Tial BOV Spring Rate 1JZ
10-03-13, 11:39 PM
#1
Tial BOV Spring Rate 1JZ
'Sup Guys.
1JZ GTE VVTI. Stock CT15b single turbo, tomei turbo outlet, 3" downpipe, 3" midpipe, Blitz nur spec R exhaust, FMIC, HKS filter, SAFC2.
I have been getting flutters/gobbles since I installed my TIAL Q bov (does open) and plugged off the stock recirculator housing and fitting. 11psi spring and 3/8" (I think) vacuum hose. Vacuum is -20hg at idle. Bov is welded on the U intercooler pipe before the pipe that goes to the throttle body (simply because I have no space for this gigantic bov on the pipe that goes to the TB).
2 ways I have in mind to hopefully eliminate or reduce the flutter/compressor surge:
- Get a softer spring rate for the bov. Currently at 11psi, thinking about going 10psi (I'm afraid 9psi would be too soft).
- Get a stronger vacuum source. I heard the brake booster vacuum source is the strongest and I should Tee it off with the bov.
Which one would you guys recommend me to do first?
Thanks,
David
1JZ GTE VVTI. Stock CT15b single turbo, tomei turbo outlet, 3" downpipe, 3" midpipe, Blitz nur spec R exhaust, FMIC, HKS filter, SAFC2.
I have been getting flutters/gobbles since I installed my TIAL Q bov (does open) and plugged off the stock recirculator housing and fitting. 11psi spring and 3/8" (I think) vacuum hose. Vacuum is -20hg at idle. Bov is welded on the U intercooler pipe before the pipe that goes to the throttle body (simply because I have no space for this gigantic bov on the pipe that goes to the TB).
2 ways I have in mind to hopefully eliminate or reduce the flutter/compressor surge:
- Get a softer spring rate for the bov. Currently at 11psi, thinking about going 10psi (I'm afraid 9psi would be too soft).
- Get a stronger vacuum source. I heard the brake booster vacuum source is the strongest and I should Tee it off with the bov.
Which one would you guys recommend me to do first?
Thanks,
David
Last edited by jintei; 10-03-13 at 11:45 PM.
10-04-13, 08:52 AM
#2
That is already a good sized vac line. get a lower spring and if its too low, then use big washers like for a 1/2 bolt under the spring one at a time till you get the right stiffness. The place I ended up setting mine was between 2 of their spring rates, the spring down was too soft and the spring up was too stiff, so it take a little experimentation to get it perfect. I don't recommend Teeing anything into your brake booster, you need brakes more than you need a working blow off valve if something goes wrong.
The piston should just be barely past closed on idle, and push down when you get on the throttle, and pull up and open for like a second when you let off then go back to closed. If it does not open go lighter on the spring, if it does not close at idle enough then get a heavier spring or shim it till it does. once you get it perfect the Tial will really sound good and if you dial it in like this it will blow off even at lower boost levels
The piston should just be barely past closed on idle, and push down when you get on the throttle, and pull up and open for like a second when you let off then go back to closed. If it does not open go lighter on the spring, if it does not close at idle enough then get a heavier spring or shim it till it does. once you get it perfect the Tial will really sound good and if you dial it in like this it will blow off even at lower boost levels
10-04-13, 09:53 AM
#3
That is already a good sized vac line. get a lower spring and if its too low, then use big washers like for a 1/2 bolt under the spring one at a time till you get the right stiffness. The place I ended up setting mine was between 2 of their spring rates, the spring down was too soft and the spring up was too stiff, so it take a little experimentation to get it perfect. I don't recommend Teeing anything into your brake booster, you need brakes more than you need a working blow off valve if something goes wrong.
The piston should just be barely past closed on idle, and push down when you get on the throttle, and pull up and open for like a second when you let off then go back to closed. If it does not open go lighter on the spring, if it does not close at idle enough then get a heavier spring or shim it till it does. once you get it perfect the Tial will really sound good and if you dial it in like this it will blow off even at lower boost levels
The piston should just be barely past closed on idle, and push down when you get on the throttle, and pull up and open for like a second when you let off then go back to closed. If it does not open go lighter on the spring, if it does not close at idle enough then get a heavier spring or shim it till it does. once you get it perfect the Tial will really sound good and if you dial it in like this it will blow off even at lower boost levels
10-04-13, 12:17 PM
#4
it should work out, yeah sometimes when going down a spring it goes too far and hence the washers.
I don't have a pitcure its just a flat washer that is the same size or larger than the spring and fits in the bottom area of the bov. I put it under the spring normally, so you take the top off, take the spring out, pop in a washer, pop in the spring, wrestle with it to get the top back on and bolted, and then test.
I would try it first with the new spring, and if its not closing at idle anymore, then go up 1 washer at a time. I have left it open before but I am on a map sensor ecu, so you could have issues if its open at idle with the maf setup.
I don't have a pitcure its just a flat washer that is the same size or larger than the spring and fits in the bottom area of the bov. I put it under the spring normally, so you take the top off, take the spring out, pop in a washer, pop in the spring, wrestle with it to get the top back on and bolted, and then test.
I would try it first with the new spring, and if its not closing at idle anymore, then go up 1 washer at a time. I have left it open before but I am on a map sensor ecu, so you could have issues if its open at idle with the maf setup.
10-04-13, 12:41 PM
#5
it should work out, yeah sometimes when going down a spring it goes too far and hence the washers.
I don't have a pitcure its just a flat washer that is the same size or larger than the spring and fits in the bottom area of the bov. I put it under the spring normally, so you take the top off, take the spring out, pop in a washer, pop in the spring, wrestle with it to get the top back on and bolted, and then test.
I would try it first with the new spring, and if its not closing at idle anymore, then go up 1 washer at a time. I have left it open before but I am on a map sensor ecu, so you could have issues if its open at idle with the maf setup.
I don't have a pitcure its just a flat washer that is the same size or larger than the spring and fits in the bottom area of the bov. I put it under the spring normally, so you take the top off, take the spring out, pop in a washer, pop in the spring, wrestle with it to get the top back on and bolted, and then test.
I would try it first with the new spring, and if its not closing at idle anymore, then go up 1 washer at a time. I have left it open before but I am on a map sensor ecu, so you could have issues if its open at idle with the maf setup.
Gonna do this after work. I'll keep you updated with before and after vids. Thanks Ali.
03-04-15, 08:09 PM
#6
Pole Position
O.P, how did this ever turn out? Just curious if the OP ever figured out how to dial in the BOV to perfect settings
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