CAS Regulator (FI Stroker)... where do I start?
Thread Starter
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Joined: Nov 2001
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From: Raleigh, NC
CAS Regulator (FI Stroker)... where do I start? OK... I just completed the 8-Rib and pinned crank/Superdamper install, fuel rails and Boost Referenced CAS regulator.
So, I flatline the Inj Flow Rate Table, now, right?
I would like to have a lower base pressure (less than the 58~60) so I can let my Hi-Z 55# injectors pulse-widths be a little more at idle and slow cruise; is that plausible?
What is the lowest recommended Fuel Pressure (at idle and minimal throttle) I can use on this LS1?
Also, I expect 13, 14 or 15 PSI peak boost. (58 to 60) + 15 = (73# to 75#) peak fuel pressure at WOT may be a bit higher than necessary.
I would like to target as low a peak pressure as possible to make ~ 80% Inj Duty Cycle at WOT,
Any advice?
Any insights, Boost Referenced / Adj Rate Regulator users?
Thanks!
So, I flatline the Inj Flow Rate Table, now, right?
I would like to have a lower base pressure (less than the 58~60) so I can let my Hi-Z 55# injectors pulse-widths be a little more at idle and slow cruise; is that plausible?
What is the lowest recommended Fuel Pressure (at idle and minimal throttle) I can use on this LS1?
Also, I expect 13, 14 or 15 PSI peak boost. (58 to 60) + 15 = (73# to 75#) peak fuel pressure at WOT may be a bit higher than necessary.
I would like to target as low a peak pressure as possible to make ~ 80% Inj Duty Cycle at WOT,
Any advice?
Any insights, Boost Referenced / Adj Rate Regulator users?
Thanks!
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Joined: Nov 2001
Posts: 2,659
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From: Bellevue, Wa
I recommend starting at a base of 50. seems to be low enough to get the injectors happy at idle/cruise. You can always go lower and just monitor duty cycle. If it gets too high at full boost turn up the FP a little to compensate.
Yes you use the same value accross the board in the IFR table when you use this type of regulator.
Yes you use the same value accross the board in the IFR table when you use this type of regulator.
i set mine so that with the vaccum not connected to the regulator you get 60psi, just like stock. when you hook the vaccum up the fp will drop to 50ish..
that is still plenty as the injectors are rated at 3 bar which is 43#
i would also keep the max fp that it goes to under 80.. which would happen if you got over 20# boost.
that is still plenty as the injectors are rated at 3 bar which is 43#
i would also keep the max fp that it goes to under 80.. which would happen if you got over 20# boost.
TECH Addict
Joined: Nov 2001
Posts: 2,659
Likes: 1
From: Bellevue, Wa
so you set your base to 60 then.
I doubt he will have to set it that high but you never know.
you bring up a good point though. Mike, you set the base pressure with the vacum line disconnected.
so you set it to 50 for example then hook up the line and the guage will read low 40's but your effective fuel flow at the manifold is indeed that of 50psi. The whole point of a referenced regulator. No matter what, your effective flow will be that of what you set your base pressure to. When your in vacum there is less resistance at the manifold thus the regulator drops the pressure, when you go into boost your increase the resistance thus the regulator increases pressure. The net effect though is fuel flow of your base pressure setting.
Hopefully that makes sense.
I doubt he will have to set it that high but you never know.
you bring up a good point though. Mike, you set the base pressure with the vacum line disconnected.
so you set it to 50 for example then hook up the line and the guage will read low 40's but your effective fuel flow at the manifold is indeed that of 50psi. The whole point of a referenced regulator. No matter what, your effective flow will be that of what you set your base pressure to. When your in vacum there is less resistance at the manifold thus the regulator drops the pressure, when you go into boost your increase the resistance thus the regulator increases pressure. The net effect though is fuel flow of your base pressure setting.
Hopefully that makes sense.
Thread Starter
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Joined: Nov 2001
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From: Raleigh, NC
I set the base pressure to 60. I put the vacuum hose back on and it dropped to 55. I put it in gear.. the same. I drove around the block trying not to vary vacuum. 55 PSI.
So, are you saying from this point, my Fuel Pressure is really 5# more than I'm seeing at the gauge at idle or cruise at minimal throttle? If so, I'm assuming at zero vacuum, I'd see 60# fuel pressure.
That being the case, I'm understanding that 15 PSI peak boost would be 75 PSI fuel pressure. Do I have it?
Thanks!
So, are you saying from this point, my Fuel Pressure is really 5# more than I'm seeing at the gauge at idle or cruise at minimal throttle? If so, I'm assuming at zero vacuum, I'd see 60# fuel pressure.
That being the case, I'm understanding that 15 PSI peak boost would be 75 PSI fuel pressure. Do I have it?
Thanks!
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Verdad Gallardo TECH Addict
Joined: Nov 2001
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From: Bellevue, Wa
yes at 0 vacum your guage will read 60 and at 15psi it will read 75, you have that correct.
now as far as what you see on the guage when it reads 55 it is 55, but your seeing the exact same amount of FP at the manifold as you would with the vacum line off at idle with the guage reading 60. So you set your base to 60 well when your driving around in vacum there is in essense negative pressure against the fuel injectors/rails so to keep the same volume of fuel flowing the regulator lowers FP, thus the 55psi you see on the guage. Now when you go into boost your fighting the injectors/rails 1 psi at a time, so to over come that the regulator raises FP. So your FP is what it is on the guage but at the manifold it is ALWAYS 60psi.
No I don't think it's crazy to lower to 55 assuming you have enough injector. I actually run 50 base rising to 60.
now as far as what you see on the guage when it reads 55 it is 55, but your seeing the exact same amount of FP at the manifold as you would with the vacum line off at idle with the guage reading 60. So you set your base to 60 well when your driving around in vacum there is in essense negative pressure against the fuel injectors/rails so to keep the same volume of fuel flowing the regulator lowers FP, thus the 55psi you see on the guage. Now when you go into boost your fighting the injectors/rails 1 psi at a time, so to over come that the regulator raises FP. So your FP is what it is on the guage but at the manifold it is ALWAYS 60psi.
No I don't think it's crazy to lower to 55 assuming you have enough injector. I actually run 50 base rising to 60.
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From: Raleigh, NC
Originally Posted by MIGHTYMOUSE
i set mine so that with the vaccum not connected to the regulator you get 60psi, just like stock. when you hook the vaccum up the fp will drop to 50ish..
that is still plenty as the injectors are rated at 3 bar which is 43#
i would also keep the max fp that it goes to under 80.. which would happen if you got over 20# boost.
that is still plenty as the injectors are rated at 3 bar which is 43#
i would also keep the max fp that it goes to under 80.. which would happen if you got over 20# boost.
I wish I could have gotten all this together earlier to see how it ran in cooler weather. I guess that will have to wait til fall.
I hope my 4L60E lasts that long.
I don't intend to get it any stronger than whatever this setup does for a while. I'm not willing to go to a TH 350 or 400, yet and I can't afford another rebuild right now.