Ok, I have the 19% pulley, GIAC remap, Bosch 380cc injectors, alta air intake, WEBB exhaust, DT BPV, JCW engine from the factory. I was thinking of adding either the 0% standard lightweight crank pulley or the 2% overdriven crank pulley. Does anyone think I may be getting into a danger area doing this modification,and if so what will happen to my car if I do this modification. Thanks

 

1 vote 0% lightweight crank pulley.

I have a similar setup and am keeping my stock crank pulley.
No reason to cause any trouble at this point for me.

 

do you have the stock crank pulley or the lightweight stock crank pulley on your car like alta sells? If you have the lightweight crank pulley, did you notice a difference in performance in your car? Thanks

 

I have the original stock crank pulley. I never changed it. I have 19% reduction SC pulley GIAC, injectors etc.

I have a friend with similar setup and lightweight crank pulley installed. Makes a little difference, not that much for street or autocross use. Might be OK for track use.

If you had 15% SC pulley then 2% crank pulley might be a option. With 19% SC pulley I'd suggest 0% crank pulley- just reduce the weight if anything.

 

The major difference from my reading and experience is the lightened crank will allow the engine to rev faster. Also you will see a tad more boost. If your not getting a overboost codes now then you probably will. With 18psi being the magical overboost amount people have found.

 

hardly seems worht chancing tossing a rod through the engine because of no engine dampner just for a smidge faster revving engine...

dont know just my .02

 

You will enjoy the crank pulley. My only concern with your set-up is that you don't have anything to help cool the air. You may want to consider a more efficient inter-cooler especially if you would like to add a %2 overdrive. In the past I refused to believe that the super heated air from the super charger (SC) having a smaller pulley had any effect. After many hours and days on the dyno, dynoing different minis I'm coming to realize it does. Another thing to think about too is that there's the potental to redline the SC and possibly catastrophic failure. Let us know what you decide

 

OK, but somthing again to think about, why does the MC not have a dampner from the factory

 

cause the mc doesnt put half the strain on the engine as the mcs does. why do you think they put them on our in the first place? think about that one.

 

Has anyone actually tossed a rod that was blameable on having a lighter crank pulley?

And to my knowledge back when the crank pulley swap outs were "new" to our cars, someone with a good reputation apparently spoke directly with the engineers who designed the Tri-tec engine, and said they never designed it with a heavy engine damper. It was said that BMW added it themselves, either as a precaution, or more likely if you ask me, as a money thing taking from the parts bin for the 3 series.

Last from me on this topic... I have to agree with Johan, if you're going to run a 19%, it's a good idea to stick with a 0% and keep your revs down a bit.

 

If you have a 02-04 car you may want to consider putting on the newer 05-06 OEM pulley. The pulley is about 2lbs lighter.

 

all of that seems like hearsay similar to actual engine failure that can be attributed to running w/out a harmonic dampner.

That being said... the tuner's that i trust most in this industry do not like them or suggest them and thus, i do not want one on my car. Likewise most if not all of the old school euro and domestic tuners will not run their cars without a harmonic dampner... the tritec maybe an exception to the rule... but im not willing to chance the 10k engine bill to find out.

gl with your mods

 

When you are talking about engine dampners, are you talking about a dampner like texas speedwerks sells, or something totally different? I do have an 04 mini cooper S, so would you say run an 05-06 stock crank pulley or an Alta standard lightweight crank pulley which is I think more than 2lbs lighter than factory? Thanks for all the information on this thread.

 

You are so right.

He should leave the stock one on and be happy. Don't just bolt on parts based on ifs or mights.

Longboard

 

+1

If you have a 2002-2004, try to get a stock 2005-2006 crank pulley...a couple pounds lighter.

 

I wasn't suggesting or pushing you get one... the crank pulley is definitely a "make your own decision" type of modification. All that said, I've really enjoyed mine, and have had it on for about a year and a half now with a full season of autocross somewhere in there.

Again... who has throw a rod? I'm seriously curious if someone out there had had a real deal engine failure attributed to a modified crank pulley. (Please don't take my "tone" as being smart here... I'd love to hear from someone if this is a real issue, and not a hypothetical one.)

 

Ask MarioKart or Tuls...maybe one of them could lend some insight.

 

Hmm. Good question. Could it be due to the multiple engine failures BMW saw with the 3 series chassis 6 cyl engine in the late 80's? I think so. Not that a 4 cyl inline and a 6 cyl inline long block have anything in common.

Seriously can we limit our comments to the OP's question and avoid an issue that continues to get thrashed out about every 3-4 weeks here. Suffice to say, run a LW crank pulley if you want. If you are worried about your engine, don't.

 

this is from Roland on the GTT webby and i think it is sound advice were this is concerned the last bit says it all for me

 

F15EWeapon
If you do a search on the M7 M62 project and read thru several posts you will find a section there about the lightweight crank pulley. They are blaming the engine failure there from additional vibration from the lightweight crank pulley. Given that this car had a 8000 rpm redline which is much more than most of us see. Also it would be difficult to pinpoint what really caused this failure IMO. But deep down in my gut tells me that a mod such as this is not going to show failures until a lot of miles have been put on or cars which are really pushed hard such as the example. Personally I plan on keeping my car a long while and don't think the risk is worth the reward.
Steve

 

Steve, thanks for the info... I'll be sure to read up on it shortly.

 

most tuners wont vocally speak up on this subject as many of the "big name" mini aftermarket companies produce a pully such as the one in question. That being said simply questioning the validity of this part is almost like questioning the tuning ability of the parent companies in addition the tuning knowledge of aftermarket companies and small mini shops.

I am in no way trying to do that... but simply trying to imply that yes this part can make more power... but it has to be based on your comfort level. If you aren't prepared to deal with the hassle that could potentially come 10, 20,30, 40, even 100k down the line... maybe this mod isn't for you.

 

...and so it continues....

 

It does as I am simply trying to answer this question from the op...

*drk