I did a UR underdrive pulley install today and AEM cold air/dry filter yesterday night on a 06 Acura RL. This isn't my car but a friends of mine. Just an FYI if you are running the smaller pulley from UR, you will need to run a smaller belt (dur!) however, after many searches online and in acurazine, i couldn't find anyone supplying this information. Even the damn instructions ask you to supply the information if you find it ... This is the perfect size belt for that pulley.

I used a Dayco Belt from Advance Auto Parts

Dayco Poly Cog #5060835 6PK2120

As for the install it's rather easy.

1: Take off rim
2: Remove 3 small tabs off lower fender liner and pull liner forward
3: 19mm and break off crank pulley bolt (i used a craftsman impact gun)
4: go to the top of the car and remove passenger side plastic covering of engine bay
5: under the power steering pulley you will see the belt tensioner (only mess with the top tensioner)
6: use a 14mm on a breakerbar, push tensioner toward firewall to release tension on belt and remove
7: take off stock pulley and admire the weight of that POS (do not lose the crank key, small slider key that will lock pulley and crank together).
8: install new pulley and slap on the crank pulley bolt.
9: install new belt, push tensioner and wrap onto the power steering pump last.

This took me about 2 hours of driving to the parts store trying to find the correct belt to use. total took me about 2.5 hours. this honest to god should take you no longer to do than 35 minutes once you break the pulley bolt lose. i hear people having horror stories about that.

Sorry for no pictures guys, still have to install headers on an SC430.

 

Great work! Thanks for the information.

I guess it's too late to ask for a pre-mod dyno so that we can see how much objective gain there is in adding this part. I'm thinking about doing at least a stock-size pulley myself and would love to have real numbers.

Would your buddy submit to a post-mod dyno, at least?

 

Very cool. How were the gains on your friends car? Primarily the acceleration difference due to the pulley? Mine should be on its way soon. Can't wait to get it on my RL...

 

uhhh... honest to god i haven't even tested the car since the pulley install... friends in korea for business and he dropped the car off with me for a few weeks for me to install all his goodies... i feel that the intake made a big difference... but all i did was move the car up and down the driveway since i installed the pulley... UR says to give it a few days for the ecu to realize the less rotational weight on the crank and will then adjust to it... i'll be doing the 5zigen exhaust on monday... maybe i'll try to do a DIY install on that... since my driveway and garage won't have 4 car's being worked on at the same time...

 

I've always though that pulleys have absolutely no effect on performance, its another snake oil. All that changing the pulley does is make you change the timing point in order to compensate for the different diameter! Cams ,on the other hand, do change, valve lift, phasing and duration thus can have positive (or negative) effects on performance.

 

Pulley's imho are one of the best bang for the buck. I've had them in my last 3 cars and the RL. Very impressive mod. On my RL using the RSM the pulley shaved of the same time in my 50-100km/h run as doing the intake.