I just finished reading an article in the new Import tuner. I want to see what you guys think.

There was a test done concerning the pressure drop off, after throttle is released, between the VTA and recirculated. Both tests were done using the STOCK BOV and TURBO. Now keep in mind the test only concerns 1 seconds after the throttle is released. So this could reflect opon shift times.

The pressure drop seemed to favor the Ricirculated over the VTA. The Recirculated BOV seemed to help keep boost a little higher. At .25 of a second, there was a 2 lb difference. At .5 of a second there was a o.7 lb difference. At 1 second they were both at 0.

Now it appears to me, that the recirculated BOV seems to help keep the turbo spinning at a higher rate of speed after the throttle is released. This can help the car rebound with power faster between each shift. Also it can also give the car and extra 20 hp and Tq earlier, by not having the delay of the power fall off. Keep in mind I am just using the 20 hp as a reference, since on average 1 psi can usually create 10 hp. So intern, "IF" you shift fast, you can possibly improve vehicle response and times by recirculating.

They also speculate that this difference in psi can be changed if a person were to go with a larger aftermarket BOV. Since the larger BOVs can flow more air, they would be able to keep the turbo spinning. hence even less power fall off.

They also say there is a possiblity that a larger turbo would possibly hold even more psi after throttle release. Since they also flow more air.

So what do you guys think? It makes a lot of sense to me. This could also benefit the guys on speed density. Even though you don't need the recirculation.

 

I wonder what the difference is with a .12 second shift time. Based on this info it would appear that it could make a difference of 3psi

 

kinda dumb question really. there is a lot of pressure coming out of BOV. do you want it wasted to atmosphere or put to use to keep turbo spooled up?

 

Agreed

 

I was asking if you would agree with their findings. Meant more to be informative than a question. Considering it was a test. I know how people love to question tests.

 

I think its great that some one did an article on it and tried to quantitatively show there is a difference. I dont doubt their findings. sounds like it was a good article. the kind magazines need.