Mod Vacuum Secondaries (non mechanical)

Similar results to mechanical secondaries, but without having to worry about re-jetting to deal with that flat spot.

So you take the Secondary vacuum diaphragm, open it up, take the spring that's in it(its about 45mm long IIRC), Cut about 1/3 of the spring off, stretch it back to roughly 45mm to make the spring stiffer. **Make sure to flatten the cut end so it seats properly to avoid any damage to the diaphragm!** Put it all back together and take it for a drive.

You should notice that the secondaries activate sooner than before, and without the annoying flat spot, and it's a smooth transition just like stock.

Takes about 5 minutes to do, and there is a noticeable difference.

Here are some pics I stole from ausrotary.

Vacuum Diaphragm:

Original Post from Colbskee on Rx7 club