http://www.vwdiesel.net/phpBB/viewtopic.php?t=1956Thats my thread on my mTDI that I'm building.
There are also "others" up in the threads on the TDI forum as well.
Now, a few bits and then I'll leave you to read as this is more do in the TDI forum.
You can use the IDI TD pump, however, it operates at about half the pressure of the stock TDI pump. You could put it on, you can turn it all the way up and its only going to make under at at stock TDI power numbers...
A couple other draw backs of the IDI TD pump vs. the stock TDI pump
-17mm input shaft (as mentioned above), vs. 20mm input shaft
-DI pumps usually have some extra housing reinforcement vs. that of the IDI pumps due to the max pressures they must run to run the motor
- IDI pumps use an 9mm head/plunger combination vs. a TDI pump which runs 10mm stock (manual) or an 11mm (automatic cars only )
-IDI and TDI camplate profiles look quite different as well...
There are a couple different routes you can go. If your looking for a relatively stock TDI, then you could get along with the IDI TD pump with some modifications...namely making it that word that is often thrown around with mechanical TDI's , "hybrid" pump.
This would consist of using the TDI pumps 10mm head/plunger assembly along with the camplate of the TDI (which needs slight modification and should be left to precision machining) all swapped into and replacing the same IDI TD pump components... they run, they run good (depending on who you are
) I've heard of these working great....and I've also heard of shafts snapping or other failures. Alot of this work was done DIY though and not professionally. Also know of a few that have been in and out of pumps quite a bit and have had no problems... They don't go over 110 to date though from what I've seen...
If your after more power, above stock TDI power, etc. I'd suggest going a different route. You'll get the larger input shaft of a DI specific pump along with the housing reinforcements to the pump too which allow it to operate safely at the higher injection pressures needed. You can read through the thread but I am going use a Cummins 4bt injection pump. Its DI specific, comes stock with a 12mm head and only needs some modification to the governor assembly to work nicely. Mine was test run on a Vanagon Westy TDI synchro and it ran beautifully after we worked things out on it. So much so that the guy who was testing it went and bought a few new units of his own to have. They run smooth, they start smooth and there is lots of power. 12mm might be too large for some applications but nothing says your couldn't step down in the fueling by going to an 11mm or 10mm head if you wanted. The main thing that needs to be changed is the gov. assembly which isn't entirely hard and you have the task of the injection pump pulley but since you have an MK4 motor you'll have all that you need to do the modification to make it work. Check out the above thread and there are details about what you'd have to do.
Man, that was a little longer than intended...
Joe
Topic: turbo idi pump on tdi block (Read 3583 times)
