I just added a 15% pulley, CAI, and beru plugs to my R53 and really just want to know if it is recommended that i tune the ecu, especially since i run autocross a lot? I dont care about tuning for power gain, just worried about damaging the engine if i have a smaller pulley and no tune.
Any input would be greatly appreciated.

 

NO.

BUT.....

I think you will run in a modified class with the pulley. If so, you're going to want the best tune you can get.

 

I think you are fine with a 15%..... if you had a 17%, then the story might be different ( then again, you should not auto-x with a 17% IMO).
If you go the tune route, most tuners prefer bigger injectors...but since you don't care about hp gain, just engine longevity, I think they will be able to work with what you have.

 

I found that after my 15% pulley the car ran great. One month later, I had a RMW tune the car ran much better- stronger throughout rev range, better throttle response and he also made the DSC less touchy. Stock injectors. So would say yes to a tune.

 

how was your mileage affected by the pulley? And after the tune?

 

I think that the mileage always goes down for the first couple of weeks after installing any engine performance parts. And then after the newness wears in you drive sanely again and the mileage goes back or better. But why would you even think about performance if you are worried about gas mileage?


Average mileage thread.......
https://www.northamericanmotoring.co...erage-mpg.html

 

I enjoy driving the Mini but I think it's absurd that a car this small making less than 200 hp gets barely over 20mpg in this day and age.

And frankly, if doing a pulley gets worse gas mileage (let's say in the high teens) with or without a tune, I'll put the $850 or so it'll take to do the pulley install and tune to getting another car - maybe a second generation S which will give comparable performance (or better) with much better gas mileage.

 

My overall mileage increased by about 1 mpg with the 15% pulley. Guess it all depends on how you drive.

 

The mini is not very aero-dynamic...an economy car it isn't...and useing cheap gas only makes things worse, especially on an r53. With 93 octane, 17% reduction, cai....and JCW 380's (untuned), my car gets about 28 mph highway...high teens, very low 20's in town...worse if I get on it. If I drop the octane to 90...I quickly loose mpg's...
I expect an upcomming tune to improve both mpg, and drivability...after the thrill of more hp is gone, and I drive normally again a few weeks after the tune!!
The advantage we get over the turbo cars are less lag, and IMO a better drivers cars that is much more moddable!!

 

Yeah, I always use the local Chevron 93 octane and get about 21mpg combined (90% city, short trips).

If I can maintain the same mpg with a pulley and tune, it'd be worth it. I'd be interested in your experience. Jan/RMW is coming to my area in late April and I have an appt with him.

 

Our mini's run so rich ( look at the black around your tail pipe) that running with a 15% reduction, and cooler plugs is not going to change your mpg by much.
When I put the 17% on my car...I think my mpg stay pretty similar, but it was soo much more fun. IMO a 15% is safe...a nobrainer...heck take a look...many used cars have them, and folks don't realize it! I think our cars should have been delivered with the 15 installed...or the jcw pulley atlest...but the $5000 for the jcw upgrade would have made no sense. I think marketing folks picked the hp to sell these cars at....
But off that tanget...my mpg did not really drop till I put the jcw's in...but the answer is simple..I'm running rich...the ecu can adjust the mixture under light throttle useing the 02 sensor..but during harder acceleration, the computer looks up the fuel level to inject on tables, that are now incorrect till a retune....so city mpg falls off...hense the need for a tune. But the extra hp, wow...the 17 needed more fuel IMO.
But IMO, the 15% is just about perfect....no tune needed...it could get slightly more power/drivability with a tune, but since the stock fuel injectors are maxed out...not much more hp can be found without more gas...but the mpg, once you drive like you did before the pulley, will be pretty close to what you get now...just more fun, and less black soot on you tailpipes!!

 

There has been some debate on tunes lately...some off site, etc.
The fact is a tune can make a car run cleaner...making less polution, and more hp, and mpg in many cases. This should make the greens happy, as we are optimizing our cars...I know my car is running a bit rich, making more polution than needed...a tune on almost any modded car is a godsend from an enviormentalists point of view, as long as they admit you have the right to add/Change parts!! We have a person on this board/or a guest reader, that tries to use state/goverement rules to find ways to cancel tunes...like the one in CA a few months ago.
To the person who does this..do you want poorly running cars driving around spewing large volumes of noxious chemicals into the air, or can we spend $$ to make our cars run clean?!
On top of this, most folks use flash boxes to carry legal offroad tunes for track events where offroad racing fuel is used....that way we can drive to an event race, then drive home. Take away that option, we will get big SUV or pickups to tow our cars to events, causing more harm, burning more gas....just a thought!!
End of rant!!