Is anyone using the M7 16% supercharger pulley without the 2% Crank pulley?
How are your accessories holding up?

 

I have just the M7 pulley, and love it! What exactly do you mean by "How are your accessories holding up?"

-Cody

 

Get the "alta-nator" - you'll be glad you did.

Paul

 

I imagine the reference is related to over-reving the water pump from the s/c reduction pulley. If you are running at 6,000+ rpms all the time, it could be an issue.... But for street use, I have a 17% s/c reduction pulley, with no hot-running. In fact, one could argue that the 17% s/c reduction pulley spins the water pump a little faster, which adds to the cooling ability....

I don't know which I like more - the power addition from the 17% s/c reduction pulley or the sound from the Gates belt....

 

The SC pulley has no effect on any other components. Only the crank pulley + or - can effect the other components, water pump, alternator & including the SC.

"I don't know which I like more - the power addition from the 17% s/c reduction pulley or the sound from the Gates belt...." Same here, gotta love it!

 

"Furthermore, M7 decided to use a 16% reduction for their pulley. It is more than the standard 15% reduction which provides you with better engine response. Once you incorporate a 2% crank pulley, your change of accessory RMPs will be a little more within safe margins. "

This is a quote from the M7 pulley ad. They seem to indicate a change in accessory RPM with pulley swap. As stevecars60 points out the reduction in supercharger pulley diameter should not effect any other components.
Interesting. 16 it is then.

 

About 6 months ago I noticed the same thing on their website, so I called up m7 directly. I can't remember their explanation, but they assured me that there is nothing to worry about. It would be great if someone called them up (again) to clarify the comment or, even better, if m7 could post a response themselves.

 

The crank pully is the boss, no clue as to what M7 could mean, unless they are talking about including the 2% pulley upgrade.... gotta be

You will like the M7 unit. It's a tweener, little more than a 15, little less than a 17. I have 1 & would not have it any other way......

 

Thanks for the replies. I will contact M7 tomorrow, maybe they can reword their item description to clarify a bit.

 

Why so? Could you explain a little more please?

 

With any of the + crank pulleys, the SC, the water pump & the alternator spin faster. The alter-nator pulley will prevent the over sipn, as it is larger to compensate.

 

I just purchased the ATI 2% crank pulley and an M7 16% SC pulley. Haven't installed them yet but I'd like to know if anyone has had issues. Or if there are recommendations on re-mapping the ECU or injectors if necessary? Thanks!

 

We never recommend over 17% reduction as those boost levels are not good for tuning or heat build up as you are just spinning the blower too fast.

You would be better going with a standard size ATI crank pulley

 

Thank you WMW! (I actually purchased the ATI pulley from you a couple weeks ago) I'll work on sending it back and swapping for the standard size.

Do you think then it's safe to just go with the 16% SC pulley? Should I worry about getting different injectors and a tune or will it be fine for daily driving with the stock setup? I really appreciate your guidance!


2006 Mini Cooper S R53 (77,k miles)
DDM Works CAI
Milltek Catback Exhaust