mount catchcan at an angle?
10-17-2009, 08:43 PM
#27
Here's the stock 317 port:
Lift......Int...........Exh
.100" ..64.8........53.3
.200"..142.1.......111.6
.300"..204.3.......146.8
.400"..233.5.......164.9
.500"..250.0.......174.2
.550"..251.2.......181.2
.600"..253.0.......184.4
PRC stage 1 317
.200"..147.......114
.300"..207.......148
.400"..255 .......187
.500"..292 .......202
.600"..313.......220
The stock 6.0 cam is something around .470 lift. If you extrapolate the above #s the ported heads are flowing something like 30 cfm more at that point. I didn't think it was that much of a difference. Today I put in a 02 0411 pcm and loaded up stock lq9 tune. It was doing like .750-.890 on the narrowband o2s, so it's pretty lean. I'm going to order the LC-1 and see what it reads. So, as the cause of my knock I ruled out so far fuel pressure, intake manifold and gaskets, PCM, oil mist, etc. I will fatten up the tune with the wideband on there and if it's still knocking at good AFR, I will add race gas and see what it does.
Lift......Int...........Exh
.100" ..64.8........53.3
.200"..142.1.......111.6
.300"..204.3.......146.8
.400"..233.5.......164.9
.500"..250.0.......174.2
.550"..251.2.......181.2
.600"..253.0.......184.4
PRC stage 1 317
.200"..147.......114
.300"..207.......148
.400"..255 .......187
.500"..292 .......202
.600"..313.......220
The stock 6.0 cam is something around .470 lift. If you extrapolate the above #s the ported heads are flowing something like 30 cfm more at that point. I didn't think it was that much of a difference. Today I put in a 02 0411 pcm and loaded up stock lq9 tune. It was doing like .750-.890 on the narrowband o2s, so it's pretty lean. I'm going to order the LC-1 and see what it reads. So, as the cause of my knock I ruled out so far fuel pressure, intake manifold and gaskets, PCM, oil mist, etc. I will fatten up the tune with the wideband on there and if it's still knocking at good AFR, I will add race gas and see what it does.
10-17-2009, 08:43 PM
#28
The spec according to the GM manual is 55-62 PSI with the key on, engine off. With the engine running at normal temp the pressure is supposed to drop 3-10 PSI. So my pressure of 49-50 PSI was in line. Also, I just took the videos and my FP is 58 PSI at WOT which I believe is perfect, someone correct me if I am wrong. I also pulled off the vacuum to the FPR at it was 60 psi at idle.
10-17-2009, 08:46 PM
#29
Is that the return or returnless GM spec? i guess since it is fine at WOT the pump is not causing your problems, maybe you should look into replacing that regulator... personally i would not want my FP to drop down to 49-50, wanna talk about leaning it out and toasting a motor....
btw, the intake, rails, injectors, fpr, etc are all brand new. The FPR is working perfectly. I pulled the vacuum to it and FP went up to 60.