intercooler myth needs de-bunking

So bonnet up the other day and my neighbor has a look under and notices i have a 200TDI but without the radiator unit for it (Oil cooler, inter cooler & rad). Just a bog standard Radiator.

He works at a farm vehicle fitters yard, and mentions he can get us a 200TDI radiator unit for nothing. Winner! But...

"I'd been told that an intercooler lags the boost from a turbo more?" said I. Which I had from a guy I trial with.

"Maybe if your in a Veyron, yeh! but not with this little turbo!" says he.

I've been chewing it in my head for ages now, but could do with some input with those in the know.

Which is it? does an inter cooler lag boost more than without?

bigger intercooler = more lag, lower egr, more power
smaller intercooler/no ic = less lag, higher egr, less power

Ultimately the extra volume added to the inlet side will delay pressure build-up, but once built up it will have no detrimental effect on the output. Further, as the incoming fuel/air is cooler, you'll get more in the same volume so power will increase.

EGR effects discounted as most have them removed anyway.

Peter

As above - all good advice.

I fitted a front mount intercooler I had made that had four times the surface area compared to the original but only twice the internal volume. My air charge temps dropped from peaks of 55'c to 30'c (summer time with high ambients) with no noticeable increases in lag, so I can only imagine the benefits when adding an ic to a system devoid of one. Engine was only 1.3l so had to work harder to fill the intake system.

No Landy but the principles are in many ways comparable - i say get one fitted.

Tom

A 200tdi doesn't have an EGR valve does it?

No. 300tdi onwards I think...

Tom

Anything that lowers intake temps are good. obviously taking it too far a massivly bigger volume of intercooler will have more lag.

I ran a 90 with a 2.8 Isuzu engine in it that didn't have an intercooler. when I had a Fearns one fitted it made a huge difference! Much better performance...like night and day...and no difference in lag at all.