Thread: 300tdi fuel pump tune

Originally Posted by DiscoMick

When the guy from British Offroad did mine he said not to turn it up by more than a quarter of a turn. Does that help?

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Turn up what?

Just turned the star wheel a quarter of a turn clockwise. I've got the turbo spooling much quicker (around 1800rpm as opposed to 2500rpm). Do I need to adjust the bolt in the fuel pump cap to make it flush with the underside of the cap as per Rover Tasmania's video? I haven't adjusted as yet. What is the benefit of this? It's a 300tdi auto. Many thanks.

Originally Posted by Blknight.aus

Take the feed for the waste gate off of the manifold take the compensator from the turbo. If you have a boost gauge take it off the manifold

could you explain this to me please? i have a madman ready to install once ive finished clutch and gearbox stuff and i will tune the pump at the same time. i dont have a boost gauge though, is that info still relevant to me? thanks

sure thing.

theres 2 (3 if you have a boost gauge)things that want to know what air pressure is happening in the engine

the first is the wastegate acutator. This controls the overall boost made by the turbo. Between the turbo compresor and the inlet manifold is the intercooler, this causes pressure drop. Taking the sense line for the wastegate actuator from the inlet manifold compensates a little for turbo lag and a little for pumping and intercooler losses. tapping the manifold for the boost gauge tells you what the engine is actually getting and not what the turbo is pushing. In the event of a holed intercooler, blown hose, delaminated hose you'll notice it immediately in the gauge. it will also begin to pulsate like crazy if you get any kind of inlet valving issue and will "feather" if you leave out the filter and overspool the compressor into slip or overload the turbine into stall conditions.


The boost compensator lives on the fuel pump and is responsible ffor emission and economy reasons. Taiking the feed line for this from the turbo directly gives you a more direct response as the boost begins to come on.

This is my stage 1 mod and on a spec tuned tdi gets you between 1.5+2 psi extra boost and a little more pick up, it lowers the EGT's on medium to high cruise power at the cost of a little more smoke and a higher EGT on initial acceleration. For most people who want just a "little" more its usually just about enough.

This is always my start point for all TDI(X)00 work as it usually produces a reliably similar performance increase for very low cost. I then have the owner give me a before/after comparison so I know how much of a talking to I have to give to everything.

Thanx for that info Dave. That will give me something to tinker with on the weekend. Sounds just what im looking for as I tow a pop top van and live in the Adelaide Hills.

Is Stage 2 just as easy?

Thanx
Dave

Originally Posted by SouthOz

Thanx for that info Dave. That will give me something to tinker with on the weekend. Sounds just what im looking for as I tow a pop top van and live in the Adelaide Hills.

Is Stage 2 just as easy?

Thanx
Dave

that depends very broadly speaking

stage 2 usually involves tweaking the waste gate actuator and messing with the compensator and I wont go much past "just a little more" without mandating you have both boost and EGT fitted and demonstrate you understand what they are telling you

stage 3 is normally more compensator tweakery fuel screw wind in-ery and you wont get that from me without having boost, egt and a low coolant sensor

Stage 4 is getting into turbo replacement and rewheeling, intercoolers, required fitment of an actually accurate coolant temp monitor and a very very firm warning that you need to understand that this is getting your engine into "If you dont drive the gauges you will make pistons go insideoutsidemelty"

Originally Posted by Blknight.aus

that depends very broadly speaking

stage 2 usually involves tweaking the waste gate actuator and messing with the compensator and I wont go much past "just a little more" without mandating you have both boost and EGT fitted and demonstrate you understand what they are telling you

stage 3 is normally more compensator tweakery fuel screw wind in-ery and you wont get that from me without having boost, egt and a low coolant sensor

Stage 4 is getting into turbo replacement and rewheeling, intercoolers, required fitment of an actually accurate coolant temp monitor and a very very firm warning that you need to understand that this is getting your engine into "If you dont drive the gauges you will make pistons go insideoutsidemelty"

so am i understanding this correctly? the feed line that sends pressure to the fuel pump or something along those lines is removed and ends blocked off? or it is diverted? and also taking boost actuator line away from manifold and blocking ends off?

and tweaking the fuel pump is your 3rd stage? am i correct?

the ems2 i bought was a kit. has a pressure sensor which can be used for oil or boost, low coolant alarm which is two stainless self tapping screws that go in the header tank and will give an alarm when there is no longer water to complete the circuit (still not sure about putting screws in the plastic header tank, sounds like invitation to leak) EGT sensor, coolant temperature sensor, transfer case oil temp or other temp, in built volt meter too.

i was going to use the pressure sensor for the oil, do you suggest i use it for boost instead? im always a bit scared when i start tapping into crucial pieces like inlet manifold etc.

and thanks heaps for your detailed reply.

not quite

you take the line from the turbo comressor housing that runs to the wastegate and you put that onto a fitting on the inlet manifold, you then put the boost gauge on the same line

the fitting you now have vacant on the compressor housing of the turbo you blank off. you leave the boost compensator conected to the fitting on the turbo.

the main benefit of this mod is that the turbo waste gate now reacts to the pressure in the manifold and not what the turbo is doing. this compensates for the losses through the intercooler(s) and the plumbing

at the end of the day if you had your boost gauge hooked up to the turbo and it was readin 15 psi now it would read about 17, if you had it in the manifold and it was reading 13psi it would now read 15.

this puts you in a more air same fuel situation and it slows down the opening of the waste gate so you get "that little bit more" up near the top end when you need it most as the boost is still coming on and the compensator is seeing a little more pressure. as a bonus the EGT's come down a little under acceleration.

as I said earlier, it gives a very standard improvement. the most important thing for me is that it lets me calibrate my customer so I can correctly interpret what they want. Doing it this way also turns it into a 2 stage job for me which means I've had my hands and eyes inside the engine bay and since I usually book out a whole day for anything past "a little bit" of stage 2 the customer gets a chance to get some "freebie" maintenance done when they come back for the pump tweakery