GU 3.0lt boost

Wayne

No it wasn't the "perfect conditions" that nissan perform their tests for their specs.
plus bonnet was up so no air was going through intercooler.

Have you got a standard paper air filter or one of the oiled sponge variety? If the sensor is downstream of the air filter and it picks up any oil, it will stuff up quickly.

Agree with Sky Pilot.
I think it has a lot to do with the air cleaner element. I notice that the Nissan service shedule says to change the filter element every 40,000 K's, or more frequently in dusty conditions. However I've noticed that the filter element gets very dirty, very quickly. This would restrict the airflow, causing the airflow sensor to detect lack of air and give "false readings" to the ECU..... My theory anyway.... Therefore I check my Filter element regularly and I'd change it 3 to 4 times a year. At around $30 from Nissan, it's not too much to ensure clean air flow to the engine.

Rob

Hi,
I don'r know why you say it would give "false readings". If it measures less airflow and passes that on to the ECU, you would get less fueling and therefore less power, that would be my theory.
Cheers

Indeed;
So why is the turbo overboosting? seeing it spins off the exhaust gasses,
less power, less boost. Perhaps the vanes (variable vanes) are sticking?......................... Enter someone more knowledgable.

was that before or after the exhaust was fitted Bill please?

Afterwards John........Going to Berry tomorrow for a turbo changeover; new Schwitzer unit and I think they might dyno-it again after that too. Will post my results tomorrow night (all going well......it's a 4 hour drive each way).
Cheers
Roachie

Roachie, I know all dyno's are different, but mine was 120 kW after being tuned etc at MTQ in Toowoomba. Turbo and exhaust, boost to 12psi

Forgot to add, as soon as bonnet scopp fitted, will dyno again and see what difference AWilll4x4 intercooler has made.

30% drive line loss as a rule of thumb.

Where were the figures taken from?, Fly wheel you have lost power, rear wheels you have gained power.

Hi John, and all the other T/D owners.

While we are discussing Turbo KW's and Intercoolers. Just wanted to put some food for thought out there. I spoke to a Top Turbo mechanic, he used to do the Motors on the Nissan Rex Skylines for racing in the sports car class, and he mentioned a pretty relevant point to me when I had my T/D Bravo. Scoops etc only work if the vehicle is moving, as it needs airflow over the thing to get any benefit worth talking about. This is pretty deflating if you think about it. In your T/Deisels you are working there way through hills or sandy area's in low range and just where you need the horses to be at max you are usually travelling to slow to have any amount of cool air flowing across the intercooler. (of course it probably hot enough to cook a roast under the bonnet anyway,)

Most hotrod clubs when testing for most power stick dry ice on the intercooler and have a fan blowing over it when they are on the Dyno, as it bangs out bigger ponies. I had a small 12volt fan fitted to my cooler just for this reason, seemed a lot better to spend the money here than on a scoop, which only worked down the highway at above 40kph.

Might have been blind faith by me, but seemed to make sense.

Fan probably wouldn't fit on 3.0 lt top mounted cooler & would retard airflow when cruising. Not that either would make a huge difference.
There was a post a few weeks ago about the 3.0lt scoop pushing hot air out of the engine bay instead of cool air into it......
I placed 4 bits of elecy tape on my scoop with 2inches flapping to see & at 20kmph they were pushed into the scoop. Thats even with 2 rally 4000's on top of bullbar disrupting airflow. mythbusted
PS....truckster, xmas is coming, ask nicely and you might get one!!!

From memory, the GU 2.8 t/d has a fan under the intercooler for this purpose. I don't know why this wasn't carried forward to 3.0.

Hugh