BOOST and N75

[00s4slvr]

ok so i was having boost problems before with my giac x ecu which would hold about 14-15 and spike to 17 then back down to 14-15. So i changed my N75 valve to the ecs tuning race n75 valve and now im my giac x holds 16-18psi with spikes up to 20-21 then back down to 16-18.

does this sound normal now?

[00s4slvr]

also is the race n75 supposed to fit back the same exact way as the stock one like in the rubber clip and stuff. Because when i matched it up with the stock one it seemed to be completely diff...

[00s4slvr]

is this normal??

[Boosted-S4]

hope someone replies back with a good answer cause im thinking of getting that same n75!!

[00s4slvr]

yeah i am comparing the stock one i have to the picture of the ecs tuning one and it looks a little different.

[00s4slvr]

i mean i have the ecs tuning n75 in my car and it works great (boosts does spike higher :P) but it doesnt fit back in the clip so its kinda hanging there...

[espo4442]

i mean i have the ecs tuning n75 in my car and it works great (boosts does spike higher :P) but it doesnt fit back in the clip so its kinda hanging there...

Question is does the car feel like it's performing better? Pressure test and see if you have any leaks

[RolledMySTi]

From talking to 034 Motorsports that sounds normal. I went there to get a new N75 when mine took a dump and asked about the race N75. They said it would work, but would run 1-2 psi higher than a regular N75 which can cause problems for some chips. As long as you are not going into limp mode you should be cool.

[RenegadeEngr]

Nope, it doesn't mount in the same place, I relocated it back along the firewall with the other large electrical couplings, I ran new lines to so that no kinks were possible....

[00s4slvr]

so far its working good and my ecu chi is running about where it should be now 16-17 spiking to 19-20 so im happy that my car is running strong again. I figured it wouldnt fit so im just gonna leave it there since its in there pretty tight but thanks for all the info!!

[espo4442]

have you noticed any difference in performance such as throttle cut or anything

[00s4slvr]

throttle cut?

the only thing i noticed is that my boost in Pump performance mode is normal and spikes higher than before and the throttle you dont have to push as far down to get a rush of power.

[espo4442]

throttle cut?

the only thing i noticed is that my boost in Pump performance mode is normal and spikes higher than before and the throttle you dont have to push as far down to get a rush of power.

haha meaning it feels faster then huh. I meant do you feel it sometime fall on it's face for a split sec when you floor it. I guess thats the best way to describe it

[CONTROL ONE]

Well thanks for making my decision easier. When my N75 goes, I'll be getting the direct replacement, not the 'race version'.

[AudiSportB5S4]

throttle cut?

the only thing i noticed is that my boost in Pump performance mode is normal and spikes higher than before and the throttle you dont have to push as far down to get a rush of power.

just be careful, running so much boost on K03s is asking for trouble.... Thats why unless you are tuned for the N75 "race" it really isn't necessary. GIAC tunes for stock N75. That program when logged with ECUx it shows you that at redline it wants 14-15 PSI. with a 18-19 Spike

[00s4slvr]

i thought the giac x ecu was supposed to be 15-17 psi spiking to 18-19. When i spoke to AWE tuning they told me that the giac x should be doing that and said that my n75 was probably faulty, so after i changed it, i started getting boost levels like they said. hold 16-17 spiking to 18-19 and i saw 20 but maybe i misread since i was trying to focus on driving and quickly glanced over. as for the race n75 I spoke to ecs tuning and they told me the race n75 was a better thing because sometimes the stock ones fail...??

also i usually keep the car on stock mode an occasionally turn on the ecu to pump performance for a day (like when i do car meets) so im hoping that will help the k03's last.

[joe dub]

Yes thats all normal.
I just put a longer hose coming off of the ambient pressure side, then tucked it down closer to the Y pipe, I have no kinks, leaks or problems with the valve and my APR ecu.

[00s4slvr]

my n75 is tucked by the Y-pipe also on stock tubing. Im hoping that the platic tips on the n75 dont crack. they havent already so im hoping everything is good.

[Rajan147]

get rid of the n75, go with mbc and set the boost at a level you feel comfortable with :)

[CONTROL ONE]

get rid of the n75, go with mbc and set the boost at a level you feel comfortable with :)

Is there a DIY on how to do this?

[Rated S]

That's running it in parallel (with n75) however, if you want to run it in standalone, can you just put the side of the MBC on the blue line (Wastegate Control Pressure) and the bottom of the MBC, on the green hose (from the turbo) and iirc you just plug up the ambient (not shown) hose which would be the third hose off the n75.

If you're running in standalone MBC you will need a bleedvalve on your MBC, however if you run in parallel, you do not (and if you do will have a boostleak).

I run in parallel, as most people will tell you to do so.

[AudiSportB5S4]

Is there a DIY on how to do this?

yeah, you take off the BOTTOM and the RIGHT hoses off the N75, leave the one from the left hooked up to the N75 and leave the electrical connection still on the N75 so that it doesnt throw a code, then change boost as desired. very easy.

[AudiSportB5S4]

That's running it in parallel (with n75) however, if you want to run it in standalone, can you just put the side of the MBC on the blue line (Wastegate Control Pressure) and the bottom of the MBC, on the green hose (from the turbo) and iirc you just plug up the ambient (not shown) hose which would be the third hose off the n75.

If you're running in standalone MBC you will need a bleedvalve on your MBC, however if you run in parallel, you do not (and if you do will have a boostleak).

I run in parallel, as most people will tell you to do so.

you beat me by some seconds. you bastard. LOL. AND you have a picture. i SO lose this one

[Rated S]

you beat me by some seconds. you bastard. LOL. AND you have a picture. i SO lose this one

The war isn't over yet.

[00s4slvr]

lol i dont need a MBC im happy with the n75 lol.

[CONTROL ONE]

Any advantages of running the standalone MBC? (great diagram btw)

[AudiSportB5S4]

Any advantages of running the standalone MBC? (great diagram btw)

there is no real advantage only that you can set the boost to whatever you want it to hit. the DISadvantage to running it in standalone is your N75 in the winter will reduce the boost since the air is more dense thus requiring less boost pressure to create the same air. with your MBC in standalone it is going to hit Xpsi all day all no matter what temp it is. i found it to be a very choppy ride, on and off with power.

[Rated S]

there is no real advantage only that you can set the boost to whatever you want it to hit. the DISadvantage to running it in standalone is your N75 in the winter will reduce the boost since the air is more dense thus requiring less boost pressure to create the same air. with your MBC in standalone it is going to hit Xpsi all day all no matter what temp it is. i found it to be a very choppy ride, on and off with power.

The n75 is a failsafe, where if something happens, it cuts your boost (a la 'limp mode') however, if the n75 is disconnected/standalone, you don't have that safety. There are a lot more negatives than positives for running in standalone.

[AudiSportB5S4]

exactly... thats why Mike @ VAST is so set on tuning with the N75 and not using a MBC with his fueling kits. Prince said i want parents to be able to drive this car and not know anything has been changed to the motor... unless of course they step on it :-p.... The MBC in standalone was annoying.

[will175]

I installed my MBC in parallel to help limit my boost. I only took it for a short spin and it stopped the boost at 14psi. I still need to turn it back up to 22psi. Just wanted to make sure it was working correctly. Vast guys rock. I talked to Prince today and the guy is top notch. But I forgot to ask there is a little hole on the MBC what is that for, and do I need to cover it.

[Rated S]

But I forgot to ask there is a little hole on the MBC what is that for, and do I need to cover it.

That's the bleedvalve/hole. If you are running the MBC in standalone, you need that. However, if you are running it in parallel to the n75 it will cause a small boost leak. Either patch it up or get another one without the hole.

[will175]

Why you trying to tell me to go out and spend more money I fricken just bought the MBC,lol just playin bro. Okay Ill go and plug that HO. Thanks for the info.

[Unispeed]

The only problem I experienced with a MBC in standalone, even when I had the giac, was deviation when accellerating... Like the ecu was expeting 5psi but because of how quickly the boost built up it would get 8 and so on. Its not a good idea to run a mbc in standalone unless you have the JHM tune (wich is made for a MBC) or the VAST mbc tune.

[s4Xcelence13]

I already have GIAC-X chip in my car, and i wanted to run a MBC, could JHM or VAST used the GIAC-X or am i SOL