I have been able to do minimal mods to my MCS since I got it (intake, wheels/tires, aero kit, some custom paint) but, because of a lot of other costs, I have not been able to make any real power gains. I have seen how cost effective a pulley can be and I have this question: Can I get a pulley installed (probably just a 15%) and drive around for 6 or 7 months without getting an exhaust or ECU retune? I would prefer to have my ECU retuned after I have gotten the pulley and a full exhaust, but the prices for these components are still absurd ("Only" $695 for the Milltek cat-back! Ha!). Help a poor, post-college kid out: can I do it?

 

Absolutely. You can drive indefinitely on a pulley without ECU tuning. Here's why:


The ECU doesn't use a mass air flow sensor, it uses a manifold air pressure sensor to determine A/F ratio. Therefore, you are just about identical with or without the pulley as far as safety goes.

Hope that helps!

Randy

 

Although I agree that a pulley by itself works fine, I don't understand your reasoning. Whether your engine management uses a MAF or a MAP, the airflow is still being measured. With a MAF, increase airflow and the MAF sensor will feed that data to the ECU to provide the correct fuel. With a MAP, increase airflow and the MAP sensor will feed that data to the ECU to provide the correct fuel. The only difference is that the ECU also need uses data from the IAT and RPM sensors to calculate airflow when a MAP sensor is involved.

 

You two are always going at it.

Thanks!

 

You could do the one-ball exhaust mod cheaply, and that gives power and weight reduction.

 

CTMINI -

That is the exact combination I have had for the last 17K miles. 15% pulley, Alta CAI, no ECU, stock exhaust. Randy Webb installed my pulley 14 months ago and I have had absolutely no problems with it. I thought the exhausts were too expensive for their minimal gains, but now that the GIAC chip is out I am going to try that. Also looking at a larger throttle body from m7. Maybe I'll do the one ball exhaust mod too.

"Friends don't let friends drive stock"

 

CTMINI,
Your plan is fine. The 15% pulley is a great upgrade and doesn't require a shorter belt or anything else right away. When you are ready, a Cat-back exhaust upgrade should be a nice addition (check out the scorpion or those from Rspeed.net or pick up a new JCW or used exhaust on the NAM marketplace)

ECU is a good thing to upgrade last. You'll know the extent of your mods so that is info that can be given to the ECU upgrade company to get the most appropriate software map(s).

 

what do you think about a used exhaust?

so far, the best one i've seen i think is an NRP exhaust (used by mini-mania) for like...$300.

what are your thoughts on a used one assuming it is not screwed up?

 

nrp is not great.. but i know someone will say quite a few good things about it

as far as cost vs. good exhaust.. scorpion (what i have) is probably still the best.. for 550 bucks US you get a REAL good quality exhaust... others like miltek and uuc maybe more expensive, but i doubt they have some magic stuff inside that allow it to be much more powerful than my scorpion

sides, you don't go exhaust for performance.. for sound and flow rate is what you are after in the exhaust... i believe magnaflow is also relatively inexpensive if you want a real loud one

 

As Randy and Andy said, you definitely don't need an ECU or exhaust (or anything else for that matter) with a pulley. Ever. You could just add a pulley and never add an ECU and exhaust. So go for it. You'll wonder why you waited...Epecially since it costs a fraction of the aero kit and wheels/tires!

 

I actually feel better low end torque with the stock exhaust than with the Milltek header/catback combination. 17% pulley used. Go for it.

DDTUNG

 

I have enjoyed the Helix 19% pulley for the last 8 months. Stock ECU, stock air cleaner & intake, stock exhaust. Everything worked fine.

I just tried the HAI (hot air intake), another inexpensive alternative, which improved sound and throttle response even more. The one-ball is next on my list, and I will try the zip-tie mod to the throttle body.

All nice performers, and low buck

 

that is exactly what I now have:15%,CAI,Irridium plugs ,but otherwise bone stock(exept for the M7 device). Mucho satisfied with the results.I will replace the exaust with a scorpion when the stock one dies,and I don't think I'll ever start messing with the ecu, really don't feel the necessity.The only other thing I have on the near horizon is a short shift kit.

 

My pulley was my first mod, before the CAI, the Unichip, the plugs and cat-back. I drove with only the pulley mod for some eight months. More power than stock, and ZERO problems. So go ahead and get your 15% installed.

 

Here's the gains I saw (before and after, completely stock except for the addition of the 15% pulley):

 

OK, I'm sold... so who's pulley does everyone recommend?? (price, fit, etc...)

 

Helix13 hub and pulley allows you to switch to 17% or 19% later on quite easily. Alta does not supply 17%.

DDTUNG

 

Wow, this response has been awesome. Thank you all.
Now, I missed out on the opportunity to have this done by Randy a while ago in New England. (I'm in, you guessed it, CT.) Does anybody know anyone that will do a quality install in SW Connecticut?
Also, what are the "one-ball" exhaust and zip tie throttle body mods?

 

Unless there has been a change of heart with Randy, I don't think he does 19% pulleys. You could make the run down to Helix 13 in Philadelphia, and get a 15-17-or 19% pulley, and probably the one-ball (removal of one side of the muffler/resonator, originated, I believe, by Helix). The zip-tie mod is from the yo-yo chronicles, thanks to Ryephile, which calls for using a zip-tie to hold the butterfly valve closed on the throttle body to improve responsiveness & hesitation experienced by too many MCS owners. You should do a search to get all the info and how-to.

 

I just installed the Alta 15% at Steves Auto Body here in LA, and it is awesome! Steve and his crew are top notch and have done many installs, and I am very happy with the end result. I also got the M7 device put on my car at the same time, and the car does feel better when letting off the throttle. All in all a great day.

 

The MTH software is around $70 if you have a cable. This is a whole lot cheaper than the pulley alone. In my MCS, the performance improvement was about the same as the pulley.

I'm not sure which pulley I have. It was a group buy and cost around $90. We had a group install so there wasn't any other cost, other than the pulley removal tool rental.

If you can get your hands on the cable. Do the MTH software. It's cheaper and is a great performance improvement.

 

Was this measured somehow?

 

Didn't you know andy, every human has a dyno built right in

 

A 15% pulley is the only performance mod to my MCS. I made dyno runs before and after and it showed I picked up 10 hp in the process. My car had a higher than normal horsepower base line. My stock ECU[virgin] has almost the same A/F curve as a modified one. If you're going to make any mod - the pulley is the way to go.

The Alta pulley was installed by Randy at one of his pulley parties over a year ago. I've experienced ZERO problems with the engine

 

I don't own a Mini Cooper S yet and I could be wrong, but from what I have read the 19% reduction pulley works best with the stock ECU. Gives more power than 15%. Stock motor is rock solid. Just throw on a (Borla?) exhaust some day.

I'm looking forward to ordering a 2005 Mini Cooper S with aero kit and adding a 19% reduction pulley, exhaust, rear sway bar, then suspension and wheels at some point.