Giles, modify a TDI pump, already!

[TDIMeister]

I can arrange to get you a guinea pig, if that's what it takes.

Also, will you be able to make it to the June 18th GTG in Dorchester?


Cheers,
Dave

[Giles@PerformanceDiesel]

yes that would be good for the experimental pump. i've had one
apart but i don't have a core to play with.


where is Dorchester?

Giles

[TDIMeister]

PM sent with directions

[Slave2School]

Aside from modifications does anyone know of a good TDI pump rebuilder in Canada?  I got a 12mm pump, but it appears that something is wrong with it as it won't actually pump.  The fuel  that came out of it was "Skanky smelling" as my mechnics have said, I don't know if that indicates anything in particular though.  The vendor has offered to refund me the money on the pump, but I have to send it back to him and that isn't going to be cheap, neither has the labour been so far to install the Fubar'ed pump.  I am almost to the point where I want to cut my losses and have a new 11mm pump installed, but I liked the idea of the 12mm pump and wouldn't mind sitcking with it....doh!  What to do indeed...

PS-In case youare wondering the mehcnics have installed more than a few of these, and probably close to 100 of the TD pumps over the years...so I think they know what they are doing.

[Slave2School]

W00t, car is working great now, just needed to have an electric fuel pump hooked up to the car for ht einital start, then it slowly sped up to full speed idle, now I just have to breathe on the keyin this weather and the car starts up and runs sooo smoothly with gobs of extra power in the 12mm pump...I know I am not making full use of it without a chip, but that will be for the future.

[vwmike]

I know up until 2004, the cars still used VE pumps. Does that mean that you can use a standard VE injection pump head? I can get those in 12mm, that's why I ask.

[lord_verminaard]

Any update to the TDI pump mods?  Just curious.  My main question is that if you make mods to the pump, what's that going to do to the ECU?  And, do we know what kind of RPM capabilities a modded TDI pump can make?

This is exciting stuff.

Brendan
84 Scirocco 8v
00 Camaro L36 M49

[Giles@PerformanceDiesel]

hi guys

you're not getting the idea of electronic controls

the computer controls the pump if i change things in the pump
it won't take effect unless u program the computer to use the
new settings.

no one has given me a core yet for me to try things. when that
happens then i will see what i can do to fool the computer that it's
still stock but it has my settings.

Giles

[RedRotors]

I doubt that "magic" can be done with those pump.. There's nothing inside the pump. The only thing i can do ( and has been done many time ) is to put a bigger plunger/head assembly. Im running a 12mm instead of a 10 in my TDI and let me tell you that it rock!

Marc/

[QuickTD]

doubt that "magic" can be done with those pump..

I agree. The only mechanical limit is the displacement, which can be increased with a bigger head/plunger. There is no mechanical governor and the advance and injected quantity are both controlled by software.

[vwmike]

What was that pump head intended for? I can get 12mm pump heads fairly cheap. They're supposed to be for a cummins, but I don't see why they wouldn't fit.

[RedRotors]

What was that pump head intended for? I can get 12mm pump heads fairly cheap. They're supposed to be for a cummins, but I don't see why they wouldn't fit.

The head im using is a direct swap. Cummins head dosen't fits. The place where the spring guide pins sit is not the same. I order them in Europe.

Marc/

[malone]

doubt that "magic" can be done with those pump..

I agree. The only mechanical limit is the displacement, which can be increased with a bigger head/plunger. There is no mechanical governor and the advance and injected quantity are both controlled by software.

Someone I know is CNCing a custom timing cap for the TDI pump to physically allow more timing advance. Of course, software will be modified to take advantage of the new timing range.

I want to rev higher than 5,500 RPM eventually. I had a 12mm plunger and head on my TDI pump but a friend of mine with the same setup seized his pump at 5,500 crank RPM. Most 12mm pumps are limited to approx. 1,800 to 2,000 RPM (multiply by 2 for crank RPM). So I went back to 11mm for now. I may buy a brand new 10mm TDI pump in the near future and keep it that way.

A TDIclub member dynoed 190whp with a 12mm pump but he stops at 4,000 RPM. For better street drive ability and more horsepower potential I want to push the big lump of torque into the higher RPM range.

Over 300lb-ft at the wheels below 3,000 RPM is still possible with a 10mm or 11mm pump, so I don't find the low RPM 12mm appealing anymore.

My 12mm pump head & plunger are for sale if anyone wants it

[QuickTD]

I want to rev higher than 5,500 RPM eventually.

You figure there's much power up there? From what I've seen of the TDI torque curve it begins a pretty steep plunge at about 2500rpm. By the time 4500rpm rolls around and the ECM begins to pull back the fueling they are usually down to about 30% of the peak. This seems to be common to all TDI's, chipped, injectored, big turbo or not, even TDIRS's mechanical pump engine has roughly the same torque curve. I'm thinking its just charge mix/burn time thats killing the power. More timing advance can help with ignition lag but it can't speed up the burn. I think for the TDI the power needs to be made with cylinder pressure (torque), not rpm.

[malone]

You figure there's much power up there? From what I've seen of the TDI torque curve it begins a pretty steep plunge at about 2500rpm. By the time 4500rpm rolls around and the ECM begins to pull back the fueling they are usually down to about 30% of the peak. This seems to be common to all TDI's, chipped, injectored, big turbo or not, even TDIRS's mechanical pump engine has roughly the same torque curve. I'm thinking its just charge mix/burn time thats killing the power. More timing advance can help with ignition lag but it can't speed up the burn. I think for the TDI the power needs to be made with cylinder pressure (torque), not rpm.

You "think" something is killing power up there; I still can't take anyone's assumptions or theories to be 100% true. I don't recall anyone having actually tested a high RPM TDI. Today's powerful TDIs featured at tdiclub.com still aren't at their limits; we're just scratching the surface of their power potential, compared to what the tractor and Cummins guys have already done years ago.

Nobody thought a few years ago that a 6cyl 12v Cummins motor would make useable power above 4,000 RPM. Now it's possible. Piers Diesel is currently building a 6,000 RPM motor.

Unless someone can provide credible data stating that extra RPMs will not yield more potential HP in a VE 1.9 TDI, I am still going to continue with this project because I'm curious This is a drag only project so I'm willing to blow the engine. Then I'll have the block rebuilt (or another block purchased). The design of the internal block parts, and the pump, can be modified. Manufacturing for custom TDI pistons and cranks are already available (there is a 2.2L stroker kit for VE 1.9L TDIs in Sweden, but for low RPM application).

Despite the peak torque usually occuring at around 2,500 RPM in a relatively stock TDI motor, the peak HP with a "bigger" turbo, injectors, and stock cam is just above 4,000 RPM and it stays relatively flat up to 5,500 RPM with good tuning. This is one of the most powerful TDIs I've seen so far, with a nicer torque curve for street use.

FYI I tune chips in association with another tuner in Europe. The fuel maps can be adjusted well past 4,500 RPM. The ECM pulling fuel by 30% you mentioned has already been addressed a while ago.

Can the HP curve be made to remain flat or gained just after 5,500 RPM? I think it's possible, and it may gave better HP results than having to resort to excessive cylinder pressures in low RPM.

There was a pump timing / high RPM discussion on tdiclub.com a while ago, although there wasn't much content:
http://forums.tdiclub.com/showflat.php?Cat=0&Board=UBB4&Number=987518