i have an 04 cooper s with an m7 16% pulley and a k&n intake , jcw exhaust. Do i need bigger injectors ?

 

Not unless you are going for a dyno tune or ECU flash. Take a baseline dyno graph and see if you are running rich or lean or if fuel is running out short in the high rpm, then go with larger injectors.
There are threads of discussion about this, try searching for more info.

 

Klein you shouldn't need injectors for those simple bolt-ons because the ecu will adapt to the mods which is one of the very impressive features of the MINI and the MINI motor is known to be a Positive Power Adder or in short you throw a popular bolt-on mod at it and it will love it and won't hold up a flag saying I NEED A TUNE or in your case INJECTORS. Getting a dyno-tune will be the determining factor of what size of injectors to keep the AFR happy with the new redline that is made during the tune.

 

i don't mean to sound dumb but when you get a dyno tune doesn't that reset your ecu or are they different

 

I posted with Jan and he didn't feel I needed new injectors with my 15% pulley.

As for the tune, a customer tune adjusts the software from generic to car specific.

 

Even with your basic mods, injectors would be a good idea if you track your car, autocross, etc. In those high rpm environments your injectors will be operating at close to maximum flow for extended periods of time and this could to problems. Running lean just once on the track could damage your motor. I too was on the fence about these prior to my RMW tune a couple weeks ago. I had a set of JCW 380cc injectors on hand and Jan said they would be "cheap insurance" so went with them. This, of course, also allowed Jan to raise the redline and take advantage of the additional flow.

 

Thats good to know because i do plan to autocross as soon as i get some more info on it.if any one is in the san diego area please give some info on racing autocross

 

Sorry, I don't live in the San Diego area but here is a place you can start getting info http://sdbmwcca.motorsportreg.com/.

Our local club has good explainations http://www.sasportscar.com/forum/log...al_content.asp

 

MINI thinks you need them with a SC reduction pulley, even with the largest one you can get.

 

Chuckt I love the wheel in your sig what is it.
Not sorry about hijacking....

 

Looks like the OZ Ultraleggeras

 

I have a CAI and a 15% pulley, installed years ago. Since then, the car would take quite a few more clicks to crank from time to time. Recently I put the JCW 380cc injectors in before Jan's tune. To my surprise, the car cranks on the very first click every time now, and both the low end and the high end run smoother. If I knew, I would've put in those injectors together with the pulley upgrade. This is what I observed, probably there's another reason. I'm just guessing it's all related to the injectors.

 

yup

 

try this, seems pretty accurate
http://www.rceng.com/technical.aspx