Ford Racing Pulley kit + a few extras 700 HP


gtinmyblood

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Feb 23, 2007
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Quote"if you really want to correlate/compare your numbers to the majority of us, visit a shop with a Dynojet dyno, "end quote.

I think that's really a good idea. I have a conversation going with Jason Heffener about it. He says the GT750 usually has 640 to 650 RWHP. Somewhere I seem to be missing about 100HP. Could it be the quality of the tune or the dufference between a mustang dyno anda dynojet? I'd have no prob shipping it to Jason for an extra 100hp just out of a tune!
 

DoctorV8

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I suspect the Heffner small pulley would net you 30-40 more rwhp than your tune; just an educated guess. You're probably going to see 570-580 rwhp, SAE Dynojet, with your current setup.
 

gtinmyblood

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i will chase down a dyno jet and see what it does and let you all know. What is the size difference between the heffener pulley and the ford racing pulley? What boost difference is generated? I will look into that with Jason as well.
 

gtinmyblood

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Just got done having ADS in Chandler AZ install the following:

Ford Racing pulley kit
Ford Racing headers exhaust system
k&n Filters
Accufab intake support tube
Accufab hose support coils
Accufab throttle body
SCT Tune with ADS specs
Accufab magnetic drain plugs
Ford Racing Trans cooler
Upgraded clutch (specs and pics to be posted later)

Mustang dyno numbers at flywheel are 700.13 HP with 693 Ft lbs of torque

As soon as I get them I will post the dyno sheets. They ran them both based on centrifugal load and dyno jet settings so we can compare. I will also post the drive train factors that they used to calculate from the rear wheels back to the flywheel.

First gear is now useless and it pulls like an MF through the range.

I Consider it my Christmas gift to my second favorite person! My wife didn't get pissed so she's still number one!:lol
 

DBK

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Why would they bother trying to convert it to crank hp on a chassis dyno? :willyWhat kind of clutch did you go with?

Either way, it's definitely faster right? :biggrin
 

gtinmyblood

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conversion is just for comparison purposes. I will post the RWHP sheets as soon as I get them so you all can see them too.

They are sending me the specifics on the clutch so I can post them as well as pictures of the install.

Definately FASTER!

Oh, We also changed to the Castrol High heat clutch and brake fluid since I boiled the stock fluid other day at Firebird Raceway and we did the Accufab axle bolts just before that.
 
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Team Jeff

GT Owner
Sep 8, 2007
557
Glad your happy with the ride! I was down at ADS last week and took a peek under your car....I was amazed at how clean it was!

How do you like the new exhaust note?
 

gtinmyblood

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How do you like the new exhaust note?
The new exhaust is mellow untill you jump on it and then all hell breaks loose. Personally, I like it! i could see how some people might get tired of the note but it works for me.
 

ViperJoe

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What % driveline loss did you assume in calculating bhp?
 

DoctorV8

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Looking forward to rwhp before/after curves. Did they stick a wideband O2 sensor up your tailpipe?

<bracing for the jokes already>
 

gtinmyblood

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Here are the RWHP dyno sheets. The factor used to convert back to flywheel for drivetrain was .75 (take RWHP /.75) same factor for torque.

The first sheet is after a detune for street to keep me from blowing it up. The second is the max we got. It is choppy because we were getting slippage on the dyno.

513.6 RWHP /.75 = 684.8 HP at flywheel
483.1 RWTQ / .75 = 644.13 ftlbs at flywheel

525.5 RWHP /.75 = 700.67 HP at flywheel
524.7 RWTQ /.75 = 699.6 ftlbs at flywheel

For oxygen sensors they welded bungs on the headers.

Comments? Am I looking at this right? some of you guys know a heck of a lot more about this than I do. I could learn something from you all...
 

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ViperJoe

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15% is about the max driveline loss I would assume. So based upon the formula used, 513 (rwhp)/.85 = 603 bhp. I would have expected considerably more rwhp given the mods made to the car. Also, the difference in the torque numbers is highly suspect.
 

DBK

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The numbers they are using to convert to flywheel are really optimistic. The driveline loss is more like 10-12%.

Otherwise, it's hard to tell. Did they not do a baseline dyno of your vehicle stock? It's a Mustang Dyno, which will typically read lower than a Dynojet, and your peak numbers are close to alot of stock cars. I'm in no way saying your car is making stock power, because dyno numbers can greatly vary from one to the next, but without the base line to judge the delta, it's hard to tell what you picked up.

Dyno sheets are something to stick in your drawer and say "neat", so as long as you know it feels alot faster, that's what counts.
 

Bill Oxley

GT Owner
Jun 15, 2006
138
Denver area
.

I heard these conversion numbers all the way from a low 7.5% to, like this one, 25%.

It sure seems like the loss percentage from flywheel to "rear wheel" could be a little more definitive. I'm know there are varibles, but these transaxles are all the same, etc.

Can anyone enlighten me on that? Gtin, not to steal your thread here, but I'm sure we're both interested.
 

DBK

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I heard these conversion numbers all the way from a low 7.5% to, like this one, 25%.

It sure seems like the loss percentage from flywheel to "rear wheel" could be a little more definitive. I'm know there are varibles, but these transaxles are all the same, etc.

Can anyone enlighten me on that? Gtin, not to steal your thread here, but I'm sure we're both interested.
On an engine dyno, most GT engines will make 575hp, so make of it what you will. I've never seen it done, but that's what Jamal told me. Worst case scenario you're looking at the 10-12 range, and definitely nowhere near 25.
 

gtinmyblood

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Hey, you guys know alot more about this stuff than I do. Every dyno sheet I've ever seen has been questioned by people who know a hell of a lot more than who ever has the sheet. Thats why I posted it all up there for you to judge for yourselves. They did not run a baseline because I took it in to the shop hurt. I boiled the clutch fluid at the track and it turned to jelly so no baseline was gonna happen. Think what you want. Conclude what you want. I won't agrue with anyones opinion on train loss etc cause I honestly don't know the technical details. All I can tell you is that this is not the same car it was before the mods. It definately puts a huge smile on my face!
 
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gtinmyblood

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Here are a couple of pics of the clutch pack that went into it. I will post the specifications when I get them in a postable form.
 

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Indy GT

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I agree with Dave and ARCJoe, using a power reduction factor (ie. power loss in the conversion of flywheel available power to rear wheel available power) of 0.25 is in my opinion is way to high. (Dave this is "conservative" not "optimistic" as it leads to the dyno guy telling you the engine is producing "less" power than it actually is making (assuming a reduction factor of 10-12% is more accurate) thus a conservative estimate).

I'm sure Jamal and the team know or at least reviewed this paramater when they sourced the transmission/transaxle design from Riccardo. Pretty easy paramater to measure (if you have a stand-alone transaxle, input torque source and output measuring equiptment). The delta between input and output power is the "power" consumed by friction (and thus heat) in the transaxle. And I agree a value of 10-12% is much more accurate than 25%. Possibly even lower with the Riccardo sourced transaxle fluid, the use of low friction bearings throughout and FEA optimized gear contact areas. (See SAE publication 2004-01-1260).

Dave's other point is also well taken, what we as owners care about is REAR wheel horsepower. That's what accelerates our car and is what is measured on a chassis dyno. Thus what ever conversion factor you want to use to "back out" engine BHP at the crank is analytically intersting, but in reality means very little (unless you want to compare the results of your engine to some other engine that was engine dynoed outside a vehicle).

If owners are interested in really knowing the power enhansements any of the plethora of performance mods available to our cars it is VERY important to conduct a "baseline" run (or calibration) before you apply your upgrade. If the mod and post-mod dyno run can be done the same day all the better. This insures the "cleanest" way of assessing individual performance modifications without adding pressure/temperature atmospheric and different dynos variables which can slant or obfuscate performance results.
 
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gtinmyblood

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I'm having a hard time with the "in my estimation" thing. I wish someone who actually knows the numbers for loss would speak up. Surely the guys on the Ford team have those numbers. I agree, all that matters is where the rubber hits the road. At this time I regret ever posting my dyno sheets.
 

DBK

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A long time ago, I asked Jamal that question and here is the answer he gave me: 7 and change. Nobody seemed to believe that answer, but he was the Program Manager for the Ford GT, and he's a lifelong engineer. Most mid-engine cars are somewhere in the low double digits (10-12%). He said that if you run a 5.4L Ford GT engine on an engine dyno, it will produce about 570-575 hp at the crank. This is why most stock Ford GT's will produce
somewhere between 510-530 rwhp. There is a bit of variation because of the way the engine was built.

So that's the answer. There's just no way it's anywhere near 25. That's why I said I think your tuner has a dyno that reads low. Most Mustang Dynos will read lower than a DynoJet anyways, it's just that this one seems particularly low.

As you've said, it feels a lot faster. In a car that comes with 550hp from the factory, you wouldn't notice much of a difference if you didn't legitimately pick up quite a bit of power. My guess is that your car would probably make 560-570rwhp on a different dyno, maybe more. The Ford Racing Headers, K&N, Accufab TB and air inlet stiffenere alone would probably turn out 525+ on most dynos. So like I said, dyno sheets are something you stick in the drawer and say "neat".