ttranssam

iTrader: (10)

Ok, I dont understand how to get the boost and how to match the wg to the bov??? I have a 38mm tial wg and waiting to order the bov.

Now I have a forged 347 and i wanted to run about 12-15 psi, the wg i have is a tial 38mm with a 10lb spring, I want the motor to run to about a solid 12psi. But the tial 50mm bov does not have a spring to match the combo im looking for? Its like a to big or too small? and how do i go about getting/matching a blow off valve to the wastegate?

I do have a 32x12x4 intercooler that is said to drop 1.5 psi, and i will be running my devils own meth kit with progressive meth controller.

SO MY QUESTION IS...
How do i get them to push 12 psi and match and what springs do i get? Im also running the gate off the spring only...

PLEASE help me out here cus i have to pick up my motor tuesday and have two weeks to finish building this turd!!!

ttranssam

iTrader: (10)

and thanks for the help in advance...

also vendors i need a bov...lol

black98ws6ta

iTrader: (77)

A bov spring is rated by how much vaccume your engine pulls at a warm idle. Stock cammed cars may pull 18+, medium sized cams 15 or so, and larger cams around 10-12. You would rather be on the lower side then high.

ttranssam

iTrader: (10)

can i get a little lession on how the work in conjuction and how to set them up?

rao

iTrader: (18)

They really aren't related. The wastegate spring has to have a lower spring pressure than the amount of boost you want to run if you are going to use a boost controller,otherwise it will run approximately the amount of boost that the spring opens at.

The BOV or bypass valve will be using the boost pressure to hold it closed until the engine sees vacuum, and then it will open. There are several ways to run the vacuum lines and several variations on the BOV's. Generally you want a lower spring rate as described above.

ttranssam

iTrader: (10)

so what springs in each???

XtremeDime

iTrader: (16)

Is 12 the most you want it to run or is that bare minimum? If the bare minimum then get a 12psi spring in the WG and get a boost controller to raise it from there. I cant help much with the BOV since Im running an inline BOV, Im pretty sure the only one running one here.

Call up Rob @ Modular Turbo he helped me throughout my build with questions like this. His contact info is at modularturbo.com, hes always been good about replying to emails and calling back promptly too.

1320

iTrader: (6)

I d only run a bov if your a 6 speed car.

Bird-Of-Prey

iTrader: (23)

A BOV is used to release the pressure created by the turbo when the tb is closed. This pressure has to go somewhere. If the throttle blade is closed it could back up into the turbo and cause it to stall. Not good. Too much load on the turbo isn't a good thing. Find out what vacuum your engine pulls at idle and choose the closest spring for your BOV. IE as soon as you let off the gas and your engine goes into a vacuum you want the BOV to open. More important for 6 spd cars but important none the less. As far as your 38mm Tial WG, what's your set up? It's a great gate but sometimes not quite enough depending on your set up. Might see a little boost creep. I believe you can't go too big when it comes to a WG. I personally run a Turbosmart 48mm Progate.

reamo04

iTrader: (9)

Why did grand nationals not come with BOVs than?

Just saying, on an automatic is it a good idea still? Yes, but there are ways around it. I personally will always run one, but there are a TON of grand nationals in the 10s and faster not running them.

ttranssam

iTrader: (10)

yea, i know how and what the bov does, so its alright to run say a 14psi wg and a 12-13psi bov spring?

The Fugitive

iTrader: (6)

what's good for the goose isn't always good for the gander. It is always good to protect your investment. You don't need a lot of things but is it highly recommended to avoid other problems yes.

reamo04

iTrader: (9)

hook up your boost/vacuum guage. Tell us how much vac. you have at idle, and we can tell you what spring to get.