Ok well i spend most of yesterday with Rob from Pineapple Racing (pineappleracing.com) with chris from corksport stopping by to help with some ideas.
The first thing we tried was to put in a bigger opening before the bov. The idea was if this was the bov making the turkey this bigger area would allow more pressure to build up before it vented, hopefully with fewer, stronger vents.
This did nothing.
We then caped off the intake pipe and the intercooler pipe and ran the car without a bov at all. Same turkey.
So we know the BOV has NOTHING to do with the actual turkey sound. Our bov is almost 100% quiet.
What does this leave? most people say wastegate. When i brought this up he said there is no way that the turkey is a sound coming from the wastegate. If it was we would hear it in our exhaust. When we took the last peace off the Ingen CAI we could hear the turkey coming from down the pipe, the turbo.
He then concluded that the turkey was this:
When your forcing air into the block everything is fine, when you release the throttle it causes the engine to close the intake not allowing air in. What then happens is the air that was between the turbo and the block is stuck. It builds up against the turbo then causes the turbo to actually spin to release the pressure, once it does this another build up, then so on then so on. Thats why there is a flutter.
He had some ideas on how to remedy this. First thing he noticed was that the line coming off the intercooler pipe to the bov was very small. He had a thought that if you made another hole, then another on the intake, and ran 2 stock bov it might actually help.
Another idea chris from corksport had was to use a twin chamber bov that would release any excess pressure but would stilll hold some in.
I was kind of wondering why mazda recalculated instead of vented. Rob had a fast answer and actually really liked that it did this. He explained than when you vent you loose all the pressure you built up. With it recalculating it then throws that pressurized air right back into the intake causing for a faster response between shifts.
I might have missed something but i tried to remember everything.
comments?
The first thing we tried was to put in a bigger opening before the bov. The idea was if this was the bov making the turkey this bigger area would allow more pressure to build up before it vented, hopefully with fewer, stronger vents.
This did nothing.
We then caped off the intake pipe and the intercooler pipe and ran the car without a bov at all. Same turkey.
So we know the BOV has NOTHING to do with the actual turkey sound. Our bov is almost 100% quiet.
What does this leave? most people say wastegate. When i brought this up he said there is no way that the turkey is a sound coming from the wastegate. If it was we would hear it in our exhaust. When we took the last peace off the Ingen CAI we could hear the turkey coming from down the pipe, the turbo.
He then concluded that the turkey was this:
When your forcing air into the block everything is fine, when you release the throttle it causes the engine to close the intake not allowing air in. What then happens is the air that was between the turbo and the block is stuck. It builds up against the turbo then causes the turbo to actually spin to release the pressure, once it does this another build up, then so on then so on. Thats why there is a flutter.
He had some ideas on how to remedy this. First thing he noticed was that the line coming off the intercooler pipe to the bov was very small. He had a thought that if you made another hole, then another on the intake, and ran 2 stock bov it might actually help.
Another idea chris from corksport had was to use a twin chamber bov that would release any excess pressure but would stilll hold some in.
I was kind of wondering why mazda recalculated instead of vented. Rob had a fast answer and actually really liked that it did this. He explained than when you vent you loose all the pressure you built up. With it recalculating it then throws that pressurized air right back into the intake causing for a faster response between shifts.
I might have missed something but i tried to remember everything.
comments?
if not, you would stall. The MAF accounts for ALL air taken in, if you vent to atmosphere, the PCM is adding the fuel for the air, but the air is not there, causing a flooding condition.
