Bypass valve?
 

Just wonderin if anyone has changed their bypass valve? If so do they make after market valves that have diferent sounds like blow-off valves for turbos?

be kind of cool to pass some turbo'd car with a crazy bypass noise. :razz:

The function of the valves is fundimentally different..
 

so there's no big noise with our valve. It's used to connect the post and pre SC intake paths when there is little load on the engine to reduce the parasitic drag of the SC for improved gas milage.

There are ways to modify it, and different ways to hook it up, and a couple of companies that will sell you modified valves... Look around...

Matt

Just wonderin cause I smoked some srt-4 the other day and all I heard was his damned blow off valve behind me. just made me want something noisy to drive the point in. nawmean!

You sure the Neon didn't miss a shift? :sly:

It is the driver, you know that........:nod::thumbsup:

Bomboasy

I saw 2 SRT-4s at the drags a few months ago, and they were running over 1 sec faster than me, so my guess the driver you "smoked" missed the shift.
Go to RennTV ( a German who makes race videos) and get the one of the twin turbo Porsche driving around Nurburgring--now that's some turbo blow-off valve music there!

i've always wondered about venting manifold pressure to atmosphere. Matt, do you think it's possible, without upsetting the ECU?

Would sound awesome

who else beside detroit tuned makes a modified valve

GTT also makes one I think??

I don't think a blow off valve would work with a supercharged motor. I'm not an engineer, but SC's are belt driven and, as such, don't have the same off-throttle pressure build-up that free-spinning turbo generate.

The srt-4 didnt miss a shift. Ive been instructing racing for PCA, and NASA for 4 years now and have been racing sense I was 16. and like Bomboasy said, its the driver baby!

The addition of the DTBV was a great change, really changed things in the performance realm.

It is a good choice for all MCS Minis.

Paul

yeah im looking at one right now. How is the install on it? I did my own 15 % and it came out ok. in relationship to that how would it be?

:) well you're right in saying that superchargers don't create boost in the same way that turbochargers do, but on the contrary, i would've thought that the off-throttle boost pressure on a supercharger would be higher....as the turbo is driven by exhaust gases, of which there won't be much under no throttle, whereas the supercharger is driven by the amount of revs, which won't drop significantly under no throttle.

Our cars have blow-off valves, however, they vent the manifold pressure back into the intake stream, just before the SC.

FYI guys, the DTBV is a BPV with a stiffer spring, and it also closes properly, unlike most stock BPVs. GTTuning doesn't make a new BPV, they just modify the old one to shut properly.

And on the subject of racing. Yes the driver matters, but let's try to remember that a lot of cars come out of the factory faster/slower than others. Maybe El_Griton has a faster than usual MCS, and the other guy either can't drive, or has an unusually slow srt-4.

I've beaten a lot of cars that i shouldn't have had. 350Z, Boosted Skylines, JCWs (back in the day when all i had was an Alta CAI and MTH)

SC slows down with the motor...
 

but right after a serious dose of boost, the intertia in the turbo rotors keep it spinning fast for a bit, even if the motor has slowed.

Matt

OF course, in un-controlled environments, one car and driver could "beat" another combination with similar, or uneven power and performance characteristics. The closest we can get to a controlled environment is the drag strip. Yes, there are driver differences, but their impacts are drastically reduced after the light beam has been tripped. The SRT-4s at the drags were putting out around 300HP, compared to my 200HP. It's a no-brainer that if I would ever get to the end of the 1/4 before them, something went wrong in the other lane.
And of course, we're not talking about street racing at all, full stop, period...never.
btw, I'm not selling my MINI for a steenkin Dodge!

If you were able to get the pulley changed you would definately be able to follow Detroit's well written instructions.

There are a couple of tender points that require a gentle touch not to break some somewhat breakable parts, but follow the directions cause this bull in a china shop did it successfully.

I believe you'll like whart you have afterward.

Paul

Does anyone buy old BPVs?

Just wondered what to do with mine. Maybe Partsman would want it.

Anyone that does, just PM me and it's all yours for shipping.

Paul

you got a header? that's noisy ....

mine has been sitting on the kitchen counter for not 1 but 4 freakin' weeks !!!!!

get with it man! Opulence of acceleration is forthcoming.

Get thou off thy can and doeth I say.

You'll really feel the smoothness.

Paul

how shakespearean of you!

it's always something needs doin' you know? but this doth be the weekend me thinkith.

Here's what you do...
 

Adjust the butterfly position and stop, and if you're up to it, open the diaphram and stretch the stock spring 3/8-1/2". This isn't really the same thing as the detroit tuned valve... They both need more vacuum to open, but the stock spring will open farther once it starts for a given increase in vacuum........ The valves fail every now and then (not often, but more than most parts) and it's good to have a spare in the Mini parts box....

Matt

I'll take it.:grin:
pm sent