Reflash/Parts to replace?

[Blacky D]

Here goes, got the car reflashed about a year ago. I have been reading up on everyone having mixed thoughts/results on using the 710N diverted valves. At the sametime should I replace the n75 as well? I don't believe they have ever been changed and I'm in an extra hot climate. Is it worth it because of the heat and extra boost on these 10 year old parts. Anyone have any thoughts on this?

[PoP-PoP-BANG]

Whats the part number for the diverted valves? Presumably this is the DV that people reference in their posts. I'm changing my n75 at the moment, presumably i should change this too?

[SuprSi]

I got those bits changed on mine on my recent visit to MRC, the diverter valves can fail and are hard to diagnose as a pressure test won't show if they're leaking or sticking. They're not expensive either. Make sure you get the 710P not 710N as a few members have reported weird resonating noises with them, described as "moosing" if you want to search it.

Speaking to Doug, the N75's get 'lazy' or unresponsive sometimes when they're old and you'll end up with boost that's spiking and not holding at a steady pressure. Or you won't build boost as quickly as you should if it's not bleeding enough air to hold the wastegates shut.

They're not expensive so might as well change them for peace of mind.

[Blacky D]

Thanks for the heads up super si, unfortunately I already bought the 710n. I read about the molding, I don't know if that will bother me or not. Now the biggest thing with no definitive answer is if the 710n holds the extra boost better than the 710p? Pop, pop, I'll get you the part number when I get off work tonight.

[PoP-PoP-BANG]

Thanks - I looked on the forum and found 06A 145 710N but that's for the N not the P, just want to make sure i'm getting the right part. Do you need two of these?

[Blacky D]

Yes, you'll need two.

[sweegie]

Now the biggest thing with no definitive answer is if the 710n holds the extra boost better than the 710p?

I can categorically confirm that the 710n does not hold boost better than a 710p. It does have a stronger spring that will close the valve earlier on part throttle, but both valves use air pressure to seal themselves at full load, not spring rate.

Now, what is important is if you fit a 710p valve to your car is the N249 valve which operates the 710n/p valve via a vaccum resevoir and is controlled by the engine ECU. Its operation is specifically calibrated for the 710p valve's spring rate and if you change to 710n valves, technically you should change your ECU map too. I did and it reduced the moosing a lot, but it's still not 100% absent. It also changes the way the car drives on part throttle / part boost.

Needless to say I got a good deal on the 710p valves but will be switching back to P's at the next change.

[Blacky D]

Perfect brilliant answer, thank you sir. Time to trade the N's back in for P's )

[lswing]

Here goes, got the car reflashed about a year ago. I have been reading up on everyone having mixed thoughts/results on using the 710N diverted valves. At the sametime should I replace the n75 as well? I don't believe they have ever been changed and I'm in an extra hot climate. Is it worth it because of the heat and extra boost on these 10 year old parts. Anyone have any thoughts on this?

You'll need a new trans, easy part to replace