Factory Boost Control VS upgraded boost assembly (pill)
Hello Bryan,
Once when i was working on a rally IX group N, i was concerned about the destruction of the turbos in the rally environment - not from ALS - (here in Romania all the rally cars are using a 0.3 mm restrictor on the turbo side and that's all).
So i tested the metal pop-off valve.
And i made a rig to see at what pressure the pop-off is cracking open. So i found out that at exactly 1.5 bars, the pop off is opening.
The plastic one is opening at 1.2 bars.
So i changed that with a pop-off valve from HJS England which has a screw to set the preload. I set it up to crack open at 1.7 bars and the car had a better top-end and it kept more pressure after the peak.
After that i tried to incorporate this on a street car but where are some downside problems. When you drive the car normally, the car is stuttering because of the opening and closing very rapidly of the pop-off. So after 4 types of pop-off, i didn't found one that has the same neutral comportament like the oem one.
Maybe when you have time, you can check this on your dyno to see if there are some improvements of power and boost when using different pop-off.
Once when i was working on a rally IX group N, i was concerned about the destruction of the turbos in the rally environment - not from ALS - (here in Romania all the rally cars are using a 0.3 mm restrictor on the turbo side and that's all).
So i tested the metal pop-off valve.
And i made a rig to see at what pressure the pop-off is cracking open. So i found out that at exactly 1.5 bars, the pop off is opening.
The plastic one is opening at 1.2 bars.
So i changed that with a pop-off valve from HJS England which has a screw to set the preload. I set it up to crack open at 1.7 bars and the car had a better top-end and it kept more pressure after the peak.
After that i tried to incorporate this on a street car but where are some downside problems. When you drive the car normally, the car is stuttering because of the opening and closing very rapidly of the pop-off. So after 4 types of pop-off, i didn't found one that has the same neutral comportament like the oem one.
Maybe when you have time, you can check this on your dyno to see if there are some improvements of power and boost when using different pop-off.
Yup, we have found that the plastic BOV from the USDM 03-05 evos do open at low boost and are basically piles of do-do.
The OEM metal bov works well for most applications. We have seen them vary in pressure they can take before opening, some open at 1.5, some open at 1.8, etc etc
If you crush them at different levels, they will hold more before opening, however if you crush them too much (too much pretension on the spring), then you get the issue you explained above with the drivability issues.
We have found the best OEM style BOV is the Tomei BOV which is a modified OEM metal valve.
If you are running higher boost and the BOV is leaking, you will for sure see torque and horsepower increases going to a BOV that doesn't leak as much.
For example, the last car that I had crushed the OEM bov after finding it was leaking at 28psi, gained almost 40wtq/40whp in the midrange.
http://www.cobbforums.com/forums/ima...mWorksv109.pdf
its for a subi, but should be the same thing basicaly.
This is the hose that is connected to the black turbo compressor outlet pipe and has 3 metal clamps on it. The middle clamp is where the pill is.
Evolving Member
Joined: Dec 2008
Posts: 149
Likes: 0
From: Seattle, Wa
so is this the whole piece we need if we want to unplug our stock and replace it with the new pill and everythingon my x?
http://www.gstmotorsports.com/store/...oducts_id=1058
http://www.gstmotorsports.com/store/...oducts_id=1058
so is this the whole piece we need if we want to unplug our stock and replace it with the new pill and everythingon my x?
http://www.gstmotorsports.com/store/...oducts_id=1058
http://www.gstmotorsports.com/store/...oducts_id=1058
The pill is the same for both and is found here:
http://www.gstmotorsports.com/store/...oducts_id=1050
We are debating on offering the whole assembly or just the pill and that section of vacumn line (it's much easier to swap out just that small section with everything on the car). Obviously the pill and vac line section would be at a cheaper price point.
