3 inch exhaust

[Dhuddo Lurker Find all posts View Profile Close Dhuddo]

Thinking about fitting a 3 inch exhaust to my baby. I here it's a good way to loose some turbo lag, has anyone had one fitted, was there a noticeable differance, and any thoughts would be appreciated thx.

[ToeEdge Junior Member Find all posts View Profile Close ToeEdge]

Hi Dhuddo,
There are several threads on this topic worth searching for.
I have a Genie 3" system with straight through Cat and muffler along with a 3" dump pipe on my 120.
From my experience, I would put it lower on the list of upgrades. And, in fact in hindsight, I would go for a 2.75" system.
Reports from others on this forum and also from my experience, it seems if you get rid of all of your back pressure in the system, the turbo spools down too quickly and you actually lose boost... sure it might spin up quicker, but the lag is already there.
I've also noticed it seems to struggle keeping the variable veins stable. At constant throttle I can actually hear the turbo and exhaust pitch changing as it tries to adjust boost (well that is my theory anyway).
So, my tip, do a bit more research.
Cheers.

[Dhuddo Lurker Find all posts View Profile Close Dhuddo]

Thx, been looking in to it, most people reccon a high flow muffler is the way to go, looking at that now, don't want to chip her, I hear to many bad things

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

After agonising over the same question for a long time settled on high flow muffler, which the exhaust place surprisingly said was best bang for buck.

Also added a Steinbauer which doesn't mess with rail pressure/turbo like some chips, so doesn't give massive boost but noticeable when towing and no effect on engine reliability.

[Dhuddo Lurker Find all posts View Profile Close Dhuddo]

Just after that little bit extra respose down low when towing, hopefully the high flow will give it a bit more without worrying about engine longevity.

[brockbaker Lurker Find all posts View Profile Close brockbaker]

Thinking about fitting a 3 inch exhaust to my baby. I here it's a good way to loose some turbo lag, has anyone had one fitted, was there a noticeable differance, and any thoughts would be appreciated thx.

Hey Mate,
I was also wondering the same thing so I called up Just Autos who specialise in 1KD engine performance. They told me I'd be wasting my money on upgrading the factory exhaust as they have flowed over 300+ RWHP through the Stock Setup, all you would be achieving is noise basically.

I have read a lot of threads where guys have just changed there factory muffler out for a straight through muffler if you want a better note.

[yowie Advanced Member Find all posts View Profile Close yowie]

With my petrol 150, I had a 2.5 inch exhaust fitted (the muffler guys said 3 inch was too big and would lose some H.P. - or K.W. for the younger drivers)

The muffler is a small diameter free flow and there is a small muffler (resonator) just before the end of the tail pipe to reduce the drone noise.

The petrol engine breathes better, and towing the van is a bit less effort (until I hit the big hills, such as up Mt Ousley near Wollongong)

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

Hey Mate,
I was also wondering the same thing so I called up Just Autos who specialise in 1KD engine performance. They told me I'd be wasting my money on upgrading the factory exhaust as they have flowed over 300+ RWHP through the Stock Setup, all you would be achieving is noise basically.

I have read a lot of threads where guys have just changed there factory muffler out for a straight through muffler if you want a better note.

I went to a sports muffler and was very happy that it makes almost no extra noise. It definitely improves flow and reduces back pressure which you can see in how the engine runs on a tiny bit longer when you kill the ignition. Great upgrade, combined with a Steinbauer really noticeable when towing

[Nik83 Member Find all posts View Profile Close Nik83]

I went to the local exhaust shop and asked for a muffler that wasn't any louder but had a better flow... He put a glass packed straight through on and the lag when accelerating is no longer there, well, relatively speaking of course. It's a great cheap improvement at $250... Especially when coupled with a snorkel.

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

Are there any facts or figures available that show airflow or performance improvement from snorkels? Isn't the primary purpose of a snorkel dust extraction and raising water crossing height?

[Nik83 Member Find all posts View Profile Close Nik83]

I'm actually not entirely sure. I've gone off heresay. I got my snorkel and muffler on the same 24hr period and I noticed an improvement for sure. I understand there is a slight improvement from a snorkel due to cold air and a slight ram effect - breathing is easier anyway... But I put any noticeable differences to the muffler.

Someone may correct me on any of the above though. Definitely a lack of hesitation around 1500rpm - much smoother through the Rev range.

[CliffHangar Lurker Find all posts View Profile Close CliffHangar]

I picked up a 2014 GXL T/D auto with 7700km on the clock. Drove it around for for about 2000km including country runs then fitted a snorkel.

Fully loaded with family and gear on christmas eve Canberra to Melbourne, 8.5-9.0 litres per 100km sitting on ...well just say it was a fast trip. Very happy with that fuel use.

Yes I think there is something to the ram effect with a snorkel. Only negative is the vibration I get right on 800rpm where the air box pipe hits against the inner guard skirt. CH