[86TOYO2k17]

Originally Posted by churchx

86TOYO2k17: it seems to me that also that it might be safe at track to underdrive generator, as after all, for track prep one can precharge battery, and will drive at much higher rpms then when daily driving. And possibly with AC/music off.
Water pump .. but what if one turns up fans in tune to cool coolant more to somewhat compensate slower pumping speed? And if there is oil cooler installed?
There is possibility of also having much redundancy/extra in standard setup of standard car, designed in by manufacturer that may have wished much higher safety margin then minimally necessary. Manufacturer also may have chosen parts from it's part bin of maybe ones optimally fit for other cars, to save on R&D and manufacturing.
But again, i don't have any real data, hence why i asked, how much power is used up in turning generator, how much for A/C, for water pump, so thanks for posting that. Would like to know in addition to that what is considered to be safe in underdriving. Aand, then again i'm not considering even in future do overdriven/underdriving mods .. it just seems interesting topic to hear more about for one wishing to learn more about cars . Prefering to have that (even though redundant) safety margin in, even more so as mentioned gains seem too small to bother.
EDIT
btw, what do you think of underdriving/undersized crank pulley, AND underdriven/oversized accessory pulleys? As in - for same cumulative underdriving effect, but with use of standard length belt?

I am pretty sure most car manufacturers over engineer things like alt / water pump which is why underdriving 15% shouldn’t cause any negative efffects. I think on a stock car running everything at once requires 100-110amps? Which is right where you would be at if you where underdriving it. Ppl can add crazy sound systems and headunits and still run on stock. I wouldn’t stack oversized accessory pulleys with undersized crank unless It was a complete set. 15% underdriven seems the max You would want.

But Personally I’m not a fan of swapping stock crank pulley unless it’s with a better dampener. The ati one is 10% underdriven but I’ve read it’s not well
Built and requires maintainance. That’s y I would just stick to stock or upgrade to fluidampr. Testing shows it’s much better at dampening especially in higher rpms. Also looking at mustang/s2000/vw forums everyone praises fluidampr and there is more testing data on those forums showing the benefits.