larger exhaust or not.+UHF CHANNELS

As a very general rule, better flowing exhaust i.e. less backpressure results in better performance from a turbo engine and may reduce EGT'S. It's not always that simple but you may get benefit from a bigger exhaust and maybe beneficial in conjunction with other mods such as fuel and boost increase.

gday mate i think there are advantages for using a bigger exhaust power wise ,there is a big improvement as the engine will breath a lot better as in getting rid of the gases a lot quicker and with a bigger exhaust the engine gases released run cooler so with a cooler motor comes more power.I would be using a three inch exhaust on a landcruiser or patrol engine and i think a 2 1/2 inch would be suitable on anything else smaller if the motor was a standard turbo or aftermarket.So yes i think a bigger diameter exhaust would be beneficial to you go and speak to all the 4wd shops that you respect about what they think im sure they will say they same. Just one more thing the most important point to remember if you buy a larger exhaust it has to be a mandrell bent one other wise you are wasting your time.By that i mean when they bend the exhaust at the bends the diameter of the exhaust pipe gets smaller say if you buy a 2 1/2 inch exhaust at the bend it will probably only just be 2 inches so restricting the gases flowing where as a mandrell bent exhaust say if you buy a 2 1/2 inch exhaust the pipe will stay just that on the bends achieving what you originally set out to do less gas restriction and cooler running gases which all add up to more power for your vehicle .Hope i helped mate.

Warren, there have been heaps of discussion in the past, I had people say to me there is little benefit but the other side is they hadn't also made a change to a larger dump pipe.

The dump pipe is the pipe, usually cast iron out or the turbo. If that is the standard one, it is about 1.7" diameter and very restrictive. I have photos of it still and can reload them if you need to see them. The new pipe is fabricated 3" and free flowing.

I actually had a 16% improvement in the 0-100kph acceleration after fitting. Not bad for a bolt on jobbie last Christmas day.

UHF 40 is often pretty noisey, but 18 is the camper trailer and caravan channel. Depends if you need to talk to someone really. If you can stand listening to the language and crap from the truckies all day.........

UHF CB radio channel allocations.

11 calling channel established by law. To call or locate another station. Parties then switch to a conversation channel.
9, 12 to 17, 19 to 21, 24 to 30, 39 conversations. Used for conversations between stations
29 Highway communications. Mainly used by truck drivers and other Highway users on the Pacific Highway (Sydney to Brisbane) in N.S.W.
40 Highway commnications. Mainly used by truck drivers and other Highway users Australia wide, but not usually on the Pacific Highway (Sydney to Brisbane) in N.S.W
18 caravanners, campers. Holiday maker's communication channel, e.g. when in convoy
10 4WD drivers. Use by 4WD enthusiasts, clubs, convoys and in National Parks
5 Emergency calling channel established by law. Can be used by anyone in an emergency situation ONLY
1 to 8, and 31 to 38 repeaters established by law. In duplex mode, repeaters need two channels to work. Receivers on 1 to 8. Transmits on 31 to 38 (automaticaly). When within range of a repeater it will increase the communications distance. Operation in simplex mode on these channels is not permitted when within range of a repeater.
22 and 23 data transmissions established by law. No voice transmissions allowed on these two channels (access to 22 and 23 is not available anyway on some UHF CB radios).

My brother installed a 3" exhaust on a 2.8 6 cylinder turbo diesel and it has never run better. It is definitely worth the effort.

My answer would be.Probably not all that much improvement but still a small improvement.
There are a lot of mods we can do which will marginally improve/or decrease engine performance and fuel. Individually quite insignificant but added up can make a lot of shange. I had a vehicle fitted with a performance chip and got and extra 15% power on the dyno but fitting a raised suspension, roof rack, A/t tyres, larger diameter tyres, Driving lights(restricted airflow for intercooler), negated that inctreased power. This was all checked on a dyno.

My advice is wait until the exhaust is worn out and then replace with a bigger one. To spend $1000 on something that will only give minimal improvement is not really worth it.

A lot of people will tell you of huge improvements but that does not usually translate to the dyno. Louder noise does not necessarily mean increased power but sometimes it helps justify (in their own mind) t6he cost of the modification.

A larger exhaust (within reason) will provide;

1. improved turbo spool up - particularly at low revs
2. lower EGT - important if you intend to add a performance module or tow heavily
3. marginally improved peak power
4. improve mid range power under acceleration - as result 1 above

The improved mid range response may be all you are looking.

If done correctly there will not be any noticeable increase in exhaust noise, and there will not be any interference across the complete vehicle articulation range - this can be a problem with 3" systems on some vehicles.

It wont provide huge steady state power increases - this is essentially reserved for modified ECU fuelling and timing using diesel performance tuning modules, chips, and downloads.

Dave