2005 GT vs. 2001 Bullitt/03-04Mach 1

kirkyg said:

Again the 3valve heads are great and the right choice by ford for a mass produced mustang GT...however they will not in the end have the same potential that 4 valve heads have. Thats it end of subject and if you disagree with that FACT then you are just wrong.

kirkyg

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Yes, with all else being equal, 4-valve heads have the edge over 3-valve heads. But you're naively assuming that the number of valves is the only aspect of engine design that dictates potential for power.

For the hundredth time, as everyone has already pointed out, there are a number of engineering "advancements" that have been made with the 3V engine, including VVT.

You can talk all day about the theoretical superiority of 4-valves, but what matters at the end of the day is what us consumers will pragmatically be able to achieve (tuning, aftermarket, etc) with each of these engines. I'm willing to bet right now that, dollar for dollar, the Mach's 4V engine will offer no advantage whatsoever in the long run.

Alright, so if what you saying is true and other 'advancements' are making these 3valve 'god-heads' if you will...why is ford continuing to produce a more expensive to manufacturer DOHC heads for the all new cobra and lightning to be mated to a Twin Screw supercharger?????????

Explain PLEASE.

Oh, and no what really matters is if i take these 3valve heads and these 4 valve heads to a shop to have them p&p'd which ones will flow better and produce a better longer powerband? Thats what matters...not how well they flow stock.

kirkyg

At the end of the day, and at the end of this thread, when all you can point to is the "POTENTIAL" (as in, if you were to ship your mill to Sean Hyland with a blank check and a note that says "push the envelope") of your 4V heads as being the only possible advantage to the outgoing Mach, well then, fine. You can have that point. So where does that leave you in this debate? A little bankrupt I think. It's like comparing two houses, and the only thing that comes out on the "plus" side of one house is that it's got a little more land that would allow you to build another foot onto the back of the garage, IF, you wanted to. I love the new Mach as well. I ride in one to the gym with my buddy every flippin day. It's the best package to-date that Ford has put together, hands-down, and a blast to drive (yes, I've wringed it out). But MAN, is it due for a retirement. No insult intended, I don't don't mean to dig on your cars at all. But even with the subframe connectors he has to crreeep over speedbumps as the car bends and stresses. That chassis is obsolete. I had a TON of fun in my '88 GT convert, the '96 Cobra I had, and I've still got my '97 S351. But I don't think that these "comparison" threads really have any basis, it's a foregone conclusion. But you don't have to be defensive about your Machs, I think everybody here has stated their respect and fondness for them...

backrupt? dude anybody who is at all serious about having a car that runs good looks at head porting. Its a good way to gain a considerable amoutn of power whether you are building a supercharger/turbo motor or a n/a setup. so yes what i said is correct for most people that are seriously into performance...they want to know what potential do i have down the road as well as what performance the heads have stock. I think you'll find that stock the 4valves will outperform slightly all other things being equal and the potential for the 4valve heads will be considerably more power.

kirkyg

I understand the benefits of head porting, every time I throw boost to my ported aluminum TFS's on my 351. But I still believe you're grasping at straws, or as my Grandfather likes to say, picking the fly $hit out of the pepper. If initial dyno reports are actually in-fact true, then the 3V motor in the '05 is already a touch more powerful stock, right out of the gate. Whenever you talk about the "potential" of the Cobra mill from modifying, you can't at the same time discount or forget the possible modding potential of the 3V mill. If you can port 4V heads for gains, you've got to allow for the fact that the same holds true for the 3V. If, ULTIMATELY, the 4V heads offers some more flow POTENTIAL (which of course only equates additional "performance" if that flow can be utilized fully within the rest of the powertrain package), then big stinking deal. How far must you go before that additional potential actually allows you to start pulling away from a similarly modded 3V that's had an equal amount of time and money spent on the flow bench? It's like the old Mustang vs. Camaro arguments where one guy says "give me a Mustang and $5,000, and I'll spank your Camaro". And the Camaro guy says, "big deal, give me that same $5 grand and I'll be right back in front of you" and so on and so on. Sure a 4V head may have a bit more potential, but that won't keep you from being obliterated by a guy in a stripped-down '79 ghia with a Nasty stroker and a 4-link. It's all relative. Bottom line, is that until the '05's are out for awhile and race shops start playing with the heads and publishing dyno results, you're just speculating on how much this "potential" advantage may be. Given the different torque curves, it may not amount to diddly. And when you look at both cars as a whole, the entire package, it becomes even more insignificant. So the 3V motor trades off a smidge of flow for more usable torque and VVT. I'll take it. And if some day you actually tap into that extra bit of "potential" you've got, then an '05 owner will just tap a bit more out of his motor, and back, and forth, and joust, and parry, until one day you run an 8.40 in your car that's no longer streetable, which may be two tenths faster than the fastest 3V-er out there, and all of the guys with modded street cars in the sportsman and trophy lanes will think "gee, I should have bought an '04 Mach, it had more "potential" in the heads"????? I think not. I know I get a little sarcastic when I debate, and I'm not saying your wrong. I'm just arguing that your context is a little far out in left field, that's all.

The only people grasping at straws are the people saying 3valve heads have been touched by god. Here is the deal. Ford had to strike a balance in the evolution of the mod motor to create more power but keep costs down to a reasonable level. The obvious answer was 3-valves keeping only 1 cam / bank and allowing there to be considerably better flow than the 2-valve heads. In the process they have found a median between 2 and 4 valves for all motors to come out and raise their fuel economy, engine efficiency, and power output all at the same time.

That being said unless ford maxes out the heads in terms of port size then you can forget it out flowing a 4valve head. within reason the more ports there are the better potential placement and more power can be produced. Potential for alot of things doesn't matter but when your talking about heads its the basis for all the power your engine will make. No breathing, engine choked, and no power.

For the 18th time i will finish...the 3valve heads are exactly what they are supposed to be a good low cost alternative that can provide alot more power than current application...but thats where it ends. They are not perfect and they are not going to be the best flowing heads ever made. BTW, the 290 rwhp is just a rumor...i doubt very seriously ford would tune the engines to that output stock...they have always been more concerned about the entire package than the rwhp the engine creates.

kirkyg

The only people grasping at straws are the people saying 3valve heads have been touched by god.

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Whoever said that?? Who even inferred that? EVERYBODY'S agreed that the 4V heads have some more potential. But the relativaty of that, I tried to lay out clearly, but I'm done trying. You can have your better heads. You won't know for awhile now whether dollar for dollar, your superior heads really get you that further ahead of the game, and they're still bolted to an outdated and tired old design of a car.

Jeez man. You've got half this board crying for lost pushrods and the other half wanting a twin cam 4 valve head. I don't think anyone here is really qualified to say how good the new heads are or not.

The sohc 3 valve VVT in the GT is an improvement. Would you rather see them put the sohc 2 valve back in?

I didn't think so.

Hey, haven't been able to do 1/4 time in my Mach yet but I got to find out what I can do 0-60. 4.7 with the wheels spinnin and my 200lb friend in the car All I have is a catted Magnaflow X and magnapacks which really isn't much of a mod and really doesn't help 0-60 much, can't wait to see what I can do with 17 x 9's on it. I really don't think the 05 GT is gonna be as close as you guys think in the acceleration dept.

I can't wait to get harassed for this one

kirkyg said:

Alright, so if what you saying is true and other 'advancements' are making these 3valve 'god-heads' if you will...why is ford continuing to produce a more expensive to manufacturer DOHC heads for the all new cobra and lightning to be mated to a Twin Screw supercharger?????????

Explain PLEASE.

Oh, and no what really matters is if i take these 3valve heads and these 4 valve heads to a shop to have them p&p'd which ones will flow better and produce a better longer powerband? Thats what matters...not how well they flow stock.

kirkyg

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Obviously, your preferred debating tactic is to twist everyone else's words into something that is easy to rip down, and then go on to do so. God heads? I don't recall attributing any divine qualities to the 3V heads, but whatever.

I'm not talking about the "potential" of 3V vs. 4V per se. I'm talking about Ford's 3V ENGINE vs. Ford's 4V ENGINE. That's right, the entire engine, not just the slabs of aluminum that sit on top of them. The number of valves is only ONE of the many differences between the two powerplants.

Why is Ford sticking with the 4V for the supercharged engines? I'd have to say there are two reasons: 1) Cost is not as much of a factor in "high end" models; 2) The extra valve starts to make more of a difference with forced induction.

Here are some points you may not be considering:

- Intake flow is far more important for power than exhaust flow
- There are more mechanical losses associated with turning 4 camshafts as opposed to just 2
- VVT improves volumetric efficiency -- and thus torque -- across the rev band and should easily offset the effect of one less exhaust valve
- The single exhaust valve is bigger than the exhaust valves on the 4V setup, so it's not like they're cutting the exhaust flow in half

Like someone already said, if you had a limitless budget to work on both engines, you may very well have an edge with the 4V. But let's get real here. What percentage of Stangers P&P their heads? What percentage of Stangers add a blower or turbo? These people amount to a mere drop in the sea. It's the general Mustang population that is going to be establishing the reputation of each of these cars, not the rare oddball fanatic.

By the way -- if you find P&P such a natural and effective thing to do, why haven't you done it yet?

Like I said, at the end of a thread for which the original premise was a comparison of entire CARS bumper to bumper, and when by process of elimination all that Kirky's got left to hang on to is the "potential" volumetric efficiency of the cylinder heads..... He's gonna hang onto that tidbit like a Pitbull on a shoelace. Actually Kirky, I know you're probably getting irritated with me, and I don't want things to go south. I've said you're right, I know the 4V heads have more potential. It's just my take that, in the big picture, engine to engine, it's not that significant a deal. I'm ready to call a truce, worthy adversary.

Mach428, your 0-60 test doesn't sound terribly scientific. What did you use, a stopwatch? One of those performance computer thingies?? You may as well count "one mis-a-sip, two mis-a-sip, ...." That's about how accurate those devices wind up being. Take your Mach to the track and have a blast. Your car IS fast if you're a swift driver. Cool weather (which is not in ready supply this time of year) should have you in the low 13's.

kirkyg said:

Alright, so if what you saying is true and other 'advancements' are making these 3valve 'god-heads' if you will...why is ford continuing to produce a more expensive to manufacturer DOHC heads for the all new cobra and lightning to be mated to a Twin Screw supercharger?????????

Explain PLEASE.

Oh, and no what really matters is if i take these 3valve heads and these 4 valve heads to a shop to have them p&p'd which ones will flow better and produce a better longer powerband? Thats what matters...not how well they flow stock.

kirkyg

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Why stop at 4 valves? It's been proven that 5 valve heads are better, that's why most of the Formula 1 race engines use them.

Again, your comments about "porting" is just grasping at straws because you don't know how the heads flow and if porting really will gain you anything.

Now I will tell you the 2 things that ARE better about DOHC 4V and 5V heads.

1. With separate intake and exhaust cams you can implement DUAL variable valve timing. That is you can change both the intake and exhuast valve timing INDEPENDENTLY. This is what the BMW Dual Vanos system does and it is part of the reason why BMW can get so much HP out of the little M3 engine and meet emissions requirements. Porsche also has a similar system.

HOWEVER, Ford has NOT yet implemented any form of VVT on the 4.6 or 5.4 4V engines let alone dual VVT. So there is no real advantage here.

2. You can increase the angle between the valves, creating a larger distance across the bore which allows more valve area. More valve area means you can use larger valves. Larger valves mean you can flow more air. More air means more HP.

However to be fair, we have to talk about the downsides of DOHC 4V and 5V heads.

1. They cost significantly more. Remember we are talking about a $25K Mustang GT, not a $60K BMW M3 or a $100K Porsche.

2. They are physically larger.

3. They are physically heavier.

4. They have more moving parts. More moving parts means there are more things that can fail or wear out.

Every engineering decision made in designing a car is a compomise between price, performance and weight.

The bottom line is that the new Ford 3V heads are a GREAT compromise between performance, cost, size and weight.

Whining for 4V heats on a $25K GT is down right silly.
The Cobra and Lightning are EXPENSIVE special models, so they can absorb the cost of 4V heads.

Time to this thread.

kirkyg said:

Alright, so if what you saying is true and other 'advancements' are making these 3valve 'god-heads' if you will...why is ford continuing to produce a more expensive to manufacturer DOHC heads for the all new cobra and lightning to be mated to a Twin Screw supercharger?????????

Explain PLEASE.

Oh, and no what really matters is if i take these 3valve heads and these 4 valve heads to a shop to have them p&p'd which ones will flow better and produce a better longer powerband? Thats what matters...not how well they flow stock.

kirkyg

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"god heads". That's funny.

Interesting thing about "potential", not that I'm trying to make a direct comparison, Mercedes' new flagship vehicle, the SLR McLaren, has a 5436 cc supercharged V8 with sohc, 3 valve heads. That car is rated at 617 hp @ 6500 rpm and 575 lbs-ft @ 3250-5000 rpm.

Mach428, your 0-60 test doesn't sound terribly scientific. What did you use, a stopwatch? One of those performance computer thingies?? You may as well count "one mis-a-sip, two mis-a-sip, ...." That's about how accurate those devices wind up being. Take your Mach to the track and have a blast. Your car IS fast if you're a swift driver. Cool weather (which is not in ready supply this time of year) should have you in the low 13's.[/QUOTE]


I am going to try and get my car to the track this week or next. I'm not sure what to expect but I have perfected 0-60 runs which will help me big time when doing a 1/4 miles start, i'll let youknow what my times were for the hell of it

I can't wait to see what the new 3 Link suspensions are like on the new 05's

Mach428 said:

I can't wait to see what the new 3 Link suspensions are like on the new 05's

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Probably so much better than what we have now it'll be like driving a whole different car. Oh wait, it IS a whole different car. Whatever.

I'll be interested to see if the 3-link suspension improves straight line traction. On an SN95, adding a torque arm does wonders for straight line traction, night & day I'm told. Perhaps the '05 only needs 235/55 tires because the suspension is so much better? Gotta be some excuse...

Dave

CatmanJJ said:

It's kinda weird but the more I see the new GT the less I like it. It's like when it first came out, I was ready to give my left nut for it but now after the initial droolfest has worn off I'm kinda like meh. I don't like the foglights, spoiler, hood is too plain, seeing the mufflers out back is ghey and the rear is too dumpy. The semi fastback roofline is hot and easily my favorite part of the new Stang but I think I like my 25 y.o. Stang just as much if not more then the new Stang lookswise...

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The only thing i dont like to much is the hood, and the mufflers sticking out, but its no big deal. The hood i will replace anyway, and same with the exhaust. Im hoping aftermarket catbacks will hide the mufflers somehow... if not ill just run straight through from the cat on without mufflers.