Nihilation

Yea like the topic says...rev to about 7k rpm in neutral and the boost gauge reads a peak of about 4.5psi, same with my Greddy Profec B Spec2. Is this normal?

It started after I tighted the wastegate bracket down to the turbo(cause it was loose). That was the only change I made. So now when I drive the car it seems as if the wastegate isn't even there, 1st gear spiked to 9.9psi(Profec B reading) by the time I had the reaction to let off. Really don't want to blow the motor, I double checked my wastegate vacuum line and then replaced it just to be safe. Still does the same thing. It builds boost a hell of a lot quicker too, 9.9psi was at ~4k rpm when I let off the gas in 1st gear.

I turned the boost controller on, and set the boost limiter to 8psi...but the limiter doesn't seem to work. Doesn't beep and turn red like it should. I may take off the boost controller and try it that way. Any other ideas?

DA9-T

Just go grassroots on it and take the boost controller off first. Process of elimination.

Nihilation

Drove the car to work and had the ***** to hold it through to redline in 3rd gear while on the highway to see what the boost gauge tells me. It appears that it's spiking to around 9psi when it first spools up, then settles back down to 6.5 or 7psi. It does this in 3rd, 4th and 5th gear. Haven't tried 1st or 2nd yet. That's with the boost controller "off".

m R g S r

9psi on the greddy kit? You have nothing to worry about, as long as it's tuned. . .

Chris F

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nihilation &raquo;</TD></TR><TR><TD CLASS="quote">Yea like the topic says...rev to about 7k rpm in neutral and the boost gauge reads a peak of about 4.5psi, same with my Greddy Profec B Spec2. Is this normal?</TD></TR></TABLE>

No, that ain't normal!! You should be in serious vacuum at any RPM in neutral. The turbo could spool and cause pressure against the throttle plate, but you should be measuring boost AFTER the throttle plate, so there should be vacuum. Boost after the TB will be an accurate measure of what your engine sees.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nihilation &raquo;</TD></TR><TR><TD CLASS="quote">I turned the boost controller on, and set the boost limiter to 8psi...but the limiter doesn't seem to work. Doesn't beep and turn red like it should. I may take off the boost controller and try it that way. Any other ideas? </TD></TR></TABLE>

Limiter can't do anything but try to open the wastegate more. It changes the "set" value to the "warning set" value (so, maybe from 10% to 0%). (Warning isn't a limiter, just changes the set % for you.)

Boost controller turned off should just run of of the wastegate spring.

Chris F

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nihilation &raquo;</TD></TR><TR><TD CLASS="quote">Doesn't beep and turn red like it should. </TD></TR></TABLE>

Hey, my Profec B Spec II has never beeped. I'm kinda pissed about it. Manual says it should beep. Is there a setting for that? I can't find it.

Bailhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccfries &raquo;</TD></TR><TR><TD CLASS="quote">

No, that ain't normal!! You should be in serious vacuum at any RPM in neutral.
</TD></TR></TABLE>

yes it is normal, nearly all turbo cars can make at least a little boost in neutral if you rev them.

I'm surprised you can only get 4.5psi by reving it that high. Who cares? is what I want to know.

Nihilation

About building boost in neutral- I just wanted to make sure that was normal, as the past months of being boosted, I've never expirienced this...lol.

While driving home tonight...I noticed if I give it partial throttle in 5th, maybe 50% or so, the turbo is very audible from inside the cabin, and it builds boost extremely quick at partial throttle as well. When I let off the gas after partial throttle(boost reading 3-5psi), I will hear what sounds like crazy compressor surge. BOV seems to be extremely loud now as well when it goes off too. Again, this may be normal, maybe I'm just not used to it.

But back to my main concern, what could be causing such a large spike? It never did this before...even with the full 3" testpipe & catback. I must say though, if that's what 9psi feels like, I want some of that...haha.

093turbo16

iTrader: (2)

Starting to get a little colder.. everyone knows how turboed cars react to the weather.. probably part of your problems... what do you think...

B18C1CYA

how do you have your controler hooked up? and where are your lines taped?

Nihilation

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1CYA &raquo;</TD></TR><TR><TD CLASS="quote">how do you have your controler hooked up? and where are your lines taped?</TD></TR></TABLE>

Profec B setup:
The wastegate has a vacuum line going to the Greddy under-hood unit which is mounted behind the drivers side headlight, the other vacuum line for that unit is run across the engine behind the intake manifold and is tapped into the charge pipe right before the throttle body. There is another vacuum line run from the fuel pressure regulator going inside the cabin to the Greddy display unit.

BOV is tapped into the back of the intake manifold.

Boost gauge is tee'd off the vacuum line which runs into the cabin for the Greddy display unit.

B18C1CYA

maybe take the line that is hooked to the charge pipe and put to the intake manifold and see if that helps any,

93TurboSi

when my sohc was stock with the greddy kit on it would just stay at 0 no matter how much i revved it in neutral. cars with tiny little stock turbos can sometimes make boost revving in neutral but not very much. but the engine normally needs load to make enough exhaust to spool the turbo. and its wierd that its doing it all of a sudden. you officially have gremlins

ITRpwrdEG

Like the other guy said, try tapping into the intake manifold instead. People would be tapping into the charge pipe if it made sense, but no one goes out of their way to get a vacuum reading from there. You want to see the vacuum and pressure right before the engine combusts in the cylinders. Getting that too soon may throw off your readings. But if you have had it set up like this for a while and now it is just starting to act up, then you may have other issues you need to address.

racinskittle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccfries &raquo;</TD></TR><TR><TD CLASS="quote">No, that ain't normal!! You should be in serious vacuum at any RPM in neutral. The turbo could spool and cause pressure against the throttle plate, but you should be measuring boost AFTER the throttle plate, so there should be vacuum. Boost after the TB will be an accurate measure of what your engine sees. </TD></TR></TABLE>

I can't believe you just said that. I would probably be a spectator in FI for a while till you get the jist of it

On smaller turbos you can build boost in neutral, but the bigger ones you can't. My T3 with a .63 exhaust doesn't come close to building boost in neutral. But a Greddy kit may build a lb or 2.

civicguy

i do have the same problem,building 14 psi on neutral,but with t3/to4e .63 ar,dont know why,but its weird,by the im using a haltech f9

94dxt

something is wrong, maybe your gauge? Pretty sure it's impossible to reach 4.5 psi w/out load.

ComputerJLT

your wastegate is probably too tight.

you have a greddy kit right with the adjustable arm?

loosen it up; that should let the bc'er do a better job.

i loosened mine up and with my mbc i can set it between 4-15psi with some fine tuning

Nihilation

Noticed a little pinging today ~6k rpm in 3rd gear. Can't have any more of that...and its a while til I can get this ****** tuned again since few reputable Hondata tuners are in the area.