Why 12PSI on stock comp with Meth?
Thread Starter
Joined: Jan 2008
Posts: 9,570
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From: New Jersey
Why 12PSI on stock comp with Meth?
Ok, so I have seen one or two people upping the boost on the stock HeadGasket, I think someone on here is running 12PSI onstock HG with no Meth or anything.
I understand I could safely run 12PSI with METH, but why? I know I will run a cooler temperature but what does that have to do with how much PRESSURE the stock HG can withstand, I mean Hot or Cold, 12 PSI is 12 PSI no?
I understand I could safely run 12PSI with METH, but why? I know I will run a cooler temperature but what does that have to do with how much PRESSURE the stock HG can withstand, I mean Hot or Cold, 12 PSI is 12 PSI no?
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Joined: Dec 2007
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From: Raleigh, NC
It's not the head gasket. Detonation is the only thing you should worry about. Det is caused by the charge igniting itself in an explosive matter instead of burning from top to bottom. This results in VERY high cylinder temps and VERY high pressure pulses that melt and crack pistons and cylinders. You stop det by either lowering the charge temp to prevent the compression from pushing it above flash point, or you raise the octane which raises the flash point of the mixture. W/M does both. Most people change the head gasket to lower compression which results in the charge not being squeezed as hard. This causes a lower charge temp at ignition. The whole point of this is to ensure that the fuel is only lit by the spark plug.
Also:12psi isn't 12psi. Psi is a function of volume, or cross area of the pipe. A bigger pipe at 12psi is flowing more air than a small pipe at 12psi. CFM is what you should use to judge a system. The reason our turbos run out around 10 is heat. the smaller compressor is squeezing harder to reach 12 than a larger turbo. You start running into det as discussed above.
Also:12psi isn't 12psi. Psi is a function of volume, or cross area of the pipe. A bigger pipe at 12psi is flowing more air than a small pipe at 12psi. CFM is what you should use to judge a system. The reason our turbos run out around 10 is heat. the smaller compressor is squeezing harder to reach 12 than a larger turbo. You start running into det as discussed above.
Thread Starter
Joined: Jan 2008
Posts: 9,570
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From: New Jersey
you da man, 
, I understand , which makes sense I did know that by compressing air it heats it up, why I didnt relate it to this is beyond me 
, Yeah I am trying to figure out if I am going to spike past 12PSI with my Berk HFC, it spiked a lil bit past 10 yesterday and it wasnt even sub 70 out 
.
, I understand , which makes sense I did know that by compressing air it heats it up, why I didnt relate it to this is beyond me , Yeah I am trying to figure out if I am going to spike past 12PSI with my Berk HFC, it spiked a lil bit past 10 yesterday and it wasnt even sub 70 out .
Registered User
Joined: Dec 2007
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From: Raleigh, NC
That has to do with flow. I can't answer that question for you, as I don't know yet myself. I have a Ti-C 70mm single and the OEM cat, but my clutch died before I could make a WOT pull with it. I'd like to see how you do with the HFC. How high did your turbo go without the boost controller? I know i had much better controll once I adjusted my WG actuator. I was boosting to 10psi though... 
Thread Starter
Joined: Jan 2008
Posts: 9,570
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From: New Jersey
I dont know I have only had the Berk HFC in with the Manual Boost controller
Hey my Turbo is off my car should I try and adjust the W/G actuator, is it complicated, I don't want to break anything but my turbo is just sitting in the garage so lonely
Hey my Turbo is off my car should I try and adjust the W/G actuator, is it complicated, I don't want to break anything but my turbo is just sitting in the garage so lonely
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Thread Starter
Joined: Jan 2008
Posts: 9,570
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From: New Jersey
This sound right
For future reference, here is the procedure to check to make sure your actuator is set correctly:
1. While the turbo is off the car, remove the C clip securing the actuator arm to the wastegate flapper arm.
2. loosen the 10mm lock nut on the actuator arm.
3. At this point you will notice that there is slight tension on the actuator arm if you try to pull it off.
4. Pull the actuator arm free from the wastegate flapper arm.Twist (loosen) the end of the actuator arm so that the arm lengthens to the point where it can slide off and on to the flapper arm freely.
5. From this point, turn the end of the actuator arm back (shorten), 3.5 turns.
6. The actuator arm should not easily slide onto the wastegate flapper arm, so now there is a slight bit of tension. Pull on the actuator arm if you need to, in order to get it onto the wastegate flapper arm. Tighten the lock nut back up against the actuator arm. TRBOKEV I SUSPECT YOU HAVE TOO MUCH TENSION HERE, WHICH DELAYS THE OPENING OF THE FLAPPER VALVE
7. Put the C clip back on to secure the actuator arm and you're done.
8. To test this, you can get a mechanical boost gauge, an air compressor and a 3 way fitting and test when the actuator arm starts to move. It should start to move at about 8-8.5 psi
For future reference, here is the procedure to check to make sure your actuator is set correctly:
1. While the turbo is off the car, remove the C clip securing the actuator arm to the wastegate flapper arm.
2. loosen the 10mm lock nut on the actuator arm.
3. At this point you will notice that there is slight tension on the actuator arm if you try to pull it off.
4. Pull the actuator arm free from the wastegate flapper arm.Twist (loosen) the end of the actuator arm so that the arm lengthens to the point where it can slide off and on to the flapper arm freely.
5. From this point, turn the end of the actuator arm back (shorten), 3.5 turns.
6. The actuator arm should not easily slide onto the wastegate flapper arm, so now there is a slight bit of tension. Pull on the actuator arm if you need to, in order to get it onto the wastegate flapper arm. Tighten the lock nut back up against the actuator arm. TRBOKEV I SUSPECT YOU HAVE TOO MUCH TENSION HERE, WHICH DELAYS THE OPENING OF THE FLAPPER VALVE
7. Put the C clip back on to secure the actuator arm and you're done.
8. To test this, you can get a mechanical boost gauge, an air compressor and a 3 way fitting and test when the actuator arm starts to move. It should start to move at about 8-8.5 psi
Joined: Sep 2003
Posts: 10,301
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From: New Jersey
Originally Posted by SgtB,Oct 11 2008, 05:24 PM
It's not the head gasket. Detonation is the only thing you should worry about. Det is caused by the charge igniting itself in an explosive matter instead of burning from top to bottom. This results in VERY high cylinder temps and VERY high pressure pulses that melt and crack pistons and cylinders. You stop det by either lowering the charge temp to prevent the compression from pushing it above flash point, or you raise the octane which raises the flash point of the mixture. W/M does both. Most people change the head gasket to lower compression which results in the charge not being squeezed as hard. This causes a lower charge temp at ignition. The whole point of this is to ensure that the fuel is only lit by the spark plug.
Also:12psi isn't 12psi. Psi is a function of volume, or cross area of the pipe. A bigger pipe at 12psi is flowing more air than a small pipe at 12psi. CFM is what you should use to judge a system. The reason our turbos run out around 10 is heat. the smaller compressor is squeezing harder to reach 12 than a larger turbo. You start running into det as discussed above.
Also:12psi isn't 12psi. Psi is a function of volume, or cross area of the pipe. A bigger pipe at 12psi is flowing more air than a small pipe at 12psi. CFM is what you should use to judge a system. The reason our turbos run out around 10 is heat. the smaller compressor is squeezing harder to reach 12 than a larger turbo. You start running into det as discussed above.