Noob Bov psi question.

[Artsaves666]

Im going to be ordering a tial qr in the next couple days and im wondering what psi spring i should get. I plan on running 11psi of boost. Engine is an s14 built kade. Also can anyone explain why i should pick that psi spring.

[derass]

http://www.tialsport.com/documents/w3_tial_qqr_sp.pdf

[Artsaves666]

Im still completely lost lol. How do i tell wich one is best suited for my setup? Idk how much vacuum i need or have.

[!Zar!]

The plain one should be fine.

You'll probably be around -17

[Def]

Stock KA will be around -20 in-Hg at idle. Standard spring should work fine.

[RalliartRsX]

Im going to be ordering a tial qr in the next couple days and im wondering what psi spring i should get. I plan on running 11psi of boost. Engine is an s14 built kade. Also can anyone explain why i should pick that psi spring.

Did you read the PDF derass posted?? Spring pressure is determined by (idle) vacuum and not ultimate psi.

Also, make sure you have a dedicated 1/4" vacuum source (ended up drilling and tapping a dedicated source on my intake manifold).

Goodluck!

[Artsaves666]

I did read the pdf but i dont know how much vaccum my system makes. But if i have to drill and tap my intake mani should i just go with a different bov? Something that will work with my current setup?

[Artsaves666]

And if i have to drill and tap for a new vaccum source where should i do it on the plenum?

[Def]

Anywhere on the Plenum, -20 in-Hg. Standard spring.

End of thread

[dorkidori_s13]

just curious, why tial? HKS SSQV is probably one of the best BOV's you can get. its impossible for them to leak under boost. It is not uncommon to see 750+ HP Supra and GTR builds running them.

[Artsaves666]

No particular reason really. Ive just always heard good things. If i was to go hks would i still have to drill and tap my manifold?

[Artsaves666]

One reason i was gonna go with the tial qr is its a recirculating bov. And i can get it with a greddy flange that i need for 280 from atp.

[dorkidori_s13]

HKS has a recirc adapter... i have one, works just fine.

[Artsaves666]

This is obviously my first turbo build lol. Sorry for annoying ass questions but do u have to drill and tap the manifold to run the hks ssqv?

[dorkidori_s13]

uh, not sure about drilling and tapping (im assuming youre looking for a vacuum source), ive never run a KA-T before so im a complete noob on that one.

[Artsaves666]

Ya apparently the tial needs a larger vacuum port so it needs to be drilled and tapped. But if i can runs the hks without having to do that ill definately buy hks lol.

[Def]

Either of these BOvs will drive like crap on a draw through MAF setup. I'd recommend an aluminum Bosch type recirculate valve. The HKS recirc'd isn't that great either because of the partial throttle compressor surge it gives.

[anti tyler]

Just run your MaF in front of the intake manifold. In a blow thru setup. And don't worry about recirculating your bov. It's simple, cost nothing, and will save you money on trying to recirculate.

My KA-t is run like this, has been for 5 years with no issues at all.


just curious, why tial? HKS SSQV is probably one of the best BOV's you can get. its impossible for them to leak under boost. It is not uncommon to see 750+ HP Supra and GTR builds running them.



And listen to this ^^^

Also running a SSQV 3.

Awesome sounding, no issues as well in the past 5 years.

[Def]

If you get the MAF warm it will split apart at the sensor seam and leak like crazy.

[derass]

In the first post, you mentioned it is a BUILT KA. If the engine was build perfectly the vacuum could be higher than -20 in/hg. Are you running cams? If so, the vacuum will be lower than -20 in/hg. I would either wait until the engine is running to determine the vacuum and required spring, or buy a few different springs so that you have what you need when it is running.

As for the vacuum source, I have one of these valves and have it connected with a dedicated 1/4" hose to one of the nipples on the throttle body, it works well. This is on an SR though.

[Artsaves666]

It is a built bottom end. Stock head tho. Instead of drilling and tapping the manifold couldn't i just run a vacuum distribution block off of my brake booster?

[derass]

That's a good option, it will provide a strong vacuum source.

[RalliartRsX]

I would personally advise you to go back and review the manual posted above again.

A vacuum block "may" work, but any additional source will cause a delay in actuation. I personally drilled and tapped my manifold for a direct 1/4" source, but with the BOV on the hot side and tap for the vacuum source on the opposite end of the engine bay from the manifold, the line is longer than I would prefer and does delay actuation some (tested from several sources).

However, I will say this: If you have no idea on vacuum actuation and refuse to read the manual, there is a good chance you really do not need to run such a large BOV as the Tial.

Also, in addition to what Def said about running blow through: Another issue I have seen arise is the fact that now you are pressurizing the MAF much more than atmospheric and I have seen MAFs "explode" from the increased pressure. These MAFs are all fairly old, so they have somewhat fatigued over time