just switching the tubes works great for free
Boost ByPass Poll-The Final Verdict
- Thread starter 04-MystiChrome
- Start date
i wll be trying the RPM free mod at the track tomorrow...ive been skeptical on this also but have to try for myself.
dunno if this matters..but i did the boost bypass..and went .3 faster today at thr track and gained 2mph....stock pulley...see sig..last week was a 12.24@118
car SEEMS to pull a bit harder on the highway....could be imagination though....:shrug:
car SEEMS to pull a bit harder on the highway....could be imagination though....:shrug:
Dyno results of "Boost Bypass" mod
This is in regards to the "RPM OUTLET" mod, which consists of re-routing two vacuum lines.
The car felt somewhat stronger after I'd completed the modification, but I decided to spring for fifty bucks for a single pull on a Mustang dyno (I was on the same dyno two weeks ago).
The only differences since my last dyno outing was a twenty-six degree drop in outside temperature and the boost bypass mod.
The car felt slightly weaker during the pull, but the truth quickly emerged at 5486.18 (R.P.M.) when all hell broke loose. The car went into a hissy fit, which caused me to quickly get off the gas pedal. At that point there was a loud backfire that really pissed me off. :mj:
The chart shows that my car reached 391.77 HP before going Section-eight. My previous dyno reading was 407HP at the same exact point. There was a definite drop off in HP across the board with the mod.
The Dyno guy showed me how utterly lean the car became and recommended I go another route, such as replacing the 8psi factory valve with a 12psi valve to compensate for my 2.93 pulley change.
I'm running an '03 Cobra with:
Cold Air Intake
2.93 non-slip pulley with 1 100mm idler
Gatorback belt (soon to be replaced with a Gates because of excessive wear after only 400 miles of use)
Diablo Preditor with standard 93 octane pulley tune.
I'll get back with the results of the valve update in about two weeks when I bring the car back in for another tune.
Peter M
This is in regards to the "RPM OUTLET" mod, which consists of re-routing two vacuum lines.
The car felt somewhat stronger after I'd completed the modification, but I decided to spring for fifty bucks for a single pull on a Mustang dyno (I was on the same dyno two weeks ago).
The only differences since my last dyno outing was a twenty-six degree drop in outside temperature and the boost bypass mod.
The car felt slightly weaker during the pull, but the truth quickly emerged at 5486.18 (R.P.M.) when all hell broke loose. The car went into a hissy fit, which caused me to quickly get off the gas pedal. At that point there was a loud backfire that really pissed me off. :mj:
The chart shows that my car reached 391.77 HP before going Section-eight. My previous dyno reading was 407HP at the same exact point. There was a definite drop off in HP across the board with the mod.
The Dyno guy showed me how utterly lean the car became and recommended I go another route, such as replacing the 8psi factory valve with a 12psi valve to compensate for my 2.93 pulley change.
I'm running an '03 Cobra with:
Cold Air Intake
2.93 non-slip pulley with 1 100mm idler
Gatorback belt (soon to be replaced with a Gates because of excessive wear after only 400 miles of use)
Diablo Preditor with standard 93 octane pulley tune.
I'll get back with the results of the valve update in about two weeks when I bring the car back in for another tune.
Peter M
maybe this was mentioned before...
...or maybe not
(this post is too big to read)
for what its worth, i think this is specifically mentioned in the Ford workshop manual
SECTION 303-12: Intake Air Distribution and Filtering 2004 Mustang Workshop Manual
DESCRIPTION AND OPERATION Procedure revision date: 06/25/2003
--------------------------------------------------------------------------------
Intake Air Distribution and Filtering —Supercharger, Charge Air Cooler Printable View (10 KB)
The supercharger (SC) is a positive displacement pump. Its purpose is to supply an excess volume of intake air to the engine by increasing air pressure and density in the intake manifold. The supercharger is matched to the engine by its displacement and belt ratio, and can provide excess airflow at any engine speed.
NOTE: The supercharger is repaired only as an assembly. Disassembly of the supercharger unit may void the warranty.
NOTE: The supercharger is not a bolt-on option. It is part of an integrated engine system. Many components of the supercharged engine are not interchangeable with similar parts from a non-supercharged engine.
The supercharger contains two three-lobed rotors. The helical shape and specialized porting provide a smooth discharge flow and low level of noise during operation. The rotors are supported by ball bearings in front and needle bearings at the rear. The drive gears are pressed into place, therefore the supercharger is installed new as a unit, and is not repairable.
The supercharger system is a blow-through type with the fuel injected directly into the intake ports. The supercharger is belt driven off the crankshaft through an idler pulley. The throttle body controls the amount of intake air to the supercharger through the intake plenum. Air from the supercharger is routed through the charge air cooler (CAC), then to the intake manifold. The resulting denser air charge in the combustion chamber provides for a higher power output of the engine over a non-supercharged engine of the same displacement.
NOTE: It is not possible to increase manifold pressure or engine power output by altering the bypass valve or the actuator.
At partial-throttle opening or when vacuum is present in the intake system, a vacuum-controlled bypass valve reroutes some discharged air from the supercharger back through the intake plenum. This prevents the supercharger from cavitating, causing reduced performance, increased temperatures, and poor fuel economy.
The supercharger has a self-contained oiling system that does not require a fluid change for the life of the vehicle. However, at every 30,000 mile interval, the supercharger fluid level should be checked. The vehicle should be parked on a level surface, the engine cool, and not running. To check the oil, remove the Allen head plug located at the front of the supercharger. The oil level should be at the bottom of the fill plug threads when cold. If the fluid level is low, add Synthetic Supercharger Fluid E9SZ-19577-A or equivalent meeting Ford specification ESE-M99C115–A
Supercharged vehicles are equipped with a charge air cooler (CAC). The CAC cools the pressurized air from the supercharger, increasing the air density, which improves combustion efficiency, engine horsepower and torque.
...or maybe not
(this post is too big to read)
for what its worth, i think this is specifically mentioned in the Ford workshop manual
SECTION 303-12: Intake Air Distribution and Filtering 2004 Mustang Workshop Manual
DESCRIPTION AND OPERATION Procedure revision date: 06/25/2003
--------------------------------------------------------------------------------
Intake Air Distribution and Filtering —Supercharger, Charge Air Cooler Printable View (10 KB)
The supercharger (SC) is a positive displacement pump. Its purpose is to supply an excess volume of intake air to the engine by increasing air pressure and density in the intake manifold. The supercharger is matched to the engine by its displacement and belt ratio, and can provide excess airflow at any engine speed.
NOTE: The supercharger is repaired only as an assembly. Disassembly of the supercharger unit may void the warranty.
NOTE: The supercharger is not a bolt-on option. It is part of an integrated engine system. Many components of the supercharged engine are not interchangeable with similar parts from a non-supercharged engine.
The supercharger contains two three-lobed rotors. The helical shape and specialized porting provide a smooth discharge flow and low level of noise during operation. The rotors are supported by ball bearings in front and needle bearings at the rear. The drive gears are pressed into place, therefore the supercharger is installed new as a unit, and is not repairable.
The supercharger system is a blow-through type with the fuel injected directly into the intake ports. The supercharger is belt driven off the crankshaft through an idler pulley. The throttle body controls the amount of intake air to the supercharger through the intake plenum. Air from the supercharger is routed through the charge air cooler (CAC), then to the intake manifold. The resulting denser air charge in the combustion chamber provides for a higher power output of the engine over a non-supercharged engine of the same displacement.
NOTE: It is not possible to increase manifold pressure or engine power output by altering the bypass valve or the actuator.
At partial-throttle opening or when vacuum is present in the intake system, a vacuum-controlled bypass valve reroutes some discharged air from the supercharger back through the intake plenum. This prevents the supercharger from cavitating, causing reduced performance, increased temperatures, and poor fuel economy.
The supercharger has a self-contained oiling system that does not require a fluid change for the life of the vehicle. However, at every 30,000 mile interval, the supercharger fluid level should be checked. The vehicle should be parked on a level surface, the engine cool, and not running. To check the oil, remove the Allen head plug located at the front of the supercharger. The oil level should be at the bottom of the fill plug threads when cold. If the fluid level is low, add Synthetic Supercharger Fluid E9SZ-19577-A or equivalent meeting Ford specification ESE-M99C115–A
Supercharged vehicles are equipped with a charge air cooler (CAC). The CAC cools the pressurized air from the supercharger, increasing the air density, which improves combustion efficiency, engine horsepower and torque.
That blurb about the bypass just refers to the bypass valve itself, not the computer actuated solenoid that the bypass mod addresses (disables). The mod only removes computer control from the bypass valve...that's it.
1fastford, you can do this with any pulley.
1fastford, you can do this with any pulley.
Users who are viewing this thread
