My APS single is finally, mostly, done. I should be picking it up today so long as a few minor corrections were made since I drove it yesterday. The car has three major issues right now. 1) It smokes like a mother when run under boost. I've had the APS check valve installed, although the car hasn't seen significant mileage since its install. The hope is that it will burn off, although i'm wondering if i should pull the exhaust up to the turbo and brakleen it. 2) fuel smell in the cabin (as in, will knock you the F*^* out with the windows closed). most likely i didn't get the tank gasket back on right, should be quickly fixable. 3) BOV doesn't work right I don't think, and this is the one I'm actually most concerned with. sound schmound, but this chatter would appear to me to be causing compressor surge. i'm afraid its going to damage the turbo. is there any way to adjust the BOV? i've checked most of the vacuum lines (no idle issues) and don't see an issue there... anybody know wtf i'm talking about?

ahm

 

Theres no screw or spring? Usually u can just adjust it by loosening a screw or changing a spring right?

 

The BOV is designed to vent back into the intake under low boost, and vent to atmosphere on high boost, but you probably already knew that. Or you could have a bad BOV out of the box, like I did....

 

is it a chatter sound or a flutter sound

 

Mine makes a ... I guess flutter... goes "Chuuu chuchuchu chu"... how descriptive is that?

Is your's more of a mechanical grinding sound? I know one person who had something that sounded more akin to "chatter" like clutch chatter.

~Josh

 

nope - perfect description with the 'chuuu chuchuchuchuchuchuchu'.

good news though - picked up the car, and after just a few miles, the visible smoking is just about gone. still smell it (and probably will for a while), but the APS/GRD provided solenoid oil check valve seems to have fixed the problem. obviously, i've got probably 20 miles on the car, so its a little early yet to declare victory, but things definately seem better.

i know its a low-boost recirc, more boost vent to atmo BOV, but that's not really the issue. i worked with AAM and we loosened up the spring with no change in symptoms. i'm going to try tightening it back and see if that helps. i may even try spraying a little lube into the BOV and see if that makes a difference.

AAM replaced the fuel tank gasket (which i must have gotten fuel on so it swelled and wouldn't seal), and i think the fuel smell is going away. i had filled the car all the way when test-driving it yesterday, and so i'm sure a little splashed when taking out / putting back in the pump assembly.

car pulls great, nice and smooth, building boost progressively until about 3500rpm when it really spins up hard. AAM had a problem getting the UTEC to control boost via the APS solenoid, so its running on wastegate pressure. seems to be around 7-9lbs, no taper at all. guess i got lucky on the actuator (although I know AAM had to tighten it down to get it to hold boost).

anyone have any other suggestions for how to fix the BOV?

ahm

 

take it off and put another one on it.

 

http://www.350zmotoring.com/forums/s...ad.php?t=36622


i believ this will have your answer

 

When I took my car to GRD, Tuan had to replace my BOV because it was litterally stuck closed....he couldn't even pull it open with pliers.

 

I had the same sound and replaced the APS BOV with the Greddy RS. Problem solved.

 

so long as you mean that mine still doesn't sound right, you'd be correct

Mine does not sound like the monsterexhaust_1 video andypandy references. i know the aps doesn't sound like most other BOV (with the psshht noise), its more of an extended chirp, but mine doesn't sound like that either. mine is making a stuttering noise.

as for the suggestion to get a greddy BOV, i'd really rather not. the one in the kit should work. if its really broken (not sure how - its such a simple mechanical device), perhaps.

ahm

 

'chuuu chuchuchuchuchuchuchu'........its really just the sounds of air being released since you didn boost up to max psi..............alot ST cars do this

watch a vid with a Single Turbo Supra......or something with one mideuim-large turbo and youll hear this sound

 

you can take the BOV off, and push on the piston on the intake side, it will take a good bit of force but it will open if its not seized up. mine made a sound like yours does, and it was fine. it was just too quite for me so i bought another one.

 

i took it off this morning, cleaned it up and sprayed some lube on the sliding surfaces (depressed the piston, spray, let piston up), and set the spring pre-load to as little as possible. i backed the pre-load screw all the way out, then put it back in and hand tightened until it contacted the adjuster. set the locknut there.

results? much better. not perfect, but much more 'normal' noise that i'd expect to hear from the BOV. under light boost, when i lift i still get a little of the flutter (you can barely hear it), but under WOT its venting like it should.

whats weird though is that it doesn't have that 'APS sound'. is sounds more like a 'normal' BOV. oh well. we'll see how it as the miles go by.

ahm

 

Mine makes the same noise..It's fine because the aps blowoff is made under light boost to slightly open and let out a little...Under 100% throttle and full boost it opens al the way and makes loud normal BOV noises...Everythings fine..

 

check your bov. when i took mine out, it had scrapes along the secondary port and the primary port. i measured the scrape to 5mm.. when i opened the valve up to where the scrape ends, the bov primary outlet opened up to 2-3mm. i still believe i was getting a BIT of compressor surge, hence the fluttering sound. so switched it out with with a SARD r2d2. uses a hose same as the APS bov.. no welding required!

at low boost, the same beautiful flutter but at high boost a fat woosh. full atmosphere dump.