ported NPI heads VS Stock PI heads
02-28-2007, 04:10 AM
#14
2nd Gear Member
Thread Starter
Join Date: Dec 2005
Location: Ny
Posts: 475
RE: ported NPI heads VS Stock PI heads
well i know vtstage 1 cams will clear pi heads...so i assume the same for npi heads....i have hurd ppl had issues with comp cams....but lightly modded cam ( liek a stage 1) will work
02-28-2007, 04:43 AM
#16
6th Gear Member
Join Date: Jan 2004
Location: United States
Posts: 12,575
RE: ported NPI heads VS Stock PI heads
ORIGINAL: droptoppony
ported NPI's are as good as ported PI's so what do you think you should do?
ported NPI's are as good as ported PI's so what do you think you should do?
stock PI < ported NPI < ported PI
Also, the stock compression on a 99-04 is not 8:1. Its either 9 or 9.5:1, I am fairly sure 9.
02-28-2007, 04:54 AM
#17
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Join Date: Jan 2007
Location: doylestown, pa
Posts: 386
RE: ported NPI heads VS Stock PI heads
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
02-28-2007, 05:38 AM
#18
6th Gear Member
Join Date: Jan 2004
Location: United States
Posts: 12,575
RE: ported NPI heads VS Stock PI heads
ORIGINAL: incubus1275
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
02-28-2007, 10:26 AM
#19
5th Gear Member
Join Date: Jul 2006
Location: Charlotte, NC
Posts: 3,151
RE: ported NPI heads VS Stock PI heads
ORIGINAL: 2000GT4.6
I am 99.936 percent sure that the 99-04 (PI) engines do not have a stock compression ratio of 10:1.
ORIGINAL: incubus1275
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
02-28-2007, 11:07 AM
#20
4th Gear Member
Join Date: Feb 2004
Location:
Posts: 1,895
RE: ported NPI heads VS Stock PI heads
ORIGINAL: incubus1275
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!
ok hold up! there are soo many false statements here it isnt funny. FIRST OFF any engine machinist will tell you that A LOT of your power is made up in the heads. PI heads use a totally different Intake port set up than NPI. NPI is much smaller and restricted than PI. The stock compression ratio for 96-98 mustangs is 9:1 and for 99-04 it is 10:1. With PI head your compression ratio will go from 9:1 to 10.25:1 because the pistons have less of a dish than the pistons in the PI motors upping the ratio to better than 99-04 standards. You will find about equal gains, but the cam profiles are different on each car. PI heads use cams with more lift and less duration than NPI heads.
Dont forget, if you get ported NPI heads...thats as far as you can go. you can port PI head out to flow much more than NPI. Do you really think for spends millions of dollars a year on research for nothing? they switched to PI for a reason. lets use some common sense here. also....why are the only real aftermarket heads PI??? because they can make way more power!