How To: Modify OEM Auto Tensioner for JRSC

[beechstreet]

Here's a quick "How To" on how to modify your OEM auto tensioner to work with your JRSC setup on an EP3 (K20A3). I don't take credit for figuring out how this works. I'm just putting all this information together in one post so people will not have to search through multiple threads and posts. Credit goes out to neoamd, 04EP3Hatch, K20A EP3, Ba82Ep3, Jmercado (of clubrsx.com), and others for posting up info related to the tensioner. I'd also like to thank ecsahs3 for donating an OEM auto tensioner to me.

For this "How To" I will be referring to a JRSC Race setup on a K20A3 (which includes a JRSC, 440 injectors, 3.8" SC Pulley, the k24 "skeletor" crank pulley, and the 3" idler pulley on the OEM tensioner).

What you need:
OEM Auto Tensioner (K20A3)
Cut-off tool, preferably an air powered one
A belt equivalent to the Gates/Gatorback k070622 (neoamd also suggests a K080620 with a rib removed)

First step:
You want to remove one of the mounting points on the OEM tensioner that will hit the neck of the JRSC. The part that needs to be removed is circled in red:


I'd suggest doing this with an air powered cut off tool. Be sure to wear protective eye wear and some heavy duty gloves. Dust/debris from the tensioner will be flying everywhere.

Once done, it should look like this:






Be careful, where you cut the chunk off will be sharp. I'd also suggest smoothing it up with an angle grinder or grinding wheel if you have access to one.

Once the tensioner has been modded, install it in place of your manual tensioner. You will only need two bolts to mount the OEM tensioner. Depending on the JRSC pulley and crank pulley you are using, you can most likely use the Gates/Goodyear k070622 or as neoamd suggests, the Gates/Goodyear k080620 with a rib cut off for some extra snugness. I'd suggest putting the belt on all of the pulleys and leaving the S/C pulley for last. Like most auto tensioners, use a long handled socket wrench to swing the tensioner arm loose and create slack. I needed an extra hand to hold the wrench while I forced the belt over the S/C pulley. Start up the car and check for any noises.

That's it:


More links if this "how to" doesn't help you much.

k24 skeletor pulley

Modding OEM Tensioner Discussion