Outer Limits 4x4 Board

G'Day,
Just read "Differance between 200 TDi & 300 TDi" and up2nogood got me thinking re Turbo and other "Basic" mods.

Im interested to hear about any simple and cheaper mods that can be done to a TDi?

My 300 has clocked up 250,000km of highway k's so I relise I cant boost up the turbo because the donk may not handle it.

Any tips ?

Also from being from the SS v8 scene I know F***all about Turbo's , so what does the waste gate do and what does it look like?

Wastegate vents excess exhaust pressure which slows down the compressor turbine, preventing the inlet side from over pressurising the engine.

Messing with it will allow the pressure to increase, but this can cause some nasty damage.

i did a write up on here a while ago about modding the bosch fuel pump on these.

Search and you will find.

3 inch mandrel bent exhaust, no muffler. tubro spools up much faster so engine comes on boost sooner.

do pump mods.

lpg injection????

serg

Please read tuning procedure in 'difference between 200 and 300 Tdi' post, I put it there instead of here...

JC

I tweaked my fuel pump from TuffRR's write up a while ago and its made a BIG difference. Just make sure you use a pyrometer so's you don't overdo it. Gives noticeably more poke in the mid to upper rev range!

I tweaked my fuel pump from TuffRR's write up a while ago and its made a BIG difference. Just make sure you use a pyrometer so's you don't overdo it. Gives noticeably more poke in the mid to upper rev range!

250k is still running in!

zen wrote:250k is still running in!

I hope your right ! I was changing motor oil at 10,000km....now a mate thought it would be better to change at 5,000km as the Disco has higher KM on it now

TuffRR wrote:i did a write up on here a while ago about modding the bosch fuel pump on these.

Search and you will find.

Thanks TUFFRR, Justinc & others for info.

Just a few things...what are EGT's?...Exhurst Gas Temp by any chance?

Ok all that sounds fairly straight forward but I dont have a pyrometer...can I do 1/2 measure's and still be safe.

Im mean if you said to do a 180 turn I would do only 90 and 90- 45 just to be safe....would that be ok do you think?

I got my disco from an old guy(60+) and Im sure the pump hasent been moded, but without an pyrometer Im happy to get just a small gain for now but not game enough to go looking for more + my 300 has done 250,000km.

Also why is it so important to cheak valve clearence's? I noted this in the Haymes workshop manual and it said it should be done evry 6000miles or 6 months

Anyway looking forward to hear anymore simple and cheap mods

uninformed wrote:3 inch mandrel bent exhaust, no muffler. tubro spools up much faster so engine comes on boost sooner.

do pump mods.

lpg injection????

serg

I'm putting a muffler on mine, the drone at cruising speed is too much on a trip..............

You need a resonator in the rear, otherwise the droning will shit you up the wall. Perhaps even turn down the tailpipe, as per Disco's.

Yeah, EGT is as you said. I did the mods as per TuffRR's write up and find that unless I have my foot flat to the floor up a v.steep hill, my EGT's don't go too high ie. much over 600deg. If its blowing lots of black smoke; back off! A pyrometer or EGT guage should only set you back a couple of hundred $(cheap insurance I reckon). VDO do an analogue one which is around the $250 mark from Repco or similar, or Jaycar do a probe that can be hooked up to a multimeter that's around $30, though it can't really be permanently mounted. I got mine through a specialist in that area, and it was about $220 all up with a digital readout. I'll send you their details if interested.
Chris.

If you do the pump mods and don't have a pyrometer to measure the EGT, then black smoke is your only guide.

JC did a good write-up on adjusting the pump in that other thread.

The only adjustment that he did not mention is the smoke adjustment screw on top of the boost control housing (covered by a pressed in cap).

The smoke adjustment screw, adjusts how much fuel is injected when there is no boost pressure. Since the turbo is driven by exhaust gas, screwing the smoke adjustment scew in will increase the fuel, and the turbo boost will come in earlier when taking off. Back the screw out if you have excessive black smoke when taking off. A little smoke wont hurt.

You will probably have to adjust the idle speed screw (idle speed will increase from adjusting the smoke screw in). The screw that stops the lever, which the accel cable is attached to (when the accel is released).

Do not adjust the other screw which adjusts the maximum speed, or you will likely destroy the engine.

Rotating the diaphram and adjusting the star wheel as JC advised, increases the fuel through the full range of boost pressure. Back these off if you have excessive black smoke in the mid range.

The main fuel adjustment screw, at the back of the pump, adjusts the fuel when the accel pedal is flat to the floor. This adjustment has the biggest affect on power and EGT. The 1/3 turn that JC recommended should be ok if you drive sensibly.

If you are worried about the EGT, don't adjust this screw, or watch for excessive black smoke when pulling up long hills. If the smoke is there, back off and grab a lower gear - higher engine revs means that your engine will have more air to burn the fuel required for the load and this will drop the temps.

Diesels like to run lean air/fuel mixtures - rich causes high temps. Black smoke when the engine is warm, indicates incomplete combustion of the fuel. Ie. there is not enough air to burn the fuel completely.

Before adjusting the pump, it is worthwhile doing what you can to increase the amount of air that the engine is getting.

They get crud in the intercooler which restricts air flow. Check the boost pressure - normal for a 300Tdi is approx 1 bar (14 to 15 psi). I would not go higher than this, with the mileage that is on your engine, as they are prone to blowing head gaskets at lower km's.

Thanks all for your help......had a litle play with the idle for a start....just wondering...the black knob on the top of the plate where at the bottom the acc cable fits...whats that knob? Im guessing its a fine tune for the idle maybe?

The main fuel adjustment screw, at the back of the pump, adjusts the fuel when the accel pedal is flat to the floor. This adjustment has the biggest affect on power and EGT. The 1/3 turn that JC recommended should be ok if you drive sensibly.

I never bothered touching the main fuelling screw, I easily exceeded 720* just by winding up the star wheel on the hills around here. I had to back it off close to 30* from the original 60* adjustment, and I have a 3" pipe feeding the air cleaner from the snorkel rather than the pathetic restrictive OE hose and have hacked off the small ID spigott off the snorkel.
Ian Petersen of Thermo-Guard fame found the same thing with his Disco, it was very, very easy to exceed maximum safe EGT's with the main fuelling screw.

Just a few more questions thanks guys,
Will fuel consumption be affected at all/significantly?
Will the injectors be affected at all?
Will the overall benefits be significant without any further mods?
What power/torque increase can i expect?
Why doesnt L/R tweak before hand?
If done correctly is there any reduction in the longevitey of the motor?
Cheers Dean.

cutfenders wrote:5)Why doesnt L/R tweak before hand?
6)If done correctly is there any reduction in the longevitey of the motor?

I suppose #5 got something to do with #6...

cutfenders wrote:Just a few more questions thanks guys,
Will fuel consumption be affected at all/significantly?
Will the injectors be affected at all?
Will the overall benefits be significant without any further mods?
What power/torque increase can i expect?
Why doesnt L/R tweak before hand?
If done correctly is there any reduction in the longevitey of the motor?
Cheers Dean.

Depends how much the pump is tweaked and more importantly on how you drive it.

I can't see how the injectors will be affected.

You will defenitely notice the difference without further mods. A larger free flow exhaust from the turbo back will improve it further. As will a larger intercooler etc.

I'm guessing 15 to 25%

They build vehicles for use in a wide range of conditions. If they tuned the injection pump for Australia, it would be too rich at the high elevations in the Andes, where the air is less dense.

If the engine is in reasonable condition to start with and the EGT's are kept within reasonable limits, the engine life should not be affected. The life of the rover Tdi engines depends more upon looking after the lubrication and cooling systems.

Thanks John.