[ferocity02]

For those of you guys using a Tial BOV, I highly recommend upgrading the vacuum line and nipple to full 1/4" ID.

I've gone nearly a year using a 3.5mm ID (roughly stock) line with the stock plastic nipple on the intake. After switching to 1/4" the BOV is much much more responsive, I didn't know what I was missing! It opens instantly even at lower boost and the flutter I was getting at lower boost is gone now. I think the plastic nipple on the intake was the bottleneck.

I removed the intake and cut off the old plastic nipple, then drilled/tapped the same hole for 1/8" NPT in order to thread in a 1/4" brass hose barb fitting. NPT threads seal very well already but I used a good amount of high-temp RTV to better seal it to the intake. JB Weld probably would have been a better and more permanent solution but I didn't have any.

Except for drying time of the sealant, it took just a few hours to do. I think Tial recommends a 1/4" line too.

[335NJ]

Did mine this way when I had the walnut blast done

[musc]

Seems like a good idea. I still use DVs but I have seen a bunch of these nipples break off on friends cars. Should provide a more stable connecting point as well as increasing flow.

[Bme30]

Pics?

[335NJ]

Originally Posted by Bme30

Pics?

Here's mine-

Before (After flicking off the glued connector)

After (Before wiping up the little bit of JB)

[ferocity02]

Originally Posted by 335NJ

Here's mine-

What size is that hose barb? Looks like 1/8 or 3/16"?

[335NJ]

Originally Posted by ferocity02

What size is that hose barb? Looks like 1/8 or 3/16"?

I want to say it's only an eighth inch. I plan to try and remove it to thread in a larger one, like the 1/4 most people seem to prefer.

I was in a pinch & had to hit 3 different hardware stores to even find that.

But, my BOV sounded a LOT more responsive opposed to the plastic nipple.

[ferocity02]

I feel like an 1/8 fitting is maybe barely bigger than stock, but that's good that it made an improvement. A 1/4 should definitely help even more. I even bored out my 1/4 fitting to get the largest ID possible.

[335NJ]

Originally Posted by ferocity02

I feel like an 1/8 fitting is maybe barely bigger than stock, but that's good that it made an improvement. A 1/4 should definitely help even more. I even bored out my 1/4 fitting to get the largest ID possible.

Now you got me thinking.. How the f*ck am I getting that sucker out with JB weld holding it in?

[Game]

I notice OP mentioned the nipple is on the intake, did he mean throttle body?

[musc]

Originally Posted by Game

I notice OP mentioned the nipple is on the intake, did he mean throttle body?

No. It is on the intake manifold right next the throttle body but on the intake manifold itself. Look at 335NJs pictures above. They show it well.

[Game]

Originally Posted by musc

No. It is on the intake manifold right next the throttle body but on the intake manifold itself. Look at 335NJs pictures above. They show it well.

Ahh yes, sorry I was just confused by the intake terminology. Thank you.

[ajsalida]

I just did a similar fix of broken off intake mani vac nipple. Drilled and tapped for 1/8 NPT brass fitting and then 5/32" hose.

What I found was the old plastic vac nipple ID was very small, smaller than 3 mm on the inside of the manifold even though the plastic barb itself was more like 3.5mm ID. Some improvement but not as great as cleaning up a restriction in the Forge DV's vac ports. It was due to too much grease being used (from new) that clogged the ports.

[Jeff@TopGearSolutions]

Yea I've heard of many customers upgrade the lines to 4MM and doing this mod and it improves a lot of the issues. Most misconceptions pointed the issue to the Tial when it was actually the lines/orifice the whole time.

[335NJ]

Originally Posted by Jeff@TopGearSolutions

Yea I've heard of many customers upgrade the lines to 4MM and doing this mod and it improves a lot of the issues. Most misconceptions pointed the issue to the Tial when it was actually the lines/orifice the whole time.

Agreed, Jeff. Tony @ VTT said the "standard" 11in/hg Spring is too strong for this platform previously, any input on that? He said that's the main cause for flutter. I'd think you have both options to eliminate the flutter, lighter spring, or this modification (which I prefer).

[Jeff@TopGearSolutions]

Originally Posted by 335NJ

Agreed, Jeff. Tony @ VTT said the "standard" 11in/hg Spring is too strong for this platform previously, any input on that? He said that's the main cause for flutter. I'd think you have both options to eliminate the flutter, lighter spring, or this modification (which I prefer).

I think the band aid for the 11 psi spring is going to 10. The real problem is the vac lines and this orifice being too small.

The other issue which some don't realize is tiny vac leaks and or different elevations will change the vacuum at idle.

[tc535i]

Originally Posted by Jeff@TopGearSolutions

Yea I've heard of many customers upgrade the lines to 4MM and doing this mod and it improves a lot of the issues. Most misconceptions pointed the issue to the Tial when it was actually the lines/orifice the whole time.

any gain from upgrading just the line, or is the nipple the major bottleneck?

[Stucks]

I have a 4mm silicone hose from intake manifold to my tial q bov and have run the bov with the 10 psi plain metal colored spring and the 11 psi yellow colored spring. At idle, with the 11 psi spring, the valve is completely closed. at idle with the 10 psi spring, the valve is slightly cracked open barely. maybe a hairline crack lol.

upon letting off the throttle, the 10 psi makes a larger psh noise. the 11 psi spring still makes a psh noise but its not as loud. both activate at the same speed upon letting off the throttle. idk if this helps, but just sharing my experiences with different springs in the tial q bov while using a 4mm silicone vac hose.

[Jeff@TopGearSolutions]

Originally Posted by tc535i

any gain from upgrading just the line, or is the nipple the major bottleneck?

The lines should be done at a minimum. The nipple only if problems persist.

Originally Posted by Stucks

I have a 4mm silicone hose from intake manifold to my tial q bov and have run the bov with the 10 psi plain metal colored spring and the 11 psi yellow colored spring. At idle, with the 11 psi spring, the valve is completely closed. at idle with the 10 psi spring, the valve is slightly cracked open barely. maybe a hairline crack lol.

upon letting off the throttle, the 10 psi makes a larger psh noise. the 11 psi spring still makes a psh noise but its not as loud. both activate at the same speed upon letting off the throttle. idk if this helps, but just sharing my experiences with different springs in the tial q bov while using a 4mm silicone vac hose.

That is helpful. You actually need a 10.5 spring haha.

You technically want the BOV just closed at idle but barely.

[Stucks]

Originally Posted by Jeff@TopGearSolutions

The lines should be done at a minimum. The nipple only if problems persist.



That is helpful. You actually need a 10.5 spring haha.

You technically want the BOV just closed at idle but barely.

lol yeah i currently just run the 11 psi yellow spring. either one would be ok in my opinion. i did notice a teeny tiny bit of lag when i hit the gas and am using the 10 psi spring. when i switched back to the 11 psi yellow spring, that lag had decreased. my guess is it comes from the valve having to fully close and just have a tiny bit more distance to travel vs the 11 psi spring setting.

[1Spec]

I wonder if this makes a difference with the HKS BOV

[maximum96]

I did this with my forge diverter valves...upgraded line from 3.5mm to 4mm....I do hear the blow off sound more and throttle tip in is quicker ...time to upgrade the nipple on the manifold....I think 1/4 inch line would be too big as it is closer to 6mm...