Power pulleys - what’s the verdict?

[M5fanaticc]

Hey everyone. I was thinking about doing a power pulley on my E90 M3 that’s currently bone stock in terms of any tune/upgrades. I was thinking about doing either a Dinan power pulley or a Mahcht Schnell pulley kit. What do you guys think? Have they given any actual notable power gains or any issues?

[Asianoak]

Most people will tell you they're a waste of money - no power. But me personally, after installing a macht schnell pulley and an afe intake think it's totally worth it. The improved throttle response is noticable and makes the car much more enjoyable and lively around town.

There's only so much you can do to make power without going FI so for me focusing on anything that would improve throttle response in order to make up for the lack of torque makes sense.

[wyatth]

It’s mild, but there’s also not much we can do to these cars without compromise. Worth it if you’re interested in squeezing out all you can, but some might think $350 for a couple HP and marginal increase in response is a waste.
Dinan is a tight fit and can be tough to wrestle on as a DIY, otherwise all of them are more or less the same.

[Redd]

Installed MS pulleys not long ago. It was literally the last mod I did after everything else. I only really felt any improvement when starting to move from a standstill. The car felt 'lighter' and accelerated better. Once it was moving I didn't really feel much difference.

[CamasM3e93]

I went with Turner and did the mod with one or two other things at the same time, including cold air intake. I thought it was a reasonable improvement upon install but the feeling of that marginal change disappears quickly. Then when I was prepping to supercharge the pulley had to come off - and going back to the original pulley was the only change I did that weekend - which was a big nothing. I've still got the thing posted for sale but I'm honest with anyone that inquires - these provide marginal gains (about the same as switching your AC off) and the cost/effort is probably not worth the time.

[kevin @ eas]

The Macht Schnell pulleys gains on the dyno. It underdrives the crank pulley and the power steering pulley. We see about 8-10whp on the dyno. The biggest different I noticed is a quicker revving engine.

[Redd]

Fwiw, the MS pulleys don't affect power steering or aircon in any way. It gets bloody hot here and I didn't notice any difference in a/c coldness or steering effort.

[bigjae1976]

Good for cars that see a lot of time at high RPMs.

I've had a Dinan pulley for years. Did not notice any difference when I put it on. When I have to change the belt, I'm putting the OE pulley back on.

[Richbot]

To me it seems like underdriving the PS pump a bit might help with cavitation at high rpm on the track, has anybody looked at that?