OBX Underdrive Pulley

I dont see how it wouldnt give the same or better gains in forced induction as it would NA, I mean the basic theory of the part stays the same in that it is trying to reduce rotating mass and therefor reduce the amount of power leeching that happens. that is where the gains come from as I understand pulley kits, weight and size makes up less rotational mass or something.

Anyway form the info I got here I will plan on switching to the red top battery(thats the deep cycle one?) and then get the pulley, either OBX or UR
 
Equinox said:
apparently the pulley doesn't give gains in a forced induction setup well, so I've heard, nothing to back that up tho.

kieth from fm has gave a few good explanations why it it bad for a FI vehicle... One of the MSP that blew their engines had the pulleys, and mentioned a oil problem. Keith mentioned the pulleys will cause the oil pump to fail, if i remember correctly.
 
paulmp3 said:
kieth from fm has gave a few good explanations why it it bad for a FI vehicle... One of the MSP that blew their engines had the pulleys, and mentioned a oil problem. Keith mentioned the pulleys will cause the oil pump to fail, if i remember correctly.
that's it, thanks again Paul
 
ah i see, as per the extra stress already on the oil pump because of being FI in the first place. would make sense. But as I have seen many Jspec tuner cars in mags that are running high boost and pulley kits it is possible, but you need alot of other backup work to the oil system and others stuff to make it work without problems. Seems pointless in the end, as you said.
 
alright guys, I have a stock car, this is gonna be one of my first upgrades. So what do I NEED for this to run properly in my car as in what do I need to change to be safe with this part in my car? Some of you guys say it's fine without changing things but some say alternator and battery and crap so let me know guys because I just brought it today. Thanks
 
red top battery and make sure u use good belts. Thats it. Although it will work fine w/o the battery if the alt. is under load alot then a battery is a good idea
 
what kinda belts should I get? I don't need a alternator with this crank pulley as long as I get a red top battery right?
 
well if u get the OBX they might have recommended belt type and sizes. UR did. they suggested Gates belts. As did shops around me. I unfortunately got bando belts cause the shop bs'd me. I dont have a redtop either. These are things i will get but i wish i had known when i got the pulley. But even w/o it really hasnt been a problem. If u can, get the redtop but its not necessary. I did install a ground kit though and that helped a bit too.
 
I got an e-mail that said that the OBX pulley is not available yet. Vaporware strikes again.

Looks like UR is the only one. I saw it somewhere on the web for less than $200.

As far as the Oil pump goes, I don't understand how an UD pulley would make it fail. The oil pump is not belt driven, is it? I thought it was an internal component driven off the crank.
 
www.nleonline.com has them for $199.75, it says free shipping but for items over $150. It cant be too much for shipping, maybe $10. Thats a very good price, i paid $245 at a local performance shop for the (cavalier) UR Pulley......ill be getting mine from here for the P5.
 
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dont forget rr-racing has one coming out early feb

and you're right the oil pump is driven directly off the crank. the problem comes from the crank pulley not being a balancing agent for the engine.

having said that i'll still get an underdrive pulley....has anyone seen a non turbo car have problems from an underdrive pulley???? i certainly havent.
 
yeah it may be from the fact that the pulley can unbalance the engine but mainly that the FI engine is much more sensitive to oil consumption and availability. Honestly Its not a big deal mod. I am surprised so much has been said about it. But still i would highly suggest getting the UR pulley. The OBX might be of questionable quality... the UR was well researched so they made sure to not make it too small or too light. The OBX might over do it and then u might run into alt. and water pump problems(cavitation).
 
Unless the lower pulley from the factory is truly an harmonic damper, you have nothing to worry about. Us Ford guys (especially Mustang guys) have been using UDPs for YEARS! You only have cooling and charging problems if you use a Race kit. Only a crank pulley, or a street kit should cause no problems.
 
i already posted this in another thread in the msp forums, but id figure id post this in a the general performance section also, more views!! thx

was just reading the protege faq and it had this to say about underdrive pulleys...

"Are there any underdrive pullies available?
Unorthodox Racing makes underdrive pullies however it is not recommended to
use any underdrive crank pullies from any company at all because it can cause
oil pump failures. All Protege engines are directly crank driven and if an under-
drive crank pulley is used, it can cause accelerated wear in it which will event-
ually lead to failure! Typical underdrive crank pullies do not have a harmonic
balancer and therefore all the oscillating forces from the crankshaft are
transmitted elsewhere. Even on the typically well balanced stock crankshafts,
there is always a very slight imbalance in them and as such the forces caused by
them results in the oscillations. Many turbo Miata engines have blown up from
oil pump failures due to the installation of underdrive crank pullies. Be warned!"

so can we mod our cars at all then? if the oem engineers already thought of everything to squeeze out all the power, then why do we show gains when we replace this stuff? also if you used the appropriate belts with the underdrive pulley and tensioned it right, would it not lead to a oil pump failure?
 
Speaking of resurrecting DEAD thread, hehehe.

The only reason why people say that UD pulley causing an oil pump failure, is because it does make strain on the pump. NOW! The only Protege that has this kind of problem is a Protege with a turbo setup! Mazdaspeed Protege or any other Protege with aftermarket turbo. Just because Forced induction creates a great deal of presure on the crankshaft it is not recommended to have UD pulley on F/I protege. All other N/A (naturally aspirated) Protege's can run UD pulley with no problems. I had mine for quite a while now, and no problems.
 
I had mine for years.... My only problem was they could squeel when wet or cold, but it was aggravated by my system (1200watt max). Oil pump wise i havent heard of a protege failing from a failed oil pump. However there have been quite a few who did fail from oil problems, not neccesarily from having a UDP. In actuality it was found that the oil pan was poorly designed. Also MAzda definatley didnt squeeze all the hp NA they could from that engine. If anything it was very restricted for emissions reasons, ULEV II designation etc... So how is the header DIs? BTW the oBX is a 41 header not 421. It must pull really nice in high rpm.
 
well i figured id post in an existing thread rather than create a whole new thread...

ok, thx. i think that makes a lil more sense.
 
akhilleus said:
So how is the header DIs? BTW the oBX is a 41 header not 421. It must pull really nice in high rpm.


Man! I love this header SOOOO MUCH! But im curious about something...After the instalation, it keeps bothering me. WTF is that wistling noise!??!!? Is it suppose to be like that? Is that the new air flow from the engine through the header? Anyhow, I tested it out on highway, slowed down to 60 and then gunned it in 4th. HOLLY s***!!! I got to 80 pretty damn quick!!!! Eh man, so how are you doing? I hope everything is good for you.
 
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