2.5" Exhaust

[Witchdoctor]

Southport Exhaust fitted a custom system to my MU
2.5" from the turbo back with a sport resonator very well tucked up out of harms way good improvement in HP with no intrusive noise.

Dave

[Yarno]

So how much did that set you back? As I am looking at doing this mod next.

Cheers
Yarno

[Witchdoctor]

Yarno just found the paper work $295.00 drive in drive out.

Dave

[Yarno]

Gee thats not bad... had a quote for a 3" half way from turbo including dump pipe and 2.5" muffler to back all mandrell bent for $750...

[Graham]

I think that at 3" diameter, mandrell bends wouldn't be absolutely necessary. 3" can make a big difference to price as well. Not all shops have the equipment.

Has anyone tried a truck exhaust place???

It's on my list to do as well.
Cheers! Graham.

[Harry]

I work for a place that makes stainless steel mufflers for heavy machinery,so I built my own 2.5" system.Don't have a tube bender so used bought bends.Muffler is 3".With 2" lift Iwas able to run the pipe over the g/box tail shaft.Didn't notice a huge improvement but is only marginally slower than my intercooled 1990 lwb.

[bendownsouth]

Just a question where are these guys, the two place i got qotes from when i was up in auckland (pitstop and another place) both reckoned about 550- 600

where is this Southport exhausts?

Cheers,
Ben

[IsuzuMu]

197 Nerang Rd, Southport, QLD 4215
07 5532 4707

[Harry]

Probably cheaper to get it done in Auckland!

[Garth]

Or at the muffler place in Blenheim now you're down south! shouldn't be more than $500 as long as you don't want stainless

[Dave]

Got a quote of $375 from exhaust shop here in Blenheim late last year. Might have to see if they can still do it for that price.

[Stu]

What size is the stock system? Are their any noticable gains/losses in torque across the rev range? I'm trying to convince Dad to change his system but he's unconvinced that the low down torque wont be affected.

Cheers

[geeves]

I was suprised at the differance mine made. Power is up slightly across the whole range but more importantly before the 2.5 exhaust it ran out of wind around 3700 now pulls hard all the way to the rev limiter and at the bottom end things now start happening around 1600. Mid range coming up Ngaranga Gorge used to be 80kph in 4th now 85 -90 in 4th. Economy also improved measureably but not enough to pay for an exhaust in its liftime. If your replacing it anyway definatly go 2.5 inch.

[Stu]

Interesting. We've changed the intake around quite a bit and done the front mount setup so was thinking the exhaust was next. Ive got all the gear to tig weld it up myself so it'll only really cost the materials. Was really only concerned with a loss of low down torque.

It'll tow the boat up the Bombays in 5th now (although it doesn't like it all that much so we just sit in 4th and cruise up) compared to struggeling in 4th before.

[Jimmu]

Hey Stu,

Any chance you can send me some pics of your front mount setup?

I am deciding between front mount and top mount.

Also have any lag issues with it?

Jimmy.

[Graham]

Hi Jimmy,

Stu has posted pics of his front mount installation before, so if you do a search for posts by him, you should be able to find it.

Cheers
Graham

[Graham]

I just tried to find the pic myself, but I think it's been removed off the net. Hopefully Stu can repost or email it to you then.

Ciao,
Graham.

[Stu]

Sorry fellas, have been super busy and didn't have time to reply till now. The front mount setup is fairly straight forward bar a couple of things namely the inlet manifold and finding the piping route up the passenger side of the vehicle.

I can only find build photos and not the final product at the mo. Will have a dig around for a photo of the engine with the new air intake etc when I get a chance.







The factory air intake has since been scrapped and a custom setup made. I'm in the process of making a new drop pipe off the turbo and thinking about running a external wastegate to allow for a turbo upgrade I have in mind. Just like with cars, when you start modifying, it becomes never ending

[Garth]

Just put 2.5 inch system in my 2.8 bighorn and seems to be good. Went from the flexi joint back with just one free flow muffler. $500 fitted, all mandrel bent. Used 2mm tube with aluminium clading to slow down the corrosion. The old exhaust was had it so decided this was the best way to go.
Seems to be a little more power, lots quicker on turbo spool up and looks to be around 14psi (off the scale of my old boost gauge).

[Graham]

Gee, it's been almost 2 years since I said in this thread that I was looking to put a bigger exhaust on my 3.1 Mu.

Well, even though I'm trying to sell the MU, I've just gotten some quotes for a 2.5" system.
1st visit was Carline mufflers at Victoria Ave Castle hill. He quoted me $1,000 for full exhaust (from turbo) or $400 for replacement muffler and tailpipe!
next up was an exhaust shop just behind them at #4 Hoyle Ave - $480 for turbo back. I almost booked it in there and then.
Last place I checked out is at 23 Windsor Rd Northmead (performance exhausts or something?) and he quoted $600 for turbo back and showed me the muffler that he'd use - it looks like it would flow very well.

So I'm going back to the $480 place and check what muffler/materials he'd use and probably getting that unless someone buys the MU first.