The Detroit Tuned Bypass Valve is a re-worked new OEM valve that is modified by Detroit Tuned to eliminate the "Yo-Yo" in early year ('02-'04) Cooper S's, but is available for all Gen 1 Cooper S's. What is the "Yo-Yo" effect? It's the opening and closing of the valve around 2500 rpm's so that it feels like your stepping on and off the gas, but you're not. So we added a stronger spring to overcome the vacuum condition that it sees so that it will not open as soon or as much. Our BPV closes at 6" of vacuum, as opposed to the factory value of 0" of vacuum.
The DT BPV uses a stiffer return spring, resulting in quicker boost generation, and thus quicker throttle response and transitions. Most cars see about 1psi total @ redline. The butterfly assembly is also adjusted as much as possible to close fully, allowing for maximum boost. This is done by centering of the butterfly door and adjustment of the set screw that sets the openness of the butterfly. Perfect for the aggressive driver or racer. It is possible to see a very minor loss in fuel economy, but you will see a great improvement in throttle resolution and smoothness.
Every valve comes with full how-to instructions (below) and all necessary hardware. Easy to install in about an hour. No core charge. This only fits the 2002-2006/7 Cooper S with the Tritech motor.
Posted by Sergio Savoy on 9th Dec 2013
I purchased the bypass valve and installed it myself. The full throttle hesitation the car had is gone and the boost the supercharger makes is allowed into the engine sooner - something you can feel when you don't downshift and punch it in traffic. Plus the extra oomph can be felt all over the power band. Overall this was a great purchase and the effects of the tuned valve are immediately felt.
Posted by Jerry S. on 24th Oct 2013
I was noticing my boost numbers were low and the car just didn't seem to pull as hard as other R53s that I know. I had my mechanic ziptie my OEM bypass valve closed and immediately noticed the difference. When we figured this out there wasn't any question if I was going OEM or DT. Now it's installed and it pulls just as well as the OEM one that was tied closed. I haven't noticed ANY negative side effects and the car PULLS HARD!!! I have owned this car for 3 years and it had always ran like that. It's like having a NEW car. Rest assured when the time comes to replace the one on my sons car it will be a DT bypas valve. Thank you Detroit Tuned!!!!
Posted by B on 26th Sep 2013
The product is exactly what it is described as. Fixed my yo-yo issue. took about hours. Be careful with the silacone house to the charge pipe
Posted by Matt on 30th Jul 2013
I started feeling throttle lag as my stock bpv began to fail. After switching to the Detroit tuned unit the throttle is better than ever before!!
Posted by David R. on 14th May 2013
So ive been looking for sometime for parts that do what they claim, and i have to say detroit tuned has severely understated the capabilities of their product. Now i should say i have the colder range plugs by ngk and a 15% pulley. For starters lets talk performance on the track and twisties it gives u a larger useable RPM range from about 2k till redline not more power but, the boost comes sooner resulting in a faster lap time. Next is the yo-yo thats dead and gone now feels great. Throttle response is on point as well no waiting for the old bypass to close power is there when u want it. Highway driving at 70 mph is fantastic just give it the gas and she flys no downshift its great. Lastly gas mileage did suffer lost about 4-6mpg intown and about 6 on the highway but yours may differ because i cant resist all the extra fun this product offers "SOLID 5 STARS"
Posted by Paul T on 13th Mar 2013
Made my first purchase with Detriot Tuned and couldnt be happier. The person I spoke with on the phone was very friendly and helpful - the odering online was very easy - the shipping was very quick - and the instructions were terrific. The bypass value made a huge difference to the performance of my MINI and it is now much more responsive. Highly recommend both the company and the product!
Posted by mcannon-gso on 8th Feb 2013
I was having some boost issues as the stock BPV had 118k on it. Bought this and had my mechanic install this as well as a new belt tensioner, stop, belt and a Autologic tune.
All things completed and the yo-yo effect is gone, more power in the boost and the boost comes in earlier. Best mod done to this car yet! A+++++
Posted by Marc Vipond on 17th Dec 2012
Great quality product that even comes with installation instructions! Takes about an hour, two if you're a novice. While you're installing make sure you clean your intercooler and throttle body. The cars ability to build and hold boost has increased dramatically!
Posted by Kristian on 24th Nov 2012
I'm very happy with the bypass valve. The spring is noticeably stiffer and the butterfly is fully closed unlike my stock one with 75k on it. My advise for install is to remove front bumper and pull rad support forward a few inches on driver side to access the supercharger intake pipe bolt. Loose the bolt before separating the bpv and the intake pipe. I didn't do this and broke the thin plastic tab holding the pipe onto supercharger. It's an extra step but if you break the pipe you have to do it any way plus $150 for pipe and gasket :( I would recommend the bpv as my boost feels stronger and comes in earlier.