[Shiv]

I think that is good old fashioned i-club paranoia. In fact, it was Vishnu himself that created a lot of that paranoia (before he released his own crank pulley of course).

... after two years of watching, waiting, testing and investigating. I don't see what's wrong with that.

As for gains, we've documented 10-11 wheel hp gains (on a dynojet) with the pulley alone. With no discernible loss in lighting or AC effectiveness. After testing various diameters and weights, I think the final product is about as good as it can be as far as performance goes. And the gains are indeed perceptable to even the most casual drivers.

Cheers,
shiv
vishnuperformance.com

 

[Shiv]

I agree Vishnu. I'm sure the pulley works great! I've always had great luck with underdrive pulleys on Toyotas and Hondas. My beef is with all the paranoia on i-club about it being bad and my question to you is why were you advising against it before you had finished your research.

First of all, not all of the paranoida surrounding underdrive pulleys is unfounded. In certain applications, they can indeed be troublesome. And I have seen this be the case in Miatas and BMWs. This being the case, it would be irresponsible of me to offer (or recommend) them until I conducted sufficient testing, both on the street and on the track (with the USTCC race car). Once satisifed, the next part of the testing was to figure out optimal diameter for the pulley.

And contrary to popular belief, the whole "lightweight" aspect to underdrive pulleys is utter nonsense. Nearly all the gains provided by an UD pulley is through underdriving effects-- not from a reduction in rotational weight. This is easily quantifiable on an intertial dyno. It also makes sense when you look at the raw numbers and consider real physics. So the challenge is to find out the speeds at which individual accessories like to run at (minimal parasitic losses) while still doing their work. Too slow and everything suffers. Weight is not even a consideration.

My 2c,
shiv