I have recently got my octy vrs remapped and it suffers quite badly from surging from around 2k right though the rev range. On the advice of my tuner I uprated the DV but this made no difference. He has advised I now change the N75 for a H pattern but after alot of searching through the forums Im confused as to how effective it could be and the many contradicting posts regarding the differences between the H and J patterns - I keep reading the H valve has a higher boost spike and is likely to send the car into limp mode whereas the J valve is smoother and much less likley to do so. Any thoughts as to which I go for?

How does this surge manifest itself?

How does this surge manifest itself?

Usually when you open the throttle the boost will surge and then drop off in increments of around 500 rpm right through the rev range. It isnt as noticable in 2nd gear but 3-5 its very prominent. Previous to getting the car remapped there was a slight surge in the higher gears but not really that noticable. There we no error codes showing before the remap was done.

Hmm, i had a similar problem, but only at low revs, more noticeable in 1st and 2nd, but not so much in higher gears. For me it was the dirty throttle body.

Do you have access to a vag-com to do some logs?

Hmm, i had a similar problem, but only at low revs, more noticeable in 1st and 2nd, but not so much in higher gears. For me it was the dirty throttle body.

Do you have access to a vag-com to do some logs?

Unfortunately I don't

Have you tried replacing the standard N75(F)?

I had this problem years ago, I simply replaced the unit and all was great!

IMO dont p!ss around changing to a H or J spec N75...NO point.

Steve:)

p.s. Who mapped it?