Outer Limits 4x4 Board

Having had a GQ with an after market turbo resulting in a cracked head and subsequently blowing oil into the air filter causing me to sell the vehicle, I now have a GU with a 4.2 factory fitted turbo. My questions are:
Would I achieve much more performance with a chip?
Would the fuel consumption improve?
And if they are as good as the adds try to make you believe, why don't the engine manufacturers fit them as standard?
After my previous expereience, I'm very reluctant to have anything done to the motor.

can't chip it mate, its mechanical injection

you would need a 3 litre pootrol for that not 4.2TD ... fraid you're in zaust,bigger turbine,modded fuel pump zone now

Fair enough, thanks for your input.

Nissanman wrote:Having had a GQ with an after market turbo resulting in a cracked head and subsequently blowing oil into the air filter causing me to sell the vehicle, I now have a GU with a 4.2 factory fitted turbo. My questions are:
Would I achieve much more performance with a chip?
Would the fuel consumption improve?
And if they are as good as the adds try to make you believe, why don't the engine manufacturers fit them as standard?
After my previous expereience, I'm very reluctant to have anything done to the motor.

Firstly, your after market turbo didn't cause the cracked head nor would a cracked head cause oil to blow into your airfilter.
If you've had a problem with your previous engine it was more than likely a tune fault, as if the boost was set at a safe level and your fuel was set at a safe level then no damage would occur. A N/A TD42 is good for 15 psi all day and night with the correct fuel settings.
Second, as mentioned you can't chip your TD42.
Thirdly, there are several reasons why manufactures don't 'chip' computers from the factory. Any new vehicle needs to be able to be modified other wise it loses it's appeal with some of the market. Emmissions laws are easier met on a world wide base with a lower tune. Often they'll leave a 'little in reserve' so they can upspec a future model, etc.
Cheers Dan

The GQ's engine was overfuelling in one spot and it turns out it had been since it was fitted according to the records. The fitter blamed a flaw in the metal but according to Nissan if that was the case it would have cracked a lot earlier and yes, apparently it was tuned badly by him.

Nissanman wrote: And if they are as good as the adds try to make you believe, why don't the engine manufacturers fit them as standard?

because of the emmissions rules.

The factories have to pass these rules before anything can be sold, it's only after it's out of the car lot that you can bend the rules.

generally the chips clean up the standard ECU fuel map.

For example
instead of getting a lean out at 2250rpm
the "chip" will say to the ECU your running less fuel than whats really required... the ECU is tricked into adding some fuel in at that point.

same thing if the fuel maps adds too much fuel, the chip will say to the ECu your adding too much fuel, it's tricked into adding less fuel.

On the dyno runs/paper you want straight, clean lines not wobbling lines, this in turn gives you better power and you end up using less fuel.

A chip allows you to play around with the fuel map.

Some chips are preset meaning you can't program a map.
some you have to program a map, in which case you need to goto a dyno to get a base map for your engine.

you need a petrol or diesel with EFI system.

Nissanman wrote: And if they are as good as the adds try to make you believe, why don't the engine manufacturers fit them as standard?

I hate to be the bearer of bad news, but nothing is as good as the ads want you to believe.

Chipping (or any other way to get more power/torque from an engine) increases the stress on the engine, cooling and everything in the drivetrain.
Manufacturers design and tune the system to survive in the worst likely conditions. A high state of tune without an alert driver watching the gauges can lead to meltdown in many situations. Especially at altitude, in hot climates and towing. Let alone combining all three.

When I had problems with the cracked head and spoke to Nissan, the engineer told me they "shudder" when they hear people put after market turbo's on. She said that Nissan spend millions of dollars developing their engines and you can't just go and bolt something on that the engine wasn't designed for. And on my experience, I have to agree.

Nissanman wrote:When I had problems with the cracked head and spoke to Nissan, the engineer told me they "shudder" when they hear people put after market turbo's on. She said that Nissan spend millions of dollars developing their engines and you can't just go and bolt something on that the engine wasn't designed for. And on my experience, I have to agree.

i think thats a bit of "dealership ego". what has nissan done to a lot of its atmo diesels....fitted turbo's to them. i think some of the early ones where even aftermarket turbo setups fitted after the factory untill nissan started building them in the factory.

basically the company line (regardless of manufacture) is aftermarket gear/mods is bad.

tweak'e wrote:

Nissanman wrote:When I had problems with the cracked head and spoke to Nissan, the engineer told me they "shudder" when they hear people put after market turbo's on. She said that Nissan spend millions of dollars developing their engines and you can't just go and bolt something on that the engine wasn't designed for. And on my experience, I have to agree.

i think thats a bit of "dealership ego". what has nissan done to a lot of its atmo diesels....fitted turbo's to them. i think some of the early ones where even aftermarket turbo setups fitted after the factory untill nissan started building them in the factory.

basically the company line (regardless of manufacture) is aftermarket gear/mods is bad.

I agree. An aftermarket turbo done properly is a very good thing for a diesel engine. Less soot, less smoke, cooler EGT's etc.

You've been spun a line.

It is fairly simple that to make more power there must be some reduction in engine life, increased power comes from higher cylinder pressures, increased ring, ring land, bore wear is expected, its a trade off. The more power the shorter the life expectancy. The tuner needs to be sure the exhaust gas temps are acceptable and the pump timing is correct. The average tune involves looking at the average exhaust gas at the collector, if you had the time and money you would fit a pyro to each exhuat port and assure all the cylinders are performing the same, a poor, injector, faulty pump or poor ring seal allowing oil ingestion or even poor inlet manifold design and flow can cause large differences in combustion temperatures across the cylinders (allthough the average at the collector may be fine)and potential failure.
We fit a lot of chips, and in all my tuning I do preliminary EGT runs and then add fuel and boost providing a power increase while retaining similar to stock EGTs, it is possible to make more power but the cost can outway the benefit.
Also you need to look at the application in competition cars that run shorts bursts of full power you can run hotter EGTs than in a tow vehicle for example that may be wide open throttle for minutes on end up and down hills with a large load.

Joel

Cheers

Joel

zagan wrote:

Nissanman wrote: And if they are as good as the adds try to make you believe, why don't the engine manufacturers fit them as standard?

because of the emmissions rules.

The factories have to pass these rules before anything can be sold, it's only after it's out of the car lot that you can bend the rules.

generally the chips clean up the standard ECU fuel map.

For example
instead of getting a lean out at 2250rpm
the "chip" will say to the ECU your running less fuel than whats really required... the ECU is tricked into adding some fuel in at that point.

same thing if the fuel maps adds too much fuel, the chip will say to the ECu your adding too much fuel, it's tricked into adding less fuel.

On the dyno runs/paper you want straight, clean lines not wobbling lines, this in turn gives you better power and you end up using less fuel.

A chip allows you to play around with the fuel map.

Some chips are preset meaning you can't program a map.
some you have to program a map, in which case you need to goto a dyno to get a base map for your engine.

you need a petrol or diesel with EFI system.

Manufacturers make their product for the "lowest common denominator" as fuel quality goes, ie. a lot of markets run 87 octane wheras we run a 91 octane minimum. All most of these "performance" chips (powerchip, unichip, dchip and so on) do is calibrate the ECU for optimum performance on the 91 octane. Similar principle with diesel, but they can also play with valving to the turbos (variable nozzles, air bleeds etc) to extract more power/torque from them.

Unless the rechipping is radical, there is no discernable difference in the emmissions.

australia is dropping the 91 octane petrol and the min will be 95 octane from next year, i believe.

then again if your've done up your motor why would you be running crap fuel through it?

same sort of deal with diesel, the "high grade" diesel is just 0% sulfer diesel as the current diesel 5% sulfer is getting fazed out from next year in western countries and the only diesel you can buy in 2010 and on.

zagan wrote:australia is dropping the 91 octane petrol and the min will be 95 octane from next year, i believe.

then again if your've done up your motor why would you be running crap fuel through it?

The octane rating is not a quality rating. There's no point in running 95 in an engine that doesn't need the knock resistance.