Suggestions 1.9dci 120 standard

[R55VYS]

NA petrol engines are affected by back pressure, Turbo Petrol engines are not, any size exhaust and so on, diesel turbo engines are a whole different ball game to a petrol turbo engine, the boost and pressure running thru a derv is much different to an engine that will be refered to in "Tuning the A-Series Engine" by David Vizard.

I don't wana to talk to you no more, you empty headed animal food trough wiper. I fart in your general direction. Your mother was a hamster and your father smelt of elderberries.

[Anthony]

Please explain how the pressure created is different, I am intrigued.

[deebz]

ok im confused XD im in no rush anyway!!

[R55VYS]

Please explain how the pressure created is different, I am intrigued.

Did i say anything about pressure created being different?

Right high power diesels ie a 1.9dci are built with the minimum back pressure in mind, this is done to prolong the engine and turbo life, if you loose some back pressure it stops the turbo spooling as it should, giving you lag, and loosing power, and putting more strain on the engine.

Stop being a jumped up little tit, and shut it, im now not replying to you as you are annoying me with your fat headed stance.

[Anthony]

Don't reply then, but you're talking utter bollocks. Back pressure is not a desirable trait in any engine/exhaust system combination full stop.

[Anthony]

ok im confused XD im in no rush anyway!!

Sorry pal I know this topic has gotten a little off point. Just follow the advice in his first post.

[R55VYS]

Back pressure is not a desirable trait in any engine/exhaust system combination full stop.

Appart from diesel and non turbo engines. believe me i have had problems with a non turbo'd petrol car because of loss of back pressure, resulting in shat acceleration, it was sorted by a performance garage and that was their verdict, and they sorted the problem.

[davelowe]

Calm down guys! Name calling isn't going to advance the debate a great deal.

[Anthony]

Calm down guys! Name calling isn't going to advance the debate a great deal.

I know, there was no need to get personal.

[davelowe]

I suggest that if anyone wants to further the debate about exhaust back pressure, flow velocity or any other matter, they should find authoritative sources and cite them accordingly.

It's worth bearing in mind that turbos alter the flow rate dynamically in the variable geometry range anyway, so comparisons to normally aspirated engines don't necessarily apply, and neither do those of 'standard' turbos with external waste gates. With that in mind, apart from the back box, you will probably not improve the performance either negatively or positively by messing around with the area immediately around the cat. You don't want weird pulsing effects from too little back pressure, and you don't want an excess that chokes off the spool up time. By the time you get to the back box, there is sufficient tubing to absorb the exhaust pulses with respect to the cylinders firing at the full rev range, to give a sensible pressure range.

Basically, stick with the stock tube dims - they were designed by lots of people with many letters after their names for a reason!