N75H/N75J discussion

[Namreg Rac]

Has anybody ever done comparisons between these 2 valves on a bigger turbo/chip tuned AAN?

I guess the N75H (race valve as 034 calls it) is stock for the AAN while the N75J is stock on the 3B.

I have also read that in some circumstances people have swapped to the N75J to deal with boost onset spikes on bigger turbo/chip tuned Audi's? I haven't really read about any experiences with AAN's.

Anybody want to share their knowledge and experience with this?

Sean

[varia]

"j spikes higher, h holds boost longer..."

[loxxrider]

"j spikes higher, h holds boost longer..."

Now, that is totally dependent on whether you're running standalone engine management or stock. Sure, the valve has different properties which is why it reacts differently given the SAME control parameters by an ECU. But if you have something like VEMS where you can control those parameters, it doesn't matter which valve you have.

[Namreg Rac]

"j spikes higher, h holds boost longer..."

I have read that and I have read the exact opposite.

Was curious if anybody has tried doing a comparison on a chipped Motronic

[varia]

"j spikes higher, h holds boost longer..."

Now, that is totally dependent on whether you're running standalone engine management or stock. Sure, the valve has different properties which is why it reacts differently given the SAME control parameters by an ECU. But if you have something like VEMS where you can control those parameters, it doesn't matter which valve you have.

http://forums.fourtitude.com/showthread ... -N75J-N75H
ive read it here few months ago

[booested4door]

I've only played with these on a 1.8t, but, in my experience the j is smoother and the h is spikey.

[Namreg Rac]

I've only played with these on a 1.8t, but, in my experience the j is smoother and the h is spikey.

Cool. Was the 1.8T stock?

[booested4door]

No. And I now run a k valve with a big turbo. Nice and smooth.

[Namreg Rac]

No. And I now run a k valve with a big turbo. Nice and smooth.

Right on, I have a GTX3071 with an N75H and get some boost spikage with high load.

I am going to try a J

Sean

[booested4door]

any smoother?

[Namreg Rac]

any smoother?

I haven't gotten home yet. I will test it our in a week or so when I return from work.