200tdi exhaust back pressure and intercooler cleaning

[feraldisco]

With recent posts about whacking in a 3-inch exhaust without muffler, I thought about just replacing the current muffler with pipe on existing system and maintaining tailpipe resonator box for some noise reduction. Before embarking on this, I thought I'd see how the 200tdi (disco) ran with the exhaust disconnected just before the muffler. Apart from being bloody loud, I couldn't detect faster turbo spool-up/performance - could too short/unrestrictive an exhaust actually detract from performance?

Also, how important is it to clean the outside (and inside?) of an intercooler. I've done 250K k and this has probably never been done.

Thanks

[PhilipA]

Feral,
My experience is with a Charade Turbo of all things.
It had a Right angle turn out of the turbo directly into catalytic converter housing, which was empty.
Replaced it with a 2inch dump pipe into standard exhaust, and the spool up was much , much quicker.
Could it detract ? NO . Any reduction in back pressure is positive to Turbo.
However the waste gate ensures no extra boost/power once it opens so you do not get extra power once the wastegate is open. But it fills the bottom of the torque curve.
You would probably only feel it with a load in a diesel eg sand as they are so slow to rev.
Regards Philip A

[cookiesa]

Don't know about the inside, after all in theory it is only clean air with a little breather fumes (oil?) going back to the engine.

BUT as for the outside no different to a radiator. If it is 50% blocked then you can only expect 50% cooling ability. Like running a smaller intercooler! Unfortunately I assume it is like the 300Tdi one and isn't exactyly "overkill" now! LOL

I seemed to get smoother mid range after cleaning it before putting mesh on the front. Could just be because I knew how much crap came out of it though!

[LoadedDisco]

I would be interested if anyone knows if there are any negative affects with backpressure on fitting extractors to a 2004 Rover V8 4.0Ltr. Or any negative effects with changing the exhaust system to larger diameter.

[duff]

You are supposed to clean the inside of the intercooler periodically. It is in the TD5 maintenance schedule, on the 02 and onwards it is called for every 80,000 kms.
I bet your friendly LR dealer didnt do this at 80000, mine didnt, it is being done now while the radiator is out for warranty replacement.
LR list a intercooler element flushing fluid but you can simply flush with a petroleum based cleaner, then an automative degreaser(flush with water really well,, really well. and then air dry by running the engine with the intercooler to inlet manifold hose dicsconnected. keep it running until no liquid is being pumped out of the intercooler

Extractors and a larger exhaust on the V8 will benifit ngine performance. it is not the backpressure that is provided by the exhaust that helps. any restriction is simply extra load on the engine,,, turbo or "natasp".
the reduced performance from stuffing around with exhausts on naturally aspirated engine has got far more to do with the return gas slug(shock wave) (pulse timing). you can induce gas draw caused by restricion in the centre part of the system,, but increased Pipe diameter will benefit performance greatly,,,the pipe dia must fit a directly related formula along its length. some relative restriction in the centre portion of the system will serve to draw gas out, regardless of diameter.
If you are running tuned length extractors(keep in mind this is tuned to the gas slug and the tune can be differant for differant peak torque for a given rev range) you can basically work out the CFM that your engine flows and place a pipe after the extractors that provides no backpressure, simply carries the gas to the back.