Turbo folks, please step in

[SleeperLS]

I have a couple of odd symptoms going on since I went turbo that I was hoping someone might recognize as a specific issue. Thanks for the help in advance.

First, when I rev my motor in park or neutral there is a turbo sputtering noise as the rpm drops back down to idle. Sounds just like the spooling noise is sputtering. Second, when I do not have my MBC hooked up my car boosts to 5psi no prob since that is the spring I have in my wg and drives normal. But, if I hook my MBC up to the wg then the car will try to die if i let off the gas too quick after accelerating a little bit, not building boost at all just maybe to "0" on my boost gauge. The car that this kit was on before had the same issue and i own a different MBC. I am guessing something goin on with the wastegate? Anyone confirm or deny this?

Click to read more...

 

[Turbocharged400sbc]

hows your vac lines ran? maybe isolate your map sensor and fpr to their own port directly at the manifold/TB

 

[SleeperLS]

Vac block. Every vac line has its own port. Main vac line comes off of the brake booster/uim line.

 

[Turbocharged400sbc]

that might be doing it since they are referencing an air volume off a line for a relatively huge vacuum canister (the brake booster)

pics bitch

 

[SleeperLS]

Y u no check out my build thread?

 

[Turbocharged400sbc]

cause yer supposed to link to it dummy.....jeeeze.....do i gotta solve everything fer ya

 

[Turbocharged400sbc]

switch your map sensor to run off the nipple/vac port at the alternator end of the uim and see how it does

 

[SleeperLS]

Thanks dude, I will give it a shot. On that turbo sputter issue the idle still drops normal, the exhaust just makes the sputtering sound.

 

[1quick]

Thanks dude, I will give it a shot. On that turbo sputter issue the idle still drops normal, the exhaust just makes the sputtering sound.

Does it make the sputter sound when you get into boost and let off while driving

 

[SleeperLS]

That is a good question, I will report back with that later tonight. If I remember right it doesn't, but I am not 100%

 

[Donnie]

Does it make the sputter sound when you get into boost and let off while driving

^Beat me to it.

 

[10sec]

Sounds like the BOV isn't working and the turbo is che-che-che-che-che-ing. Which, isn't good for the turbo. What BOV is it? Some sound like that, which is hawt. But coming from 2 turbo'd 3800 cars, that's not a normal noise with any of our BOV's.

BUT depending on the BOV low loads like revving can make it chitter, which would sound more like choh-choh-choh-choh-choh VS che-che-che-che-che. If it just goes "POOOOOOFF" under load (aka driving, boosting, and letting off) that's good. If it "che-che's" that sounds like compressor surge.

Y YOU HAVE SO MANY PROBLEMZ WIF DAT TURBO BREH?!!?!

 

[Wrencher]

^ Exactly what I thought when I read the OP ^ Compressor surge.
Is it a recirculated or open BOV set up?

 

[10sec]

It should be open like most turbo 3800's. So that's why i said it's "not normal" (I come from a background) because it should just vent. It's not a big turbo either so even an ebay BOV will do the job. However if it's an SSQV or something like that (I had one on one of my turbo GTPs) it will make the described noises under low to no loads. Under heavy loads it just blew all that shit off, like a 15yr old getting banged by his teacher. But without the whole going to the cops thing. Dumb ass kids.

 

[1quick]

My question was getting towards what everybody already beat me to, damn needing sleep lol, it is weird that it does it in park since you should not be building boost anyway but it's possibly due to your vacuum source I run my bov and map off the port ware the t would normally go on the lower intake, the brake booster is all by its self and the wastegate/boost controller runs right off the turbo outlet

 

[Tommygm3]

If it is compressor surge, like previously stated, which I agree with, depending on how long it's been happening it might be wise to actually pull the turbo and check shaft play, etc. Not sure how quickly you could destroy a turbo with a non functioning BOV but I would think it wouldn't take long. Comp surge is going to happen even with a BOV, it's unavoidable but if the turbo is taking the entire backlash effect without any relief it might die a quick death. Just my thoughts but they may be more resiliant than I know.

 

[SleeperLS]

Does it make the sputter sound when you get into boost and let off while driving

After driving tonight it seems like it does this while driving as well.

Sounds like the BOV isn't working and the turbo is che-che-che-che-che-ing. Which, isn't good for the turbo. What BOV is it? Some sound like that, which is hawt. But coming from 2 turbo'd 3800 cars, that's not a normal noise with any of our BOV's.

BUT depending on the BOV low loads like revving can make it chitter, which would sound more like choh-choh-choh-choh-choh VS che-che-che-che-che. If it just goes "POOOOOOFF" under load (aka driving, boosting, and letting off) that's good. If it "che-che's" that sounds like compressor surge.

Y YOU HAVE SO MANY PROBLEMZ WIF DAT TURBO BREH?!!?!

It is a TIAL BOV and it has some miles on it. Yeah I agree, it doesnt sound normal. I drove around tonight with the boost controller not hooked up and the car does try to die even without it hooked up. When I am in boost and let off fast it is more of a che-wooooosh. If I let off the throttle slightly under a medium load, then the BOV goes che-che-che-che-che. If I speed up to just hear the turbo spool then let off I can hear that surging noise through the exhaust. and the car idle dips just slightly.

I have a special karma when it comes to this car for some reason. The guy that help me do the swap can testify to that I have needed to trouble shoot almost everything on the car so far.

If it is compressor surge, like previously stated, which I agree with, depending on how long it's been happening it might be wise to actually pull the turbo and check shaft play, etc. Not sure how quickly you could destroy a turbo with a non functioning BOV but I would think it wouldn't take long. Comp surge is going to happen even with a BOV, it's unavoidable but if the turbo is taking the entire backlash effect without any relief it might die a quick death. Just my thoughts but they may be more resiliant than I know.

I just installed a brand new turbo a short time ago and the new turbo has very few miles on it. The old turbo was making the same noise as well. I hope the turbo doesn't take a shit, but I guess we will see how it works when I get the issue fixed. Shaft play is minimal, same as new IMO.

The BOV does modulate though. If i rev via the TB then i can see the BOV moving. Is it just not working properly?

 

[SleeperLS]

3800 guys, heard anything about that basic 50mm stattama BOV? It is cheap, but does it function well?

 

[1quick]

it sounds like it's not opening enough or something try a different vac source if possible to rule that out, I run an hks knock off it was like 60 bucks shipped on ebay and works fine for me, I have not herd anything about the stattama bov as far as good or bad

 

[10sec]

Tials make that noise, the "CHE-WOOOSH" is what it's supposed to do when the turbo is full spool and you let off. The "che-che-che-che-che" is the turbo spinning much slower so there isn't enough vacuum/pressure to fully open the BOV. There should be an adjustment on the BOV so take some tension off the spring so it opens easier.

Should sound like this, which your higher boost does sound like, but low/part throttle boost should sound like this.

 

[SleeperLS]

I am going to take apart my BOV and see what spring is in there. Maybe it is a bit too loose and isn't popping the bov open quick enough?

 

[10sec]

Well it's popping it open plenty fast, but not popping it open under little/no boost. Sounds to me like it's too tight, not loose.

 

[SleeperLS]

yep, that makes sense. After doing more research, you are right on that.

 

[10sec]

:nanadance:

 

[Shadow99]

Like so?



My tial does this. I have the wrong spring in there which makes it do this noise. Similar to your noise?