850 tdi POWER!!!!!!

[thetroublemaker]

Originally Posted by fuller0554

Is there any info on fine tuning the setup once its all rigged up or is it just a case of it is what it is once everthing is plumbed in.

Hi.

Basically let us assume you are going the cheapest route of the rover ron tuning box and a MBC and have plumbed in a boost gauge.

Step 1. Plumb the boost controller in as per my diagram with the bolt all the way out (so you have no more boost than the 7-9psi waste gate spring).

Step 2. Turn the Ronbox on to 1 or 2 program and adjust the screw round as far as you like. Lets say 3/4 or 3 o clock.

Step 3. Turn the boost controller in a turn at a time and do some 4th gear pulls 1500rpm - 2500rpm. watch how the boost increases. Get to about 17-18psi on a pull at the 2300+ rev point.

Thats you pretty much maxed. If you have black smoke increase the air a little bit. If you have grey smoke you are all gravy (even if its lots of it!)

Be aware as you heat up the boost pressure will increase as the air gets less dense and therefore easier to compress but still to the same PSI. Sounds ass about face but its right - see here. http://www.myturbodiesel.com/1000q/t...rgingpage2.htm

[martin_r_smith]

Did you get your issues sorted mate?

[martin_r_smith]

Originally Posted by thetroublemaker

Hi.

Basically let us assume you are going the cheapest route of the rover ron tuning box and a MBC and have plumbed in a boost gauge.

Step 1. Plumb the boost controller in as per my diagram with the bolt all the way out (so you have no more boost than the 7-9psi waste gate spring).

Step 2. Turn the Ronbox on to 1 or 2 program and adjust the screw round as far as you like. Lets say 3/4 or 3 o clock.

Step 3. Turn the boost controller in a turn at a time and do some 4th gear pulls 1500rpm - 2500rpm. watch how the boost increases. Get to about 17-18psi on a pull at the 2300+ rev point.

Thats you pretty much maxed. If you have black smoke increase the air a little bit. If you have grey smoke you are all gravy (even if its lots of it!)

Be aware as you heat up the boost pressure will increase as the air gets less dense and therefore easier to compress but still to the same PSI. Sounds ass about face but its right - see here. http://www.myturbodiesel.com/1000q/t...rgingpage2.htm

If yours is a manual don't do 1500-2500 rpm in 4th the flywheel will shudder like a bugger. Best doing 2100 rpm onwards in 3rd.

[thetroublemaker]

Originally Posted by martin_r_smith

If yours is a manual don't do 1500-2500 rpm in 4th the flywheel will shudder like a bugger. Best doing 2100 rpm onwards in 3rd.

Pah i see your flywheel and raise you a slush box lol.

My smokings gone, i have reverted back to stock fuelling but i am only getting 35mpg at best now so i think i have a fubar injector somewhere. Going to get it in this week or next to have them checked and maybe new nozzles and pressure increased on the spring.

[Rossey]

Why increase the pop pressure?

[thetroublemaker]

Originally Posted by Rossey

Why increase the pop pressure?

Higher pressure injection = 2 things.

1 - Fuel injected slightly later and therefore slightly more injection per stroke.
2 - Better atomisation of the injected fuel.

Both things gain more power.

[fuller0554]

Mines an auto box so does that mean a different way of checking boost pressure ones everything is plumbed in.
Is it work to the pump aswel a changing the nozzles or just changing the injectors. I assume changing the injectors for higher pressure ones is all done without the ecu being mapped.

[thetroublemaker]

Originally Posted by fuller0554

Mines an auto box so does that mean a different way of checking boost pressure ones everything is plumbed in.
Is it work to the pump aswel a changing the nozzles or just changing the injectors. I assume changing the injectors for higher pressure ones is all done without the ecu being mapped.

Hi mate.

OK. The auto box you would do something similar but different. You would kick down about 60mph so it will only kick down into 3rd and then see what it goes to - you will see peak boost at about 2500-3300rpm then tail off till 11psi or so at the 4400 change point.

No work to the pump for this stage of tuning. You can advance timing to give better high rev performance at the expense of low running/idle however i would not suggest this on an auto, as you cannot manually select a gear so the 2000-3500range is critical.

The injectors do not get changed, all that happens is that the spring inside them is shimmed to increase pressure. This is something that wears anyway.

The stock pressure is 195 bar.
My last tdi at 160k was down to 165bar on all injectors.
You would get them reshimmed to 210bar they will then settle to 205bar approx after 1000 miles.

The nozzles however can be changed the SPECIFICATION from VW/Volvo is for new nozzles at 100000kms (60k mils) but nobody does this. You can use Bosio Race .205 or Bosch OEM nozzles on these car or buy the Kerma TDI ones from the USA.

[fuller0554]

So getting the injector springs shimmed is just to give them a sort of referb, mines just turned over 77k now so think i will consider getting it done in the coming months. If i change my nozzles what else would need doing along with this or is this again a case of matching boost with fueling.
Just taking the opportunity to say thanks for all the info so far, i love reading through all this kind of stuff, along with doing it aswel :-)

[thetroublemaker]

77K is no miles at all - you will to be honest probably find yours are still not far away from spec. Likewise changing the nozzles would more likely be a proactive step as opposed to a retroactive one that martin and myself approach the cars with - lol!!

I would suggest you understand that the transmission does have a finite lifespan and that this will be under more duress than the engine all things considered, so you do need to be aware of that - perhaps a proactive fluid flush/change would be a pertinent step prior to tuning.

Can i confirm yours is the 4 speed AW50-42LE rather than the 5 speed AW50-55LE box? You will tell this by the PRND321 Display rather than the PRND4321 Display. Also if yours is the 4 speed do you have just W underneath the shifter or S E W ?