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The Cosworth Plenum Installation Instructions, in step #18, mention installing a check valve in the brake booster vacuum hose. See image and picture from the instructions below.
What makes the Cosworth Plenum require this check valve? Why does the Cosworth Plenum require this check valve and not the OEM plenum? Anyone know what this check valve does?
Could it be something to stop boost from going into the brake booster? So, maybe it's not needed on an NA car?
I don't mind putting the check valve on. It's certainly not difficult... I just like to know why I'm putting something on and what it does. Have other people installed this check valve when they installed their Cosworth Plenums?
it might be due to the fact that the cossie intake uses a split plenum vs a common, which could cause wave pulse variances that disrupt the vacuum signal--this would only be true if that vacuum hose goes to one side of the plenum.
There is already a check valve not too far from the attachment of the brake booster hose in the OEM setup. Does the Cosworth call for that hose to be removed or re-routed. If that passenger side hose/check valve is re-routed, perhaps this is their way to add it back in?
The OEM plenum has a ckeck valve. It runs from the side on the plenum to the battery compartment. The Cos plenum does not use this hose so they suppy a different one.
There is already a check valve not too far from the attachment of the brake booster hose in the OEM setup. Does the Cosworth call for that hose to be removed or re-routed. If that passenger side hose/check valve is re-routed, perhaps this is their way to add it back in?
Originally Posted by SxExCx
The OEM plenum has a ckeck valve. It runs from the side on the plenum to the battery compartment. The Cos plenum does not use this hose so they suppy a different one.
You guys were absolutely correct. The thing that threw me off is that you can't see the OEM check valve. It's completely enclosed within the tubing and you can't tell it's there. Here's a screen print from the Service Manual that confirms what you guys are saying. Hopefully it will help out someone else.
The Cosworth plenum has carbon fiber side plates. It's probably impossible to place a fitting in the same location as on the OEM plenum. Cosworth supplies a 90 degree fitting that mounts near the throttle body. They also supply a new length of hose that does not have a check valve in it. Thus the need for the additional check valve.
Have you noticed a difference since the plenum? Is your car stock otherwise? id just like to know if this is a good idea over new exhaust. Are the gains worth the $1300?
Have you noticed a difference since the plenum? Is your car stock otherwise? id just like to know if this is a good idea over new exhaust. Are the gains worth the $1300?
If you ask most of the FI peeps, they will say my car is pretty much stock... There's a link to my CarDomain site in my Sig... It has a list of the mods on my car.
I haven't installed the plenum, so I can't answer your question. I need to get a few things taken care of first.
Cosworth Plenum - Why Check Valve?
Can't wait to see your results!!!!
