Maximising Intake and exhaust

[Kitika]

G'day,
I got a HZJ80 and have recently installed a supercharger to it. I love the power and it hasn't seemed to make any difference to the fuel economy but i'd like to make it a whole lot better than 15-17L/100km.
I have been thinking of modifying the air box by putting another couple of air intakes holes into it because even at idle the single 3inch hole is under a fair bit of vacuum. Has anyone else done this? Any benefits? I was also thinking of changing the standard 3inch intake to a 4inch and then making up a snorkel to suit. For when i'm on the bitumen i'd have the extra intakes open but when on dusty roads or water filled tracks i'd have them covered so the only intake is the snorkel. Would there be enough benefits for all the fab work? I'm not to sure...
Also i'll be getting a new exhaust hopefully in the next few weeks but have another (possibly crazy) idea.
In our shed i have a twin genie turbo muffler sitting under the bench gathering dust. Would there be as much gain or more in getting 2x 2.5 inch pipes coming of the extractors (which go from the 6 to 2 to a single pipe, I would get the pipes joined before they became one) as would from getting extractors with 3 inch pipe to turbo muffler? I reckon the twin muffler would make the old gurl sound quite like a v8 which would be cool!
What does everyone else reckon about these ideas?

[BEU77Y]

Most of your ideas sound pretty good.
Was chatting to a mate today who's thinking along the same line with the exhaust on his Troopy. Twin dump pipes near the back tyre. He is thinking twin because he reckons 3" would be a bit hard to fit in.

Maybe a change of airbox. A local metal spinner makes performance pod filters that look pretty good. Home (http://www.jntperformance.com.au)

I looked into changing some of the intake system on our 105 and found the square tube(runs across the head) into the inlet manifold has about the same cross section as 3-3.5" pipe.

My mates troopy is running a new inlet manifold that has 6 pipes with 6 pod filters and a bonnet scoop. He said it's made a massive improvment to low end torque. The factory manifold is pretty ordinary for any decent flow.

Keep us posted

[Kitika]

Would a Turbo muffler be too loud by itself? As in illegal loud. The sound wouldn't bother me much as the motor and windsounds are pretty loud but don't want to get in trouble with the boys in blue.
I can't really change much to the intake apart from the airbox because of the supercharger setup. I'll see about modifying the airbox in the next couple of weeks.
I'll get some pics of it too and any results;)

[wombat_831]

every engine is different when it comes to exhausts as my old hq one tonner and my mates hq monaro both had 253s with quadrajet carbys and same exhaust setup 2.5 inch with turbo mufflers mine used to go 95db his used to go 97db which put him over the limit by 1 db but in saying that as long as you dont standout too much and get the attention of the boys in blue u should be right i run straight out 2.25 inch at the moment and one will occationaly look but as long as im not driving stupid they pay no further attention to me i even passed 2 rta roadblocks yesterday one each end of our bypass road and i was under a bit of load and the first bloke took a second look as i went past but i never got stoped and they werent that buisy

[Kitika]

I suppose if it's a little bit to loud i could put some resonators or something like that in there at a later date! Cheers for the info peoples i just got get out into the shed and start modifying now!:)

[Kitika]

Well i haven't been able to find any extractors in my price range (they want $720 just for the extractors:cry:)
So what I've done is cut the rear muffler out and done a side dump pipe under the sliders. It sounds like a tractor at idle which is way kewl! And has made it so much more revvable. The bad part tho is the noise at about 1600 rpm to 2000rpm to is huge! Like a massive diesel thunder god or something of the like... What would be the best way to quieten it down just a tad and not lose the freeflow benefits? Cheers for any help

[Sic Lux]

Ricer canon or milo tin:thumb: best bet would be a resanator should quiten it down my lux had a horible fart in it with one resanator so put one from a El falcon in the mix and shut it up just a scweet sound now. My 80 runs 3In of the turbo dumping out the side which happens to sound better again:D

[Kitika]

Any idea on the price of a resonator? I don't want a big ricer milo tin i think all me mates will disown me...:crazy: haha

[toy yoda]

cheaper that getting a defect notice removed!!!!! :)

[Kitika]

Aye that is true:) i'll be going down to get one tomorrow and fitted that afternoon. Well hopefully anyways:thumb:

[trekdog02]

try index (http://www.maxheaders.com.au) for extractors. i just got some for my 2.8 hilux $160 and free postage, half the price of all the other quotes!

[Kitika]

I picked up some 2nd hand extractors for $100! I need to modify them tho so they dont foul on the supercharger bracket. After getting some quotes to get the exhaust done professionally i've found it all to be out of my price range so i'm gonna give exhaust manufacturing ago.
My question is would twin 2.5inch pipes be about right for my car? Twin 2inch seems alittle bit small considering the amount of air they have to pass and twin 3inch seems alittle bit to big... Any helpfully exhaust fitters on here;)?

[Ducky103]

I made a 3" exhaust for my rodeo using 3" donuts and pipe just need to cut the angles out of the donut and weld to pipe. i made flanges to fit it together. Just need to be handy with grinder,welder and oxy. all parts should be available at exhaust shop.

[Kitika]

WOW!!! 2.5inch twin pipes made a huge difference! Sounds absolutely awesome and made the motor heaps easier to rev. The system is dumped out the side just before the rear tyre and was a bit of a squeeze to fit in but it was definitely worth it. If i could post up mp3 format i'd give a sound snippet but i dunno if thats possible?