Author Topic: Mk3 TDI boost control? (Read 5360 times)

Ecksphive · « **on:** September 10, 2007, 08:29:44 pm »

Just curious if anyone knows how the boost is controlled on a 1999 Mk3 Jetta TDI. Is it controlled by the ecu? Any help is appreciated.

And yeah, its my first post, but Im over on TDIClub.net and the CVD forums

MikkiJayne · « **Reply #1 on:** September 11, 2007, 06:23:08 pm »

Controlled by the ECU using the N75 valve.

'99 mk3? They stopped making mk3s in '98 :?

Mikki x

Slave2School · « **Reply #2 on:** September 11, 2007, 06:45:33 pm »

99 here

Ecksphive · « **Reply #3 on:** September 11, 2007, 06:48:20 pm »

Nah, they stopped making Mk3s in 99

99.5 is when they started making Mk4 jettas, and 2000 for Mk4 golfs iirc.

MikkiJayne · « **Reply #4 on:** September 11, 2007, 06:52:51 pm »

Wierd :? They only ran to '98 in Europe. I guess it took a whole year to ship your mk4s across the Atlantic

Slave2School · « **Reply #5 on:** September 11, 2007, 06:55:22 pm »

No we just get everything later over here..aka "THE" shaft.

My Golf is a MK IV 99.5, manufactured in nov 98 IIRC from the vin.

snakemaster · « **Reply #6 on:** September 12, 2007, 04:18:03 pm »

is there any way to tweek up n75 valve on my mk3 94 tdi . i have done the ristor mod on the fuel temp :lol:

dtech · « **Reply #7 on:** November 07, 2007, 03:01:46 am »

What is the ristor mod? Curious!

MikkiJayne · « **Reply #8 on:** November 07, 2007, 04:50:06 am »

The N75 is controlled by the ECU. If you fiddle with it and increase the boost without the ECU knowing about it, it will go in to limp mode.

Best way is to chip the ECU. Rocketchip, Alligator, etc

Spulen81 · « **Reply #9 on:** November 07, 2007, 02:19:39 pm »

You can use a boost controller on the wastegate or inline with the N75 to raise boost as high as you want. You will also need a bleed for the single line ecu otherwise you will hit limp. It takes a little playing around but it works.

snakemaster · « **Reply #10 on:** November 07, 2007, 04:34:27 pm »

rister mod it tells the ecu that the fuel is cooler than it is so the ecu moves the spool further = more power, i will have a play with the wast gate and blead of valve :lol: