I changed my oil yesterday, and while I was at it, decided to take the H valve out andput the stock n75 valve back in just for fun. At first I didnt notice a difference. By the end of the day, I noticed a big difference. Obviously the N75 valve is the boost controller. The H and J valves work by "controlling the movement of the pneumatic actuator which drives the wastegate. The wastegate is an internal valve in the turbo-charger which controls the amount of exhaust gas that flows over the turbo impeller generating boost. Under normal operating conditions the engine's ECU sends signals to the N75 valve asking it to open or close which adds or reduces pressure on the wastegate actuator which results in more or less boost. The ECS RACE N75 valve modifies the normal operating parameters of the original N75 valve by delaying the speed at which these ECU signals are interpreted." Key word in all that being "delaying." The big difference is just that. With the stock valve back in, boost comes full on near instantaneously. The H/J valves delay it, and spreads the boost out longer before it hits full boost, creating a more "smooth" transition. I put the H valve in over a year ago and was very pleased, and always have been. But now that Im back to the stock valve, i prefer it now. I can actually hear the turbo starting to spool sooner, and it pulls a lot sooner, and what seems to be longer too. Where the H valve would build boost gradually, the stock valve is the opposite. So, Im keeping the stock valve in... Not that I have much of a choice anyway- I broke the H valve when removing it [:@]. So if you are running an H valve, and have been for a while, I recomend swapping back to stock valve so you can experience what I have. I really dont notice any crazy spikes to 23 psi like i did with it before, but I do notice that boost at wot is not as stable. The needle bounces around a bit between 17-20 psi.
Before anyone says it... I know... MBC/EBC ftmfw! But this is on a freakin k03, so gimmie a gd break!

 

Nice review I have waiting for someone to post something just like this. I read all kinds of reviews that contradict each other after the initial change from stock to H or J.

 

Picture it like this. The H valve is like putting your thumb over the end of a garden hose, making the water build pressure for a couple seconds, and then slowlyreleasing- giving a gradualburst of flow that tapers off. Stock valve is like using no thumb or anything to delay the exit of the water, and it just flows. The most notable difference is how soon it startsand gets to full boost, and when you let off the gas it is much quicker to dump/divert the air . Boost is just way more responsive, Im really liking it.

 

There is 1 thing that confuses me though. Now they call this a race valve but why would you want the boost to come on slower if you were actually racing? I guess the fact it holds the boost longer is nice in that situation but that would only be good if you were always at full boost. With the stock if you are accelerating out a corner the faster the boost comes on the better, right?

 

The thing is, is it appears to seem more aggressive, but i dont think it is. Where the H valve lacks in releasing boost as quickly, it makes up for with a "burst" of boost moments later. It seems with the stock valve, Im able to get all the power I want down low, and with the H valve i had to wind it out more in the rpm's. And yes, the H valve does hold boost longer, but it should since it doesnt start boosting until later in the rpm's. So when all the power (steady/maxboost)with the H valve might have been between 3200 rpm's-6k rpm's.... All the stock valves power is between 2400-5300 rpm's. Those are just very rough #'s to give an example to prove the point im trying to make, but Im probably very close. The lil k03 turbo can only breath so much for so long before getting tired throughout the rpm range. The different N75's just change when the wastegate releases the boost which will change when the boost falls off. That make sense??

 

sorry to hijack a little but if you were going stage II or bigger do you have to replace the stock valve to the N75 one? I've read that you need to upgrade the valve but what if you wanted to keep the stock one for the reasons you've stated, what will happen?

 

Stage II what? If you get a bigger turbo then youd want to go with a mbc.

 

Yea I think I got it, so basically the H valve really is not needed for a K03 since the K03 has a hard time holding boost that high in the rpm's.

 

No, the k03 will hold boost pretty good in higher rpms as long as the boost inst started until later (like with the H valve). The sooner the boost is released, the sooner boost will taper off (like with the stock valve). The later the boost is released, the later it will keep boosting until tapering off. The N75 mainlydictates when the boost is released from the wastegate. When the boost stops/tapers off is determined by when boost starts. Cant think of any other way to put it.

 

I think I'll try that this weekend. I didn't really notice a difference when I put my H valve in anyway.