[Admin]

It is important to regularly service your valves to keep them in good working order. These instructions relate to the Forge dump valve BOV (FMDV004) and Forge recirculating diverter valve (FMDV006) for Saabs...

1. Remove the valve from your car and place on a flat surface on some newspaper.

2. Using an allen key carefully remove the valve top, making sure you keep adequate pressure on the top of the valve to keep the spring contained (it can fly across the room!).

3. Remove the spring, piston and components (o-ring and spacers if applicable) from the valve and clean with a cloth, removing all old grease.

4. Add new high pressure grease to components including the screws.

5. Check components move freely and the valve is working correctly. Using a screwdriver push the piston upwards against the spring and place your finger over the top nipple to form a seal. Keeping your finger tight against the hole release the spring and check the piston stays in place. Remove your finger and check the piston moves back OK.

6. Refit the valve top by adding the screws evenly (opposites) keeping the internal spring straight.

7. Fit back on your car and test drive.

If you find idle is not steady or hear a fluttering (compressor surge) it could be that your spring is either to strong or too weak. When buying a new valve always check the spring colour supplied in the valve!

If you increase the PSI of your engine use the Forge tuning kit (FMDVTUN) to keep your Valve holding the correct boost.

Valve Spring color coding (estimate guide only):[B]
[/B]Green - 5-15 PSI
Yellow - 15-23 PSI
Blue - 23-30 PSI
Red - 30 + PSI

Spacers can be used to further tune your valve.

You can buy the Forge Motorsport Valves and tuning kits at www.forgemotorsport.com.

[Saaboheme]

Excellent write-up. You have inspired me to go clean and service my Hyperboost HX BOV/BPV.
Unlike the Forge, the Hyperboost has a threaded top that screws off. Here are two pics of the valve, as adapted to operate as a BOV (the newspaper used to provide background in the second photo was chosen deliberately, and no grease stains were permitted to get on it):


After unscrewing the top, the spring remains in the cap and the piston can be pushed out with one finger through the port opposite the cap side. Here it is disassembled:

There are two O-rings set in grooves on the inside of the valve body. Remove with a toothpick and clean, re-grease (I use Valvoline Synpower synthetic grease) and reinsert them into the grooves after cleaning out the inside of the valve body:

You can use carb cleaner, brake cleaner or some other grease cutting solvent to clean the valve body. I prefer carb cleaner as it does not leave any filmy residue like brake cleaner.
I grease the threads to help seal them (probably unnecessary as they are precision machined fine threads) and to help in future disassembly:

Insert the piston (if you forgot to take notice at disassembly, the piston's tapered side goes toward the port opposite the cap end and not toward the cap end) and screw the cap and spring back on. Refit to the car and cruise away.
You check out Hyperboost valves here: http://www.stratmosphere.com/hyperboost.htm

[Admin]

Thanks, good to get the non-Forge version!

Can you post those pics any bigger?

[Saaboheme]

Sorry! Please remember I am a 49 year old Luddite and being able to post pics at all is a modern miracle. We had one computer class in my high school, learning Basic, and our computer terminal was a keyboard hooked to a remote computer with a rotary dial up modem. Heck, I competed in the State math placements with a slide rule. It took me an hour to shrink my avatar to a useable size and still have it recognizable. And the sun was in my eyes. Gimme a break you young whilppersnapper.

[Admin]

[Saaboheme]

You are a clever, clever boy.