Nissan Patrol 4x4 (Africa)

Ok cool ... I learnt something new today ... Thanks... my apologies for the misinformation.

But back to the noise issue.... This morning I let my Iron Maiden warm up for a few mins. While this was happening I walked around the vehicle at different distances and the noise level from the exhaust was definitely shadowed by the clatter clatter of the noise from the engine bay. the only sound that dominated from the exhaust was a mono pitched whistle from the turbo, that was still slightly drowned out by the engine bay noise. So I still believe a straight pipe will not be an issue unless you blast the accelerator on a fast pull away or overtaking maneuver.

Just to clarify further on the 4.5 petrol and I am not sure if it applies to the diesels or TDI's;

The freeflow and branches make a difference, coating the branches makes a further difference and I think this may have more to do with the temp drop but it still does not hop until you combine it with enough air going in. I had an aftermarket filter made up and then the differences across the range and particularly low down where very noticeable.

No idea what the differences are on the dyno but in the real world the gains where worth every cent.

I would not use the aftermarket filter without a snorkel though and I actually had 2 made so I can clean and replace every 5000 km.

I got a estimate from HMD Performance Exhaust in Nelspruit, on the"straight pipe" fitment:
R5000-R5500.

Seems a bit steep.
They say its because the mandrel bends are expensive.

Phew.... ja..... but once you put that on..... you never worry about it again !!

On the weekend, at a farm near hoedspruit, I was driving on the back of a 4.2 n/a land cruiser, which had a freeflow fitted. (actually more a straight pipe with one small box at the end). This thing had a lot of oomph with this exhaust fitted.
It created a bit of urgency on my side to have this mod done.

Yours will be much quieter if that cruiser was a n/a, even if you go with a full straight pipe without any "free flow box"

JoshJ wrote:SJC,

Why don't you start with the low cost approach to get to where you want to be. start by removing the catalysts and silencer boxes in your current exhaust. and replace them with pipe. then you have a straight pipe. if its to noisy then a bigger straight pipe wont work. ad 1 free flow box and see from there. when you got more or less what you want then you can go and redo the whole exhaust.

I had this done last week. My truck is definitely more responsive now... Will do the whole exhaust (76mm) incl. turbo down pipe, when I got some funds available.
You can hear the exhaust now, but its not loud. Sounds nice though.

Nice,

I will be keeping an 'ear' out for you on the trip

want to do the same

Just had a 76mm pipe fitted. Patrol goes nicely, but a bit loud. Will probably fit a box... interested to see how she tows. Also interested in the egts.

what would be the ideal exhaust setup for a carby tb42?
would the pipe diameter make a difference?
and the effect of just one freeflow box ?

How would you know if your current box is clogged up? is there a way to test it?