GT2871 USERS. SR motor

[jspaeth]

Originally Posted by garagelu

You don't need to get all technical on me. I know you are supposed to check fp with the vacuum line detached. I was just trying to get my point across which is when you increase the boost, a stock fuel pressure regulator may not be able to keep up when hitting full boost/max fuel pressure.

And if you are on the dyno or running on the street, you won't be reading with the vacuum detached....it would be attached. So you set it with the vacuum line off, but read it on if you are running the car.

SO YOU ARE WRONG

In case you can't read, I was agreeing with you about stock FPR not being able to keep up (even tho time and time again people have shown it works just fine for very high boost applications.

I am not wrong. You suggested that FP under 7 psi boost is 43 psi which is wrong.

Sorry, but good try.

[garagelu]

Originally Posted by jspaeth

In case you can't read, I was agreeing with you about stock FPR not being able to keep up (even tho time and time again people have shown it works just fine for very high boost applications.

I am not wrong. You suggested that FP under 7 psi boost is 43 psi which is wrong.

Sorry, but good try.

Read my first post about this. I said when you hit full boost at 7 psi not under 7psi boost. Not sure where you got that from....

With vacuum ATTACHED (I am not talking about setting fuel pressure since it should already be set) at idle if you are running stock fuel pressure you should be at 36 psi. Since our regulators are 1:1 ratio, for every lb of boost you should see an increase of 1 psi of fp. So 36 + 7 = 43 psi.

And I guess you are not understanding my logic.....you should keep an eye on the fp gauge to make sure it keeping steady fp throughout the rpm. When you are running on the dyno, the vacuum will be attached which means your numbers don't apply. So WHEN RUNNING THE CAR at stock fp, the gauge should read 36 psi and at full boost of 7psi it should be holding 43 psi to redline.

And I never mentioned anything about you disagreeing on the topic of upgrading fpr in my second post.

[jspaeth]

Originally Posted by garagelu

Read my first post about this. I said when you hit full boost at 7 psi not under 7psi boost. Not sure where you got that from....

With vacuum ATTACHED (I am not talking about setting fuel pressure since it should already be set) at idle if you are running stock fuel pressure you should be at 36 psi. Since our regulators are 1:1 ratio, for every lb of boost you should see an increase of 1 psi of fp. So 36 + 7 = 43 psi.

And I guess you are not understanding my logic.....you should keep an eye on the fp gauge to make sure it keeping steady fp throughout the rpm. When you are running on the dyno, the vacuum will be attached which means your numbers don't apply. So WHEN RUNNING THE CAR at stock fp, the gauge should read 36 psi and at full boost of 7psi it should be holding 43 psi to redline.

And I never mentioned anything about you disagreeing on the topic of upgrading fpr in my second post.

WRONG!

THe car reads 36 psi FP because the vacuum is -7 psi. So when you boost 7 psi, that is actuall 36 + 7 psi = 43 psi when the manifold is at 0 PSI (atmostpheric)

......PLUS an additional 7 psi on top of that for the boost!

So it should be 50 psi.

Someone please chime in so it's not just me on this.

[garagelu]

Originally Posted by jspaeth

WRONG!

THe car reads 36 psi FP because the vacuum is -7 psi. So when you boost 7 psi, that is actuall 36 + 7 psi = 43 psi when the manifold is at 0 PSI (atmostpheric)

......PLUS an additional 7 psi on top of that for the boost!

So it should be 50 psi.

Someone please chime in so it's not just me on this.

Set your fp to stock setting and go run your car on the dyno. Come back here and let me know what your gauge reads.

[codyace]

Originally Posted by jspaeth

WRONG!

THe car reads 36 psi FP because the vacuum is -7 psi. So when you boost 7 psi, that is actuall 36 + 7 psi = 43 psi when the manifold is at 0 PSI (atmostpheric)

......PLUS an additional 7 psi on top of that for the boost!

So it should be 50 psi.

Someone please chime in so it's not just me on this.

When your car is running, and the vacuum line is disconnected (simulated WOT, but without boost) it should read 43.5 psi. Knowing what the fuel pressure is, when idleing, should be somewhere in the 34-38 range...but this measurement is silly as it can be so different. Again, the main measurement should be vacuum line off, car idleing, 43.5.

So at 10 psi of boost you should see 53.5, 20 psi of boost 63.5.