Hello I am new to the forums, I just bought my mini a month ago (04 s). I have been reading a lot about the 15 and 17% pulleys. I was hoping someone could give me the power gains for the two and what they will do to mileage (highway, i commute long distance) also how safe each is? Thanks for any help

 

People have claimed both higher and lower MPG. For at least the first week you will be hard pressed to keep your foot out of it, which will result in lower MPG! As for safety, I think both have been pretty much proven to not cause any direct damage over the long term, but a rule of thumb is that 15% is the safest, 17% slightly more dangerous, 19% even more, etc...

 

Do a search....nothing is clear cut.
More is dependant upon driving style...
Are you a rev happy? Get a 15%
cruiser type? Get the 17%...you can still redline sometimes, but don't ride it...
More boost down low...but car will run a bit leaner at highee rpms(injectors and a tune can be done if you want to be ultra safe)
other items also go into choice...local fuel octane..higer helps...so 92/93 is great for the 17...
More boost+more heat of any pulley=more octane to prevent timing retardation=power loss...
Cilimate....generally cooler is better..a pulley makes more heat due to loss of effency at higher psi output.....big intercool (like the gp) can help on warmer days....or prolonged high rpms ar speed...again not needed , but to be safe and keep streetability/driveability on hot days...a good $$ alowing, but just an option...same for tune.
the questions you ask are kinda sujective...you end up with more hp...
So if you use it...less mpg...remember, same pedal travel = more hp used....
Driven gently on the highway, i get better mpg....around town, i get less,but due to using more zoom-zoom.

 

For MPG there are a lot of factors outside a pulley.. you need the car to move through the air with less resistance
- Intake - CAI
- Headers + exhaust - performance
- Tires - High performance which have less rolling resistance
- Keep your car clean - inside and out - no extra junk!
- Turn off your car when not using it - this is the easiest one.. cold starts are the only harmful part of starting your car.. so cold start and start driving right away.. cold idle to warm up your car is BAD.. buy some gloves (or stop being a wuss) and start driving nicely till the engine warms up. When waiting for a train to pass etc.. kill the engine.. and then pay attention when to turn it on.

every drop counts.. i love gasoline, lets not waste it.. i'll be MAD AT YOU when we run out

phil.

 

^Not to hijack the thread, but why do you say cold idling is bad? I feel like my car HATES when I drive it cold, so I always let it warm up.

 

physics.. a cold engine is the most damaging to itself and idling doesnt generate much heat.. so it's best to start driving with some load to get the engine warm asap.

phil.

 

interesting..ive always operated under the thought that you SHOULDNT load a motor until the oil temp rises a bit to ensure full lubrication...i also undertsood that the "COLD START" was the worst wear on a motor, due to the oil having settled back in the pan and had to be pumped up to get lube back into the upper protions of the motor

back to the OP question....I have a03S and have done a 15 pulley, cai and exhaust and just did the bypass valve vaccum reroute ( vgs, i think)...am extremely happy w the gains and drivability...havent really driven enough to see any change, good or bad, to mileage

my foot seems to not care about that part


oh, and i LOVE the OP handle...the FIRST time i had mine out, i got the "cute car" comment, and that was my response.....my electric blue/white mini had now transformed into a electric blue /black top w black stripe to "man it up" a bit

 

I have to disagree with this statement.. any engine which has aluminum components should reach operating temp range before driving. (in optimum conditions.) Aluminum expands with heat, and is made to seal at operating temperature. I realize it's not a direct comparison, but Harley Davidson Evolution engines WILL develop cylinder base gasket oil leaks if the engine is not allowed to reach operating temperature range before riding. I have seen base gaskets fail at very low mileage when the owner rides the bike immediatley upon starting; and on the flip side seen them last to high mileage with no leaks/wetting whatsoever when the owner allows the engine to warm up. This is recommended procedure from the factory and I think this logic would apply across the board.If you live in a climate that temps fall to near freezing or below; I would definitley advise letting the engine warm up before driving. Cold, thick oil can only be taxing your pumps ability to push it through the oiling system which equals premature wear on parts that are designed to have constant lubrication. Just my opinion.

 

^^ Rod, I recently purchased an '02 S with 45K on it and thats what I was wanting to do.. It's stock, and I'm thinking cai, pulley and exhaust... I was thinking K&N system or Injen cai, and OBX or Alta 15% pulley... good choices? First thing is rims, coming soon, then on to these mods next. Did you notice a decent return "bang for buck"? I have also seen supercharger pulleys... should I just do crankshaft and leave it at that or...? I'm looking for a boost in response and keeping my current (or gaining) mpg. Thoughts?

 

For the record, in the mini manual it says not to let the engine idle upon startup, but to start driving immediately.

Then again, the new M5 has a floating red line that only reaches 8k until you've warmed it up.

So if you synthesize the two bits of BMW advice, you won't let it warm up by idling but by very gentle driving.

Which I think makes common sense. Then again, in the winter I always, always will idle it for a minute or two upon starting...

 

I remember the Germans doing a huge study on this and found that it was not only bad for the car to let it idle warmup but also environmentally bad. They found no proof that it did anything adverse to the car. Hence, the government made it against the law to let your care idle to warm up.

I don't let it warm up as it is simply a waste.

 

With the 15,16,17% all avail the difference is the smaller the pulley the more low end boost you will have, and therefore more low end torque. But it will drop off in the higher RPM the smaller the pulley.

As for mileage, it will all be baised on how YOU drive.

 

bomber

im fairly new to the mini , but what I can tell you is this...

as far as motor mods go, ive done the cai, 15 pulley, exhaust and the vgs

exhaust was first...there MAY have been a change in performance, but i really wanted a bit more growl...not a scream or ricey sound...i went with the IE exhaust and that fit my bill, as well as a bit easier on my wallet...taking nothing away from the other choices, just where i ended up

did the pulley and cai at the same time....I went with the alta cai without the hose, again, due to price and the pulley because they offered a free puller ...that was where I FELT a real difference...cant say how much, but it WAS real and def raised the fun factor

just did the vgs mod, which is almost a free bee and easily reversible..that seemed to tie all the loose ends up as far as drivabilty goes, as I did seem to have the "yo yo"...

at this point im very happy w where my car is. also very happy w the $$ involved to get there...you can look up the prices easily, but i feel i got GREAT bang for those bucks

down the road I would like an experienced tuner to clean up the final loose ends and get the most from where im at...

in all, my car is supposed to be fun, and it is. Not gonna race it, etc...

im sure there are more experienced guys here that can/will give other products the thumbs up, and you should take it all in.. i read alot here and made choices based on that as well as personal preferences and , for whatever its worth, my experiences with other cars and what worked and what didnt for money/time invested . I have had a tendency to end up going overboard and chasing my money and time looking for the ninth degree of performance ..the mini is a great car stock, and the basic mods really made it better ..

I only hope i dont get called out later if i end up down that path again lol

in a nutshell, the MOST bang for the buck is the pulley...a REAL seat of the pants change for a couple hrs work and a low cost.

 

The above posts are correct, 15% vs 17%, if you spend alot of time in the higher rpm's (track conditions) 15%, for around town and the ocasional bursts of power 17%.
As far as mpg, the difference will not be that much and def. more noticeable with city/stop-n-go, you prob. won't notice hardly any diference on the hwy.

 

ordered a 17%, borla race, and ddm intake

 

You will enjoy it. You might want to go with colder plugs as well.