Thanks for the replys even though they went abit off topic lol, obviously turbo, intercooler, injector pump tweaks are going to make a difference but on my salary its not an option at the moment, probly should focus on getting an exhaust after my flex pipe broke off from the turbo (running no exhaust at all) i can tell you all having no exhaust like i do now goes the worst having the center muffler cut out and put stright threw muffler in went the best and having stock exhaust just went normal, so thats lead me to beleive a not so much restrictive 2.5inch system might be pretty good for it. ive heard the less back pressure for a turbo d is better but running no exhuast is really no benifit, its rediculously loud and people look at me angrily although i do like the turbo whistle haha.

I'm not trying to insult you or be rude, the fact is that what you said is not correct and then you say "There is no science to back that up anywhere", I'm afraid you are totally incorrect, there is a huge amount of scientific (your word) evidence proving the opposite of what you say.
There is a very good book Published by SA Designs called "Tuning for Performance and Economy" a great deal of the book is dedicated to improved airflow thru the inlet and Exhaust, gives you Dyno readings with and without exhaust fitted, good reading, and that's only one of many books on the subject.
Also when I contribute to a post it is from real life, I have been a mechanic for 40+ years, I have worked in Motorsport, Trucks, Mining, Motorbikes and general Mechanicing, so I have had a little experience as well.
A practical example, I had my BA Falcon GT on the dyno, by just removing the the top of the air filter box I got an increase of 8Kw at the rear wheels, with just the headers fitted and no mufflers and no tailpipes I got another 10Kw at the rear wheels. So by unrestricting the inlet and exhaust I had a Gain of 18Kw at the wheels. Where is the evidence to back your story, I would be interested to see it, forgive me if I upset you, it wasn't intended to do so, but if you are going to make a statement that has no basis in fact then you must expect some sort of rebuff, Regards Frank.

can't beat the truck turbo spool sound coming from a decent exhaust on a diesel =D

PM send and received.

Geez Frank

Anything you haven't been, haven't done ????

In THIS POST you were ......
Pull your head in and mind your manners please.

Stevo

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'95 Discovery 300tdi Auto - mine
'97 ES Discovery V8 Auto - "town car" - hers
'95 Discovery X300tdi Manual - parts

Huts Photos

Look mate at the end of the day the main thing is that your happy with the outcome on what ever decision you make. All trucks are different in one way or another and some might get a whistle from the turbo and some might not. I went with a 2 and a half inch straight through muffler which benifits me as the egt drops and gets out quicker that what I wanted and that's what I got. So go for it and hope all works out.

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95 Disco 300tdi - Now with MORE BOOST
Cheers Simo

That's right, started a mechanics apprenticeship when I was 15 (now 63) and later while working in the mining industry decided to do a Riggers ticket.
Am now a Class 1 Ticketed rigger, a ticketed Dogman, and Mobile crane driver's ticket, ticketed Scaffolder. Also have Class 5 drivers lic., I am now about to do a course to get a welders ticket, anything else you would like to know, anyway it might be better if you pull your head in sport, nobody asked you to butt in, Regards Frank.

You were rude to me that time and rude to others this time...
that time you were wrong as well .........

Mind your manners and don't "sport" me "CHAMP"

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'95 Discovery 300tdi Auto - mine
'97 ES Discovery V8 Auto - "town car" - hers
'95 Discovery X300tdi Manual - parts

Huts Photos

There have to be something wrong with the water down south
Boys we are here to have fun, and if someone have a bad day we just have to ignore their manners if any
Have a glass of red

Umm, anyway. Turbo restriction is before the exhaust vaine on the turbo. Any time that you remove "restriction" post turbo is going to be a good thing. Removing the center muffler on a Tdi Disco is going to give you better EGT's (ie. lower). For this alone, it will be worth while. It will help performance a little bit (you will still have the main muffler at the back so this will help quiten down the turbo) but, like I said, the decrease in EGT alone will be worth while. It is a cheap and easy mod to do, and once you have done it, it will be easy to change the rest of the system when funds allow. The best exhaust for a turbo application is one that increases in diameter as close to the back of the turbo as possible (so say that the outlet on the back of your turbo is 3", you would want to go to 4"), and is short and restriction free (ie. straight through).