My draw through turbo

[advinnie]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

[advinnie]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

[advinnie]

Also pump jets 50 or 70?

[Chip Birks]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

Yes, you don't want it screwing with your fuel pressure while off boost.

[Piledriver]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

Yes, you don't want it screwing with your fuel pressure while off boost.

With a draw through carb, the engine is ALWAYS NA as far as the carb can see.

You shouldn't even need a boost sensitive pressure regulator unless your bowl inlet needle won't flow enough fuel.

If you are using a Weber carb draw through you can't really feed it over 3 PSI anyway or it becomes bad fuel injection.
(uncontrolled fuel leak)

IF you are running EFI, having it connected is proper (but not required) as the manifold vacuum effects the injector flow.
With EFI you can tune it either direct connected to manifold vac or not referenced or with check valve boosted.
(not manifold ref under vacuum may make tuning it a little easier)

[panel]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

Yes, you don't want it screwing with your fuel pressure while off boost.

I ran one......you can kinda make it out behind the stainless braided line above the orange battery line/above the aluminum intake.

[Chip Birks]

Hi all I'm back. I've been reading and some people are saying I need a check valve on the boost line that goes to the boost sensitive fuel pressure regulator and some say I don't, are you lot using one?

Yes, you don't want it screwing with your fuel pressure while off boost.

With a draw through carb, the engine is ALWAYS NA as far as the carb can see.

You shouldn't even need a boost sensitive pressure regulator unless your bowl inlet needle won't flow enough fuel.

If you are using a Weber carb draw through you can't really feed it over 3 PSI anyway or it becomes bad fuel injection.
(uncontrolled fuel leak)

IF you are running EFI, having it connected is proper (but not required) as the manifold vacuum effects the injector flow.
With EFI you can tune it either direct connected to manifold vac or not referenced or with check valve boosted.
(not manifold ref under vacuum may make tuning it a little easier)

This is a sidedraft draw through fuel enrichment trick people have been doing for decades. Correct or not, it does what it needs to do float bowl is too small to provide an adequate supply, dellorto guys drill out the bottom of the float bowl to add capacity, they also add the pressure line to the regulator, with a one way valve, to quickly refill the bowl under boost. Good, bad or indifferent, its what we have done for a long time. If you don't do it while running a sidedraft weber or dell, the car won't run well under boost. Add that silly little line and the engine wakes up, makes a huge difference.

[advinnie]

Someone please help me out here I can't seem to get this right in my head.
If I fit a non return valve on the boost line going to the fuel regulator I under stand that when boost comes on the boost pressure over powers the valve and then the pressure hits the regulator and it increases fuel pressure BUT when boost decreases the non return valve will shut but surely it will hold some pressure in the line between the valve and regulator giving me the wrong fuel pressure?

[advinnie]

http://www.ebay.co.uk/itm/One-Way-Fuel- ... iid%253A15

Is this what I'm after?

[advinnie]

Can someone send me a link to what check valve I need please

[madmike]

try the 70 pump jet,, here's a pic for you, it's just a one-way 'smog valve' of some type u can blow air thew it only one-way

[advinnie]

But that's just a simple non return valve surly if I was on boost say 10psi and I suddenly come of the throttle that non return valve will close and trap some of the boost pressure in the boost sensitive fuel pressure line causing the regulator to produce to much fuel pressure?

[madmike]

Quit over thinking
It bleeds off the pressure

[Clonebug]

Drill a tiny hole in a brass nipple if you want the excess pressure to bleed out.

I did that with my MBC when I built one out of a 1/8 inch brass Tee.

[advinnie]

Ok so will this one do?
http://www.ebay.co.uk/itm/Non-Return-Va ... SwceNZTTA9