N294 Valve

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Mon Dec 08, 2008 9:55 am

When I am driving my car aggresively I get the feeling of the boost goin "off" and "on" quickly and cos the car to have a rocking feel to it. Everyone thats in my car when it does it can feel it happening and most of them dont know the 1st thing about cars so its not my imagination!

Anyway, had a browse thro the i/net and it seems the answer is my N294 valve that is opening/closing my DV quickly becos of overboosting. Has anyone else experinced this? Only reason i can think its overboosting is from exhaust still to be upgraded. Think I mite sick on the OEM N75 boost valve too for now.

Rich_T · Post by **Rich_T** » Mon Dec 08, 2008 4:56 pm

is this just on your stage 2 map or did it happen on stage 1?

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Mon Dec 08, 2008 6:13 pm

Just stage 2 mate, but seems to be the N75J valve that was causing it. Changed back to OEM N75 valve (not sure what letter) and all seems better, if not preformance has improved!!

whitegtipolo · Post by **whitegtipolo** » Tue Dec 09, 2008 8:58 pm

i had the uprated n75 and it just fooked up the drive stay with standard n75 as thats what the software is written with!! also its easy to by pass the n249 ill explain it to ya if want!!

oliverpologti · Post by **oliverpologti** » Tue Dec 09, 2008 9:08 pm

explanation woud be great another mod im up for

notice any difference in performance?

and number 1 question lol

is it easy to doo

whitegtipolo · Post by **whitegtipolo** » Tue Dec 09, 2008 9:38 pm

easy no performance gains just stops ecu opening the DV valve and when it does operate its direct from manifold pressure so quicker and louder dump!

1.

Remove the engine cover you will see two sensors on the rocker cover one on the left and one in the middle! This is the n249 the middle one! You will notice that one pipe goes to the DV valve the other from the t-piece!Basically you loop the vac pipes on the valve together using the pipe from the t-piece the small one!

2.

Then you take the longer piece and run it fron the t-piece direct to the DV

sorted so now you get instant dump when you lift the throttle and the ecu cant dump boost on a slight spike!

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Tue Dec 09, 2008 9:54 pm

But if i bypassed the N294 valve then my car would continue to overboost until engine managment light came on or buggered somethin! Personally I would keep it there, its there for a reason

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Tue Dec 09, 2008 9:56 pm

Oh and my car is pulling like an absoult dream now! Loving stage two now!!! Feels like a brand new map on my car! Cant wait for my Milltek now

whitegtipolo · Post by **whitegtipolo** » Thu Dec 11, 2008 9:14 am

no your car has other ways to kill boost if it exceeds the desired level, this mod just stops it dumping tiny amounts of pressure causing surges and on off boost! If it exceeds too much it shuts the throttle plate and opens the turbo waste gate!!

Kenny what have you done to make your car better with your stage 2???

Jeff GTi · Post by **Jeff GTi** » Thu Dec 11, 2008 11:09 am

removed the n75j and put the standard n75 back on

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Thu Dec 11, 2008 12:22 pm

As Jeff said, its soooo much better! Love my car again!

oliverpologti · Post by **oliverpologti** » Thu Dec 11, 2008 5:26 pm

kenny so what is the performance differance from stage 1 to 2 bhp ?

KennyPOLO_Gti · Post by **KennyPOLO_Gti** » Thu Dec 11, 2008 10:11 pm

Not honesly too sure mate, gonna get my car RR after exhaust is done. With stage two i felt a lot more power mid range!! Think Jeff had results of 40ish bhp through mid range!
Think stage two is just a lot more smoother and aggresive boost curve and i love it ha ha!

Jeff GTi · Post by **Jeff GTi** » Thu Dec 11, 2008 11:12 pm

40 hp in the mid range was the biggest increases, with +20 bhp more most of the way before and after it too up until peak revs

torque was also massively up, over 60 ft/lb at one point, again with a healthy +30 through most of the before and after, again, up until peak

oliverpologti · Post by **oliverpologti** » Fri Dec 12, 2008 5:08 pm

so the n valve is the thing with the silver cover on?

and looks like you just looped a bit of rubber hose between the front and the back of the silve sensor?