Can I run these safely without a tune? I have installed a 15% and a full alta intake. I'm wondering if it's safe to run these at least until I get a tune? Possible to run to rich with these installed? Will I need to mess with my AfR after I install these? Any ways to counter that?

 

You CAN, but should not run this big of an injector without a tune.
You will be very rich and in a worse case washing the oil off the cylinder walls and putting gas in the oil.
Maybe it would be OK for a day or so until you got a tune but otherwise, NO.

 

You may get lucky if they are truly 400's, the ECU will normally adapt "well enough" if you change from 330's to the 380's but even then it's advisable to have the fuel map adjusted at some time, so the extra 20cc's might be do-able, but you'll know by how it runs and if you start throwing "rich" codes.
(A factory JCW flash may even work if you could find someone to flash that in for you.)
You may just have to take them back out 'till you can get the car tuned, it "should" be really obvious before it would do any damage. (Should, being the appropriate word)

 

Short term....a few days should be fine (380 to 400 is not too much more).
You might throw fuel trim codes...run richer than optium for power production, and longer term will water down you oil, wash oil off the cylindar walls....maybe cause the cats to fail in the longer term...
400 is a bit of an odd size....420 and 450, 500 or 550 are common sizes
I am hopeing you did not buy them from big-o injerctors online, they are redrilled junk, not the oem spray pattern and may need to be removed later. With injectors you get exactly what you pay for....there is no free lunch.

 

PS
the 380's, no tune run richer than optium with a 15...most say you actualy loose power...with the 380's and a 17% i think i was pretty close, and did fine(till a tune)..400's with a 15% will be pretty damm rich depending on you mods WOT, using the stored maps, no o2 input.

 

No to be honest they are the injectors for sale on the market right now. He is marketing them as 400cc. I appreciate the input guys. Any chance you guys would know where to get a JCW tune? Wouldn't I still be running rich since the head is different as well? As well as the pulley size? Where do you guys recommend I look for injectors at? What's a safe capacity to purchase if I'm looking to throw in a cam and a couple other bolt ons in the future? Possible to de-tune 450 or 500's? Also what sort of gains would I be looking at with a cam swap along with 450s, header, exhaust and a tune? Of course that's relative but any of you guys have experience at this step in your journey of modding? Just a ballpark figure.

 

A Mini dealer should be able to flash you with the JCW 210 tune. I personally would stay away from those Ebay injectors, get some JCW 380 or check with a vendor like RMW for larger.

 

They were for sale on the market here. I assume you something I don't so I'll stay away from that purchase. Priced to good to be true. 125 bucks for 400cc?? Seems a bit off anyways. Any chance you would know how much that would run?

 

Call the MINI service center, talk to someone who knows what they are talking about, many of the folks there will have no idea what you are talking about when you say you want to reflash your ECU I am sad to say LOL. I say that just from experience calling my local MINI dealer.

 

Just called them and you were right on point.