Who here has them? and is it worth the mod? I have searched, i can only find sets where it takes out the air pump. i dont want to do this because im going to put my main cat back on to pass emmissions. What do i do? PS what kind of HP gains am i looking at? 10hp??

 

The Unorthodox set is expensive, yet from my understanding is worth the money, if your as far as you can go on stock ECU. I have the greddy ones that eliminate that air pump, im not sure about HP, but the motor revs a bit easier (free's up recipricating mass).

 

What is recipricating on a rotary engine ? ( frees up recipricating mass ).

 

The Pettit TKT Power Pulley kit is the only kit designed to retain the airpump.

As far as gains, there will be some, but not a lot (nothing like going from the pre-cat to a downpipe). It's also not advised to run an underdrive pulley kit if you plan on installing a large stereo or if you like running the A/C.

 

Im sorry I think I mean to say unsprung weight. Doh now you mixed me up! =P

 

Unspring weight = wheels and suspension ,try rotational mass .

 

There ya go, I was getting the two mixed up. Dam car lingo and mumbo jumbo . Thanks man

 

I am a woman so you are mixed up hahahaha .

 

Yes again!! DOH! Thanks

 

I would get the car inpected and then put the kit on and keep your parts around becuase taking that airpump off really helps the horse power. Not like a huhe amount but enough and is worth it. I think I gained something like 12-15hp with all the mods after i dynoed it.

 

It's not necessarily "removing" the airpump which freed up the power gain you noticed. It's underdriving all the other accessories that freed up that little bit of power.

 

Bad idea. Not worth the HP gain, which is probably pretty small.

Keep the accessories working at full blast and spend your money with a tuner. Far more bang per buck.

 

Wow...i didn't know about the Pettit one. I thought airpump removal was a must...

Mahjik, when you're talking about an underdrive pulley being not good if you have a large stereo or use A/C a lot, I'm guessing you're referring to a full pulley set? Cuz I'm running the Greddy Pulley, so it's just the water pump & alternator, and airpump removal. I have a very large stereo, and I use my A/C on and off. No ill effects. I do have a cap for the stereo though (if that makes any difference)

 

I don't believe there will be any ill effects if you don't change the main pulley. Pullies kits (that replace the main pulley) are designed to underdrive the accessories, thus freeing up some HP.

I noticed a big difference after installing the Pettit's TKT Power Pulley kit with my A/C (or lack there of now). I rarely if ever use it, so it's not important to me. I just have the stock BOSE system so there is no trouble powering that either.

 

Gotcha. Yea that's what I initially thought, and the thought of no A/C in a black car in DC's summers quickly crossed that idea out for me. I thought I read pulleys that change the main pulley aren't really recommended for street-driven cars. What's your experience/opinion on that?

Thanks for the quick reply btw

 

i am going to flaunt my ignorance here, but does that underdrive slow down the water pump? if it does wouldn't it be ill-advised to put on pulleys; being that our cars have an underpowered cooling system as it is?

 

I've been using the Pettit TKT kit for a few years. Aside from the A/C difference, I didn't have any problems.

I'm now running a combination of the Pettit TKT Power Pulley kit and the Rotary Performance Air Pump removal pullies (with a 28.5" 4-rip belt). It works just fine.

I honestly have no idea if the TKT pullies gave me anything. I did that mod with several others all at the same time so there was no way to tell the effects aside from the loss of the A/C coolness.

 

I thought the same as well...

Yes the Greddy pulley set slows down the water pump and the alternator. But from what I understand, our waterpumps run too fast at higher rpm anyways, pumping water faster than it can be efficiently cooled. So slowing down the waterpump a bit should actually help w/ cooling at higher rpms. Mahjik...is this correct?

Also, I was always curious...if you underdrive your alternator, wouldn't my sound system drain my battery faster than normal, since the alternator would take much longer to fully recharge the battery?

Ditto on if I noticed much diff w/ my greddy pulleys, since I got rid of the airpump and installed the PFS SMIC on the same day.

 

Rather than type it myself, I'll just use a very good quote:

 

I hope the quote in my last message answers some of these questions. Let me know if it doesn't.

Well, I doubt you'll notice anything, power-wise, unless you change the main pulley.

 

It did answer all of them. Thanks again Mahjik

 

I just ended up yanking out my TKT Power Pulley and going back to stock. With TX summers, I want all the AC I can get.

And no, I already sold it.

 

Hey PVerdieck, I see you changed your avatar...lol. I'm def. feelin that shirt haha

 

I saw no ill effects going to the Rotary Extreme main pulley. It didn't impact a/c functionality much, but it seems like my a/c always worked better then the average RX-7. I have a few additional electrical demands over stock and a R51 with no charging problems.
I don't know if it made a power difference as I did several other mods. Not that my but dyno is that accurate anyhow.

Sorry, I have to disagree with the following:

quote:
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Originally posted by duboisr
slowing the alt will help it last longer, slowing the waterpump may stop high speed cavation(sp) which does not help cooling ,
The only time this is an issue it prolonged periods above 6500rpm (i.e. road course). Mazda recommends an underdrive pulley to reduce cavitation. If a pump is cavatating, it is not moving fluid effectivly. How could this not help cooling? I did some other mods at the same time as the pulley, so I can't make a direct comparison in track temps. I did swap pulleys afterwards 2x and didn't notice a temp difference in street driving.

slowing the pump will let the water absorb more heat and let the radiator do its job better , more HP, not much but some ,worth having ? I would say yes for the better cooling

I believe this is related to the old t-stat myth. It defies the laws of thermodynamics.
It originated in the 50's with the circle track racers. The problem was inefficient downflow/upright radiator design used at the time. The major problem was unrestricted flow would overwhelm the radiator caps. Prolonged high rpm and elevated temps would cause coolant to slowly leak out around the cap. Restricting pump flow, thus lowering the pressure, masked this problem. Additionally, the radiators didn't cool very evenly across the surface and had much wider fin spacing compared to today’s offerings. Slowing the coolant and adding turbulence allowed the old radiator to work a little better. The racers incorrectly surmised that the slower moving coolant absorbed more heat when it was really a radiator design deficiency. This isn't an issue with modern radiators.


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Edit: I am no longer using the RE main pulley since eliminating the smog pump. It was only used for a few months and I have all the belts and hardware. PM me if you want it.

 

Sorry to bring up an old thread, but I was just trying to do some searching/research on airpump removal. Well I'm in the process of installing a single turbo and I've already removed my airpump. The question I have is very simple, does anyone know exactly what size belt I'll be needing if I retain the stock pullies?

I'm not looking to go underdrive because I have a system and I use my A/C and plus my batteries already weak. PLEASE let me know, I'm sure someones decided against the underdrive, but remove airpump route as well. Thanks in advance.

Riz