BOV and cog belt advice for Vortech owners
BOV and cog belt advice for Vortech owners
This has been dealt with in other threads, however, I'll share my own experience.
BOV--On the factory setting recommended by Vortech (spring adjuster all the way out), I seemed to be losing boost until really gunning it over 4K RPM. I could hear the BOV scrubbing off pressure even when accelerating around 3-4K. This was immediately fixed with a big increase in boost (perceived, not measured) by adjusting the spring preload set screw in so it was showing about 6-7 threads above the jam nut. I listened carefully for any flutter which indicates excessive back pressure when lifting off the gas--none at this setting. How you do it: using a 13 mm box end wrench, back off the jam nut at the base of the screw until loose. Using a small Allen key (I think 3 mm) on the end of the screw, wind in the screw (shorten) a few turns until 6 threads or so are showing above the jam nut when you tighten it back down to set the screw at that position. Be sure to listen for deceleration flutter. If you get this, reset the screw outwards until eliminated. You can check this just by revving the engine and then letting of the gas--no need to drive it.
Cogged drive belt: This needs to be loose when checking the underside--about an 1/2 inch or so of play both up and down. I know it's crazy, but the idler pulley on top of the cog belt between the two cogged pulleys will keep the belt in full contact even though the belt seems rediculously loose. How to set it: while engine is idling, hold the 19 mm nut with an open end wrench and grab the 17 mm bolt head with a box end. Loosen, then slowly pull up (ie. loosen the pulley on the belt) until the clunky vibration at low idle is quieter but you don't hear cog noise (sounds like the cog belt would start jumping teeth). There's a sweet spot. Tighten firmly here and place a few drops of red LockTite on the threads behind the fixing nut. Now, at idle, there shouldn't be too much vibration in the jack shaft (a sign that the pulley is set too tight). After turning off the engine, the bottom of the cog belt should have the play mentioned above. If the belt starts jumping teeth or is getting prematurely chewed up, the pulley needs tightening later.
Hope this helps.
BOV--On the factory setting recommended by Vortech (spring adjuster all the way out), I seemed to be losing boost until really gunning it over 4K RPM. I could hear the BOV scrubbing off pressure even when accelerating around 3-4K. This was immediately fixed with a big increase in boost (perceived, not measured) by adjusting the spring preload set screw in so it was showing about 6-7 threads above the jam nut. I listened carefully for any flutter which indicates excessive back pressure when lifting off the gas--none at this setting. How you do it: using a 13 mm box end wrench, back off the jam nut at the base of the screw until loose. Using a small Allen key (I think 3 mm) on the end of the screw, wind in the screw (shorten) a few turns until 6 threads or so are showing above the jam nut when you tighten it back down to set the screw at that position. Be sure to listen for deceleration flutter. If you get this, reset the screw outwards until eliminated. You can check this just by revving the engine and then letting of the gas--no need to drive it.
Cogged drive belt: This needs to be loose when checking the underside--about an 1/2 inch or so of play both up and down. I know it's crazy, but the idler pulley on top of the cog belt between the two cogged pulleys will keep the belt in full contact even though the belt seems rediculously loose. How to set it: while engine is idling, hold the 19 mm nut with an open end wrench and grab the 17 mm bolt head with a box end. Loosen, then slowly pull up (ie. loosen the pulley on the belt) until the clunky vibration at low idle is quieter but you don't hear cog noise (sounds like the cog belt would start jumping teeth). There's a sweet spot. Tighten firmly here and place a few drops of red LockTite on the threads behind the fixing nut. Now, at idle, there shouldn't be too much vibration in the jack shaft (a sign that the pulley is set too tight). After turning off the engine, the bottom of the cog belt should have the play mentioned above. If the belt starts jumping teeth or is getting prematurely chewed up, the pulley needs tightening later.
Hope this helps.
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liqalu04
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Jan 2, 2022 12:58 PM
