N75 dumped in favour of manual boost control valve

[tartan_rob]

Guys - has anyone dumped their std N75 in favour of a manual boost control valve (NOT an in-car adjustable). I've heard that the pick on a manual job is better, the only hassle is setting it up initially - takes a lot of faffing around.....

[Verruckt]

On K03's it's not a good idea. It will overstress the turbos much more than the N75 will. It will give you the most aggressive boost response, but part throttle response will suffer. I ran one for a while on the K16/K04 turbos and went back to the N75.

[tartan_rob]

Okay - swapped the N75 for a MBC and although was getting more boost was not happy with the results so swapped back. No probs or issues but lesson learnt and can now start thinking about going back to revo set-up....

[Verruckt]

Okay - swapped the N75 for a MBC and although was getting more boost was not happy with the results so swapped back. No probs or issues but lesson learnt and can now start thinking about going back to revo set-up....

What types of problems did you have?

[tartan_rob]

The spool up at high revs was great - almost instantaneous but at low revs I felt she was less responsive than with the N75. Also the boost would remain constant around .9 bar but around 5k revs the car seemed to loose accelerative force. My passsenger did not notice it but as the driver, I did. I would rather have the low down kick and torque that I get with the N75. Its a shame as as it would have been a very cheap alternative for getting a touch more power from the car....

[JonnyX]

Probably worth logging group 003 to see if you were getting throttle cut.
Thats the problem with a flat boost curve.

[Dippy]

Jonny,

Sounds interesting - could you expand that a little?

[Verruckt]

Jonny,

Sounds interesting - could you expand that a little?

He's right. In theory, an MBC will spool quicker than the N75. You are probably getting throttle cut. Log throttle position angle and see what happens.

[tartan_rob]

But how could I resolve if this is to blame?

[Verruckt]

But how could I resolve if this is to blame?

It depends on what software you are running.

[tartan_rob]

Verruckt - okay - talk to me. What is involved in "fixing" this problem..?

[Verruckt]

Verruckt - okay - talk to me. What is involved in "fixing" this problem..?

Like I said, it depends on what software you have. The "solution" involves a few mods some consider "hacks", but they work well. A Zener Diode on your MAP will allow you to run an MBC without throttle cut. This works great on GIAC X software, and not so well with others.

[tartan_rob]

The big question though....would the cost of modding the car and using an MBC be more than spending £600 on revo?

[Verruckt]

The big question though....would the cost of modding the car and using an MBC be more than spending £600 on revo?

Well, an MBC only works if you already have some sort of remap. It won't work with a stock ECU.

Assuming you already have software, it will cost less than £50.

[S2tuner]

Rob, why not get a proper remap for your car, that will take care of all this without worrying for throttle cut or anything like that??? There's several options available out there IMHO.

About the X-chip, it's a nice chip, but heck I won't use it on K03s for anything in the world. 1.3 Bar peak and 1.0 at the redline is defo way too much for the K03s...

Mihnea