TD5 TDI intercoolers

I had a basic intercooler upgrade some time ago and the fuel pump tweak was a requirement, otherwise there wasn't going to be much effect. More air into the engine but no more fuel apparently. Try doing the pump and seeing if it makes a difference.

Note that my intercooler went from a standard 300TDi intercooler covering about a third of the radiator area to a massive one covering the whole front of the radiator.

On or around Sat, 12 Mar 2005 19:02:14 +0000, Ian Rawlings enlightened us thusly:

mind I dunno what that does to your engine cooling.

AIUI, the point about increasing the intercooler size is that it allows you to increase the boost pressure, which in turn may require pump (or ECU, as may be) tweaks.

The converse point is that there's little gain from upping the boost without increasing the intercooling.

There's a little more to it than that, the cooler the air the better the mix burns and the more power you get as a result, plus of course you can get more air in there at the same pressure than you can if the air's warmer. As the air expands when it's hot a pipe at 1 bar pressure will hold less hot air than it would hold cold air, so without altering the boost pressure you get more air into the cylinders. Slightly unintuitive perhaps... On my plastic rocket a popular-ish modification is to increase the size of the chargecooler, this gives about 0.5-1BHP extra per 1 degree C that you reduce the post-turbo air by according to temperature probes and dyno runs. Increasing the size of the intercooler on a landy has the same effect but I don't know what kind of gains you get on a 300TDi.

Of course if you cram more air into the engine then you'll need more fuel to make good use of that.

IIRC there is a point in doing it, but it does start to become self-defeating as the extra boost gets cancelled to a degree by the increase in air volume due to the extra heat. You can also start getting early detonation, certainly in petrol engines, I'm not sure how that translates to diesels.

I'm afraid most of my understanding of turbocharging and intercooling comes from Lotus turbocharged petrol engines with water-to-air chargecoolers, not sure how well it translates to Landrover air-to-air intercooled diesels!!

On or around Sat, 12 Mar 2005 21:44:32 +0000, Ian Rawlings enlightened us thusly:

it's rumoured that too much boost on a standard TDi leads to melted pistons. Hence not bothering to up it unless you also increase the cooler capacity.

Yes, that's the effect of detonation, the pistons and head get torched, on high-performance engines the piston tops and injector spray patterns are shaped to avoid it amongst other things, I'd expect the same to be required even in a 300TDi. It's also what water-injection kits are designed to prevent, so you can boost higher.

There's no substitute for cubic inches! Just whack a small-block chevvy in there....

On or around Sun, 13 Mar 2005 00:07:54 +0000, Ian Rawlings enlightened us thusly:

Those 6.2 V8 diesels have a certain following.