I find it ironic nitro that you signature says "Consider even the smallest things can increase performance" yet you are arguing semantics of how this mod works. It does work and it take allot more work than a 3$ spring. I have watched Chad build this unit. Well I have seen him build hundreds. Frankly I wouldnt wanna do it. It's a PITA and very time consuming. Is it rocket science? No. But it works.
Don't know how long a BPV is supposed to last. It was replaced on my JCW at 34k. Along with many other things that are supposed to last a lot longer. Clutches, brakes, slave cylinders, axles, exhausts. The list is long and comprehensive. I guess I just drive harder then most. Rest assured that when the current BPV goes I will be giving the Detroit guys a call.
Sure it does. If you are losing boost due to a softer spring then you will gain. (be it what you SHOULD have it's still gaining) If the BPV is set wrong it's still a loss. So you get that back. Then you have a tighter spring and therefore now have the valve close sooner or quicker.. it will increase throttle response due to the boost stacking sooner. you are bringing stupid NAM style semantics over here to M/A. It needs to stop. I wish I had a dyno. I'd gladly chart the difference right now. Just like the intercooler BS that used to go on from the internet experts. "they dont make power" well not exactly they dont. But you sure can see the diff on a dyno... so... uhhh it worked! You can feel the diff when you drive... so uhhh it worked! Leave the semantics at the door. Not every question needs to be addressed with the answer to life the universe and everything. I can spout all kindsa blah blah blah. But the questiong was... "I was wondering if someone has installed the Detroit Tuned Bypass Valve yet? if you think its worth it?" So... Nitro, do you have it installed? Was it worth it? When I was SC only. Yes, and it was worth it.
This is the reason I've heard for it being there and it makes sense if under low-load conditions the supercharge can just move extra air back into the intake stream rather than force it all the way to the cylinders. 42, case closed.
Ok guys, lets kill the rhetoric here. Without a boost gauge and a history of readings, one has no idea if the BPV has a weak spring or not. The change would be very gradual as well, since the spring, unless broken, will slowly weaken from use and exposure to the heat of engine compartment. Hence the car owner, especially if the car is second hand, has no idea if there an issue or not, most of the time. We all don't have those finely tuned buttdyno's that a select few of you are blessed with. The OP asked who uses one and what that thought of it. Well I do use one and since I installed it with 2.5K miles on the car at the same time I added a head, headers, pulley and host of other items I can attribute nothing to nor take anything away from the DT BPV. I installed it as a precaution against the issues I had learned about the OEM one and felt that for my use a stronger spring would suit my needs. Lynn, you say they do nothing for a perfectly operating system. I don't disagree with you there. You go to say that a higher mileage it's not needed to change unless there is an issue. No disagreement there. Now the OP is about to perform some mods to this car. The OP also has no BPV performance to compare his BPV performance to. There is no history of boost readings. We also have no idea how the car was cared for in the preceding 74K miles. Given the fact the car is in TX, where it is hot a lot, the BPV is made of a rubber like material and the OP is looking to increase performance I contend that one has to "Consider even the smallest things can increase performance" and look at the BPV as a candidate for replacement. It's also been said that before the mods are performed that the OP go over the entire vehicle, change fluids if last date and/or mileage of change is unknown in order to provide the most stable platform for the changes to be most effective. I think that wraps this conversation up nicely. On to other problems to solve...the lot of you...
This is done unless it is something factual and useful about bypass valves. Anything else will be removed. Remember the first item in the Member Policy "Don't be a jerk". Well...this thread is making some of you forget that.
Boost builds in the intake manifold because more air is delivered than can be consumed, the crossover point from vacuum to boost occurs at a point determined by the speed the SC lobes are turning (air charge temps excluded), under boost, the diaphragm in the BPV no longer has vacuum pulling against it, so it allows the spring to push the plunger and pivot the butterfly plate. The Eaton sweeps air into the ducts downstream, any boost that has been created and allowed past the BPV’s butterfly plate, is recycled, not lost. To be lost it would have to escape upstream through the throttle body, but negative pressure in the supercharger intake duct and atmospheric at the throttle body cause it to seek the lower pressure area behind the supercharger and be swept up through it; this is governed by the laws of physics. I think this is where the proponents of a stiffer spring loose sight of how this thing works, it “reacts†it does not create. A healthy spring can only close the door in the absence of vacuum. Our air/fuel/spark system monitors the air component for speed and density, if the butterfly valves remains open and allows more density to be present in the supercharger intake duct than should be there in relation to what it records in the intake manifold than what the maps say is appropriate, things get out of sorts and interventions occur and we notice poor performance behaviors and/or fault codes are generated. A healthy stock spring is more than capable of preventing this condition. Unfortunately the illustration below doesn’t have a good view of the BPV, but it does show the relative proximity of the rest of the charge air path to it. For the readers who are not familiar with the location it is directly behind the first arrow entering the fresh air opening. Notice the direction of the arrows, imagine a loop with the BPV open. Three stock build versions of the OE BPV. The most common BPV failure is due to a broken spring.