Thread: TD5 High EGT - Intercooler vs 3 inch

I found my Serck intercooler drops EGTs by maybe 50C(estimated) in my 2002 EU3 auto

I run about 21-22Lbs and have a Powerflow lightly baffled muffler and your other mods.

I have a modified BAS tune with boost cut and MAF inputs modified.

I still have to reduce speed on hills when towing my approx 900KG camper trailer.

I really cannot use cruise control on anything but very flat ground or it flattens it on a hill and EGTs go to 750+. Mine also runs at about 350-400 average at 110 towing on flat ground.

AFAIK the outlet to the turbo is 3 inch, and really all that should be necessary is to increase maybe the first metre or two, as the gases contract as they cool.

However I can still climb quite steep hills running at say 650-700C . An example if you know it is the last steep hill southbound before Buladelah where I can start at 110Kmh and still be doing 100at the top locked which is far better than my modded RRC 3.9 could do.
You just have to drive by the EGT gauge. After all it is really a tiny engine to be pushing a block of Flats weighing 2.5-3 tonnes loaded.

Regards PhilipA
To answer your question .
Yes the intercooler reduced EGTs but maybe not by as much as expected, but it's hard to know. I felt boost increase achieved more. I have a Turbosmart boost controller that to me allows faster boost gain over 15PSI.

I doubt whether a 3 inch exhaust will give large gains. One way to testis to test the PSI in the exhaust by plumbing a pressure gauge in near say the front of first muffle location.. I have a Britpart first section which has a better design of the flexible part .

The outlet of the turbo itself is about 1.75”
The pipe (dump) flanges out to 2.5”

Optimum on a worked TD5 is 2.75” and a 3” doesn’t gain anything.

The factory flex joint is often the restriction on later vehicles as it reduces on internal diameter.
Replacing this with a full sized bore helps immensely.

The intercooler and the above flex joint would be my first port of call

Another good tip - take the wastegate boost feed from the EGR delete also, it is then real boost, not pre-intercooler.

ok, couple of questions.
so when you say bore. you are referring to the flex joint?

@phill. you said 3inch but Tombie is saying 2.5. if I'm reading this correctly .

does anyone actually have measurements?

has anyone replaced the flex joint and what improvements where had.

so just to be clear im not after any additional power. only reductions in EGTs. without dropping my MAP back to standard lol

Originally Posted by TroyMortimer

ok, couple of questions.
so when you say bore. you are referring to the flex joint?

@phill. you said 3inch but Tombie is saying 2.5. if I'm reading this correctly .

does anyone actually have measurements?

has anyone replaced the flex joint and what improvements where had.

so just to be clear im not after any additional power. only reductions in EGTs. without dropping my MAP back to standard lol

Are you running the stock turbo still?

If so I'd suggest that is a large part of the problem, coupled with the boost box, which is another bad idea.

The stock turbo is only good to about 1.5 bar boost at the most, after that the pressure ratio is off the chart, and it's also in over speed. At this point it's making more heat than air. So is probably not a cooling issue you have, it's a heating issue.

Having said that, that is some really extreme egt figures, I wouldn't normally see those, even on reasonably tuned vehicles running stock hardware.

Can you post a log up?

Cheers
James

Edit:

Also note that not all td5s whether EU2 or EU3 had a restrictive flex joint, I've gone to upgrade a few in the past, one that still had the cat, and it was already full size. I don't know which ones were restricted, but obviously some were, I've seen 3 or 4 of varying ages that were stock, but also fine.

Originally Posted by TroyMortimer

ok, couple of questions.
so when you say bore. you are referring to the flex joint?

@phill. you said 3inch but Tombie is saying 2.5. if I'm reading this correctly .

does anyone actually have measurements?

has anyone replaced the flex joint and what improvements where had.

so just to be clear im not after any additional power. only reductions in EGTs. without dropping my MAP back to standard lol

Mine are actual measurements.

OK I respect Tombie's measurements. Mine was a guess from observation I have often wondered what a straight turbo outlet and gently curved pipe would add .

I had a Daihatsu Charade Turbo once which had a right turn from the turbo into an empty cat box, and replaced it with a gently curved 2inch? pipe.
It made a tremendous difference to the car.
The cat delete pipe has a good sized flexible hose section.EU2 pipes could be a cheap source.
Regards PhilipA

I went 3 inch exhaust and manaul version of the Allisport intercooler with was $980 landed last year and with my td5inside hybrid turbo and remap I get 650-700c quickly but drops down when I let off, the sensor is on the collector of the Allisport Manifold

I run 25-28psi but will upgraded head studs soon I'll go 2.0bar with the turbo and map