Tial 50mm Bov Q
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From: Anaheim
Joined: Dec 2001
Posts: 671
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From: Portland, OR
Also please post where you're tapping the vacuum for this, as well as the spring. Here's the issue I'm wrestling with currently. Car pulls 15-16" vacuum at idle, warmed up.
Ordered with 9 PSI spring (18" vacuum) which is painted white. Car had flutterdump when hooked into the same vacuum source my HKS BOV worked fine for years with -- the forward vacuum hose that also runs to the emissions / canister. BOV not opening soon enough.
Moved the vacuum line to tee off of the back of the manifold, where the line begins to run to the brake booster. Way more vacuum there, which caused the BOV to open partially at idle and become open during boost.
So I ordered a new spring, this time the 11 PSI (22" vacuum), hooked into the back (stronger) source of vacuum. So I get flutterdump again at low boost, but at high boost it holds fine and when I close the throttle I get the trademark whoosh with no flutterdump.
I call Full-race, ask their advice. They say the last resort is to trim the spring. So I trim it, a half coil at a time using my angle grinder. Carefully. 1.5 coils later, I get rid of flutterdump. And the darn thing loses boost again at 10 PSI. Argh.
Thoughts? What vacuum source are you guys using?
Ordered with 9 PSI spring (18" vacuum) which is painted white. Car had flutterdump when hooked into the same vacuum source my HKS BOV worked fine for years with -- the forward vacuum hose that also runs to the emissions / canister. BOV not opening soon enough.
Moved the vacuum line to tee off of the back of the manifold, where the line begins to run to the brake booster. Way more vacuum there, which caused the BOV to open partially at idle and become open during boost.
So I ordered a new spring, this time the 11 PSI (22" vacuum), hooked into the back (stronger) source of vacuum. So I get flutterdump again at low boost, but at high boost it holds fine and when I close the throttle I get the trademark whoosh with no flutterdump.
I call Full-race, ask their advice. They say the last resort is to trim the spring. So I trim it, a half coil at a time using my angle grinder. Carefully. 1.5 coils later, I get rid of flutterdump. And the darn thing loses boost again at 10 PSI. Argh.
Thoughts? What vacuum source are you guys using?
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From: Around
Originally Posted by Slows2k' date='Jan 2 2009, 06:20 PM
You've got a 50mm Tial on the car and no boost gauge?
Joined: Dec 2001
Posts: 671
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From: Portland, OR
A chime in from Evans Tuning? Honored. Thank you so much. I'm a big fan of your tunes and your work. Wish I was closer & I'd have you tune the car.
I tried a big vacuum line directly (unshared) from a big vacuum port on the top of the manifold, as well as a shared one off the back of the manifold. No difference, but better than taking it off of the evaporative/canister feed that taps from right behind the throttle body and runs to the canister in the rear.
BOV is located a couple of inches from the throttle plate, as shown in the photo at this link http://picasaweb.google.com/stantaur3/S200...094331865304674
Tried the 9 PSI spring which opened at idle and opened/leaked at > 13 PSI.
Fail.
Tried the 11 PSI spring, which fluttered at anything below 5 PSI because it wouldn't open. But it would hold boost at least.
Fail.
Trimmed the 11 PSI spring (last ditch recommendation from Full-race) 1/3 coil at a time. Four times. Result = barely flutters under 2 PSI but won't hold boost.
Fail. Again.
And we all know what a PITA it is to remove / reinstall the O-ringed V-band TiAL with its 6 allen screws and ridiculously long spring that you have to compress, EVENLY using at least three of the allen screws once you have it close enough for thread contact, EVENLY to gently, slowly compress the spring down onto the housing and not pinch or unevenly load that f-ing diaphragm.
12 times.
Going to ask Full-race to see if we can do something to remedy / partial credit refund this TiAL and get an HKS S-SQV. I had that on the car before with perfect results (whistled more than I preferred; I'd just like a subtle whoosh).
Bottom Line for those with > 15 PSI who are considering the TiAL 50 mm BOV: Reconsider. Either go HKS S-SQV or use the newer TiAL as Evans recommends.
Yikes.
Stanford
I tried a big vacuum line directly (unshared) from a big vacuum port on the top of the manifold, as well as a shared one off the back of the manifold. No difference, but better than taking it off of the evaporative/canister feed that taps from right behind the throttle body and runs to the canister in the rear.
BOV is located a couple of inches from the throttle plate, as shown in the photo at this link http://picasaweb.google.com/stantaur3/S200...094331865304674
Tried the 9 PSI spring which opened at idle and opened/leaked at > 13 PSI.
Fail.
Tried the 11 PSI spring, which fluttered at anything below 5 PSI because it wouldn't open. But it would hold boost at least.
Fail.
Trimmed the 11 PSI spring (last ditch recommendation from Full-race) 1/3 coil at a time. Four times. Result = barely flutters under 2 PSI but won't hold boost.
Fail. Again.
And we all know what a PITA it is to remove / reinstall the O-ringed V-band TiAL with its 6 allen screws and ridiculously long spring that you have to compress, EVENLY using at least three of the allen screws once you have it close enough for thread contact, EVENLY to gently, slowly compress the spring down onto the housing and not pinch or unevenly load that f-ing diaphragm.
12 times.
Going to ask Full-race to see if we can do something to remedy / partial credit refund this TiAL and get an HKS S-SQV. I had that on the car before with perfect results (whistled more than I preferred; I'd just like a subtle whoosh).
Bottom Line for those with > 15 PSI who are considering the TiAL 50 mm BOV: Reconsider. Either go HKS S-SQV or use the newer TiAL as Evans recommends.
Yikes.
Stanford