You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
There's no "adjustment" for this... though somewhere, in the internals, I think it's just a matter of it triggering when it reads a particular voltage... so it's certainly possible that someone with the proper skills (not me) could modify the circuit to trigger earlier...
But you can block the flap open all the time or remove it altogether.
That said... why?
The engine is NOT starved for air through the front snorkel until you hit higher RPMS. And the supercharger doesn't really start to whine until about the 4000ish point... so I don't really see what you gain here.
__________________
I'm Paul, The car is Blimey--- BlimeyCabrio's Blog--- 2006 MCSCa w/lotsa mods and Union Jacks
Ten-time Dragon Veteran - Occasional Trackrat - Extreme Twisty Addict - Rhymers Ferry Road Fanatic
I was told by Outmotoring that the flap is set to 4500 because of noise regulations in the UK. They also recommended modifying the flap so it stays open. The only way I can do that and not worry that it will close again is to remove it. Would be nice to leave the box in tact and have it open at a lower RPM
Good question! But that said when my car was Dynoed for the Jan Tune it has a very smooth power curve with no dips. Don't see any reason to change it other than to make more noise and cars with open CAI's at the tune were no better....
Exactly. There is NO performance benefit I have see to opening the flap earlier.
I've heard the "noise regulation" story also... not sure I buy that. I think the flap is there to mask throttle whistle which occurs at lower RPMs and would be viewed by many owners as undesirable...
__________________
I'm Paul, The car is Blimey--- BlimeyCabrio's Blog--- 2006 MCSCa w/lotsa mods and Union Jacks
Ten-time Dragon Veteran - Occasional Trackrat - Extreme Twisty Addict - Rhymers Ferry Road Fanatic
I think it probably is for the EU (not UK) noise regulations, but as Blimy points out, the engine gets plenty of air below 4500RPM without the flap. All you would do is make noise more often. Ho hum.
__________________
"You can fool some of the people all of the time, and all of the people some of the time, but you can not fool all of the people all of the time." - Abraham Lincoln
That sure would have been nice to be able to pick the rpm the flap operates at. No way that I know of to change the operational rpm.
I agree that the mod to remove the flap is only a noise maker. Some folks feel noise = power, I don't. One of the beauty things about the JCW intake is the way the flap works, quiet when you are just tooling around & loud when you are on it.
If my JCW flap function ever dies, then I'll mod it. Until then I'm happy with the way it works.
Last edited by Crashton; 12-31-2008 at 01:09 PM.
Reason: speelin meesed upp
Does anyone know if you can change the rpm's from 4500 to something lower for the flap. Would be great around 3000
You can modify it with a JCW CAI flapectomy--Click here. The flap and the plug below it are then always open.
__________________
2006 MCS PW/B, 15% pulley, JCW CAI, 22mm Alta rear sway bar, first owner---www.SooperCooperinfo.com-a very complete MINI aftermarket/DIY/information library
Thinking about the flap and the need for it to be open above 4500 rpm. Is there a point of engine modification where that rpm threshold should be lower?
So, for a stock JCW engine there is no need to open below 4500 rpm, let's accept that as fact (However, do we have dyno data to support this?), at the stock 210bhp breathing needs.
1. What about with a 15% pulley? or 17, or 19%
2. What about the addition of a header, and/or a better flowing catback?
3. What about a high perf cam addition?
4. What about the addition of a large valve, and ported, high flow head?
5. What about a stroker to 1.8L or 2.0L
6. What about a larger/better SC, Rotrex or TVS?
7. etc.
Or thinking about this just in terms of air flow required for hp levels. How far up the hp scale is the JCW designed 4500 rpm flap open good for? 210, 250, 275hp? I dunno. And at which point might it be advisable to just take the flap out altogether. Again, I dunno, a nice and neat little table of when to do what with the JCW flap, backed up with dyno data of course, sure would be nice.
Personally, I am at about 285bhp, and my flap is permanently open, but still in there. Sometimes I like the extra whine, sometimes not so much. Is it helping me make power? I dunno, I have only had one tuning session on the dyno, and this was not the focus.
Exactly, at some point, it is going to make a difference. So, it is not entirely accurate to simply state, 'the engine gets plenty of air below 4500 rpm without the flap'. Changing that to 'the stock engine...' well that would certainly be true, but without that qualifier, there is a point at which the modified engine will not breath optimally with the flap opening at 4500 rpm, or even the flap being in there at all.
Sorry OldRick, not trying to pick on you, just being a little exacting I guess.
I am pretty sure that Jan ran his JCW airbox with the flap removed on his GP, until he switched over to the Voltage airbox. Not sure about his hp, but I am sure it is up there.
__________________
Last edited by mini_racer; 12-31-2008 at 10:09 PM.
It would be nice to be able to set it to open when you want it to. If there was a simple mod I might have it open about 3800 RPM. I'm no electrical whiz but sense the vacuum provides the force to open the flap it would seem that all you would need is a selinoid or whatever you call it that activates at a lower voltage... Dr O?
A while back I read that that someone was working on a mod to toggle switch between normal operation and always open but I do not think that effort was successful in the end.
...there is a point at which the modified engine will not breath optimally with the flap opening at 4500 rpm, or even the flap being in there at all.
That's a bit speculative - there *may* be such a point... but we don't know that yet... should be simple engine math... I just don't know the math... the stock "snorkel" is about 2 inch diameter. How much air can you flow through that at x vacuum, and how much power can that much air make? My bet is that's a pretty darn big number.... remember, the throttle body is only *slightly" larger in diameter than the snorkel...
Quote:
Originally Posted by mini_racer
A while back I read that that someone was working on a mod to toggle switch between normal operation and always open but I do not think that effort was successful in the end.
I talked about doing it, but never did... I'd need to probe the signal wire that the airbox uses and see if it's just looking for a voltage to unlatch, or ?
Then replicate whatever it's looking for on a switched circuit. Should actually be pretty easy. You'd just need to be making enough vacuum to power the diaphragm... but, again, the SC doesn't make a lot of sound at lower RPMs, and I KNOW that I'm don't need more air for my car, so I'm not very motivated to do it... though I *am* the king of cool, non-power-generating mods.
__________________
I'm Paul, The car is Blimey--- BlimeyCabrio's Blog--- 2006 MCSCa w/lotsa mods and Union Jacks
Ten-time Dragon Veteran - Occasional Trackrat - Extreme Twisty Addict - Rhymers Ferry Road Fanatic
Without the empirical data or the math to calculate, it is definitely speculative to think the 'point' is reached in a range that we care about. Yes, it could be way up there in terms of engine mods, without data we just don't know. This is where that neat little table would come-in that I spoke of earlier.
The flap operation toggle mod would be a nice empty toggle filler, I don't know where else it could go and still be aesthetically acceptable. Maybe this is one of those stealth mods that should be tucked away where it can't be seen, and used for those special times when you need that extra .00001 hp at 4100rpm, and so need the flap to be open all the time. (And yes that was speculative)
If I remember correctly the JCW airbox available from the JCW garage (before they closed) was the same box but with the flap removed. Something tells me that those guys were pretty smart and probably would not have removed the flap if they didn't think it was an advantage.
Steve
Well, the Euro parcel-shelf has a nice little removable panel that was apparently used by MINI for a driving lighting switch, according to the installation PDF.
I suspect that MINI_RACER is probably right, and at some point in boosting engine output, the flap would be constricting, but for a car making up to the stock JCW HP, my guess is that it's probably fine as is. My opinion may be biased by my dislike for unnecessary noise...
__________________
"You can fool some of the people all of the time, and all of the people some of the time, but you can not fool all of the people all of the time." - Abraham Lincoln
The MINI's used in the challenge series used that airbox. Like any race car all power gains are used. Even the smallest one can make a difference. Here in the world of street driven MINI's you'd never be able to feel the difference. You may hear it though.
Quote:
My opinion may be biased by my dislike for unnecessary noise...
I suspect the biggest advantage of the JCW race airbox was simplicity - no flap to fail, no hinky vacuum hoses to come unplugged, etc. I doubt they gained performance over the normal one... but they had something that was more reliable and didn't have an unneeded feature (noise reduction).
__________________
I'm Paul, The car is Blimey--- BlimeyCabrio's Blog--- 2006 MCSCa w/lotsa mods and Union Jacks
Ten-time Dragon Veteran - Occasional Trackrat - Extreme Twisty Addict - Rhymers Ferry Road Fanatic
Reading all this information is great but I should have posted that I have no other engine mods. Maybe a pulley later this year and an exhaust if I can swing it but that would be it.
Also, the small plug at the bottom of the air box can also be removed for additional air. What say the crowd???
Reading all this information is great but I should have posted that I have no other engine mods. Maybe a pulley later this year and an exhaust if I can swing it but that would be it.
Also, the small plug at the bottom of the air box can also be removed for additional air. What say the crowd???
If you are asking whether or not you should do the JCW airbox flap mod........
I think the consensus would be that with this level of modification the engine does not need any more air below the JCW flap opening of 4500rpm.
As such the only reason to perform the flapectomy would be to hear the SC whine more at <4500rpm. Some do this mod to get as much whine as possible, others view this as just making more noise.
