'll get an apexi super silencer to fit on the megaphone to tone it down a lil bit more.

[FLYSLY]

On my Onevia i had a custom exhaust, which had 2 magnaflow mufflers fitted from cat back they are a high flowing muffler and i passed epa with that system on, there was absolutely no droning, although it was not a cannon. And still sounded awesome, it was probably one of the best sounding RB engines going around except for the RB26 of course

Ps. They were 3" inlet and 3" outlet but just a normal shaped muffler

[AlexCim]

Exhaust technologies is where my exhaust is from, 110% happy.

Magnaflow mufflers are also nice and quiet with good flow.

DO NOT GET A CANNON. Listen to me, ive have three exhausts on my Stagea and the one with a cannon was the worst! The single cabin doesnt help and the drone is intolerable for normal driving. Booting it is fine, sounds mad, but I much much much prefer my oval mufflers!

[pixel8r]

I'd like to reiterate the above - DO NOT GET A CANNON

I had a cannon muffler on a s13 silvia which sounded kind of "ok" but nothing special. Cannon mufflers are pretty much all droney as are resonators.

I got a custom exhaust from AAA exhausts. $1400 for full stainless steel from the turbo back with 2 3" magnaflow oval shaped mufflers.

Oval mufflers give a much deeper and nicer (imo) note. From my experience cannon mufflers give a sharper more high pitched note - think riced up hondas - it can sound really bad.

When i got my exhaust they originally put in a mid resonator and just a single muffler at the rear - but the drone was way too much at around 2000rpm due to the wagon. I then took it back and got them to replace the mid resonator with a 3" muffler and that fixed it up completely!! (both mufflers were straight thru - with a slight bend in the middle but certainly not S shaped)

So yeah make sure you have 2 mufflers - I'd strongly recommend oval shaped ones and I can vouch for magnaflow mufflers being good quality and good sounding. My stag isn't loud - there's no drone, and yet it does have a note that says its more than just a wagon

[Tangles]

Hhhmmmm - food for thought, cheers for the opinions.

Looks like then I'll search for a oval muffler of some description, 3inch in / out and internals.

Current setup is very quiet... 3inch dump, 3inch highflow cat, 3inch pipe to a welded-on section (looks like a resonator perhaps?), which connects straight to the current muffler.

Being so quiet means to me that it must be a restriction.

[GoldZilla]

Being so quiet means to me that it must be a restriction.

Not necessarily, Brendan, although not too long ago I would have thought the same thing...

Off topic: How are the knees?

[Tangles]

Knee is sore Thats life, cheers tho

Found a Magnaflow centre to centre 7" round polished stainless steel 3inch straight thru muffler, sells for $160USD found it for $120USD delivered to Australia (7 week wait!).

Will let it go for a while, for another day. Cheers for the advice

[AlexCim]

Cannons are OK for manual cars, they are loud but you can deal with it because the revs pretty much DONT move around.

With an auto, its shitty because the revs can change between 1500rpm and 3000rpm all at the same speed, aka, 80kph.

This is where the annoying drone comes from (Fark you torque converter!)

[sandyb]

My 32 GTR came with a 3 and 1/2" mild steel exhaust with 4 and 1/2" cannon, wasnt too loud, made 237rwkw. I changed it for a 3" stainless, peak power dropped by 4kw (7000rpm) but gained 5kw from between 2500 and 6000 rpm. The 3" is very quiet, but doesnt sound as aggressive when booting it, and looks almost stock.

Cheers, Sandy

[someonestolecc]

As the gas cools it reduces in volume the further down the pipe it travels and thus flow and restriction at the far end are less of an issue.

I'm not sure I agree. As it cools it expands, not 'reduces in volume'. Same as when you leave your beer in the freezer and it pops.

[someonestolecc]

Cannon or no is a moot point - it's personal preference so pick whichever you like.. it's just what you need to do to reduce the drone after you do.

I got my cefiro (sr20) with a bodgy exhaust. manifold > cat > cannon. It was loud as shit and didn't sound very good (imo).

I had a resonator fitted. This took out much of the drone but none of the body. If you want a cannon and don't want drone you need a resonator or two. The other alternative is if you want a cannon is to get a biggest middle exhaust you can. Some of the nicest exhausts I've heard have been of this composition.

After the resonator went in I was still not happy with the cannon, so I welded on a Trust exhaust with a big tip. The sound went from a bark to a tough low gurgle. Just what I wanted.

So... if you get a real muffler you'll probably only want one resonator in there (just to deflect the drone/bark).

Good luck.

[munchstagea]

I'm not sure I agree. As it cools it expands, not 'reduces in volume'. Same as when you leave your beer in the freezer and it pops.

Blow up a balloon and put it in the freezer, if it gets bigger when it cools down then your are correct... It will get smaller though.

Freezing liquids and cooling gasses are 2 different physical reactions. As liquids freeze they expand and become a solid, as gasses cool they become more dense and thus reduce in volume. There is also another factor that will effect the restrictiveness of the exhaust and that is velocity, as the gas moves further down the pipe it slows so restriction is less likely to occur the further away from the engine the gas travels.

Cheers

Luke

[AlexCim]

Resonators are designed to cut out certain resonance frequencies. Most people these days dont think, just chuck it in and think it will make a difference. You need to make sure you get the correct resonators, for the correct frequencies you want to cut out (aka, the drone)