max boost on a 4 bolt head.
02-27-2015, 03:31 PM
#21
Bringing back an old thread. 454 LS Iron Dart Block. 9:4:1 F2 Procharger. 4 bolt head with a 28.5 psi pulley. Boost went above 30psi but the graphs show 22 psi when the coolant pressure spiked. Essentially the heads lifted at 22psi with cometic head gaskets 4.205 gaskets.053 thick.
02-28-2015, 12:27 AM
#23
TECH Apprentice
Join Date: Dec 2004
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
overboosting too early in the rpms and excess cyl pressure too early can bend up some pretty nice parts
a little bigger turbo and lag that ramps upstairs and really comes on can be a good way to go
I have the ttix kit and it actually hits a bit hard with the tiny turbos
a little bigger turbo and lag that ramps upstairs and really comes on can be a good way to go
I have the ttix kit and it actually hits a bit hard with the tiny turbos
02-28-2015, 01:48 PM
#28
Haha a. Steam cleaned. Yea...I felt bad. KP Racing. I'm having to pull the motor to get to the rear freeze plug that blew out behind the flywheel too. Tapping then bitches this time and sealing for good. If it lifts the head this next time hopefully it'll blow out a radiator hose lol and not a freeze plug.
And that guy who says he's running 35psi on a 4 bolt head is either running 8:4:1 compression or he's Oring-ed his block and head or he's a liar. 22psi and **** got ugly real quick on a brand new engine. I just showed that. What computer are you running. What kind of car. The Corvettes factory PCM can only read 22 psi of map,after that the Tuner can add up to 30psi through hp tuners into the computer. Past that point an aftermarket computer is required.
And that guy who says he's running 35psi on a 4 bolt head is either running 8:4:1 compression or he's Oring-ed his block and head or he's a liar. 22psi and **** got ugly real quick on a brand new engine. I just showed that. What computer are you running. What kind of car. The Corvettes factory PCM can only read 22 psi of map,after that the Tuner can add up to 30psi through hp tuners into the computer. Past that point an aftermarket computer is required.
02-28-2015, 05:40 PM
#30
TECH Apprentice
Haha a. Steam cleaned. Yea...I felt bad. KP Racing. I'm having to pull the motor to get to the rear freeze plug that blew out behind the flywheel too. Tapping then bitches this time and sealing for good. If it lifts the head this next time hopefully it'll blow out a radiator hose lol and not a freeze plug.
And that guy who says he's running 35psi on a 4 bolt head is either running 8:4:1 compression or he's Oring-ed his block and head or he's a liar. 22psi and **** got ugly real quick on a brand new engine. I just showed that. What computer are you running. What kind of car. The Corvettes factory PCM can only read 22 psi of map,after that the Tuner can add up to 30psi through hp tuners into the computer. Past that point an aftermarket computer is required.
And that guy who says he's running 35psi on a 4 bolt head is either running 8:4:1 compression or he's Oring-ed his block and head or he's a liar. 22psi and **** got ugly real quick on a brand new engine. I just showed that. What computer are you running. What kind of car. The Corvettes factory PCM can only read 22 psi of map,after that the Tuner can add up to 30psi through hp tuners into the computer. Past that point an aftermarket computer is required.
02-28-2015, 07:25 PM
#31
TECH Senior Member
iTrader: (7)
At the risk of mudding the water and possibly making myself sound like a moron, why is everyone concerned about boost number? Making power is not about boost, but about flow capacity. Boost is a measure of resistance and past a certain point will only generate heat, not power.
Having the right components like good flowing heads, proper cam, etc...will allow you to make more power at lower boost levels, which should ultimately be the goal for anyone.
Andrew
Having the right components like good flowing heads, proper cam, etc...will allow you to make more power at lower boost levels, which should ultimately be the goal for anyone.
Andrew
02-28-2015, 08:17 PM
#32
Boost and Flow Andrew,
I agree with you. I was just surprised the 454 cid set up popped like that. Maybe those heads were too restrictive for that much flow. That's why I was wanting more information on the situation.
Denmah has shown us enough crazy good tuned up runs on here to make me curious about what is causing issues.
I agree with you. I was just surprised the 454 cid set up popped like that. Maybe those heads were too restrictive for that much flow. That's why I was wanting more information on the situation.
Denmah has shown us enough crazy good tuned up runs on here to make me curious about what is causing issues.
03-01-2015, 05:18 AM
#35
TECH Apprentice
Join Date: Dec 2004
Posts: 355
Likes: 0
Received 0 Likes
on
0 Posts
yup, boost is just stacked up air with no where to go 
on my old turbo buick, I upgraded the heads and turbo at the same time
lowered the boost from 23 to 18 psi, ZERO detonation, and the car picked up from 11.2 to 10.8
cfm and cyl pressure tell the tale, but are harder to discuss and measure
on my old turbo buick, I upgraded the heads and turbo at the same time
lowered the boost from 23 to 18 psi, ZERO detonation, and the car picked up from 11.2 to 10.8
cfm and cyl pressure tell the tale, but are harder to discuss and measure
