Dynoed and modified my GT500...read on folks.

[FordGeek]

Ladies and gents,

 

I'm an enthusiast, but not a purest. I have a hair over 250 miles on my car and I've done the dirty deed; I've made some modifications. First, let me start by saying: PLEASE NO FLAMES! I'm posting reality here folks, not what FORD might have told us. There, I said it and it was like therapy - on with the results.

 

Today, I worked with the folks from Strictly Performance here in Houston to swap out my gear. First thing, always, is a baseline dyno run. They have one of the more current models of the dynojet. Some folks think that the method utilized by this dyno tends to underate horsepower; regardless, the numbers are usually pretty close whether you use a dynojet, or a Mustang (another type of dyno). We pulled 3 runs in 4th (standard stuff) soon after I arrived at the shop. The relative humidity was high - about 87% (hey, this IS Houston), and the intake air temerature was running at a whopping 98.4 degrees. This kills some power, so I was expecting to see anywhere between 415 - 430 horses at the wheels. Keep in mind that stick shifts usually have a 15% parasitic loss in the drivetrain; add some serious heat to that and you lose a bit more. I saw the dyno thread that someone posted earlier. Many of your thoughts around 450 - 460 hp at the wheels are simply not realistic; but it sure would have been nice. The best of the 3 runs was as follows:

 

HP: 412.9 Torque: 409.2

 

These are good, but definitely NOT what I expected; even with the heat. However, one thing that immediately was obvious is that this puppy pulls like a mule right until the rev limiter kicks in and everthing shuts down (between 6,250 and 6,500 rpms). Given that at the higher RPM the engine was still increasing horsepower output, I felt that the 4.10 gearing I was planning on installing was going to make a difference. Basically, my thoughts were that the power/torque curve would shift to the left (steeper gears get you in the sweet spot of the rpm range sooner). I've enclosed some pictures of the install for your pondering.

 

BTW...while we were installing the gear, I felt it appropriate to change out the exhaust. The stock mufflers are simply too quiet for me! I want to HEAR the power. I chose the Flowmaster American Thunder 2-chambers for the job. I have them on my Terminator and love the way they sound; I have some pictures of the before and after from the rear of the car. I think it looks pretty sweet; and, of course, they sound amazing with the 5.4 liter!

 

After, the gear and exhaust install (which took a total of around 2 hours), it was back to the dyno. We only ran it twice, and the best run was...can I get the envelope....

 

 

HP: 446.5 Torque: 421.9

 

Now that's what I'm talking about! If you do the math, this equates to around 525 crank horsepower; 25 more than what this bad boy comes with. And folks there's more good news, the horsepower was still climbing!!!! Oh crap I could have pissed on myself, especially after I saw that the air intake temperature was at 104.2 degrees! It's amazing that we could pull those numbers, with that kind of heat. The only bad thing is we don't know which of the two modifications caused the spike in power because we did them both at the same time. I have a small video clip of the dyno run below; I'm standing in front of the car and you can hear my new exhaust sing to me. Robert, I may need help if it's too large for me to upload to my post.

 

For those of you that have your Shelby's, the gear change fixed the "problem" we've been experiencing with the little jiggy the car does coming out of first. I think it was simply a bog given the lower than needed gearing.

 

And now I have some general observations that you may find interesting now that I've inspected my car from top to bottom:

 

1.) Forger about changing the lower pulley to increase boost There is a nub on the water pump that's only a hair from the crank pulley. In my opinion, it's going to have to be machined in order to accomodate a larger crank pulley. The aftermarket may figure it out, but I just don't see a way around the nub. Of course, you could change the pulley, but the stocker is just barely big enough to clear the ribs on the supercharger snout; it's going to be nearly impossible to use a smaller blower pulley without changing the whole snout itself; which by the way will most likely set you back $800 - $1,000. With the terminators, swapping a blower pulley was a ten minute job using the extractor tool, and usually set you back $120 - $130 (includes buying the extractor tool). Again, someone may come up with a way, but I've worked on cars long enought to know it isn't a trivial matter.

2.) My speedometer will display higher than actual readings due to the gear change. This will go away as soon as my boys at Strictly get the algorithm template and we can begin to tweak the engine.

3.) The front fascia does indeed have the mountings for an aftermarket break cooling kit. I have a picture below of what the mounting extension looks like. All you'll have to do is punch out the pattern through the fascia and you'll be sucking fresh air in no time.

4.) If you change gears, you most likely will need a new pinion bearing. The stockers are on there like an SOB and we ended up breaking ours. No problem though, it's usually good practice to swap them out during any gear change. Other than that, the switch went smooth as butter.

5.) In my opinion, the mufflers are the real reason the car doesn't quite deliver straight off the showroom floor. Their big, heavy, and seem to be designed to reduce noise, not increase power. I have a picture of them outside the car. Besides, the flowmasters are coated black so they look much stealthier than these loud ass brass looking things.

6.) FORD has tuned the Shelby very nicely. The oxgen/fuel ratios never devidated between 11.8 and 12.4 all the way through the dyno pull. This is a very safe range; but I'd like to see it run just a bit leaner and see how the car responds.

7.) KILL THE CATS!!! As soon as we can begin calibrating the computer, the Cats are coming off. During the last dyno run I could tell the car was struggling to breathe in and especially out. The air filter assembly is hideous and a cold air kit will defintely do wonders. The Cats are just to damn big and holding back a lot of power.

 

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

[FordGeek]

Ladies and gents,

 

I'm an enthusiast, but not a purest. I have a hair over 250 miles on my car and I've done the dirty deed; I've made some modifications. First, let me start by saying: PLEASE NO FLAMES! I'm posting reality here folks, not what FORD might have told us. There, I said it and it was like therapy - on with the results.

 

Today, I worked with the folks from Strictly Performance here in Houston to swap out my gear. First thing, always, is a baseline dyno run. They have one of the more current models of the dynojet. Some folks think that the method utilized by this dyno tends to underate horsepower; regardless, the numbers are usually pretty close whether you use a dynojet, or a Mustang (another type of dyno). We pulled 3 runs in 4th (standard stuff) soon after I arrived at the shop. The relative humidity was high - about 87% (hey, this IS Houston), and the intake air temerature was running at a whopping 98.4 degrees. This kills some power, so I was expecting to see anywhere between 415 - 430 horses at the wheels. Keep in mind that stick shifts usually have a 15% parasitic loss in the drivetrain; add some serious heat to that and you lose a bit more. I saw the dyno thread that someone posted earlier. Many of your thoughts around 450 - 460 hp at the wheels are simply not realistic; but it sure would have been nice. The best of the 3 runs was as follows:

 

HP: 412.9 Torque: 409.2

 

These are good, but definitely NOT what I expected; even with the heat. However, one thing that immediately was obvious is that this puppy pulls like a mule right until the rev limiter kicks in and everthing shuts down (between 6,250 and 6,500 rpms). Given that at the higher RPM the engine was still increasing horsepower output, I felt that the 4.10 gearing I was planning on installing was going to make a difference. Basically, my thoughts were that the power/torque curve would shift to the left (steeper gears get you in the sweet spot of the rpm range sooner). I've enclosed some pictures of the install for your pondering.

 

BTW...while we were installing the gear, I felt it appropriate to change out the exhaust. The stock mufflers are simply too quiet for me! I want to HEAR the power. I chose the Flowmaster American Thunder 2-chambers for the job. I have them on my Terminator and love the way they sound; I have some pictures of the before and after from the rear of the car. I think it looks pretty sweet; and, of course, they sound amazing with the 5.4 liter!

 

After, the gear and exhaust install (which took a total of around 2 hours), it was back to the dyno. We only ran it twice, and the best run was...can I get the envelope....

 

 

HP: 446.5 Torque: 421.9

 

Now that's what I'm talking about! If you do the math, this equates to around 525 crank horsepower; 25 more than what this bad boy comes with. And folks there's more good news, the horsepower was still climbing!!!! Oh crap I could have pissed on myself, especially after I saw that the air intake temperature was at 104.2 degrees! It's amazing that we could pull those numbers, with that kind of heat. The only bad thing is we don't know which of the two modifications caused the spike in power because we did them both at the same time. I have a small video clip of the dyno run below; I'm standing in front of the car and you can hear my new exhaust sing to me. Robert, I may need help if it's too large for me to upload to my post.

 

For those of you that have your Shelby's, the gear change fixed the "problem" we've been experiencing with the little jiggy the car does coming out of first. I think it was simply a bog given the lower than needed gearing.

 

And now I have some general observations that you may find interesting now that I've inspected my car from top to bottom:

 

1.) Forget about changing the lower pulley to increase boost. There is a nub on the water pump that's only a hair from the crank pulley. In my opinion, it's going to have to be machined in order to accomodate a larger crank pulley. The aftermarket may figure it out, but I just don't see a way around the nub. Of course, you could change the supercharger pulley, but the stocker is just barely big enough to clear the ribs on the supercharger snout; it's going to be nearly impossible to use a smaller blower pulley without changing the whole snout itself; which by the way will most likely set you back $800 - $1,000. With the terminators, swapping a blower pulley was a ten minute job using the extractor tool, and usually set you back $120 - $130 (includes buying the extractor tool). Again, someone may come up with a way, but I've worked on cars long enought to know it isn't a trivial matter.

2.) My speedometer will display higher than actual readings due to the gear change. This will go away as soon as my boys at Strictly get the algorithm template and we can begin to tweak the engine.

3.) The front fascia does indeed have the mountings for an aftermarket break cooling kit. I have a picture below of what the mounting extension looks like. All you'll have to do is punch out the pattern through the fascia and you'll be sucking fresh air in no time.

4.) If you change gears, you most likely will need a new pinion bearing. The stockers are on there like an SOB and we ended up breaking ours. No problem though, it's usually good practice to swap them out during any gear change. Other than that, the switch went smooth as butter.

5.) In my opinion, the mufflers are the real reason the car doesn't quite deliver straight off the showroom floor. Their big, heavy, and seem to be designed to reduce noise, not increase power. I have a picture of them outside the car. Besides, the flowmasters are coated black so they look much stealthier than these loud ass brass looking things.

6.) FORD has tuned the Shelby very nicely. The oxgen/fuel ratios never devidated between 11.8 and 12.4 all the way through the dyno pull. This is a very safe range; but I'd like to see it run just a bit leaner and see how the car responds.

7.) KILL THE CATS!!! As soon as we can begin calibrating the computer, the Cats are coming off. During the last dyno run I could tell the car was struggling to breathe in and especially out. The air filter assembly is hideous and a cold air kit will defintely do wonders. The Cats are just to damn big and holding back a lot of power.

 

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

[ColdwaterHotrod]

EXCELLENT FEEDBACK!

 

Thank you for writing this up & being our 1st official (Ginny pig) I mean "WILD STANG". I completely understood everything you wrote & think you should send this to an editor of one the magazines for publishing so others know of this great untapped horsepower. Now go find a Z06 and show them who's BOSS!

 

 

Keeps us posted on the next modification & the results that follow. :happy feet:

[KCMO-GT500]

Now this is the kind of information I have been waiting for. :bandance: Great Results

 

 

 

One quick question, you talk about the possible impact of two mods, gears and mufflers? Why would the install of gears have any impact on dyno hp? or is the increased hp strictly the muffler swap? Never having put a car on a dyno I am wondering if I am just missing something.

 

 

I can't help but chuckle when I mention that I do law enforcement for the EPA. I promise I won't slip and mention your plans on the cats to anyone, as long as you tell us how well that works out also.

 

I actually plan to do the same myself, but I have had folks tell me that the gains will be minimal. Would love to hear your results.

 

John

[FordGeek]

Now this is the kind of information I have been waiting for. :bandance: Great Results

One quick question, you talk about the possible impact of two mods, gears and mufflers? Why would the install of gears have any impact on dyno hp? or is the increased hp strictly the muffler swap? Never having put a car on a dyno I am wondering if I am just missing something.

I can't help but chuckle when I mention that I do law enforcement for the EPA. I promise I won't slip and mention your plans on the cats to anyone, as long as you tell us how well that works out also.

 

I actually plan to do the same myself, but I have had folks tell me that the gains will be minimal. Would love to hear your results.

 

John

 

 

John, the gears might have impacted horsepower because the peak horsepower came right near the rev limiter. During the prior runs, this peak would have occurred at around 7,000 - 7,500 rpm, well after the engine would have shut down. However, the gears pull the power sooner, so you see a jump in horsepower right before the rev limiter. I hope this makes sense.

 

Joseph (FordGeek)

[ColdwaterHotrod]

John, the gears might have impacted horsepower because the peak horsepower came right near the rev limiter. During the prior runs, this peak would have occurred at around 7,000 - 7,500 rpm, well after the engine would have shut down. However, the gears pull the power sooner, so you see a jump in horsepower right before the rev limiter. I hope this makes sense.

 

Joseph (FordGeek)

 

I think I read somewhere that the software shuts the fuel pump off to the motor at 6250 rpm's & to help limit the speed to 155?

[shel-b001]

Ladies and gents,

 

I'm an enthusiast, but not a purest. I have a hair over 250 miles on my car and I've done the dirty deed; I've made some modifications. First, let me start by saying: PLEASE NO FLAMES! I'm posting reality here folks, not what FORD might have told us. There, I said it and it was like therapy - on with the results.

 

Today, I worked with the folks from Strictly Performance here in Houston to swap out my gear. First thing, always, is a baseline dyno run. They have one of the more current models of the dynojet. Some folks think that the method utilized by this dyno tends to underate horsepower; regardless, the numbers are usually pretty close whether you use a dynojet, or a Mustang (another type of dyno). We pulled 3 runs in 4th (standard stuff) soon after I arrived at the shop. The relative humidity was high - about 87% (hey, this IS Houston), and the intake air temerature was running at a whopping 98.4 degrees. This kills some power, so I was expecting to see anywhere between 415 - 430 horses at the wheels. Keep in mind that stick shifts usually have a 15% parasitic loss in the drivetrain; add some serious heat to that and you lose a bit more. I saw the dyno thread that someone posted earlier. Many of your thoughts around 450 - 460 hp at the wheels are simply not realistic; but it sure would have been nice. The best of the 3 runs was as follows:

 

HP: 412.9 Torque: 409.2

 

These are good, but definitely NOT what I expected; even with the heat. However, one thing that immediately was obvious is that this puppy pulls like a mule right until the rev limiter kicks in and everthing shuts down (between 6,250 and 6,500 rpms). Given that at the higher RPM the engine was still increasing horsepower output, I felt that the 4.10 gearing I was planning on installing was going to make a difference. Basically, my thoughts were that the power/torque curve would shift to the left (steeper gears get you in the sweet spot of the rpm range sooner). I've enclosed some pictures of the install for your pondering.

 

BTW...while we were installing the gear, I felt it appropriate to change out the exhaust. The stock mufflers are simply too quiet for me! I want to HEAR the power. I chose the Flowmaster American Thunder 2-chambers for the job. I have them on my Terminator and love the way they sound; I have some pictures of the before and after from the rear of the car. I think it looks pretty sweet; and, of course, they sound amazing with the 5.4 liter!

 

After, the gear and exhaust install (which took a total of around 2 hours), it was back to the dyno. We only ran it twice, and the best run was...can I get the envelope....

HP: 446.5 Torque: 421.9

 

Now that's what I'm talking about! If you do the math, this equates to around 525 crank horsepower; 25 more than what this bad boy comes with. And folks there's more good news, the horsepower was still climbing!!!! Oh crap I could have pissed on myself, especially after I saw that the air intake temperature was at 104.2 degrees! It's amazing that we could pull those numbers, with that kind of heat. The only bad thing is we don't know which of the two modifications caused the spike in power because we did them both at the same time. I have a small video clip of the dyno run below; I'm standing in front of the car and you can hear my new exhaust sing to me. Robert, I may need help if it's too large for me to upload to my post.

 

For those of you that have your Shelby's, the gear change fixed the "problem" we've been experiencing with the little jiggy the car does coming out of first. I think it was simply a bog given the lower than needed gearing.

 

And now I have some general observations that you may find interesting now that I've inspected my car from top to bottom:

 

1.) Forger about changing the lower pulley to increase boost There is a nub on the water pump that's only a hair from the crank pulley. In my opinion, it's going to have to be machined in order to accomodate a larger crank pulley. The aftermarket may figure it out, but I just don't see a way around the nub. Of course, you could change the pulley, but the stocker is just barely big enough to clear the ribs on the supercharger snout; it's going to be nearly impossible to use a smaller blower pulley without changing the whole snout itself; which by the way will most likely set you back $800 - $1,000. With the terminators, swapping a blower pulley was a ten minute job using the extractor tool, and usually set you back $120 - $130 (includes buying the extractor tool). Again, someone may come up with a way, but I've worked on cars long enought to know it isn't a trivial matter.

2.) My speedometer will display higher than actual readings due to the gear change. This will go away as soon as my boys at Strictly get the algorithm template and we can begin to tweak the engine.

3.) The front fascia does indeed have the mountings for an aftermarket break cooling kit. I have a picture below of what the mounting extension looks like. All you'll have to do is punch out the pattern through the fascia and you'll be sucking fresh air in no time.

4.) If you change gears, you most likely will need a new pinion bearing. The stockers are on there like an SOB and we ended up breaking ours. No problem though, it's usually good practice to swap them out during any gear change. Other than that, the switch went smooth as butter.

5.) In my opinion, the mufflers are the real reason the car doesn't quite deliver straight off the showroom floor. Their big, heavy, and seem to be designed to reduce noise, not increase power. I have a picture of them outside the car. Besides, the flowmasters are coated black so they look much stealthier than these loud ass brass looking things.

6.) FORD has tuned the Shelby very nicely. The oxgen/fuel ratios never devidated between 11.8 and 12.4 all the way through the dyno pull. This is a very safe range; but I'd like to see it run just a bit leaner and see how the car responds.

7.) KILL THE CATS!!! As soon as we can begin calibrating the computer, the Cats are coming off. During the last dyno run I could tell the car was struggling to breathe in and especially out. The air filter assembly is hideous and a cold air kit will defintely do wonders. The Cats are just to damn big and holding back a lot of power.

 

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

 

 

Great Stuff Keep us posted .

[BadTony]

why not just control this (rev limiter) via the computer software you are using and just either shut the rev limiter off or set it to a higher rpm setting?

 

I too can't see how adding a different rear-end gear would affect the 'true' flywheel HP.

[Fastbackman]

Ladies and gents,

 

I'm an enthusiast, but not a purest. I have a hair over 250 miles on my car and I've done the dirty deed; I've made some modifications. First, let me start by saying: PLEASE NO FLAMES! I'm posting reality here folks, not what FORD might have told us. There, I said it and it was like therapy - on with the results.

 

Today, I worked with the folks from Strictly Performance here in Houston to swap out my gear. First thing, always, is a baseline dyno run. They have one of the more current models of the dynojet. Some folks think that the method utilized by this dyno tends to underate horsepower; regardless, the numbers are usually pretty close whether you use a dynojet, or a Mustang (another type of dyno). We pulled 3 runs in 4th (standard stuff) soon after I arrived at the shop. The relative humidity was high - about 87% (hey, this IS Houston), and the intake air temerature was running at a whopping 98.4 degrees. This kills some power, so I was expecting to see anywhere between 415 - 430 horses at the wheels. Keep in mind that stick shifts usually have a 15% parasitic loss in the drivetrain; add some serious heat to that and you lose a bit more. I saw the dyno thread that someone posted earlier. Many of your thoughts around 450 - 460 hp at the wheels are simply not realistic; but it sure would have been nice. The best of the 3 runs was as follows:

 

HP: 412.9 Torque: 409.2

 

These are good, but definitely NOT what I expected; even with the heat. However, one thing that immediately was obvious is that this puppy pulls like a mule right until the rev limiter kicks in and everthing shuts down (between 6,250 and 6,500 rpms). Given that at the higher RPM the engine was still increasing horsepower output, I felt that the 4.10 gearing I was planning on installing was going to make a difference. Basically, my thoughts were that the power/torque curve would shift to the left (steeper gears get you in the sweet spot of the rpm range sooner). I've enclosed some pictures of the install for your pondering.

 

BTW...while we were installing the gear, I felt it appropriate to change out the exhaust. The stock mufflers are simply too quiet for me! I want to HEAR the power. I chose the Flowmaster American Thunder 2-chambers for the job. I have them on my Terminator and love the way they sound; I have some pictures of the before and after from the rear of the car. I think it looks pretty sweet; and, of course, they sound amazing with the 5.4 liter!

 

After, the gear and exhaust install (which took a total of around 2 hours), it was back to the dyno. We only ran it twice, and the best run was...can I get the envelope....

HP: 446.5 Torque: 421.9

 

Now that's what I'm talking about! If you do the math, this equates to around 525 crank horsepower; 25 more than what this bad boy comes with. And folks there's more good news, the horsepower was still climbing!!!! Oh crap I could have pissed on myself, especially after I saw that the air intake temperature was at 104.2 degrees! It's amazing that we could pull those numbers, with that kind of heat. The only bad thing is we don't know which of the two modifications caused the spike in power because we did them both at the same time. I have a small video clip of the dyno run below; I'm standing in front of the car and you can hear my new exhaust sing to me. Robert, I may need help if it's too large for me to upload to my post.

 

For those of you that have your Shelby's, the gear change fixed the "problem" we've been experiencing with the little jiggy the car does coming out of first. I think it was simply a bog given the lower than needed gearing.

 

And now I have some general observations that you may find interesting now that I've inspected my car from top to bottom:

 

1.) Forger about changing the lower pulley to increase boost There is a nub on the water pump that's only a hair from the crank pulley. In my opinion, it's going to have to be machined in order to accomodate a larger crank pulley. The aftermarket may figure it out, but I just don't see a way around the nub. Of course, you could change the pulley, but the stocker is just barely big enough to clear the ribs on the supercharger snout; it's going to be nearly impossible to use a smaller blower pulley without changing the whole snout itself; which by the way will most likely set you back $800 - $1,000. With the terminators, swapping a blower pulley was a ten minute job using the extractor tool, and usually set you back $120 - $130 (includes buying the extractor tool). Again, someone may come up with a way, but I've worked on cars long enought to know it isn't a trivial matter.

2.) My speedometer will display higher than actual readings due to the gear change. This will go away as soon as my boys at Strictly get the algorithm template and we can begin to tweak the engine.

3.) The front fascia does indeed have the mountings for an aftermarket break cooling kit. I have a picture below of what the mounting extension looks like. All you'll have to do is punch out the pattern through the fascia and you'll be sucking fresh air in no time.

4.) If you change gears, you most likely will need a new pinion bearing. The stockers are on there like an SOB and we ended up breaking ours. No problem though, it's usually good practice to swap them out during any gear change. Other than that, the switch went smooth as butter.

5.) In my opinion, the mufflers are the real reason the car doesn't quite deliver straight off the showroom floor. Their big, heavy, and seem to be designed to reduce noise, not increase power. I have a picture of them outside the car. Besides, the flowmasters are coated black so they look much stealthier than these loud ass brass looking things.

6.) FORD has tuned the Shelby very nicely. The oxgen/fuel ratios never devidated between 11.8 and 12.4 all the way through the dyno pull. This is a very safe range; but I'd like to see it run just a bit leaner and see how the car responds.

7.) KILL THE CATS!!! As soon as we can begin calibrating the computer, the Cats are coming off. During the last dyno run I could tell the car was struggling to breathe in and especially out. The air filter assembly is hideous and a cold air kit will defintely do wonders. The Cats are just to damn big and holding back a lot of power.

 

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

 

 

 

Actually, a company called lethal performance already has top pullies out for sale. They are made by metco. You can't go much smaller without a snout change, but they offer a 2.8 and a 2.7. I think the stock pully is about 3 inches. They didn't give any HP increase figures as they only had a blower and not the entire car. The price for the pulley is $159.

2.8 pulley is estimated to gain roughly 1.7 psi of boost

2.7 pulley is estimated to gain roughly 2.6 psi of boost

[FordGeek]

why not just control this (rev limiter) via the computer software you are using and just either shut the rev limiter off or set it to a higher rpm setting?

 

I too can't see how adding a different rear-end gear would affect the 'true' flywheel HP.

 

 

Can't control the rev limiter yet. We didn't want to try anything funny with the computer until we know we can put things back to stock. Right now, there's not a whole lot we can do to tune the stock config. However, we did hear that the supercharger has a bypass valve that is electronically controlled. It regulates how much boost the supercharger is making. Traditional bypass valves still allow full pressure to be achieved, but begins to back down the boost as the load is reduced (i.e. achieving a steady increase in speed).

 

I never suggested that the pulleys themselves are making more power at the flywheel. What I think IS happening, is that the gears are allowing more power to be utilized within the "useful" rpm range. This will, however, translate to more power at the wheels. Keep in mind, the power never peaked, it just kept on going up. This means there's still plenty of untapped potential. Thus, the engine may be producing 525 at the crank, but it could produce more if we're to, for example, increase the threshold of the rev limiter.

 

Actually, a company called lethal performance already has top pullies out for sale. They are made by metco. You can't go much smaller without a snout change, but they offer a 2.8 and a 2.7. I think the stock pully is about 3 inches. They didn't give any HP increase figures as they only had a blower and not the entire car. The price for the pulley is $159.

2.8 pulley is estimated to gain roughly 1.7 psi of boost

2.7 pulley is estimated to gain roughly 2.6 psi of boost

 

 

The Metco pulleys are great, but they're made for the Terminator Eatons. The clearance on these is different than the one that comes on the Shelby. BTW...I think the Shelby pulley is smaller than 3". However, I could be wrong given that we didn't bother measuring it.

[Fastbackman]

These are supposed to be just recently made for the GT500. They didn't have a GT500 but they had a GT500 blower. They were definitely supposed to be made for the GT500 though.

[FordGeek]

These are supposed to be just recently made for the GT500. They didn't have a GT500 but they had a GT500 blower. They were definitely supposed to be made for the GT500 though.

 

 

Wow, I didn't know that. I wonder, however, if they have a calibration to go with the pulleys. Right now, there's no way to advance spark so adding the pulley might cause the engine to detonate. I'm keeping my eyes open over the next few weeks and I'm planning on experimenting as much as possible.

[07 Shelby Cobra]

These are supposed to be just recently made for the GT500. They didn't have a GT500 but they had a GT500 blower. They were definitely supposed to be made for the GT500 though.

 

 

 

Fastmack is correct, Lethal is Promoting these Pulleys as 07 Shelby Specific. No calibration offered.

[old guy]

NOW we're gettin' back to the purpose of this forum. Great info FordGeek. I can't wait until we get our cars so we can all get past the bellyachin' that's been going on.

[VNMOUS1]

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

 

 

 

Outstanding! Thank you!!

 

 

bj

[Guest evilchris]

Past 600HP easy. Terminators do it easily and they don't have as nice an engine.

[07 GT500]

[quote

 

I want to HEAR the power. I chose the Flowmaster American Thunder 2-chambers for the job. I have them on my Terminator and love the way they sound; I have some pictures of the before and after from the rear of the car. I think it looks pretty sweet; and, of course, they sound amazing with the 5.4 liter!

 

 

 

Ford Geek,

My question is: the axle back that you used.......was this the same application as one would use on an '05 or '06 GT? Thanks!

 

Chris

[BlueOval]

Hey FordGeek,

Awesome write up! It's much appreciated!

[JETSOLVER]

Dont'cha just love the smell of slighty used Dinosaurs? I am addicted to fresh hydrocarbons. I hope that we will be able to help you pay(enjoy) for what should be a h of a ride!!! As a thought folks, this sort of learning curve is not cheap, but I have to admit, that once when I was asked paper or plastic, I said "plastic , the world only has to last until I die!!! Thank you for going first and we will be here to endlessly debate every move you make

[RUFDRAFT]

Yes - thanks for all the time you took to share your findings.

 

As you probably know, we've not been overwhelmed with positive news on the Shelbys.

 

This commentary will make many of those waiting for one feel much better while they wait!

[hotrodstang]

yes great info!I will be doing the same as soon as mine comes in, how did the gearing affect driveability? and do you like it ? the gearing that is!!

[requis]

Keep up the Great Work certainly appreciate the post!

 

Requis

[FordGeek]

Chris,

 

The mounting brackets for the GT500 are almost identical as those for the Mustang GT; this is especially true as you approach the rear of the car where the mufflers hang. So, any 2005 - 2007 GT muffler setup will work (Magnaflow, Flowmaster, Borla, etc...). The X-Pipe the car comes with looks strikingly similar to a Bassani X-Pipe and would do an excellent job if it wasn't for the Cats. The problem is, the entire assembly from the header collector flange, to well past the X-Pipe, is all welded. Thus, if you ever want to remove the cats, you will most likely have to buy a new exhaust system. The cheaper way may be to weld a replacement piece of pipe in lieu of the cats. It may not look pretty, but it might do the job.

[BadTony]

good stuff - lots of good pics

 

hope you have protected your VIN so that Ford does not find out and automatically void you new 5 yr 60k mile drive-train warranty

[2008GT500KR]

John, the gears might have impacted horsepower because the peak horsepower came right near the rev limiter. During the prior runs, this peak would have occurred at around 7,000 - 7,500 rpm, well after the engine would have shut down. However, the gears pull the power sooner, so you see a jump in horsepower right before the rev limiter. I hope this makes sense.

 

Joseph (FordGeek)

 

 

FordGeek,

 

This is pretty much invaluable info!!! Many thanks!

 

Not sure if all understand the numbers you are getting at that temp. I have spent a lot of time and $$ on a dyno both chassis and engine dyno's. I heard the numbers at 70deg f were in the 470hp area on the test mules.

 

Is this another way inflated Ford HP? Yes you got the numbers but it should have made the 440 minimum at wheels prior to mods. Although the ambient air and humidity play a big part.

 

Anyone else in cooler air to dyno?

 

I think you will also see higher numbers once there are a few miles on engine

 

I will have some rear wheel numbers about a month from now

[SteelSteeds]

Congratulations on being the first person on record to mod their '07 Shelby! My hat's off. I don't think you'll get flames here, were mostly enthusiasts, not too many "collectors" or speculators hanging out here!

 

I plan to do a muffler swap as soon as I get mine home, so I'm glad to hear the Flowmasters sound good. I like them on my '98 as well. I do have one question: What's your take on the shifter? Will a short throw be needed, or is the stocker good? My '98, and the Terminators I have driven, have all had terrible shifters from the factory. Thanks, and enjoy!

[kb67]

Great post Fordgeek thank you for the information.

[Guest evilchris]

We need a Kenne Bell for this thing.

[Alloy Dave]

I tried to capture everthing I could. If anyone has questions, just post a response and I'll help if I can. The bottom line is, these care are defintely going to push past the 600 hp mark. It's only a matter of a few months before that's exactly where I expect to be. Until next time...this is the Geek signing off.

 

Excellent post Geek. I do have a few questions.

1) When you say "we" did the work, are these friends of yours and you helped them..or were you just being generic in your choice of words?

2) I'd like to know how much it would cost for similar work...can you provide any guidance? It would be great if you had a breakdown by service...such as how much for ring/pinion, how much for dyno time, how much for exhaust.

3) Regarding the speedometer, I assume you can use a tuner tool to fix this? Is the issue simply that the tuner tools are not yet available for the GT500?

4) Obvioiusly the numbers are much better, and that's great. When you drove it afterwards, did it "feel" stronger? You mention it pulling hard, but I can't tell if that was before or after the mods.

5) What's the easiest way to find a dyno/upfit shop nearest to me? Are there some "chains" that are reputable?

6) You mention you can use any '05-07 axleback system. It would seem to me that the restriction level on something designed for the Mustang GT would be too limiting for the 5.4L engine...am I missing something?

 

Thanks so much.

 

Dave

[harley99fb]

G