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Turn on Supercharger


hitman007
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For new owners who were confused by the owners manual like me I would like to point out that the manual is incorrect on the procedure to turn on the supercharger. The real answer is you must drive the car for 15 miles or more non-stop to activate the supercharger. I was surprised that many dealers are putting the 15 miles on to do this before delivery. My car only had 12 miles on it when delivered.

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Not turned on? The sc is mechanically driven and is "on" the moment the engine is started just as you alternator or power steering pump. Do you me generating boost? Measurable boost is generated at a specific RPM and above. This would have nothing to do with the miles driven. I guess it is possible that the tune from the factory could prevent the engine from obtaining an RPM where boost could generated until a set number of miles are reach. Is this want you mean by turned on?

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Not turned on? The sc is mechanically driven and is "on" the moment the engine is started just as you alternator or power steering pump. Do you me generating boost? Measurable boost is generated at a specific RPM and above. This would have nothing to do with the miles driven. I guess it is possible that the tune from the factory could prevent the engine from obtaining an RPM where boost could generated until a set number of miles are reach. Is this want you mean by turned on?

 

The boost is not only dependant on rpm, it is also dependant on the amount of load being demanded of the system. If you do not put a heavy load on the engine, you can run the rpm's to redline without seeing(or feeling) any boost.

 

Form another forum I'm on regarding a similar issue:

 

Grey03Cobra:

The GT500's and 03/04 Cobra's have a boost bypass valve. When the engine is under vacuum the bypass is open allowing for the boost to be "dumped" out. You can drive at part throttle all the way to redline if you want and you will show no boost. As far as full boost goes, it is almost immediate when you mash the pedal, that is the benefit of the Eaton blowers over other types of superchargers and turbos in which the amount of boost is RPM dependent.

Edited by mustang68w
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The boost is not only dependant on rpm, it is also dependant on the amount of load being demanded of the system. If you do not put a heavy load on the engine, you can run the rpm's to redline without seeing(or feeling) any boost.

 

Form another forum I'm on regarding a similar issue:

 

Grey03Cobra:

The GT500's and 03/04 Cobra's have a boost bypass valve. When the engine is under vacuum the bypass is open allowing for the boost to be "dumped" out. You can drive at part throttle all the way to redline if you want and you will show no boost. As far as full boost goes, it is almost immediate when you mash the pedal, that is the benefit of the Eaton blowers over other types of superchargers and turbos in which the amount of boost is RPM dependent.

 

Damn, I spaced on the bypass valve. Clear as mud now, thanks.

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Interesting..there seems to be many different theories. I suspect the PCM is programmed to keep the dump valve open so not supercharging can take place until the engine has a few miles to let the rings, etc. get broken in. My dealer told me 15 miles and I continued to try to get boost while driving and the needle was pegged at 0 until I hit 15.2 miles than it started to move.

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This topic still has me stumped!? Yes I had the same issue with the blower upon delivery. NO BOOST at all! But after 5 miles of driving the boost came on. The dealer was not aware of this but as I said in a previous post, a mechanic found a memo on his computer that said that you have to drive 5 miles non- stop for the blower to " activate ". ? I do not know how this is possible? I hear mention of a bypass valve but I see nothing on my blower that even resembles a air release valve? If so how do you turn the blower off if you want your son or wife to drive it with limited horsepower? I think that is a valid question? Any Ford SVT guys out there? Thanks Guys, denohew Also without boost my family mini van could out drag race this car!

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Maybe it is RPM's? My car had 8 miles on it. But as I recall I was at redline and still no boost until the 5 miles!? Still stumped, denohew

 

Your car's 8 miles could have been a combination of 8 1 mile drives. Or 16 half mile drives. Doesn't meet the test. The owners manual clearly states 5 consecutive miles or 50 start cycles/

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  • 1 month later...
i have over 350 kms (sorry im metric) and still no boost registering. ive gone on the highway for stretches of way more that 5 Miles. still no boost. im wondering if it is 50 key start/WARM UP cycles as the manual says meaning i have to warm the car from cold to hot 50 times.

 

Hi Cobraroofer and welcome to the forums:

 

Forgive me, if you already are familiar with the workings of this type of Supercharger. Boost does not constantly turn on...it's only when you really get on the gas. An easy way to test it is get on a highway and put it in 5th gear...drop down to about 40 MPH and then step on the gas fairly hard. The boost needle should move immediately.

 

I've yet to come across someone that had to go through the 50 startup cycle to activate the supercharger. The dealer should have activated it for you. Hope that helps.

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Hi Cobraroofer and welcome to the forums:

 

Forgive me, if you already are familiar with the workings of this type of Supercharger. Boost does not constantly turn on...it's only when you really get on the gas. An easy way to test it is get on a highway and put it in 5th gear...drop down to about 40 MPH and then step on the gas fairly hard. The boost needle should move immediately.

 

I've yet to come across someone that had to go through the 50 startup cycle to activate the supercharger. The dealer should have activated it for you. Hope that helps.

thanks for the info. i guess i wasn't giving it enough juice. ill try that later today. i thought it made boost at any rpm range and that was the beauty of a supercharger vs a turbo? i would have thought i would have seen the needle move at least slightly when i was kicking it, after all, i wasnt being a pussy with it. maybe more break in time is needed.

also, will the shifter loosen up at all, mine seems very stiff and tight?

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thanks for the info. i guess i wasn't giving it enough juice. ill try that later today. i thought it made boost at any rpm range and that was the beauty of a supercharger vs a turbo? i would have thought i would have seen the needle move at least slightly when i was kicking it, after all, i wasnt being a pussy with it. maybe more break in time is needed.

also, will the shifter loosen up at all, mine seems very stiff and tight?

 

Yeah, that's probably the case. You really have to hammer it to get boost in first gear and second. It activates a lot easier in third gear and up. It's definitely not producing boost all the time....you'd probably get about 5 MPG that way. hehe. I can't speak as to how you're driving...as to whether or not something might truly be wrong with the supercharger...but in all likelihood you just haven't hit the right combination to see the boost activate...again, just a guess on my part.

 

I can't say that I've had an issue with the shifter..it's been a real pleasure to use in my time with it. I can't believe the difference from my old car! And also the clutch is so soft on the Shelby....it's just amazing.

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thanks for the info. i guess i wasn't giving it enough juice. ill try that later today. i thought it made boost at any rpm range and that was the beauty of a supercharger vs a turbo? i would have thought i would have seen the needle move at least slightly when i was kicking it, after all, i wasnt being a pussy with it. maybe more break in time is needed.

also, will the shifter loosen up at all, mine seems very stiff and tight?

 

 

The reason they don't do it is the displacement of the motor makes enough power in the lower rpm range to take care of those needs. The supercharger is meant to use it when you need it. The reason is for fuel economy and for longevity.

 

Respectfully,

 

Roger

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The reason they don't do it is the displacement of the motor makes enough power in the lower rpm range to take care of those needs. The supercharger is meant to use it when you need it. The reason is for fuel economy and for longevity.

 

Respectfully,

 

Roger

so if i was crazy and wanted more, would a different tune change the superchargers appearance? im planning to do the pulley/tune thing in the future but im not sure when.

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so if i was crazy and wanted more, would a different tune change the superchargers appearance? im planning to do the pulley/tune thing in the future but im not sure when.

 

 

If your just doing the tune no. Now Justin at VMP makes a press on pulley that looks like the factory pulley except it is smaller. This would be your best bet. The idea is to go back to stock if there is a warranty problem and the tuner will allow you to do it. The timing is usually what's advanced to make the extra power. Boost will be increased because of the reduced pulley size. If there is a problem go back to stock.

 

Roger

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The boost is not only dependant on rpm, it is also dependant on the amount of load being demanded of the system. If you do not put a heavy load on the engine, you can run the rpm's to redline without seeing(or feeling) any boost.

 

Form another forum I'm on regarding a similar issue:

 

Grey03Cobra:

The GT500's and 03/04 Cobra's have a boost bypass valve. When the engine is under vacuum the bypass is open allowing for the boost to be "dumped" out. You can drive at part throttle all the way to redline if you want and you will show no boost. As far as full boost goes, it is almost immediate when you mash the pedal, that is the benefit of the Eaton blowers over other types of superchargers and turbos in which the amount of boost is RPM dependent.

 

I dont buy that, the only time I see max boost ever is at redline

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I'd like to know how to manually open the bypass to prevent somebody else from punching it, like a valet.

 

No valet service for you :lurk: Seriously , a mechanical linkage could get tricky the ways these cars are setup. Maybe somebody out there wants to experiment with it.

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Mine had close to 32 miles on it with a paper in the windshield that said it was randomly selected for quality control at the factory. When I test drove it, the S/C was not on because 2nd was a dog.

 

BTW, anybody know the power rating of this motor without the S/C?

 

Me too...except I don't know if my sc was on or not 'cause I took it slow on the way home.

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SNIP............Also without boost my family mini van could out drag race this car!

 

2 things here. You must have a lemon for a car or....one hell of a minivan!

 

I picked up my '08 GT-500 with 5 miles on the OD and went sideways out of the dealership. Got boost a few starts and 45 miles later.

 

On another note.....I would NOT want the dealer to "unlock" the supercharger for me. I'll do that myself, thank you very much. The reason Ford did this was to prevent the lot jockies and salesmen from beating on the cars. It has nothing to do with breaking in the engine.

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Here is a picture of the underside of a stock SC next to a TVS SC (right). The bypass valve flapper is circled green and the vacuum actuator is circled yellow. They are vacuum actuated and not directly controlled by the PCM. I believe the way the PCM limits boost for the first 5 miles/50 starts is to limit engine RPMs.

 

This is what it says in my manual. And I would advise you folks not to mess with the bypass valve.

 

ALTERNATE CALIBRATION

Your 2007 Shelby GT500 Power Train Control Module (PCM) strategy

contains a feature to limit supercharger boost pressure and engine speed

to 4000 RPM for the first five consecutive miles of vehicle operation or

50 engine start / warm up cycles. This feature is enabled prior to

shipment. If neither of these conditions have been satisfied prior to

customer delivery, full power will not be available.

 

sc_bypass.jpg

Edited by 6-Speed
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Here is a picture of the underside of a stock SC next to a TVS SC (right). The bypass valve flapper is circled green and the vacuum actuator is circled yellow. They are vacuum actuated and not directly controlled by the PCM. I believe the way the PCM limits boost for the first 5 miles/50 starts is to limit engine RPMs.

 

This is what it says in my manual. And I would advise you folks not to mess with the bypass valve.

 

ALTERNATE CALIBRATION

Your 2007 Shelby GT500 Power Train Control Module (PCM) strategy

contains a feature to limit supercharger boost pressure and engine speed

to 4000 RPM for the first five consecutive miles of vehicle operation or

50 engine start / warm up cycles. This feature is enabled prior to

shipment. If neither of these conditions have been satisfied prior to

customer delivery, full power will not be available.

 

sc_bypass.jpg

i called a tech at my local ford dealer and he told me to disconnect the negative battery lead for 30 seconds. i did this and Voila! i got boost! this car now flies! im a happy boy now until i need more horses!

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