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

[Alloy Dave]

I thought new dynos compensated for air temp/humidity/barometric pressure, and spit out a consistent hp/tq rating.

 

Please keep in mind that I am an ignoramus when it comes to such matters and I could have dreamed all this up.

 

LOL @ ignoramous. It's a fair question lawdude. BTW...I'm a dufus 1/2 the time.

[Alloy Dave]

Hey Geekster,

With the 4:10 gear what kind of MPH do you get in 1st gear? I,am wandering if this gearing makes 1st gear worthless. I do like the fast out of the hole feel. Thanks!!!!!!!!! BillyRay

 

According to a Microsoft Excel model I created to calculate RPM/speeds based on trans and differential ratios, a 4.10 should produce around 41 mph at the redline of 6,250 RPM (is that the correct redline?). Here is the complete data....

 

At 6,250, the speeds by gear are below. Keep in mind these are THEORETICAL speeds. Obviously we won't have a 245 mph car here. This analysis also assumes stock tire sizes, which I calculated at 27" diameter...so the numbers may be off by a small amount, particularly at higher speeds.

 

With a 3.31 rear gear (stock):

1st gear = 51 mph

2nd gear = 79 mph

3rd gear = 103 mph

4th gear = 152 mph

5th gear = 181 mph

6th gear = 245 mph

 

With a 3.73 rear gear:

1st gear = 45 mph

2nd gear = 71 mph

3rd gear = 91 mph

4th gear = 135 mph

5th gear = 160 mph

6th gear = 218 mph

 

With a 4.10 rear gear:

1st gear = 41 mph

2nd gear = 64 mph

3rd gear = 83 mph

4th gear = 122 mph

5th gear = 146 mph

6th gear = 197 mph

 

Another thing that may be of interest....cruising RPM on the highway with different gears. Below are the RPM you should expect at 65 mph IN SIXTH GEAR.

 

With a stock 3.31 gear = 1661 RPM

With a 3.73 gear = 1871 RPM

With a 4.10 gear = 2057 RPM

 

I just went through something similar with my '69 Camaro. Two years ago I had a muncie 4 speed (no overdrive) with a 4.11 rear end. I junked the muncie and had a Tremec 5-speed installed (road race version), and my RPM dropped from about 3100 AT 60 MPH to about 2550 RPM. The trans has a .82 OD, and boy does it make the highway driving more pleasurable. Actually the way it works out is that, previously, I would only drive 55 mph on the highway to keep RPM down around 3,000. Now I drive in the low 60s and am still able to accomplish that.

 

Dave

[dreamer_GT500]

What I think may have a lot to do with the increase in HP is the motor getting broken in. Did you read the recomended method of breaking in of a new motor? It said to use a dyno to work the motor to get the ring so wear and seat properly.

[Alloy Dave]

I do have an observation on ford. The owners manual that was down loaded here with what we all thought was," old publication" with the 475hp list may have indeed been the real deal. Maybe a little bogus hype was initiated by the tang team? 500hp was just a little," wag the dog" to draw attention. Why is there no product literature? For a reason. Maybe there wont be any?

 

Anyone that has their car already....does your owner's manual state the actual HP anywhere? Or perhaps on the window sticker? What does it say?

 

Dave

 

What I think may have a lot to do with the increase in HP is the motor getting broken in. Did you read the recomended method of breaking in of a new motor? It said to use a dyno to work the motor to get the ring so wear and seat properly.

 

Where did you read this? Please be factual and quote sources.

 

Dave

[BoneDoc]

Fordgeek-

 

thanks for the information!

 

couple questions:

I thought the main issue that caused the lower 1/4 times in many mags was traction (not power)....with the front-heavy weight distribution.

 

Won't the 3.31-->4.11 gear change just make things worse the traction department?

what mod are you planning to make your GT500 stick to the ground a little better?

 

Thanks again.

[Fastbackman]

4.10's will improve traction greatly I would think. Lower gears are known for improving traction. By lower gear, I'm referrring to higher number(4.11 is lower gear than 3.31).

[DVS2XS]

Great info in this thread, and I applaud Fordgeek's information, but...

 

1 BHP (SAE) = *1.01387 BHP (PS) = 0.7457 KW = 33,000 lbs/ft/min

446.5 bhp (PS) = 440.4 bhp (SAE)

The Dynojet power ratings are CORRECTED numbers - to a standard atmospheric condition. ONLY if the engine was pulling timing during the dyno run will cooler temps and less humid air change the dyno figures.

 

If this test was done at 250 miles, my guess is that a portion of the increase is due to improving ring seal as the engine breaks in. Early loading on a dyno only HELPS seat the rings.

 

Changing gearing changes torque multiplication, not the power of the engine, nor does it move the powerband in ANY way. Increasing torque multiplication through gearing actually INCREASES friction in the dif and robs a small amount of power. I have personally seen this show up in each step from 3.27:1 through 4.56:1 gears on Dynojet and Mustang dynos.

 

Increasing gearing DECREASES traction with no other changes.

[150man]

Another thing that may be of interest....cruising RPM on the highway with different gears. Below are the RPM you should expect at 65 mph IN SIXTH GEAR.

 

With a stock 3.31 gear = 1661 RPM

With a 3.73 gear = 1871 RPM

With a 4.10 gear = 2057 RPM

 

I'm wondering why the heck does this thing even have a 6th gear? Who wants to lug the engine down the road at 1660 RPM? I guess if you're cruising the autobahn at 155, (allowed top speed), it may come in handy.

[lawdude]

The Dynojet power ratings are CORRECTED numbers - to a standard atmospheric condition. ONLY if the engine was pulling timing during the dyno run will cooler temps and less humid air change the dyno figures.

 

 

 

Does this change my ignoramus status in any way?

[BlueOval]

Great info in this thread, and I applaud Fordgeek's information, but...

 

1 BHP (SAE) = *1.01387 BHP (PS) = 0.7457 KW = 33,000 lbs/ft/min

446.5 bhp (PS) = 440.4 bhp (SAE)

The Dynojet power ratings are CORRECTED numbers - to a standard atmospheric condition. ONLY if the engine was pulling timing during the dyno run will cooler temps and less humid air change the dyno figures.

 

If this test was done at 250 miles, my guess is that a portion of the increase is due to improving ring seal as the engine breaks in. Early loading on a dyno only HELPS seat the rings.

 

Changing gearing changes torque multiplication, not the power of the engine, nor does it move the powerband in ANY way. Increasing torque multiplication through gearing actually INCREASES friction in the dif and robs a small amount of power. I have personally seen this show up in each step from 3.27:1 through 4.56:1 gears on Dynojet and Mustang dynos.

 

Increasing gearing DECREASES traction with no other changes.

 

 

This is good info but I can't believe the rings did 34RWHP worth of seating in 2 hours. But... I could be in that dufus group mentioned earlier!

 

I *think* Fordgeek said his IAT was 104F? Is that correct? If so, it might have been pulling 1 or 2* of spark but not much more than that.

 

As soon as anyone can get into the PCM (or have they already??) of the GT500, then they'll be able to maximize the engine's power. I would guess that the factory tune is a tad boring.

[mcduck]

Yes, I've got a video...it's short but you can hear the car pretty good. Does anyone have any idea how I can FTP it to this site and link to it. It's in MPG format and it's about four megs.

 

if it's only 4mb, you can email it to me and I can host it on my website.

[68fastback]

According to a Microsoft Excel model I created to calculate RPM/speeds based on trans and differential ratios, a 4.10 should produce around 41 mph at the redline of 6,250 RPM (is that the correct redline?). Here is the complete data....

 

At 6,250, the speeds by gear are below. Keep in mind these are THEORETICAL speeds. Obviously we won't have a 245 mph car here. This analysis also assumes stock tire sizes, which I calculated at 27" diameter...so the numbers may be off by a small amount, particularly at higher speeds.

 

With a 3.31 rear gear (stock):

1st gear = 51 mph

2nd gear = 79 mph

3rd gear = 103 mph

4th gear = 152 mph

5th gear = 181 mph

6th gear = 245 mph

 

With a 3.73 rear gear:

1st gear = 45 mph

2nd gear = 71 mph

3rd gear = 91 mph

4th gear = 135 mph

5th gear = 160 mph

6th gear = 218 mph

 

With a 4.10 rear gear:

1st gear = 41 mph

2nd gear = 64 mph

3rd gear = 83 mph

4th gear = 122 mph

5th gear = 146 mph

6th gear = 197 mph

 

Another thing that may be of interest....cruising RPM on the highway with different gears. Below are the RPM you should expect at 65 mph IN SIXTH GEAR.

 

With a stock 3.31 gear = 1661 RPM

With a 3.73 gear = 1871 RPM

With a 4.10 gear = 2057 RPM

 

I just went through something similar with my '69 Camaro. Two years ago I had a muncie 4 speed (no overdrive) with a 4.11 rear end. I junked the muncie and had a Tremec 5-speed installed (road race version), and my RPM dropped from about 3100 AT 60 MPH to about 2550 RPM. The trans has a .82 OD, and boy does it make the highway driving more pleasurable. Actually the way it works out is that, previously, I would only drive 55 mph on the highway to keep RPM down around 3,000. Now I drive in the low 60s and am still able to accomplish that.

 

Dave

 

 

Hey, Dave, thanks for posting the nums (and my index finger and calculator thank you too :-)

 

I'm starting to like the 4.10s a lot more, I have to admit, since the quarter mile seems to fit nicely in three shifts (with the stock tires). And the 6th gear road revs are still fine... nice!

 

-Dan

 

 

But I'm like you...I enjoy ripping out of the whole, especially when staging shallow.

 

Regards,

Joseph(FordGeek)

 

 

Joseph, I was wondering where you managed to find a set of hardened 4.10s? Ford had stated that the some aspects of the carrier were toughened and the 3:31 gearset was further hardened for GT500. Are these the std 4.10s or has FRPP already gotten out in front for us?

 

And thanks so much again for keeping us up to speed on your ride.. much appreciated.

 

-Dan (68fastback)

[Three Cobras]

Anyone that has their car already....does your owner's manual state the actual HP anywhere? Or perhaps on the window sticker? What does it say?

 

 

The window sticker does not state any horsepower figure. Shelby owner's manual supplement states 485 HP and 475 TQ.

[150man]

When Ford first released the 500 HP figure, they claimed it to be SAE certified. Doesn't that carry any weight?

[DVS2XS]

BlueOval - 34 hp is about an 8% improvement. A good portion of this is due to the less restrictive exhaust. The reason I mention ring seal is the 3% improvement in torque - a low rpm improvement that is only slightly altered with more exhaust flow.

 

With new engines (especially forced induction engines), that have not completely seated the rings, the blow by passed the rings does three things:

1.) Less total pressure is trapped in the cylinder.

2.) Oil from the crankcase and cylinder walls is introduced into the combustion chamber (possible pre-ignition issues under load).

3.) Crankcase pressures are much higher.

 

The first several hundred miles of wear are the most critical.

 

Don't take my word on it...test it for yourself.

[wildosvt]

I'm wondering why the heck does this thing even have a 6th gear? Who wants to lug the engine down the road at 1660 RPM? I guess if you're cruising the autobahn at 155, (allowed top speed), it may come in handy.

 

 

I do not waist gas while driving my 04 Snake. Im in 6th at 40MPH. 35MPH is a little too low to do it.BUt the Shelby might want you to be closer to 45 to cruise in 6th.

 

I HOPE the 07 is "close" to the 04 in terms of MPG. I love my gas milage.

[68fastback]

Ok, just for laughs: 1462HP Mustang on Chassis Dyno Damn, that's cool

 

<end of recreational break>

[LSR]

FordGeek, thanks for the pics. and info.

 

Keep us posted of any changes

[zhb353]

 

 

With new engines (especially forced induction engines), that have not completely seated the rings, the blow by passed the rings does three things:

1.) Less total pressure is trapped in the cylinder.

2.) Oil from the crankcase and cylinder walls is introduced into the combustion chamber (possible pre-ignition issues under load).

3.) Crankcase pressures are much higher.

 

The first several hundred miles of wear are the most critical.

 

 

 

 

Is getting on a dyno the best way to seat the rings or is there equally effective alternative ways?

[RUFDRAFT]

I'd like to read the responses to seating rings, too.

 

Lots of opinions on this one.

[RUFDRAFT]

I think my first road trip in the Mustang will be VA Beach....

[BlueOval]

I dunno - still doesn't make sense to me about the hp gain from ring seating. He said that the 412RWHP number was the "best" run of the initial dyno session so why wouldn't the numbers have been higher with each successive run of the initial dyno session?

 

Do they have to seat then rest for a couple of hours? Also, I don't think there's a better way to load the engine up than by "stompin' on it" on the road When I datalog my truck the load goes through the roof when that happens! Actually, sometimes it's a bit scary how high it goes :-]

 

Now, I'm NOT saying that's not where the hp gain came from - just saying that it doesn't seem too clear to me - yet.

[dezzracer]

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:

 

 

Please....its going to take a lot more than that to show a 06 Z06 "whos boss". AZ06 is what...700 pounds lighter? I currently own an 04 terminater, and know dought the GT500 will be a beast once the aftermarket gets it dialed in. Its going to take quite a bit of dialing to put the whoop on a Z06. From a handling stanpoint...forget it. The GT500 is out of its league against a Z06.

 

Also just a few thoughts on the post. The increase in power was not from gears but rather the cool down (given the conditions) and the exhaust. 250 miles on first oil is not enough before hammering on a dyno IMO. No dought there is more HP lurking once she loosens up. I would be careful about gearing this car if you plan on pushing it over 550 which should be fairly easy to do. Its no good if you cant make it stick. not flaming here just observation. Thanks for the info. Good stuff. You guys are going to love this car.

 

 

Please....its going to take a lot more than that to show a 06 Z06 "whos boss". AZ06 is what...700 pounds lighter? I currently own an 04 terminater, and know dought the GT500 will be a beast once the aftermarket gets it dialed in. Its going to take quite a bit of dialing to put the whoop on a Z06. From a handling stanpoint...forget it. The GT500 is out of its league against a Z06.

 

Also just a few thoughts on the post. The increase in power was not from gears but rather the cool down (given the conditions) and the exhaust. 250 miles on first oil is not enough before hammering on a dyno IMO. No dought there is more HP lurking once she loosens up. I would be careful about gearing this car if you plan on pushing it over 550 which should be fairly easy to do. Its no good if you cant make it stick. not flaming here just observation. Thanks for the info. Good stuff. You guys are going to love this car.

 

 

 

Not sure how my relpy ended up in this thread...sorry

 

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.

 

 

 

Please....its going to take a lot more than that to show a 06 Z06 "whos boss". AZ06 is what...700 pounds lighter? I currently own an 04 terminater, and know dought the GT500 will be a beast once the aftermarket gets it dialed in. Its going to take quite a bit of dialing to put the whoop on a Z06. From a handling stanpoint...forget it. The GT500 is out of its league against a Z06.

 

Also just a few thoughts on the post. The increase in power was not from gears but rather the cool down (given the conditions) and the exhaust. 250 miles on first oil is not enough before hammering on a dyno IMO. No dought there is more HP lurking once she loosens up. I would be careful about gearing this car if you plan on pushing it over 550 which should be fairly easy to do. Its no good if you cant make it stick. not flaming here just observation. Thanks for the info. Good stuff. You guys are going to love this car.

 

 

 

 

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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

 

 

 

Please....its going to take a lot more than that to show a 06 Z06 "whos boss". AZ06 is what...700 pounds lighter? I currently own an 04 terminater, and know dought the GT500 will be a beast once the aftermarket gets it dialed in. Its going to take quite a bit of dialing to put the whoop on a Z06. From a handling stanpoint...forget it. The GT500 is out of its league against a Z06.

 

Also just a few thoughts on the post. The increase in power was not from gears but rather the cool down (given the conditions) and the exhaust. 250 miles on first oil is not enough before hammering on a dyno IMO. No dought there is more HP lurking once she loosens up. I would be careful about gearing this car if you plan on pushing it over 550 which should be fairly easy to do. Its no good if you cant make it stick. not flaming here just observation. Thanks for the info. Good stuff. You guys are going to love this car.

 

 

 

 

 

 

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.

 

[68fastback]

Is getting on a dyno the best way to seat the rings or is there equally effective alternative ways?

 

 

IMO a traditional progressive brake-in will polish surfaces much smoother than bonsai runs, which will probably do it quicker but not as smooth. I'm still of the belief that the odds of slight cylinder scoring are dramatically increased with a 'drive-it-like-ya-stole-it break-in or early dyno runs. I understand they often break plane enginess in by running it strapped-down at a high percentage of max output for a couple of hours, but turning up early failures probably outweighs max engine output considerations in a plane. Also, I suspect if you detonate the pup with 50 miles on it, you'd be hard pressed to convince Ford you were followig the recommended break-in period.

 

I remember in the '60s, some 406 and 427s were already run-in at the factory and came with a statement 'no brake-in period required.' I didn't see any statement in the GT500 supplement so I suspect the default break-in applies (whatever that is).

 

Having said that, I think these engines are well spec'd and the risk is minimal, but you won't find me bypassing a progressive break-in

[2008GT500KR]

Yeah, I noticed that. Good discussion and good points are being made by all. For our purposes, some clarrifying points:

 

1.) HP numbers are STD, not SAE.

2.) The best of the inital dyno runs (412) came after a lengthy cool down. The swap took around 2 hours so some additional cooling may have impacted the numbers for the post-swap set.

3.) Again, just reporting reality based on what the case was with me. Everyone has a right to their opinion based on past experiences. These were mine...whenever they get their Shelbys they'll come to their own.

4.) It's commonly known that gear swaps do not increase engine horsepower; they bring it on sooner. Our findings, however, are that if we're to push the rev limiter out a bit, there will indeed be additional HP to be had because the HP curve does not taper off toward the top of the rpm range.

5.) I'm trying to contact the guys at Lethal to see exactly what everyone is talking about. It could be that they've downloaded the codes from the Shelby computer (we did the same) but have done enough research to realize they're pretty similar to something that already out there. Not sure, but I'd like to find out given that their name has come up quite a bit.

 

 

geek, were your dyno runs in 4th gear? Did you try the runs in other gears? It WILL make a diff

[68fastback]

See GT500 motor pic below... there would seem to be enough room to increase radius of crank pulley 20-25% and decrease H2O pulley by a comparable amount. That would move boost from 8.5 to 10.2-10.6 lbs boost. But, man, FordGeek is right -- not much room there! Might have to wait for some well engineered aftermarket billet kits.

 

 

Can't wait for SEMA!

 

<edit:> anyone see a pic that makes it easier to discern the inner vs outer belt path? I think I'm now half-blind trying to track the path in photoshop Looks to me like the inner/outer have different radii at the crank so there may be more room than it seems with a re-engineered pulley, notwithstanding that the above pic is a show stand motor and may not be 100% accurate >

[STSVT]

Good question CW,

 

We're uncertain at this time how much power has yet to be tapped from the headers. I do know that the 4.6 liters responded really well to header swaps. We've talked about adding this to the list of possibilities, but we first want to confirm the power being robbed by the CATS. Sometimes, the aftermarket headers have really impressive ports at the header flange, but they don't match up to the puny exhaust ports on the heads. The trick to use a design that optimizes cylinder scavenging and I'm unsure at this point what works well for the 5.4. I'll keep everyone posted once the aftermarket or FORD comes up with replacement headers.

 

Regards,

Joseph (FordGeek)

 

Thanks for all of the info ford geek

[Lightning Bob]

ForGeek,

 

Thanks for the info... very informative.

 

I have one question. At any time during your dyno session, did you unhook the battery to reset the fuel tables in the PCM to their default values? This could be the source of the relatively large HP increase you experienced. As you know from your terminator, heat and humidity dramatically affect RWHP. Your numbers are looking good so far. Keep up the good work. Some of the rest of us will be jumping on the band wagon shortly. :bandance: :bandance:

 

Lightning Bob

[BlueOval]

ForGeek,

 

Thanks for the info... very informative.

 

I have one question. At any time during your dyno session, did you unhook the battery to reset the fuel tables in the PCM to their default values? This could be the source of the relatively large HP increase you experienced. As you know from your terminator, heat and humidity dramatically affect RWHP. Your numbers are looking good so far. Keep up the good work. Some of the rest of us will be jumping on the band wagon shortly. :bandance: :bandance:

 

Lightning Bob

 

 

I believe that resetting the PCM only resets learned values like short term and long term fuel trims <- all of your "adaptive" values. Spark and fuel tables aren't learned values - not on the EEC V computers anyway.

 

The fuel trims wouldn't make it get any more power unless they were so outta whack that the thing went to fail safe mode or something but that would be obvious if it happened.

 

Hell, maybe the tires slipped the first session!!!!!

 

We just need to see more people on th' dyno and then we shall know the truth - I bet the numbers will trend closer to Fordgeek's 2nd dyno session but we'll see.

[Lightning Bob]

I believe that resetting the PCM only resets learned values like short term and long term fuel trims <- all of your "adaptive" values. Spark and fuel tables aren't learned values - not on the EEC V computers anyway.

 

The fuel trims wouldn't make it get any more power unless they were so outta whack that the thing went to fail safe mode or something but that would be obvious if it happened.

 

Hell, maybe the tires slipped the first session!!!!!

 

We just need to see more people on th' dyno and then we shall know the truth - I bet the numbers will trend closer to Fordgeek's 2nd dyno session but we'll see.

 

 

 

BlueOval,

 

You are right in that only the adaptive fuel trims would change.

But (and you may find this hard to believe), I've been drag racing both Lightnings and Cobra's for the last seven years and I have seen many instances where resetting the PCM has dropped quarter mile ET's in excess of 0.3 seconds on street driven SVT vehicles on back to back runs with no reset versus resetting the PCM. The extra horsepower to accomplish such a gain has got to come from somewhere. I believe that the fuel trim values learned when driving in normal traffic do not allow maximum power under hard acceleration. It takes a while for the PCM' adaptive learning to figure out a new stategy for drastically different driving conditions (as on a dyno) and this time can be shortened considerably by starting over with the default values. There are many guys in my Lightning club which could attest to this phenomenon.

I was only trying to point out an area which has yet to be questioned in FordGeeks results, and I would still like an answer from him if the GT500's PCM was reset in the course of his dyno session.

 

LB