!!The Best BOV For evo 9 Recommend!!
Jan 26, 2007 | 09:23 AM
#76
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From: somewhere testing various tires, brakes, and suspensions.
Originally Posted by Mike@Forge
The OEM Evo valves, however, have the intercooler piping pressure enter the valve through the port on the side of the diagram above, and this is better for three reasons.
One, the spring tension in the valve is not so stiff that the valve won't be "pulled" open at idle/under vacuum, thus it CAN open at idle maintaining proper function of the closed loop system.
Secondly, since the positive pressure enters the OEM valves from the port directly opposed to the main chamber, under load, the only pressure required to hold the valve shut is a combination of the spring pressure and the pressure reference from the intake manifold.
Lastly, at throttle lift, not only will the valve immediately open from the residual charge pressure "pushing" the disk off of its seat, but the return of the intake manifold to vacuum will also "pull" the valve open releasing the residual charge pressure before any lag or compressor surging can take place.
One, the spring tension in the valve is not so stiff that the valve won't be "pulled" open at idle/under vacuum, thus it CAN open at idle maintaining proper function of the closed loop system.
Secondly, since the positive pressure enters the OEM valves from the port directly opposed to the main chamber, under load, the only pressure required to hold the valve shut is a combination of the spring pressure and the pressure reference from the intake manifold.
Lastly, at throttle lift, not only will the valve immediately open from the residual charge pressure "pushing" the disk off of its seat, but the return of the intake manifold to vacuum will also "pull" the valve open releasing the residual charge pressure before any lag or compressor surging can take place.
Jan 26, 2007 | 09:28 AM
#77
No BOV should be open at idle (without any positive presure).... Electric ones may be (like AUDI A4 or VW ones - although I don't see any reason why they need to)... Not the mechanical one like we have in IX.....
I think you are talking about wastegate in turbo... Yes, diaphrame (Boost solenoid) should be opening the wastegate electronically when idleing.... NOT THE BOV!!!!!
If you like sound of BOV, go for the aftermarket one. But, make sure to tune it for it though... Stalling is mainly from rich AFR anyway.......
Fluttering is the cause of difference in gradual strength of spring between stock one VS aftermarket... Pretty much aftermarket springs is weaker on initial load pressure.... that's all.....
I think you are talking about wastegate in turbo... Yes, diaphrame (Boost solenoid) should be opening the wastegate electronically when idleing.... NOT THE BOV!!!!!
If you like sound of BOV, go for the aftermarket one. But, make sure to tune it for it though... Stalling is mainly from rich AFR anyway.......
Fluttering is the cause of difference in gradual strength of spring between stock one VS aftermarket... Pretty much aftermarket springs is weaker on initial load pressure.... that's all.....
Jan 26, 2007 | 09:45 AM
#80
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Joined: Apr 2005
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From: somewhere testing various tires, brakes, and suspensions.
No BOV should be open at idle (without any positive presure).... Electric ones may be (like AUDI A4 or VW ones - although I don't see any reason why they need to)... Not the mechanical one like we have in IX.....
I think you are talking about wastegate in turbo... Yes, diaphrame (Boost solenoid) should be opening the wastegate electronically when idleing.... NOT THE BOV!!!!!
I think you are talking about wastegate in turbo... Yes, diaphrame (Boost solenoid) should be opening the wastegate electronically when idleing.... NOT THE BOV!!!!!
If you like sound of BOV, go for the aftermarket one. But, make sure to tune it for it though... Stalling is mainly from rich AFR anyway.......
Fluttering is the cause of difference in gradual strength of spring between stock one VS aftermarket... Pretty much aftermarket springs is weaker on initial load pressure.... that's all.....
Fluttering is the cause of difference in gradual strength of spring between stock one VS aftermarket... Pretty much aftermarket springs is weaker on initial load pressure.... that's all.....
Fluttering at part. thrd. is caused by stiffer springs - they want to hold it the DV closed so they flutter a little. This is not an issue.
Please read that DV tech article.
Jan 26, 2007 | 09:55 AM
#81
Wrong again, you dont tune for a DV, its not a perf. adding part (in most conditions - not talking about high psi cars here - then its a perf. maintaining part...). Think about it this way our ECU is looking for the air at idle and between shifts. That air from the DV is pushed back into the intake (remember this air was already measured by the MAF) and mixes with the fuel already being sent there (based on MAF reading).
Fluttering at part. thrd. is caused by stiffer springs - they want to hold it the DV closed so they flutter a little. This is not an issue.
Please read that DV tech article.
Fluttering at part. thrd. is caused by stiffer springs - they want to hold it the DV closed so they flutter a little. This is not an issue.
Please read that DV tech article.
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