No, this should show the n75 working.It should start off shut reading approx 95.3 then open up to bleed the excess off.

To me it look like you need to smooth the boost off so it hits the specified level, then your bhp should rise. Top bhp should be achieved around 5500 to 6000 rpm.

The tough bit will be to find out why you are not achieving the boost levels set by the ecu through out the range.

So it's the Duty cycle boost pressure control valve (%) i should look at?

And why do the ecu cut the boost at 6000rpm as shown above?

Yeah, it probably won't tell us much but its always nice to do.

I can only think that the reason for the boost dropping off so badly is due to the map,as its the specified (set by the ecu) which drops and the actual follows.

Yes, probably.

But i'll log the N75 tomorrow, so we know it's doing its job.

Ok, now i've logged the N75. It's stabile on 95,3% upp to 2500rpm. Then it drops to 54%, climbs slowly to 69% @ 5800rpm. Then it makes a fast jump to 85%, only to drop back due to ECU ordered boost drops @ 6300rpm and 6600rpm.

The chip maker is working on that part, but still, the actual boost is lower then the specified between 3900rpm and 5800rpm.

The logg is made on the N75 Race.

All sounds ok there then,its really strange that it doesn't meet the specified boost properly over such a large scale.

If it were to spike it could possibly drop below specified as the n75 will vent the excess off and may over react but then it would rise back up again.

Its a real stumper any one else got ant ideas?

Im thinking about leakage in the WG or DV. I'll try with recallibrating the DV tomorrow. It's adjustable.

Seems to hit and exceed boost early in the rpm though,and n75 would read 95% or closer to 95% through the rev range.

Yours climbs to around 69% once leveled out.

Yeah, it works perfect upp to when the exceed boost hits, then it never get back to right values.

I made a new log of the N75 and boost today. First i tightend the settings on the DV.

The N75 still behaves as previously staded. But i actualy goot boost over specified level almost through the whole rev range. According to vag-com, i found 10bhp more at the peak!

It still drops after 5000rpm though, so everyting isn't right yet.

I'll make another run tomorrow just to be shure.

Great news, Is this bit circled in your graph @ 5000 rpm where it drops off. This has got to be a map problem, or did you take your foot off and put it back on?

Since both actual AND specific curve drops, it should be a program error, not the MAF. The programmer is looking in to that.

So you didnt take your foot off the gas at that point and reapply?

No, it was floored from 1200rpm to 6800rpm.

All the runs i've made i've let the engine run oc rev limiter for a second or two before i ended the logs, to make shure i get the whole rev span logged.

I made another run today. 1500rpm to 6000rpm 4th gear. The torque is quite smooth without sudden peaks or drops.

I didn't log the last 800rpm due to the high speed. 200kmh+ (125mph) on a 90kmh (55mph) road is not recomended.

Still, i suspect i would get a fast drop in that rev span, but that's because of the map as for now.

It seems like the problem was a leaking DV. Fixed by recalibration.

Nice one,it sound like an interesting Dv. Normally they just have changeable springs.

I hope they get the map sorted and you get back to full power again .

With the GFB Hybrid DV you don't change the spring. You tun a smal skrew on the top to give it more or less tention.

It's so you can adjust the amount of air you unload atmospheric. Because of this, it's possible to use it on a 1.8T.