I have an 05 MCS. I am considering a 15% pulley along with JWC CAI and Milltek exhaust. I am not interested in anything radical. I would like to skip a software upgrade. My local tuner, Out Motoring, only sells Unichip and it is far too expensive for simple modifications. Will the Mini software keep up with the 15% pulley upgrade? Is there any danger of running lean? Are there long-term reliability concerns with going the route? I have already checked with my dealer and they will not do a JCW software upgrade like some of the other dealers. Thanks for your wisdom.

 

Many people run the 15% without ECU and I haven't seen any problem, but that's only anecdotal/statistical evidence. Perhaps somebody will chime in with some theoretical/scientific evidence since that's all way above my head. If you are willing to forgo driving the car for a day or two, try Lucky Dog Garage. They seem to be doing some impressive things with the ECU and it will only cost $350 + shipping.

 

The NAM community has many members running the mods you present w/ std ecu. You should not be concerned what so ever.

If you wanted to upgrade your ECU - you could a) see if dealer will flash the JCW tune - various people have done it and seemed pleased however there is little history. b) find a GIAC dealer near you - 325 bucks / 30 day return policy. See a thread I did "GIAC ecu upgrade".

 

I've had an Alta 15% pulley along with cooler Denso IK22 spark plugs, on my '05-S for one year now with NO problems at all and my wife and I drive it a lot. We are installing a JCW CAI on Wednesday. My friend Crashton is modded the same way except he just added a JCW exhaust and he has had no problems except the need to drive the car more. It's is a rock solid mod and the car should have come from the factory with a 15% smaller supercharger pulley. Do it, you will not regret it.

 

Hey there,

I ran with the 15% and std ecu for a while with no problems. On hot days or during hard driving the engine would ping a little - but not bad -- I added some octane booster to the tanks I knew I would be driving hard on.

I have heard that if you switch to the colder ( IK22 ? ) spark plug , that will cure most of the pinging ( pre-detonation ) problems.

Good luck and have fun!!

 

If you are interested in the Unichip, I have one for sale in the marketplace that was mapped for Intake/15%/Exhaust by Outmotoring. Send me a PM if interested.

As most have already stated, you shouldn't have a problem running without a software upgrade. It does tie everything together nicely and makes for a smoother ride in my opinion, but is not a necessity.

 

I ran just such a setup with the one-step colder plugs (22's as one other poster said above) but with K&N "typhoon" CAI for over a year. I have just recently gotten a tune (Fireballed!) and header (OBX) and JCW injectors (380cc).

Have never experienced any problems. The 15% made a very noticeable difference in performance. I added the Milltek CAT-back later. It's all been good.

Only thing that might have occurred on rare occasions was some timing pulled, when knock's detected, but not terrible. I added an M7 Extreme scoop and Alta IC diverter and it really helped reduce timing retardation. And I am in CA, running on 91 octane all the time.

 

If you check out this thread: https://www.northamericanmotoring.co...ad.php?t=93689 , you willl notice that the hp & ft/lbs was achieved with a stock ECU. Even at the higher hp & ft/lbs level, the a/f ratios were in the 11 to 12:1 territory. It seems that there is a persistent urban legend that recurs every so often that if you add a s/c reduction pulley, you need to worry about leaner operating conditions. The only time that you need to worry about leaner operating conditions is when you fiddle with the ECU and fuel maps.

 

I ran a 17% for a while on my 02 S with no software. The car runs as rich a fuel mixture as it would with a stock pulley.

You shouldn't have any problems

 

I have an 06 MCS just hit 7,000 miles yesturday. The only thing that I have in there is an intake. I was considering a pulley because for the price I think you can get the most power out of, but I'm concenered about my baby's health of his engine. I also wanted to ask whats the difference between a %15, %17 , or %19 pulley. Thanks!

 

I run a 15% Alta pulley with a JCW intake & exhaust. Stock plugs & no reflash of the computer. Runs like a dream. In 10,000 miles of driving I've had zero issues.

Now onto the pulley question. 15% is the safest route to go IMO. 17% & 19% require a smaller belt while the 15% will use the stock one. The % is how much faster the supercharger will spin. The faster you spin the supercharger the shorter its life. No free lunch. I'm sure someone much wiser that I will chime in here & give you the skinny.

 

i've got a set up like yours . 15% , full alta exhaust , intake , etc. i can say if you want a huge torque jump for little more than 400.00 find a GIAC dealer .

 

I think I would go with the %15 just to be safe. Now the problem off installing it!!!

 

With a 19% pulley you may see some blower cavitation at higher RPM's, but unless you run around at 6500 RPM's all day you're not really going to do much.

I run a 15% and have no issues at all. The general concensus is that much faster than 15% and the heat you create is outweiging the additional HP you make.

17% and 19% Pulley's have shown to make a bit more power down low, and about the same, or slightly less up top.

 

Installed a 15% Alta pulley almost three years ago at 10,000 miles. I have 48,000 miles now. I've added in that time an Alta intake, performance exhaust, IK22 plugs and have been running a stock ECU. Not even updated since mid 2004. No issues what so ever and runs great. Just dyno'd last weekend and numbers were decent I guess. 180.6 hp 157.6 tq. I'm be seeing LDG at the Dragon so we'll see how an ECU remap, etc effects things. I don't know the old saying "If it ain't broken don't fix it" may apply here! Since the car runs great. But we'll see.

 

HP and torque seems low. With similar mods I pulled 192 whp and 180 torque. What exhaust are you running? Do you have a header installed? I noticed you recently dynoed your car, do you have the AF readings off the Dyno?

 

Above 190whp with just pulley, intake, and exhaust sounds a little high.

 

Not if you're on the right dyno

 

Sorry, I couldn't pass this up! 2% each

 

Actually most of the MINI's that had the mods I had were around this number. Some were 185, some 187 some 175. We only had one car get 192 and that was higher than the GP cars! Maybe it was the dyno. As for a header I do not have one. The exhaust is a Borla race muffler behind the cat with a magnaflow resonator. Basically custom. 2.5 SS. No AF readings I think.

We were all saying the 192 car was running high and the dyno must have been off.

 

My 15% Pulley has been on my '05 MCS for something over 54,000 miles.

Until recently the only other mod was a drop-in fliter.

It has consitently dyno'd in the upper 180's on California grade '91 octane and has been thrashed from day one, yet is is still kicking butt and taking names

Never heard it ping, never felt any timing pull, never had any heat issues.

The 54K miles have been hard ones too - many track days, many road trips and a lot of grid-locked SoCal driving.

Fitting it was a nightmare, but I am glad I went through with it !

 

It was a Dyno Dynamics, which is known to show lower than most of the dyno's out there. The only other modification I had was MTH software, but based on the dynoplot, we think it did more harm than help. My AF was wacked to all hell, and the plot was very rough. I've since swapped to the JCW and despite the lower rev limiter the car pulls MUCH stronger than before.

Custom tune soon anyway, so we'll see

 

I've seen a car with a Pulley, header, intake, one-ball, and software pull 206 on a dyno dynamics. It all depends on the engine, these arn't race motors, they vary widely. For example, we may have possibly discovered that my cam timing was off from the FACTORY. There's still quite a few people on the forums that think it's IMPOSSIBLE to make more than 200 whp on the factory blower .

156 ft lbs of torque seems low for a motor with a pulley and intake/exhaust though. From what i've seen on other pullied cars it should be closer to 162-168. The lack of a header may explain that, but to me it still seems low.

FYI, for the money, you can't beat the OBX header. 200 bucks, and another 100-150 to cut the stock cat off and weld it onto your new header

 

Well, I just got my 15%+one-ball+intake dyno'd on Saturday and pulled 188whp / 171tq so now I'm a believer in inflated numbers too I guess.

(mustang dyno, reads the true load, and Helix ought to know how to accurately dyno a MINI by now.)