No Boost

Can anyone help me out here? AA is closed for the weekend. I got my kit installed. Car idles perfectly supercharger blows air, but car never goes into boost at idle vacuum is -20 and goes up to 0 at full or partial throttle.

I don't feel this 100 HP. I don't hear or feel any leaks. I removed the Intercooler and reved the engine. I could feel the air from blower (driver side) and I can feel the sucking on the passenger side with intercooler off. Something isn't right. SuperCharger sound really nice, but no boost or power to match. Please Help Any thoughts?

My 323i does not have a fuel pressure regulator if that helps AA said I didn't need it.

Thanks.

Centrifugal superchargers make most of their power on top. Drive the car in second and merge onto a highway. That way you can rev it up high and see if you can feel the power.

They also say it takes a few miles for the software to adapt. When I first drove my car it did not feel very quick. Follow the break in period.

AA and their instructions, which were very very very very very poor, said nothing about breaking the software or car in. How many miles before my gauge should see boost?

If anything the car feels slower...

How many miles have you put on the car with S/Cer running??

I put about 3 miles

Yeah, you definately need to drive the car. The software needs time to adapt. Drive you car around. Dont go beyond 5000 rpms for 100 miles. Then call AA Monday if you dont see any improvement.

Oh really? I already went past that several times today and didn't feel the boost. How do you guys know about this little bit of information. I spoke to Craig from AA many times and never did he mention this break in adaptation period nor does the install manaul say this. Can someone tell me if this is in fact true?

You have a boost gauge installed and it's not moving past 0 at all?

Correct. At Idle it goes to -20, then when I drive and get up to 5-6 RPM it goes up to 0 and no further. I double check for leaks, but can't find any every hose is on tight. I disconnected the hose connected to the throttle body and the idle starting jumping up and down, but when I connected it back idle was perfect again. It just seems to me that I should be feeling some kind of boost unless the computer really is managing this.

You have a leak somewhere. If you're hard on the throttle in the upper ranges of the tach, you should see boost. There is no "break in" period for the supercharger. It will make boost right out of the box, the ECU has no control over the boost level.

Now that's what I was thinking, but at what point could I have this leak? I removed the intercooler to test both sides. Driver side has pressure and passenger side has suction. I blew air into the passenger side and it was tight no air would go through. I placed my hand on the driver side and the supercharger was trying to push my hand away no leak in the upper area. So where could a leak be? Even if it was a little leak should I see a little boost?

Originally Posted by lrogers80

Now that's what I was thinking, but at what point could I have this leak?

its the main line below the compressor. if the seal isnt right, it will hold air at atmospheric pressure (driving below boost etc) but under boost the seal will come apart and let loose all your boost, making you drive at atmosphere pressure when you should be at 130% or so. this is very hard to diagnose but seeing normal vac at idle, normal driving at low rpm,

and then seeing no boost at wot and blowing maf codes at wot is classic boost leak


if you paid for the install, have them fix it for free.

Ok I think the charger is working just fine. I went to homedepot and got some PVC piping and cuplers. I connected the boost gauge to the pvc pipe. In place of the intercooler. Picture below and the gauges does show boost when I get up to 3k RPM. It seems like my boost is getting to the engine, but Maybe the throttle boddy isn't taking it. I also replaced the bypass valve thinking that maybe it wasn't working, but that didn't help.
Also my valve didn't work I was able to blow air to both sides. I got a PCV valve from Pep post to take it's place still didn't help. Not sure what else to try now.

Originally Posted by lrogers80

but Maybe the throttle boddy isn't taking it. ]

thats what i meant. not the charger outlet, the throttle body is what i blew a boost line off.


im telling you this is the problem, you need to reinstall your upper boost lines ( from the IC back to the throttle body.

i had the exact same thing happen to me, its the only explaination if the compressor doesnt sound broken (and you would hear it)

Maybe something is blocked?
piece of paper in the intercooler maybe or something like that.

Originally Posted by Maestroxl

Maybe something is blocked?
piece of paper in the intercooler maybe or something like that.

This is exactly what I thought and that's why I removed the Intercooler and blew air into it from one side and air does come out and when i block one side and blow into it air will not come out so there isn't a leak from the intercooler it self.

My gauge is both vacuum on one side and boost on the other. At idle the needle is at the vacuum side and when I drive it does move to 0 but never passes 0.

Could I have a bad check valve?

Here's an image of the boost gauge. I thought it was at -20 yesterday, but today it's at 11-12

I just got drove about 22miles on the hwy and I am not getting 29.5 MPG. I useto get 26. Car feels good, I got up to 100MPH at 5k RPM and it still never went pass the 0 mark on this gauge.

Can you place your air filter on the hose connected to the S/Cer?? Try to bypass intercooler and see if you get boost.

somethigns off, a supercharger(as stated earlier) will perform right out of the box, you should have boost immediately, now is your gauge a vacume gauge or boost gauge? because a boost gauge wont go to -20. your engine vacume will be negative as its a steady suction created by the engine crankcase that sucks on your brake booster and will control some other aspects.

You sure the boost gauge is hooked up properly?