and for the millionth time...the wot boost bypass override revisited...

[Sp00ner]

Originally Posted by AlphaJaguar5

Ok Sp00ner you wanna rastle here we go:

When your car detects abuse on the driver your car gets limited to 9psi instead of the stock 12psi. That is common knowledge. Would GM consider drag racing abuse? Yes, I think they would. So lets say you loose 3psi because your "abusing" your car. Could that not be close to 30bhp, I think it could. And as for a better run... HELLLLLLLLLLLLLLLLLLLLLLL no. I'm going to scan ALL of my slips right now. I have 6 from my first trip and 10 from my second trip. All of the slips have which bypass I used during that run written on them.

Ummm... that's great... however, you're totally using the phrase 'abuse' in an ambiguous manner. You're defining 'abuse' in such a way that it supports your arguement, rather than as a term in which the meaning needs to be determined. If I'm not mistaken, there is a post from Wop that details exactly when the boost limit kicks in, and I don't think driving fast is one of them. My car dosen't limit the boost to 9psi under any situation. 3psi is not 30hp either. Otherwise, the Psi-Fi kit would be making 50-60hp before the additional tuning comes into play.

In addition, your slips are also pointless, unless you have exact data as to the rest of your runs. Throttle percentages, tire spin data, etc, etc, to determine if you just ran a better run, or were concentrating more.

The key for the bypass's is such:
Stock: No Bypass
Bypass 1:Plugging the line coming from the actuator to the solenoid and leaving the solenoid nipple open to air
Bypass 2:Plugging the line going to the actuator from the solenoid and leaving the actuator nipple open to the air
Bypass 3:Plugging the lind coming from the Intake Manifold to the solenoid and leaving the solenoid nipple open to the air

Give me me a min to scan all my slips but here are the pics for the way it should be hooked up:

Slips will be up in a minute...

I use the method the Psi-Fi also uses. So, I'm pretty sure it's a good one.

[Sp00ner]

In addition, I expect that you've seen the car limit itself to 9psi on your boost gauge, while doing these runs. I would also expact that you've seen that the stock boost is not really 12 psi either, that's what the boost limiter does. Without it attached you might hit 13psi. If you're basing everything on a few timeslips and how the car feels, well... not a great method...

[AlphaJaguar5]

Yes I have seen my MECHANICAL gauge limit the boost to 9psi and I couldnt figure out why until I changed my boost bypass and It went right up to 12 without even trying. And also I think basing everything on printed timeslips with the same driver, temperature, humidity, shoes, sense of how runs went is a DAMN good method of generating results. Now there are some different variables on each run of course but I will hardly... hold on a sec I have an excel spredsheet of my runs to throw up to invalidate your argument.

[AlphaJaguar5]

Slips from 1st to Last:


















Track Averages:

[Blue04RedLine]

Originally Posted by AlphaJaguar5

Slips from 1st to Last:


















Track Averages:

Pics aren't working alpha. Links are bad, so the site says when I tried copying and pasting them.

[AlphaJaguar5]

Yeah I know I just had to troubleshoot, they're fixed now

[racenpilot]

Bypass Valve Closed

Operation
Supercharger boost pressure is regulated to prevent engine and drive train damage. When the engine is operating under high boost conditions, the powertrain control module (PCM) limits boost pressure to 9 psi. The PCM disables boost under the following conditions:

* When reverse gear is selected
* When the engine coolant temperature is excessively high
* When drivetrain abuse is detected

The PCM controls boost pressure by using the boost control solenoid. The boost control solenoid is normally an open valve. Under most conditions, the PCM commands the boost control solenoid to operate at a 100 percent duty cycle. This keeps the solenoid valve closed and allows only inlet vacuum to control the position of the bypass valve. At idle, engine vacuum is applied to the upper side of the bypass valve actuator, counteracting spring tension to hold the bypass valve open. As engine load is increased, engine vacuum is decreased, causing the spring in the bypass valve actuator to overcome the applied vacuum, closing the bypass valve and allowing the boost pressure to increase. The bypass valve starts to close when the vacuum measures 250 mm Hg (10 in Hg) and is fully closed at 90 mm Hg (3.5 in Hg) . When reduced boost pressure is desired, the PCM commands the boost control solenoid to operate at a 0 percent duty cycle. This opens the solenoid valve and allows boost pressure to enter the bypass valve actuator at the lower side to counteract the spring tension, opening the bypass valve and recirculating excess boost pressure back into the supercharger inlet.

Results Of Incorrect Operation
An open boost control solenoid control circuit, an open ignition 1 circuit, or boost control solenoid valve stuck open will cause reduced engine power, especially during wide open throttle operation.

The boost control solenoid control circuit shorted to ground, boost control solenoid valve stuck closed or a restriction in the boost source or signal hoses will cause full boost to be commanded at all times and a possible overboost condition during high engine load situations.

A restriction in the vacuum signal hose to the bypass valve actuator or a stuck closed bypass valve will cause a rough idle and reduced fuel economy.

[racenpilot]

OPERATION
The supercharger is designed to pump more air than the engine would normally use. This excess air creates a boost pressure in the intake manifold. Maximum engine boost is 83 kPa (12 psi) . Because the supercharger is a positive displacement pump and is directly driven from the engine drive belt system, boost pressure is available at all driving conditions.

When boost is not desired, such as during idle and light throttle cruising, the excess air that the supercharger is producing is routed through the bypass passage between the intake manifold and the supercharger inlet. This bypass circuit is regulated by a bypass valve which is similar to a throttle plate. The bypass valve is controlled by a vacuum actuator which is connected to the vacuum signal between the throttle and the supercharger inlet. Spring force from the actuator holds the valve closed to create boost, and vacuum pulls the valve open when the throttle closes to decrease boost. The open bypass valve reduces pumping loss thereby increasing fuel efficiency.

The solenoid valve attached to the bypass actuator is an electronically controlled, 3-way valve. This valve, controlled by the powertrain control module (PCM), determines whether pressure from the manifold is routed to the bypass actuator or closed off. The valve allows pressure from the manifold to open the bypass valve and regulate boost pressure during specific driving conditions.

INTERCOOLER
The supercharger has an integrated intercooler. Cooling the air enhances the effectiveness of the supercharger. The intercooler uses conventional coolant in a separate sealed system from the engine cooling system. The intercooler system has a radiator, a reserve tank/filler neck, a pressure cap, attaching hoses, and a pump capable of a 26 liters (7 gallons) per minute flow rate. The pump is commanded ON, by the control module, whenever the engine is running.

[GuidoTSi]

The setup sounds very similar to an internally gated turbo using an electronic boost control solenoid and bypass valve. From what I've heard, the bypass valve in a turbo setup (read DSM....from experience) is incorrectly called a Blow-off Valve.

In the above setup, if the wastegate actuator arm was disconnected (wastegate fully open), no boost would develop as it would bleed off as soon as it was created. A vacuum fitting on the wastegate actuator led to the BCS, and if the hose was cut, or otherwise vented directly to atmosphere, an overboost condition develops as the wastegate would be held shut (30 psi on a stock 14B....seen it and it's scary).

The PCM in the RL seems like it manages this condition much more closely, as one of the first "free mods" in the turbo DSM world was to remove the stock BCS entirely and tee in a manual boost controller to the wastegate, the BPV vacuum fitting and to the intake manfold.

Here's a simple diagram of what I'm talking about. It ain't pretty, but it gets the point across.

DSM BCS Bypass

[AlphaJaguar5]

Well the above setup for the RL allows no boost to escape when the throttle is engaged but when you let off it goes straight to vaccum like normal. But if you even gently touch the throttle it gives you a boost till you let off, which I love and the beast loves it too