Hey. So I have been racking my brain trying to find out why my Synapse BOV would function perfect under 19 pounds of boost but fail to open fast enough at over 20. Today I finally was able to put my BOV on a friends car with no change in the configuration and it would be flawless on his car.

Here is a log.

https://docs.google.com/spreadsheet/...=0&output=html

Does this look normal as far as vacuum?

Thanks.

 

Have you checked for boost leaks? It is staying shut under boost? Is the vac line going to it sufficient in size and the same size all the way to the source?

Not very familiar with these but isnt there a few different configurations you can set these up with? May want to double check that also.

 

Dont pay attention to evoscan for vacuum readings. I know mine doesnt go past a certain number either. Look at your gauge.

 

I have tried every configuration and it never blows off at full boost. On my friends EVO it blows off just fine at full boost and we run about the same boost levels 29PSI.

My vacuum line is right from the intake manifold to the BOV port. Nothing else is attached to it.

 

ah ok. My AEM gauge reads 26 at idle so it should have plenty of pulling power. I can see the BOV working by watching it and revving the engine manually.

 

Do you guys have the same turbo/motor? If not then his 29psi is more/less than your 29psi.

 

well yea... but still shouldn't the BOV open after going full throttle and letting off the throttle?

I removed the preload spring and tried just A with B VTA, just B with A VTA and A + B. A with B VTA was the worst.. fluttered at low boost.

 

No idea on the combinations. Flutter at low boost is normal. You dont want it at full boost.

 

Yea.. I cannot figure out why it doesn't open at full boost. UGH.....

Anyone have any ideas on what I can try?

 

The spring is too stiff in the bov valve. You have to find the happy medium with on that holds the valve closed at idle and will open fully under boost release. You cant always go off the charts from the company either

It took me i think 3 springs in my tial to find the one that worked. And it wasnt the one the they had listed on the chart for my vaccum level

Just my .02