Diesel POWER how to !?

[extreme-4x4]

?

you put a valve in the turbo boost pipe... basicly as i understand it. when the engine has enough pressure it pushes the gate valve that controls the turbo... so you fit a valve into the little hose that makes the gate valve open later this will give you greater turbo boost.

bit like runnig water through a hose (normal flow) then bend the hose to stop the water then release ... you get a sudden rush then normal flow. up the turbo boost is like the sudden rush on a hose


is that right

 

[Timbo_1975]

Won't improve anything.

The stock Terrano is very underfuelled as it is. What you need is more fuel!

I wouldnt run the T25 turbo over about 0.9bar, they dont like it! The compressor is too small and you will only produce hot air.

Watch how the stock turbo struggles to maintain boost over about 3500rpm- it falls off.

If you want improvement, fit a T28 from a Nissan 200sx and have the ecu re-mapped. They fly then!!

Tim.

 

[zippy656]

Won't improve anything.

The stock Terrano is very underfuelled as it is. What you need is more fuel!

I wouldnt run the T25 turbo over about 0.9bar, they dont like it! The compressor is too small and you will only produce hot air.

Watch how the stock turbo struggles to maintain boost over about 3500rpm- it falls off.

If you want improvement, fit a T28 from a Nissan 200sx and have the ecu re-mapped. They fly then!!

Tim.

that cost proper money thar dose.

 

[makeitfit]

Won't improve anything.

The stock Terrano is very underfuelled as it is. What you need is more fuel!

I wouldnt run the T25 turbo over about 0.9bar, they dont like it! The compressor is too small and you will only produce hot air.

Watch how the stock turbo struggles to maintain boost over about 3500rpm- it falls off.

If you want improvement, fit a T28 from a Nissan 200sx and have the ecu re-mapped. They fly then!!

Tim.

Hi Tim I've now got a TDi and fancy the T28 turbo option:sly
I've found I can buy new ones from the states at £169 but wondered is it a direct replacement? Also will the rest of the TDi fuel stuff be ok, like pump and injctors? Also whats involved with an ecu remap?
Have you done this conversion yourself?
Super chips offer about 25 BHP extra for about £300 so there seems no contest!
What you think:bow

 

[Timbo_1975]

Firstly, you need the T28 off a 180 or 200SX. Its very simialr to the T25- in that it has a 0.63a/r turbine housing, but a larger compressor wheel and housing, so can flow more air- just where the T25 runs out of usable airflow. They are a direct swap to the Terrano, although you may have clock the compressor outlet around one notch to fit.

You can run the T28 at the same or less boost, and actually get more power, as you don't need to run nearly as high a drive pressure. (think of the turbine having to spin the larger T28 compressor slower to get the same airflow- the wastegate opens sooner)

Charge temps are also lower.

You will need the TDI top mount intercooler with a fan kit on it, or preferably a front mount IC.

I initially ran a PSI box to up the fuelling, but this is not really adjustable, and still underfuells with the T28.

I now have a re-mapped ECU plus an adjustable tuning box for the short term but in the midst of a home-programmable ecu, as I am still short of fuel in the mid to top end range.

The next stage is a replacement downpipe as that is the next restriction!

If you are playing to this degree you must use an accurate boost gauge, and more importantly a pyrometer so you dont melt the engine!

Tim..

 

[makeitfit]

What is a pyrometer?
Also I've been talking to "Tuneit" cause their version of PSI is tunable they say and will handle the T28.

 

[Timbo_1975]

Pyrometer = Exhaust gas temperature gauge.

Important to know that you cannot wildly alter fuelling etc without doing some monitoring. More fuel in a diesel = hotter exhaust.

600 deg C is an absolute max for a diesel- any hotter and you will melt exhaust valves and turbo or worse.

the other thing to note is that the more fuel you want to burn the sooner you need to inject it, otherwise its still burning when the exhaust valves open = even hotter exhaust.

With the TD, thats easy if alittle crude- just clock the pump around a tad.

On the stock TDI- not possible as the ecu constantly adjusts timing via the needle-lift sensor. Which is why I have a re-mapped ecu to allow some more timing advance.

Anyhow, go with the tunit box / whatever and see how you get on with the stock T25.

I can't emphasise enough though how you must must must ensure the car is running spot on first with regards to a properly working MAF that is giving a solid 4.5v under load. You won't get stock boost if not. (~12psi)

The T25 is safe to 15psi. Don't attempt to run it over this. You are actually reducing power by a) feeding the engine hot air and b) exhaust drive pressure is way to high -the cylinders still retain some exhaust gas;- EGR gone mad!.

Hope this helps. Tim.