extractors on GU 4.5 Patrol

I haven't done this on a Patrol but I can give you some good advice on addressing the heat issue. If you get a set of headers made get them high performance coated inside and out. See www.hpcoatings.com.au

This will reduce the heat to less that than the standard manifold. The trick with the exhaust people is ring around, some have done it. You don't want it loud and droning, just some good headers and better breathing muffler etc.

Yeah, I am also considering same, as the original muffler is nearly rooted after 7 years, and a small power increase would be good, as would an economy improvement.

I have discovered that one needs to address the catalytic muffler aspects - getting the right specs so that temps are suitable, without affecting the flow from improved headers & say 2.5 " exhuast pipe. I have also been advised by one supplier/fitter that a 3 " system might get a bit close to the body work when off roading.

so I encourage you to keep investigating.

I will also report any findings. One quote has been $ 522 for headers + $ 470 for 2.5 " system + $ 420 for a cartalytic convertor= $1412 total.

Cheers

RossB

I own a GU 4.5 Petrol.

I have done exactly what you're enquiring.

I have PACEMAKER (the best) extractors on and a 2 1/2" exhaust with a huge straight through muffler and a larger straight through resonator inthe rear.
You don't need a new cat. Who ever says that are just trying to rip you off for a few bucks. Who ever fits it will need to cut the Cat back to 2 1/2" to improve the flow. The 3" of the cat on either end is empty, my guy just chopped it back to max the flow out to the exhaust.

Heat is definitely not an issue. Runs fine. i even have a pair of 240 lightforce in front of the grill. Temp is normal.

The performance was noticeable immediately.

But 2 days later i got the snorkle put on. Holy fu*k. It's a new truck. Fuel economy, depends on your right foot. On a recent trip to the snows i got 700km without the light coming on.(standard tank size) around town, i'm getting 600km easy without the light.

The exhaust was very beneficial but the snorkle is required to feel the full benefit.
It is a little noisier but with the stereo on, don't notice it.

Put your foot down and it hauls ar*e.

My system cost just under $700 fitted as i know some one. normally just under $800. which is awesome.

The exhaust is also aluminised. As i go to the beach alot and been exposed to salt water, i found this prolonged the life of it.

Are you in Brisbane?? e-mail me if you want more info and i can send you to a good exhaust shop.