I'm about to get a rattling belt tensioner pulley replaced and want to take advantage of the labor to do a supercharger pulley at the same time.

I'm a enthusiastic street/canyon driver. I've never been to an autocross although I may hit one up soon for fun.

Is the 17% Pulley a safe bet?

If I go with a 17% pulley, am I REQUIRED to replace the spark plugs and/or fuel injectors? What issues may arise if I do not replace them right away?

 

Change it to what intercooler? The factory one has been tried and tested as one of the best air to air options for our car. The GP unit besting it with the same design, but two extra rows tacked on.

 

The only things absolutely required with a 17% pulley is a belt and the plugs. If anything I would say make sure to let the MINI breathe easier with a 17% by getting an intake/exhaust system.

 

You'll need a tune if you're going to have larger injectors. The 17% pulley, colder plugs, good quality headers like Mynes, full cat-back exhaust or even 1-ball exhaust and free flow filter/ intake are very good starting points.

Larger injectors plus tune will put your mods. together even better.

 

Did you get the Alta originally?

Mine rattles so much. It's embarrassing. Which one are you going with?

 

You can add jcw 380's without a tune, thats what I did and i know others who did it. Anything larger than 380's will need a tune. +1 for a tune.

 

Can you run injectors larger than 380 like 440 or 550 without a tune? Or does RMW/MYNE install the injectors on the spot before the tune?

 

Going to 440s with no tune will make the ECU throw a code cause it will be too rich. It will be fine for WOT, but for all rpm under that it will be too rich. You will need to get a tune to scale back the injector duty cycle. If no tune then it will run very rich and very poorly, it will idle very very rough.

550s will make it even worse without a tune.

 

You won't gain any HP/Tq by just putting the 380 cc injectors even if you have reduced pulley, etc. without the tune. I did that too for 2 weeks before dyno tuning and I did not feel any difference. Even the Mini tech who installed my injectors suggested to install the JCW software to take advantage of the larger injectors but told him that Dimsport tuning by RMW is on the way.
So why waste the money of $325 + $100 install for the injectors if tuning is not an option at this point?

 

All I was saying was is that you can add larger injectors up to 380cc without a tune, thats all...

Edit: Although I didnt gain any hp or tq, I did feel the car smoothed out across the powerband. Also OP if you do get injectors dont spend money to get them installed, its a simple 30 min process.

 

I believe Gray_Raven just added JCW 380s to his r53 w/o a tune:

From MassMotoring:

I don't know what size pulley reduction he's got, however....

I'm sure he can elaborate when he finds this thread.

 

I have 17% Alta and JCW 380's w/o a tune. No issues for over a year now. But for the OP, you don't need them really for the pulley, stack some bread, just get the smaller belt and colder plugs for now it will change the car

 

The JCW injectors will do absolutely nothing for the car but allow it to run rich. If that helped gray raven with his problems, he really needs to get his car checked out.

A pulley, shorter belt, colder plugs, and a tensioner stop will do wonders for your car!

 

Well, you should take a look at his old injectors:

IMG_0951_edited.jpg?t=1252523162



He also "... replaced the Fuel Pressure Regulator, a filter screen and two O-Rings."

 

I had an M7 16% pulley for about 75,000 miles, then replaced it with a 17% Helix pulley for the next 25,000 miles. You'll be fine with the 17%. In the early days, the smaller pulleys up to 19% had us all discussing about how it would impact the longevity of our superchargers and water pumps. The pulley was the best bang for the buck mod. If you wanted to improve it further and impact the sound quality, then an intake and exhaust were next.

Today, I think a pulley and a tune would be high on the list even before an exhaust.

I didn't replace my spark plugs with colder plugs until I started experiencing engine stuttering issues which turned out to be something else.

I have 380cc injectors now as well, but that wasn't until after I also did the RMW header and cam and wanted more flexibility while tuning.

Richard

 

Well then he DID have other problems to fix.......

And the ECU has no way of identifying what size injectors you have, it has to be told what size.

 

+1- Just put my 380's in. Awesome......and no tune yet.

In addition to:

17% Classic Alta Pulley
JCW Intake / Mini Madness filter
JCW Exhaust
M7 DFIC...
NGK IX Iridium ZFR6FIX-11 - gapped to .40

I noticed with the DFIC I had a dead spot or stumble at about 3K probably due to the increased air volume of the IC design...and received a lean code two times in last 6 months.

So I picked up a set of JCW's 380's, (and changed my fuel pressure regulator attached to the fuel rod at same time ) reset my ECU using the odometer method. In essence, the 380s' removed all of that previous stumbling issues and I have very noticilbe increase in power all the way up the band. Engine even sounds different, doesn't work as hard as before and takes less pedal than before.

With regards to colder plugs. I have run the JCW colder NGK's, Bosch Platinum 4, and these NGK Iridiums all torqued down to 22 ft lbs. Of them all the NGK Iridiums (for me) worked the best. Engine runs smoother, better idle, and quicker response.

So you are maybe looking to AutoX but are also looking at some Mods ? Apparently from what I have seen at these events, and read. Out of the box, MINI's with the 1.8L SC engine do very well in the "Street Class"....and are very competive in that class ( somewhat unmodified )

But, when you start adding certain mods to the MCS such as a pulley, suspension components, tunes ect, your MINI classification is bumped up competing with other tuner cars which attain more HP gains from same equipment you are looking at. Probably due to their starting out with larger engines to begin with. So competing time wise you may be better off staying stock at least initially before modding. Just depends on how serious you are about AutoX I guess. Food for thought.

 

Did you reset your ECU after installing them ? If you dont, it takes about 2 tanks of gas or about 600 miles for your ECU to learn the new hardware as they are plug and play....The ECU has the abiltiy to compensate for the added fuel demands automatically mixing in more air, and the FPR maintains pressures in the rail based upon vacuum created depending on the engines load demand. It is not an electrical component hooked to a computer.....the ECU knows all......

 

I did the 17% pulley with a 535 belt and tens stop. and changed to jcw spark plugs and msd coil, kingsborne wires, and 180 degree tstat to help.

 

honestly, the 15/16% pulley is quite safe and works fine - i'd suggest a good quality stainless steel version.. If you do the 17%, you might run out of injectors and/or hit fuel cut which is causing more headache. Colder plugs are recommended but not required (if you're old plugs have been in for a while, then changing them out would be a good bet). Of course, the correct belt size is a MUST.

Stock IC is fine... Just did a R53 cabrio yesterday, stock everything except the addition of a 15% pulley, belt, oil change and tune, netted 26whp & 24wtqe (stock IC still)...

If you add the 380cc injectors, then get those dialed in or you might run into some issues with idling and WOT. Check your AFR on the dyno if possible... Highly recommend a tune.

 

you are correct to a certain extend... the ecu can compensate as long as it has the correct scaling values for the injectors being used... it's best to check your AFR to make sure everything is within limits...

If the ECU can compensate, then why is the JCW software has different 'injector scale factor' than the regulare "S" software... just something to think about

 

i think you meant the 1.6L?

 

The ECU will compensate for the larger injectors simply by adapting new duty cycles for them to achieve the expected AFR. It will not run any different, solve any problems, make your car run better because the car is still getting the same amount of fuel as before. All you have done is shortened the time the injector is working.

 

So you guys are saying the larger fuel injectors are not required for a 17% pulley?

I thought I read somewhere that major issues can arise; This is not true?

 

Nope, not needed.