DUDE, don't waste your money on the actuator. I did, did not help the situation...well in my case anyway. I replaced that and the solenoid before the actuator...and nothing....no fix..The only way i'm able to boost 19-20 now is the boost bypass mod. That's how i've been running my car for a while. I belive my problem, and what might be yours, is that we have something wrong electrical. I still don't have any freakin clue as to why my boost bleeds. I couldn't even hit my full 19 with it, I only hit like 17 and by 5500 rpms it drops down to 5. I checked for an unplugged sensor, but I found none on my car.

BTW, do you have your rear o2 sensor removed by any chance? Also, does your car smell after your drive it (serious question, open up the engine bay after your drive it and see if you get a weird smell)

Also, how much timing are you running? Drive your car with the boost bypass mod...does it seem slower? My 2.5 pullied cobalt with every bolt basically can barely walk a gm stage 2 with intake and catback, and thats with me on 100 octane.....I'm really just thinking about picking up a brand new crate motor with the supercharger and pcm and starting from scratch

 

I was waiting for you to chime in adam... but yeah, it seems some cars do that from time to time. I say e-mail me your file, I'll make sure nothing was over looked. and if all else fails try doing a write entire. Hopefully that should fix it.

 

When you said write entire, that made me cringe lol

I'm thinking it could also be a bad sensor somewhere as well, on ethat just crapped out.

 

One of these days I'll see you again and I can take a look at what the hell is going on with your car. I'll be trying to make some the NJ meets this year so I"m sure I'll see ya at one of those.

 

[QUOTE=607Motorsports;917616]boost should not be bleeding off this much, it's dropping down to under 10psi and the top end just feels really doggish. Which line needs to be unhooked and plugged on the bypass?



It is the bottom line on the bpv it comes from the solonoid at the rear of the head.

 

it sounds like the boost bypass solenoid. (the electrical one on the side of the head) is allowing it to bleed off boost. i mean if you are disconnecting the boost line from the bypass solenoid. plugging it and holding boost it seems like that would be the cause. its not likely to be the bypass valve or actuator because that would just bleed boost back into the sc right before the rotors causing a pressure drop for sure but i doubt it would bring it to 10psi or less at wot where you should be pushing between 17-20psi. so i would say if the boost bypass mod works then it is very likely to be the bypass solenoid. i would not be inclined to think it has to much to do with the tune with no CEL espicially in 3rd gear with no torque management and no CEL.

 

I think the bypass valve is around $26.00 Broke one once. :-( Not too bad though.

 

stevo if you can get me some info on where you got you bypass, a part # or any other info I would really appreciate it.

I did the boost bypass mod tonight just to check and I get full boost of 18-19psi. When I hook it back up it bleeds off once again at 5500rpms + and now goes down to as low as 8-9psi So now I know it has something to do with the bypass or the selenoid right? Thanks for all the help so far guys.

 

You have the same problem as I do. If someone knows what the heck it is, PLEASE, OMG PLEASE LET US KNOW. The solenoid runs into the intake manifold??? Hmm...how would you replace that? I replaced my actuator and valve thingy majig....lol w/e its called

 

I would say the solonoid is leaking or something it turning it off.I recommend you unplug the electrical connector,check it for power (with key on pink wire) it should have battery voltage. The pcm controls the gnd. on the other wire.
I think the solonoid is a normally opened unit meaning when not energized it lets the signal through. If you have jumper wire you could jump the pcm wire(grey) to gnd and check the signal output of the solonoid there should be no vacuum leaking through at idle.
or boost under load.

 

That's the problem, I do get KR with the bypass mod....I had to lower my timing to stock timing. However, i'm running on 100 octane and 23 degrees of timing as of now...and no knock

 

here is the stock tune.. it shows why your loosing boost!!

 

I would just tune the car with the bypass mod in effect.Set up your timing tables so it gets no kr. My reasoning is we allways want full boost.If you want some way of lowering power output for traction don't use boost % I would use the desired torque vs rpm in the supercharger torque mangement section.

 

ummm, we aren't running stock tunes. My tune should say 100 across the board on the 1st and 2nd gear reductions....

Yeah that's what i'm probably going to do soon. Just have to do it on a day that I have time to mess around with it.

 

well.. you would want higher than 100% across the board.. Since stock it shows 200% up to the point where it bleeds boost then drops to 100%

 

yea thats gay how it says 200% boost and once you lower it once it will never go above 100%.

 

huh?

i can put 500% in there if i want..

 

mine wont go above 100 once i touch it.How do you post screen shots like that? pm me or e mail me if poss so we don't screw up this guys thread.

 

same here... I think I figured out his problem... just waiting to hear back from him. We shall see..
also with version 2.1.17 you have more control over boost limits in all gears it looks like. and it looks like you can also completly disable boost. hmmmmm.... have a few people I"d like to **** with.... lol

 

Hey Paul, I'll try this out after work today. Do you want me to flash the entire file to my car or just change those 2 parameters we spoke about? I've sent Keith an email requesting the 2.1.17 so I should have that today. Thanks man.

 

Just change the differences in the file I sent you. I think I only changed about 4 different things. But it is the exact same tune I am running in my car right now with 0 KR and full boost (20+psi) all the way to redline.

 

Yeah, I was freaked out at first when I tried putting in 200 as the boost for my friend Rob's car and it kept going back to 100...I was like uh oh....but it seems like it doesn't matter because his car runs great and is a FREAK. But his car has always been a freak.

 

still no fix for the issue i'm having with losing boost I reflashed my PCM last night with the new tune and still had the same exact issues. When I do the bypass mod the car instantly wakes up and jumps right up to 19psi and holds to redline. When I hook the bypass back up it bleeds off the boost above 5000rpms all the way down under 10psi. I'm thinking this must mean its the bypass valve, anyone have any info on how much these are exactly?

 

Like I said before it can't be the valve it is the solonoid or somthing is turning it off.

 

it was odd btwn his file and mine there were 2 different things in grey for the boost control, never saw those before.. but since I can't edit his exact file... I'll have to look into that tonight and send the table data over.