383 H/C/I Results!!
#381
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Location: Coast of San Mateo County Between Pacifica & HMB
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OP has PRC 215 Cathedrals with a much better E/I Ratio.
I still believe that a well balanced HCI, combo up to
600 Crank HP, 7000 RPM, below 4.0" Bore & 400 CI,
(lot of qualifiers LOL!) will perform better on street &
track NA with 1 7/8" VS 2.0" LTS.
My .02
I still believe that a well balanced HCI, combo up to
600 Crank HP, 7000 RPM, below 4.0" Bore & 400 CI,
(lot of qualifiers LOL!) will perform better on street &
track NA with 1 7/8" VS 2.0" LTS.
My .02
#383
11 Second Club
Thread Starter
Can't wait. Hope to get the order in this coming week. I think there is about a 2 week period after ordering the headers.
The 1 7/8 may be the best all around header for my combo. Although what I want most is 5000-7000rpm power. Seeing as my camshaft has a small amount of positive overlap I don't think the bigger primaries will hurt my tq too much at all. The main thing, in my mind, will be the reduction in pumping losses in the upper rpm range.
Maybe now it will finally put 500rwhp. Probably just get another 495-499. Lol.
The 1 7/8 may be the best all around header for my combo. Although what I want most is 5000-7000rpm power. Seeing as my camshaft has a small amount of positive overlap I don't think the bigger primaries will hurt my tq too much at all. The main thing, in my mind, will be the reduction in pumping losses in the upper rpm range.
Maybe now it will finally put 500rwhp. Probably just get another 495-499. Lol.
#385
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#386
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#387
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#389
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Thread Starter
That may be. The intake setup on the car now is not bad. Do you mean go to a single plain setup or something?
Going with the 2" headers, on my motor, is me just taking the leap. I've read a lot about header size & it is still in the tumble. Lots of people move up in header size & see no gains "at the track". Some people do see gains. Just going off the trend with the LS heads they seem to like bigger primaries. Also depending of coarse. Some guys with around 450rwhp 347ci motors see very good gains, through the entire powerband, moving up to 1 7/8 from 1 3/4. I'm also pretty sure there are some high revving 347 combos with 2" primaries. If it works, awesome. If not, my fault. Heck Pipemax has 2" headers right on there, with my combo, for better mid to high end power. Exhaust system operating range of 4200-6700rpm. 1.75"-1.875" for better low to mid power in that rpm range.
I might as well put an LS3 top end on the motor right? Then will it run 10's or something? Lol.
Going with the 2" headers, on my motor, is me just taking the leap. I've read a lot about header size & it is still in the tumble. Lots of people move up in header size & see no gains "at the track". Some people do see gains. Just going off the trend with the LS heads they seem to like bigger primaries. Also depending of coarse. Some guys with around 450rwhp 347ci motors see very good gains, through the entire powerband, moving up to 1 7/8 from 1 3/4. I'm also pretty sure there are some high revving 347 combos with 2" primaries. If it works, awesome. If not, my fault. Heck Pipemax has 2" headers right on there, with my combo, for better mid to high end power. Exhaust system operating range of 4200-6700rpm. 1.75"-1.875" for better low to mid power in that rpm range.
I might as well put an LS3 top end on the motor right? Then will it run 10's or something? Lol.
#390
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An ls3 top end isn't a bad idea, but the bore is too small. I know you were being a little facetious there.
Helping the motor evacuate more air isn't ever bad. If you're looking to upgrade your headers already, might as well do 2".
I get a little less hung up on E/I ratio etc. I tend to look more at the whole system. I do think when you upsize your headers, you'll expose or augment any shortcomings of your induction system. You may want to consider doing them in conjunction with each other.
Helping the motor evacuate more air isn't ever bad. If you're looking to upgrade your headers already, might as well do 2".
I get a little less hung up on E/I ratio etc. I tend to look more at the whole system. I do think when you upsize your headers, you'll expose or augment any shortcomings of your induction system. You may want to consider doing them in conjunction with each other.
#391
Super Hulk Smash
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MAST 240cc LS3 for the 3.9" bore would be a rabble rouser on a 383...
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
#393
10 Second Club
MAST 240cc LS3 for the 3.9" bore would be a rabble rouser on a 383...
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
#394
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#395
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Originally Posted by JakeFusion
MAST 240cc LS3 for the 3.9" bore would be a rabble rouser on a 383...
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
Throw a 240/246 112+2 on there and go for big lift. Maybe an LLR... 246/252 .700/.680 112+2 and then use the FAST LS3 with mid-length runners and a 2" header. Would scream.
Flow Data w/3.900" Bore Plate
Lift Intake Exhaust
0.100 76 57
0.200 147 110
0.300 218 172
0.400 274 214
0.500 318 234
0.550 333 242
0.600 342 248
0.650 349 252
0.700 353 257
#397
10 Second Club
#400
11 Second Club
Thread Starter
I'm just not that interested in the ram air. My car is slow.
I've actually thought of how your car is doing. Any track time/mph?