ok, I have a serious question for you ATI owners:

first time out today. I had 2 boost gauges in the car
(one permament and one temporary). I part throttled
the car (2/5) to 3k rpm. It started out under 20hg vacuum
at idle. At around 3k, it almost reached 0. So, I guess
the bypass might still have been blowing off boost,
but IS THIS NORMAL?

On part throttle, when do you see boost?
Do you have to really press it >50% to see boost?

I just don't want to mash it just yet. I applied pressure
to the FMU (manually with a pump) and I could hear it turn on...
I also looked at the hoses and there doesn't seem to
be a problem. I also know the bypass works because tons
of air comes out of it at idle and I can see the actuator
arm moved over.

thanks,
rob

 

The ATIs pop-off valve vents boost unless you really push it. At half throttle you should even hear the boost being vented as a whistling noise. If you floor it, this does not happen...

joe

 

n4spd , I assume you are the same (G35) poster over on g35driver.com as need4speed? If you really are in livermore ca. , I am in north bay and would like to check you rig our sometime , before I commit to the ATI setup for my 'o4 G35 6mt Cpe. Who did you use for the dyno and tuning?

WRT to you boost issue, I assume that the ATI bypass works similar to any other SC with a bypass valve. I have a KenneBell SC on my pickup, and the bypass is normally closed (bypassing) when there is no demand. This saves gas at cruise and reduces average heat in the compressor and Intake tract. If your gauge showed >0psi under light throttle , then I would supect a problem.

 

g3po,

yes, i'm in livermore. I guess it's working as expected then.
I'm new to superchargers and didn't want to mash it
right away (I used to have a TT rx7 so I'm more comfortable
with turbos). Without boost (part throttle), I can actually feel
the drag/loss of the supercharger (compared to prior driving
expectations). The price of the supercharger is better but I
think I like turbo behavour better...

also, I've just finished installing it but have not had it tuned
yet. I'm just trying to verify (gently) a proper installation.
Afterwards, I'm thinking of either going to Dynamic Motorsports
in Sac or just renting time on a local dyno with wbo sensor.

You're welcome to stop by and check it out. Maybe, if you
buy quick enough, we can even get tuned at the same time.
I'm moving really slow with my car because I'm actually off
at home (for 2 months) to take car of a new born...

rob

 

So I pressed the pedal a little harder after checking things
over and yes, I AM getting boost. Stopped at 3-4 psi (didn't want to push it since I'm not tuned yet). But, I also got squeal on startup at night time...

At just over half throttle, I got ~5.7 0-60 with my gtech
averaged in both directions, manual shifting at 5k. Before, I
got 6.0 at full throttle (auto).

only thing I don't like so far:

1. when VDC kicks in on launch, the car really loses power.
does this happen to you Zs?

2. the bypass is really loud (G kit vents to atmosphere).
It's louder than my borla. It's only quiet when making
boost so it makes me want to not decel, coast or idle, which
only leaves acceleration...

 

turn off the vdc

 

N4Spd, I noticed you have an automatic, someone else had posted that they had problems manually shifting the auto(350Z) when at full boost. Did you encounter this problem also with your G35?

 

menehune,

I think other auto people are having problems in auto mode,
not manual mode (as in not upshifting automatically in time
before the rev limiter). Manual mode is ok.

For me, I'm not pushing the car hard yet so both auto and
manual mode work fine. My guess is that when I go full boost,
my auto mode will fail to shift just like the others...

rob

 

Thanks. I'm leaning more towards FI now.