compressor surge or bov flutter ?

[v8killer]

Ok guys i thought i had this fixed but my car is having a surge or bov flutter problem ? It has a stock bov with the dodge garage mod. when i start to build boost in any gear around 2-4psi it will start to to fluxuate from vacuum back to 2-4psi until i give it more gas and build more boost. This is getting very annoying drive around having to go past that spot to keep it from doing it.i have both ports tee'd together right now and it is a little better. when i just use the top port it seems to make it worse.

 

[96 420a-t]

That sounds weird. Compressor surge is when you let off the gas. Have you done a blt?

 

[GsXdSmKingGsX]

Could you possibly make a video?

 

[v8killer]

That sounds weird. Compressor surge is when you let off the gas. Have you done a blt?

I done a blt a few weeks ago and found a small leak at the TB and that was it ?

Could you possibly make a video?

i will try to get one on my phone tomorrow.

 

[JusMX141]

Compressor surge is when you let off the gas.

Wrong.

http://www.youtube.com/watch?v=nCj6Spwl1CU

Surge happens any time the turbo is making airflow the engine is not using. If your BOV is too stiff or not opening when the throttle plate is closed and the engine is on vacuum, the turbo is making airflow the engine is not able to use....causing compressor surge. In the example shown above, certain compressors will surge while under boost by providing more air than the engine can use. This is commonly found on turbos with large compressors mated to small turbines.

Ok guys i thought i had this fixed but my car is having a surge or bov flutter problem ? It has a stock bov with the dodge garage mod. when i start to build boost in any gear around 2-4psi it will start to to fluxuate from vacuum back to 2-4psi until i give it more gas and build more boost. This is getting very annoying drive around having to go past that spot to keep it from doing it.i have both ports tee'd together right now and it is a little better. when i just use the top port it seems to make it worse.

Did the problem seem to come on all at once, or did it occur after you modded the valve? Have you tried swapping a non-modded valve in place?

The few Dodge-Garage 1G valves I've been exposed to would indeed cause a little flutter on vacuum when letting off at a low boost level, when the boost in the piping was not high enough to "force" the valve open....although there was never an issue while on boost.

You can have a valve that opens fast at low boost or holds high boost pressure- you can't really have both.

 

[96 420a-t]

You come in here with your knowledge and tell me I'm wrong. How dare you... j/k. I honestly never seen a snail surge under load and boost like that. That's crazy.

I appologise for the false info. Thanks for the wisdom.

 

[v8killer]

Hey guys i made a video but you can't tell much by it.In the video the needle will bounce between 7-9 psi until i give it more throttle. To me it acts like the bov is holding and releasing repeatedly.now you can here my bov release and it does have a flutter to it which i'm not worried about. It also does it worse going up a steady hill in a higher gear.

You must be logged in to view this image or video.

 

[JusMX141]

Something's definitely wrong with the sound of that BOV....it sounds like it's not even releasing at all. Are you sure the vacuum line is hooked to the top of the valve with no kinks, splits, or anything tee'd into the line?

 

[PCD_RS]

Your BOV isn't even opening at all from the sound of it. Have you checked your vacuum line? If you tee'd it off with another line, I suggest giving the BOV it's own dedicated vac line. Either that or your spring is way too stiff in your modified BOV.

 

[JusMX141]

Is there an echo in here?

 

[PCD_RS]

Lol

 

[v8killer]

Something's definitely wrong with the sound of that BOV....it sounds like it's not even releasing at all. Are you sure the vacuum line is hooked to the top of the valve with no kinks, splits, or anything tee'd into the line?

The line is new, i also have tried different sources with no tee'd connections and it still does it ? when idling with vac on top of the valve it does pull it open so the valve does move. I'm at a loss....... also i bought the car with the valve modded like that, but i have done the mod on a previous talon and it didn't flutter.

 

[JusMX141]

Then it's possible the diaphragm has a leak or someone botched doing the Dodge Garage Mod.

Try supplying 20-30psi to the upper vacuum port and see if it blows out the lower port. If it does, replace the valve.

 

[v8killer]

Then it's possible the diaphragm has a leak or someone botched doing the Dodge Garage Mod.

Try supplying 20-30psi to the upper vacuum port and see if it blows out the lower port. If it does, replace the valve.

never thought to do that, will try it this evening. Thanks !

 

[Kapok6]

Wrong. You can have a valve that opens fast at low boost or holds high boost pressure- you can't really have both.

Sure you can. All you need is a solenoid such as an FPR colenoid hooked up that you can control by setting the parameters. Could be based on TPS, MAP, or whatever. You would just have whatever tuning program you are using if it is capable to be open and allow air to only the top part of the BOV at WOT and at less than lets say 95%TPS it shuts and only allows air to the bottom part forcing it to open faster. That way you can have both features.

 

[v8killer]

Sure you can. All you need is a solenoid such as an FPR colenoid hooked up that you can control by setting the parameters. Could be based on TPS, MAP, or whatever. You would just have whatever tuning program you are using if it is capable to be open and allow air to only the top part of the BOV at WOT and at less than lets say 95%TPS it shuts and only allows air to the bottom part forcing it to open faster. That way you can have both features.

I've got a solenoid and the software........ hhhhhmmmmmmmm

 

[olmytsi]

Sorry to hijack, my buddy's 2g with a td06h 20g is doing that around 20 psi...what's the easiest fix? Lower boost?

Should he get cams to help flow?

Thanks guys!

 

[JusMX141]

Sure you can. All you need is a solenoid such as an FPR colenoid hooked up that you can control by setting the parameters.

From a technical aspect, you are 100% correct. What I was getting at is you really cannot buy any valve on the market and expect it to do both functions- the valves which hold high boost cause a little surge down low, and the valves which open quick down low generally don't stay closed during high boost.

By design, the closest valve to doing both of these functions are the push-pull valves currently on the market.

 

[DSM IN MN]

I do not mean to revive a dead thread but; I just brought my Talon home from working on it for the last nine months and my dad and I took it out and I get the sound of compressor surge... I thought it might be because I set the BOV to a harder setting so I just kept turning it down....which doesn't seem to be fixing it..

Another thing that I do not quite understand is; the car did not do this ALL the way to my house... And between my house and my dad's shop (where the car was) is about 3 miles. Most of which are short city blocks so I KNOW I would have heard it.. The surge happens when I let off around...1,800ish-3,000 RPMs... But if I stop the car, put it in park and go under the hood and rev the car from the TB, the Type-S sounds like normal... No surge or anything close to surge...

I just do not see why it didn't do it, then I messed with the spring tension, and still nothing, then drive it and it does it.. Then I rev it (while not driving), and no surge sound. The BOV DID seem to be opening early when I let off while using the hands on the TB technique however.. So from between the two ways of getting the RPMs up and letting off...I'm lost.

I might also want to add the "mods" to the car: 4in K&N cone, hard Egay upper and lower intercooler piping, and Greddy Type-S BOV...

My boost is not turned up, if anything the car is not even making the factory 12psi it should...

The first video is loud enough to listen to with normal computer speakers however, you can't distiguist MUCH.. Here it is.

You must be logged in to view this image or video.

Now this second one is quite. If you have a computer you can turn the sound up pretty loud, you should be fine. But if your like me and have a laptop with bad sound, get some earbuds or headphones and listen closely at about 0:40-1:00... Watch out because not too long after I kind of..."express" how I don't understand why it is doing what it is.. Its a little loud; fore-warning.

You must be logged in to view this image or video.

Any help would be GREAT! As I am going to start driving this car to school starting Tuesday.

 

[donniekak]

Sorry to hijack, my buddy's 2g with a td06h 20g is doing that around 20 psi...what's the easiest fix? Lower boost?

Should he get cams to help flow?

Thanks guys!

Wow, i thought mine just did it because it is a td05h. My fix is a good ebc. I lowered boost in the surge rpm area.

I was actually thinking about running the t3 10cm housing to help with the surge, but the exit is only about 2". Smaller than the exit on a 6cm 14b turbine housing.

However, this is the most fun street turbo i've ever had on my car, even driving around the surge.