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Engine Specific Info and Questions => mTDI Mechanical TDI Conversions => Topic started by: Sierra94 on January 22, 2009, 11:28:50 am

Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 22, 2009, 11:28:50 am
I use a AAZ IP with 12 mm head, gov mod, 1,6 GTD pin etc on my newly installed AHU mTdi.

When I used this IP on my AAZ engine it was really powerful. On that engine I hade bigger injectors (They were marked 314 from the company that selled them).

And on my mTdi I only have the standard 90 hp AHU injectors.

Will I find power in both swapping out the camplate for a Tdi one and get bigger (110hp AFN) injectors or is injectors enough alone?

The engine runs and starts great and is more smooth, but lacks some power compared to the old AAZ, and I canīt turn in the max fuel screw anymore because the idle just keeps rising and it starts to runaway.

Thanks in advance for any input...   :D
Title: Bigger injectors or Tdi camplate?
Post by: Christian_Finland on January 22, 2009, 11:34:23 am
Those 90 hp injectors can produce ~max 110hp and the 110 hp injectors about 130hp i think. You should go for some real performance injectors. Maybe race520 or those quite new 7 hole race injectors if you wan't to take out some power.
Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 22, 2009, 11:39:34 am
It feels more powerful than that  :D  It puts out around 25 psi of boost right now with a K24 and water/meth injection, 3 inch straight exhaust.

On the AAZ I ran in the 30-35 psi range all the time with water/meth.
Title: Bigger injectors or Tdi camplate?
Post by: gigaz2 on January 29, 2009, 06:28:49 am
you HAVE to install the tdi camplate and delivery valves, then there are timing issues as well
you can't bolt a idi pump to a tdi and expect it to run perfectly, it will start, but thats it
Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 29, 2009, 08:30:36 am
I have the delivery valves already. But it seems some guys in here run a bigger rotorhead (11 or 12 mm) instead of TDI camplate and 10 mm (or bigger) rotor.

Does the 12 mm head deliver enough fuel to pop the TDI nozzles properly? Or do I have to install a TDI camplate along with bigger nozzles instead of just bigger nozzles to gain most power out of my setup?
Title: Bigger injectors or Tdi camplate?
Post by: gigaz2 on January 29, 2009, 01:10:41 pm
even a 8mm head can pop the nozzles, but 12 is nice :D

the profile of the cam plate is different, it promotes a sharp rise in pressure that is needed for the DI process, with the idi camplate your just dumping fuel into the chamber, that's one of the reasons for the low performance.

the other main issue is about timing, idi timing is way off for a DI engine
Title: Bigger injectors or Tdi camplate?
Post by: rallydiesel on January 29, 2009, 01:32:45 pm
You need to make some changes on the pump, not the injectors. There is a detailed dyi on making an mtdi pump in the faq section.
Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 29, 2009, 02:59:58 pm
So, a TDI camplate and more timing. I already have a TDI advance piston in my IP but the camplate from the donor pump was in really bad condition. So I didnīt install it.

Does someone have a TDI camplate for sale?  :D
Title: Bigger injectors or Tdi camplate?
Post by: rallydiesel on January 29, 2009, 03:29:48 pm
You also need to alter the throttle lever (the black one inside the pump) to travel over a larger area. Otherwise you will never get the full potential out of the pump. You will be running like 35% of the possible fueling the pump should deliver.
Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 29, 2009, 03:36:27 pm
Even if I have a 12 mm head on it that worked really good on my old AAZ engine? The lever moves the control collar pretty much on the piston when pulling the lever with the pump top of.

I canīt see why I have to make the lever move more now than before? Or does the angles or something change when I install the TDI camplate?
Title: Bigger injectors or Tdi camplate?
Post by: Hey on January 29, 2009, 10:53:43 pm
The camplate slope is more abrupt.. so if the sleeve does move only 1.6mm like on your TD pump... you will inject in the cylinder for a smaller crankshaft angle.(slope is greater...camplate moves up faster...sleeve 1.6mm)... so less fuel!

look here:

http://www.vwdiesel.net/phpBB/viewtopic.php?t=6427&start=45


On a e-tdi pump, the sleeve moves about 2.6mm. On a m-tdi pump you can have easily 3mm.

For a 10mm head... the timing will be pretty good (contrary to want people say).. a 1.6td regulator might be better though.
Title: Bigger injectors or Tdi camplate?
Post by: Sierra94 on January 30, 2009, 12:13:48 am
Thanks for clearing things up for me. I kinda miss my old AAZ right now  :D

But problems are there to be solved.
Title: Bigger injectors or Tdi camplate?
Post by: Hey on January 30, 2009, 10:13:00 am
yes... the more problem you have... the more fun you get!!

I really like doing this m-IP. You cut, cut, weld... etc inside the pump so often that.. when it works!!! You... really are happy and proud of your work!!