Just changed my bypass valve on my 03 (Jan's advice because I was having spurts of power and no power low in the rpm range when the car was cool) and wow, it made a HUGE difference! The old one doesnt close all the way and the spring felt really slow/gummed up over the years. Anyways, the car no longer hesitates or goes slow under 3500 rpm. Just from the seat of my pants, the car presses me into my seat a lot harder and a lot sooner and, especially in lower rpms, it even sounds quite a bit 'meaner!' All in all, a great improvement! Thanks Jan!

 

Very interesting. Do you have any information on how to replace the bypass valve? Did you use an OEM bypass valve or something else?

Here is something I have noticed with my car, possibly it is just inherant with a blown car or possibly its a similar issue...

To me it seems like I have move power if I am continuously accelerating. For example if I stay in 2nd gear and keep it at say 3000 RPM for a while and then accelerate the car seems to have less pull than if I were going very rapidly through the rpm range from 1st to 2nd to 3rd etc... Does that make sense?

 

did you use the detroit tuned bypass valve?

 

I ordered a stock valve originally from minimania.com but they are in California and the shipping would take a week on top of the 3 days it would take for them to get the valve in stock. I decided to by a Detroit Tuned valve from detroittuned.com since they could ship imediately (only took 2 days to get here). I used the instructions from their webpage and they were very helpful. It took me about an hour and a half but I took my time and replaced the stock hose clamps on the air ducts with screw down ones.

As for the acceleration issue, I dont have a good answer for you other than its probably just that the car appears to accelerate harder. When you are shifting gears quickly you may get a little bit of engine rev/stronger boost between gears and then that sharp tug when you let off the clutch but I'm not sure.

All in all, I like the new valve a LOT and it feels like it added a LOT of power and some cool exhaust noise.

 

glad to see you got it fixed

 

It feels like I got some relatively significant gains from just putting in a new valve...could it be that the old one was really venting THAT much boost? The old one did seem pretty worn out and crappy but I wasnt expecting the kind of gain that I got...

 

When you are shifing up through the gears you are creating more load/boost, hence more power than just flooring it say in 3rd or 4th gear at 3k.

But 2nd gear is still low enough to produce load/boost from 3k rmps & up I would think.

Maybe your not running the proper size belt for pully diameter, or there may be a boost leak ?

 

yes it can effect it quite a bit once fails

 

can you please pm me the installation directions? i checked their site and didn't see any. thanks!!!

 

i just put one in myself and i agree wow i got mine because im only getting 13psi with a 16% pulley (ordered my alta 17% by the way) after checking all the vacuum hoses and my intercooler boots for leaks and nothing, so i figured why not, i didnt gain any boost like i wanted but full boost will hit about 1k faster in the rpms and it made my supercharger louder and my intake his alot more

 

Could the bypass valve be replaced with a BOV?

 

How many miles were on your bypass valves when they gave out? Just curious becuz i want to do one nnow but only if i need it. i bought the car used with like 50,000 miles so i dont know what it felt like brand new with everything working perfectly. I dont think bovs work on superchargers.

 

I had 27000 miles on my car when I replaced the valve and I've had my 15% pulley on since I bought the car with just under 20000.

By the way, detroittuned sends installation instructions with their valve. You cal also find them by googling it.

 

had this same problem with my mcs cabrio ,cant belive the difference by changing the valve ,i used a modified GTT BPV and it really pins me back when i nail it now and the sweet sound of the charger is back ,i love driving again

 

Not really, plus a BOV wouldnt really serve much of purpose on a supercharged car given that the blower is linked directly to the engine and downstream of the throttle plate, this you dont see the overboost created when you let off the throttle in a turbo car.

 

Does the Detroit Tuned valve stlll allow you to "feather" the gas any, or

is it more like either open / closed with no in-between because of the stiffer

spring ?

The reason why I ask, is because I was thinking of just getting a new OEM

unit, disecting it, and just stretching out the spring a little.......

 

It doesnt seem to be as off/on as people say it is...at least in my car. It feels very similar to stock, however, when you stomp on the gas at low RPMs, the car seems to TAKE OFF really fast rather than smoothely and boringly.

The thing does seem like it would be straightforward to modify but I dont think that just stretching the spring out in a stock one will have an affect for very long.

 

as far as feathering every will be the same the only difference is how much pedal pressure you have to use before boost starts to kick in. for me maybe bacuase my stock was so bad, at 2k rpm if i hit full throttle i would see about 9psi untill the rpms would rise and then see full 13.5 around 5.5k

now i can get about 10 psi with 3/4 throttle at 2k psi and hit my 13.5 around 4.5-5k

but to me next to the $100 pulley its the next best and cheapest mod one can do to the mini s

 

Im pretty much sold on getting one of these. I've noticed more of a "yo-yo" and "flat spot," since my 16% pulley install.

I've noticed that a few people have installed and then removed their Detroit Tuned BPV, saying it "didn't suit their driving style."

What do they mean by that?

 

If you dont want to go fast and you want your extra half a mile per gallon back, dont get the Detroit Tuned valve. If you want less responsive low RPM power/smoother slow speed driving go stock.

 

Nope and nope!

Guess, I don't mind the hit in MPGs, being that I average 21.5 mpg as it is.

Well then, Im sold. Now if Detroit Tuned would only answer their phones. I guess the point is, that at $125 you can't really go wrong.

Thanks!

 

I think this will be my next mod.....thanks for sharing info.

 

I understand this corrects a "yo-yo" in '04 and earlier Cooper S. Is there any benefit for later model cars? I have an '06 and was wondering if going to a Detroit-tuned BPV would yield any improvement.