Well I've got xexon highlights, bose, and piaa oem fogs. Do you guys think I will have any probs with this mod??? It seems most people notice the AC. Not really a huge prob here in WA.........but maybe there is something else I haven't found yet.

I installed the Agency underdrive pulley and the AEM cold air intake in the same sitting back in October-ish. I haven't noticed any problems. No dimming lights, no fade in heating/air conditioning, no stereo weirdness. And my stereo draws a fairly large sum of power.

The underdrive pulley + cold air intake made a fairly noticable difference in performance. Highly recommend it!

I, too, am interested in some underdrive pulleys. Are there ANY detrimental side effects to these pulleys? Noise, loss of topend power, etc?

I, too, am interested in some underdrive pulleys. Are there ANY detrimental side effects to these pulleys? Noise, loss of topend power, etc?Your wallet gets thinner.

Honestly, I haven't seen any dyno pulls that show you NEED this mod, power wise. Nevertheless, I have talked to techie RX7 owners that suggest the underdrive pulleys reduce cavitation in the waterpump. This MIGHT improve impeller life (though seals are what die in waterpumps) and MIGHT improve water flow at high RPM where it is needed. Might be BS, too.

As far as electrical power, you max the alternator at 1500-3000 rpm. You cant get anymore power from it after that so an underdrive pulley matters little at cruise.

There is also something to be said with additive mods, a little power freed up with a light weight flywheel, a little more with pulleys, a little more with a cat delete (if you dont like bunnies and trees), light wheels, remove rear seats, no speakers, no ac and eventually you might realize -0.3 sec in the quarter.

carbonRX8,
Thank you for your candid response. Most only post "positive" and near perfect feedback with their mods. Probably to justify the cost, etc. to themselves. I knew that there might be some drawbacks, but have yet to get it as up front as you just put it. Thanks man, you probably just saved me near $400.00+labor. :fingersx:

Your wallet gets thinner.


There is also something to be said with additive mods, a little power freed up with a light weight flywheel, a little more with pulleys, a little more with a cat delete (if you dont like bunnies and trees), light wheels, remove rear seats, no speakers, no ac and eventually you might realize -0.3 sec in the quarter.

You will do a lot better than 0.3 .......
The pulley is cheap enough & does help a little so worth it in my opinion . No drawbacks at all that I can detect .

You will do a lot better than 0.3 ....... Not with just underdriven pulleys. Maybe more with all the stuff that I listed. Say 0.5. Thats alot.

I should mention that I am not against putting these on. When I have some extra time and extra $ around, I would figure "might as well" and I would go down this route. But it will be one of the lowest priority parts on my list. More for bling. I would suggest many other things first.

Not with just underdriven pulleys. Maybe more with all the stuff that I listed. Say 0.5. Thats alot.
.

thats what I meant . The flywheel will give the most from that list.

Your wallet gets thinner.

Honestly, I haven't seen any dyno pulls that show you NEED this mod, power wise. Nevertheless, I have talked to techie RX7 owners that suggest the underdrive pulleys reduce cavitation in the waterpump. This MIGHT improve impeller life (though seals are what die in waterpumps) and MIGHT improve water flow at high RPM where it is needed. Might be BS, too.

The water pump problem that you speak of was unique to the RX-7 3rd gen; the RX-8 doesn't have that problem.