Adding an Intercooler - Improving MPG?

[jtaylor2005]

Hello All

I have a 2.0 HDI Peugeot 306. I have had it stage one mapped and had a decent flowing exhaust fitted. I can easily get 55mpg (45.8 US) and sometimes see upwards of 60mpg (50 US)

What I am thinking of doing is adding a nice high flowing intercooler setup into the mix as currently it doesn't have one.

It smokes a bit when you put your foot down as the map is quite a strong one so I am thinking adding a decent intercooler will allow me to burn that extra bit of fuel and help burn what fuel it already gets.

I would move the boost pressure take off (for the actuator) from the turbo outlet to the intake manifold to maintain the pressure that the intake manifold is already seeing now on full boost.

Any ideas whether this will make much of a difference?

Cheers,
Jack

[cRiPpLe_rOoStEr]

Intercoolers usually do improve the general efficiency on a Diesel, plus they contribute to keep the NOx emissions at a lower level due to the colder air flow. They may even increase the durability due to lower exhaust temperatures. BTW it's quite surprising for me to figure out a DW10-engined vehicle to not feature an intercooler straight from the factory.

[jtaylor2005]

That's good to hear then and yeah it was the 90hp model in the 306 and didn't feature one at all. I believe on every DW10 after this model they had an intercooler from the factory. Including the 406 HDI which ran 110hp stock and was released around about the same time

[oil pan 4]

I added an intercooler to my diesel later on after I turbo charged it.
The fuel economy didn't go down. It may have slightly increased. Power and drive ability where increased.

[twj347]

At lower engine loads, you wouldn't likely see any difference, as the turbo is hardly heating up the air when not in boost.

At higher engine loads, you'll get more power, but I don't think this would translate to better efficiency unless you take advantage of the cooler air by increasing ignition timing and/or leaning out the fueling. Without timing or fuel changes, you might actually see a decrease in economy due to higher pumping losses at partial throttle since the air is more dense. There is a reason people use warm air intakes for better economy.

[oil pan 4]

It's a diesel. The air fuel mixture is always lean.

[cRiPpLe_rOoStEr]

Originally Posted by jtaylor2005

I believe on every DW10 after this model they had an intercooler from the factory.

I have actually never seen a DW10 without intercooler.

[teoman]

This is a video by a fellow member:

https://youtu.be/IVQSdOg4mHo

[Baltothewolf]

Definitely put an intercooler on it.