how to determine the correct boost pressure

whenmunkysfly

whenmunkysfly

scratch that...going 2jz
Jun 26, 2006
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United States
I did a search but there are too meny threads containing boost, pressure and determine. How is it that you guys determine the currect boost pressure for your car. I know you have to have the right mods, but how do you determine when its going to detonate the pistons do you go off of intake temp., trial and error, or what? thanks in advance for the info.
 
tubbie

tubbie

Yes, powerful Jedi....
Apr 4, 2005
821
0
16
Hoschton, GA
as the old saying goes.....

Build motor...
increase boost...
increase boost....
motor blows up...
build new motor...
set boost 2 psi below previous engine max boost....

:bigthumb:

Really, there is no true way to determine max boost. You will just have to monitor all that you can, hoping for no detonation along the way. But if you research others that have about the same upgrades or similiar upgrades as you, you can use their max boost and it will be close......
 
EdgeSupra

EdgeSupra

New Member
Feb 19, 2006
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New Jersey
I'm assuming you are asking what the boost should be raised to safely?
If so, then tuning is what you need to do. Start off low, and slowly raise the boost pressure in increments. As long as you don't get carried away and you did things right in the build and run the right fuel, you won't have any of those nasty issues.
*Edit: tubbie beat me, lol.
 
whenmunkysfly

whenmunkysfly

scratch that...going 2jz
Jun 26, 2006
746
0
0
United States
EdgeSupra said:
I'm assuming you are asking what the boost should be raised to safely?
If so, then tuning is what you need to do. Start off low, and slowly raise the boost pressure in increments. As long as you don't get carried away and you did things right in the build and run the right fuel, you won't have any of those nasty issues.
*Edit: tubbie beat me, lol.
Click to expand...
but how do you know when to stop raising it? like tubbie said just raise slowly til it blows?
 
D

Doward

Banned
Jan 11, 2006
4,245
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36
Alachua, FL
When your AFRs get too high (running out of fuel) or IATs get too high (turbo running out of air) or the rods say 'G'night folks!' :cool:
 
M

MKIIINA

Destroyer of Turbos
Mar 30, 2005
1,825
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41
Plano, TX
a better way to look at it is like this: what power do you want to hit at what boost pressure.

if you're shooting for 350rwhp at around 12 psi a slightly upgraded ct should work.
if you're shooting for higher go from there.

a motor could take large amounts of boost from a small turbo but unable to take medium levels from a much larger turbo. its more about flow than psi.
 
2543arvin

2543arvin

Moving to Japan!!!
Nov 30, 2006
879
0
0
Jacksonville, NC
s383mmber1 said:
Healthy engine
Intercooler and pipes
BIC downpipe and 3 inch exhaust
Intake
16PSI
Click to expand...
ive already got a new fmic with 2.5 piping and intake 3.5 downpipe with 2.5 exhaust.....i was gonna set the bc to 10psi because the only fuel upgrades ihave so far is the walbro 255...what else do i need to take it to 16 psi?
 
starscream5000

starscream5000

Senior VIP Member
Aug 23, 2006
6,359
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Hot and Humid, KY
Get a WB and you'll know when you're getting close to melting pistons. That's the safest way to tune becaust you know what's going on instead of just shooting in the dark.
 
GrimJack

GrimJack

Administrator
Dec 31, 1969
12,377
3
38
56
Richmond, BC, Canada
idriders.com
- Basic maintenance - you can't run 300 whp on old seals, hoses, and gaskets.
- Fix the intake... buy a AEM dryflow intake kit or a Blitz setup.
- Take off and replace the turbo elbow, downpipe, and exhaust with 3" units. My personal favorites are the BIC DDP for a downpipe and the exhaust from him as well.
- Add a boost controller. This could be as simple as a ball and spring MBC from DrJonez.
- Pull off your intercooler and IC pipes, replace with a decent unit and hardpipes. Talk to Aaron at Driftmotion.

At this point you should be awfully close to 300 at the wheels... probably 285, anyway. And from here it gets complicated. For the next bit you need to buy bigger injectors, some fuel lines, an AFPR, and something to mess with your air signal. My personal setup is RC 550cc injectors, and Aeromotive AFPR, stainless lines from Horsepowerfreaks for the fuel, and a MAFT Pro running on speed density plus the boost control harness from DrJonez.

Then you'll need some good tuning and you should be well over your goal.
 
2543arvin

2543arvin

Moving to Japan!!!
Nov 30, 2006
879
0
0
Jacksonville, NC
starscream5000 said:
Get a WB and you'll know when you're getting close to melting pistons. That's the safest way to tune becaust you know what's going on instead of just shooting in the dark.
Click to expand...
its good to see members from kentucky...im from berea, then i moved to NC when i joined the marines.....anyways...what is a WB??
 
2543arvin

2543arvin

Moving to Japan!!!
Nov 30, 2006
879
0
0
Jacksonville, NC
GrimJack said:
- Basic maintenance - you can't run 300 whp on old seals, hoses, and gaskets.
- Fix the intake... buy a AEM dryflow intake kit or a Blitz setup.
- Take off and replace the turbo elbow, downpipe, and exhaust with 3" units. My personal favorites are the BIC DDP for a downpipe and the exhaust from him as well.
- Add a boost controller. This could be as simple as a ball and spring MBC from DrJonez.
- Pull off your intercooler and IC pipes, replace with a decent unit and hardpipes. Talk to Aaron at Driftmotion.

At this point you should be awfully close to 300 at the wheels... probably 285, anyway. And from here it gets complicated. For the next bit you need to buy bigger injectors, some fuel lines, an AFPR, and something to mess with your air signal. My personal setup is RC 550cc injectors, and Aeromotive AFPR, stainless lines from Horsepowerfreaks for the fuel, and a MAFT Pro running on speed density plus the boost control harness from DrJonez.

Then you'll need some good tuning and you should be well over your goal.
Click to expand...
i already have a K&N intake and a MBC and a big fmic w/ 2.5 hardpipes, but i have been looking at the BIC DDP so that along with a 3" exhaust is probly next. thanks
 
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