Does your GT feel fast?

[agentf1]

Agentf1 and I have the same friend, and we apparently have had the same conversation with him. This mutual friend is quite knowledgeable about cars and has owned many.

He is concerned that his particular GT is demonstrably and palpably slower than his Z06, and he gives numerous examples in several contexts as to his disappointments.

I do not believe that this is an illusion and have wondered if his car is simply tuned incorrectly.

My GT throws me back in my seat and has really remarkable acceleration, far exceeding the Viper that preceded it (which had 3.55 aftermarket gears). His, by contrast seems (to him) to be very anemic. He is, without question, quite disappointed.

I have recommended that he have the car looked over by a competent GT tech and have it dyno'd. He knows the numbers on his Z06.

It is concerning enough that he is (strongly) considering dumping the car at 200 miles...and this (at least to me) is quite a statement.

- doc

I think the only thing that may be wrong is the SOTP guage. It felt that way before the tune. The tune seemed to help but not as much as he would have liked. I think it is how the power is delivered with the SC. My L has a similiar feel to it but yet puts out some descent numbers at the track. I think the motor sitting over the wheels and excellent traction compared to the Z which will break them lose in the first 3 gears with ease also makes it misleading also. I don't think it will be available any time soon as finances pending I am in line for this car when and if it ever goes. :lol

 

[werewolf]

I'll stand by what I've always said ... it's the gearing. This wonderful machine is just geared poorly for street performance.

Remember ... you can't compare rear gear ratios alone. You must also consider rear tire diameter, tranny gears (which degrade the "effective" gearing of the GT even more) ... as well as vehicle weight and motor torque.

The entire drivetrain of this vehicle was designed by marketing to achieve one thing : hit 60mph in first gear. Even the clutch had to be designed appropriately, in order to pull out smoothly with such tall gearing.

I'll even make a prediction, perhaps it's already been said. There's gonna be a lot of pissed-off GT owners, when Shelby GT500s ... with 4.30's swapped in ... start handing them their asses on the street :frown

 

[agentf1]

I'll even make a prediction, perhaps it's already been said. There's gonna be a lot of pissed-off GT owners, when Shelby GT500s ... with 4.30's swapped in ... start handing them their asses on the street :frown

Now that would piss me off. :eek :frown

Whats an average stock GT run the 1/4 in? (average driver)

What do they advertise the 0 to 60 as?

What is the average rwhp/torque on these cars? Stock and with a pulley/tune?

I cannot believe how tall the rear tires are, this has to kill the rear end ration/gearing.

 

[cudacharlie]

Saw a video on google somewhere of a GT against some sort of (not modded) 05 Mustang at a dragstrip... The GT must be geared monstrously TALL, or else the GT guy stalled and had to restart, cause the Mustang jumped him by FIVE lengths...

Fear not.

The GT caught him by half track (just shifting to 2nd, it sounded like) and beat him by MANY MANY MANY lengths while running a 11.13 at 130mph. (I think it was 11.xx, it might have been in the tens...)

And the crowd went wild! :thumbsup

 

[abolfaz]

My car feels really slow right now, I think I've finally gotten used to it.

 

[dbk]

I'll even make a prediction, perhaps it's already been said. There's gonna be a lot of pissed-off GT owners, when Shelby GT500s ... with 4.30's swapped in ... start handing them their asses on the street :frown

:lol Not gonna happen. I've hauled some ass in the GT500 already. That car is about a 115-117mph car. With 4.30's it still won't be nearly as quick as a car that can routinely turn 125-126mph. (3450<3950)

 

[eshrink]

On the other hand, it would be great to see the Mustang be ultra-competitive, and if it is accurate that upon discontinuation of the GT, our motor will be put in the GT-R which will be essentially tubbed...the Mustang would make a great car.

- doc

 

[David Gencay]

does gt feel fast

Have the guy do a 2nd or 3rd gear run in his GT on a "safe" venue next to a friend's GT. Then have him do the same thing with his Z06 and the same Friend's GT. This should shine some reality on his concerns to help determine if they are real or imagined.

honestly feels like my viper 97 gts felt like

 

[eshrink]

Sorry, not what I was told.

- doc

 

[dbk]

You're probably right. The people I know generally have no idea what they are talking about :lol

 

[Kirby Vieira]

The GT 500 is a great looking/performing Mustang, but it's still a Mustang and will never be a GT, and both will be smoked by the Z06 SS, which will always be a Vette and never be an exotic unless a coach builder like Mark Gerisch decides to modify one... Hello, Mark, are you there?

 

[scode]

You're probably right. The people I know generally have no idea what they are talking about :lol

Dave,

Know a lot, say a little :wink That's my "MO", I have Suggested a few things on "The mustang source" only to be flamed by 14 year old kids that don't even drive yet. This is because of my post count. I was 100% correct but didn't have the time to prove them wrong. The same thing goes on "SVTPerformance". I would rather know what's coming than risking a valuable source of info. The internet is not a popularity contest, although we have made a lot of friends here and more to come in August. I am sure the rumor mill will run rampid after the event :thumbsup

Scode

 

[dbk]

Around here, as you well know, everyone knows everything. I've known random people who have cousins who had an uncle who had a friend that worked the line that know more than any national car rag. But I deleted that for your piece of mind :lol

 

[werewolf]

:lol Not gonna happen. I've hauled some ass in the GT500 already. That car is about a 115-117mph car. With 4.30's it still won't be nearly as quick as a car that can routinely turn 125-126mph. (3450<3950)

While I certainly agree about the weight disadvantage, I wasn't talking about 1/4 mile races.

 

[werewolf]

... but even if I were talking 1/4 mile, MM&FF got low 12's in a stock GT500 ... and predicts 11's with gears alone.

I'll stand by my prediction ... especially on the street :thumbsup

 

[dbk]

While I certainly agree about the weight disadvantage, I wasn't talking about 1/4 mile races.

If we were talking about anything past 1/4 mile speeds it would be even worse. Maybe it'd be close to from a 10-60 roll, but who does that?

Gears or not, you're talking about a de-tuned motor from one car stuffed in another, but adding 500 pounds and subtracting 100rwhp, shifting all the weight to the wrong end, and putting tiny little tires under a trunk with no weight to hold them down. A GT will make ~535rwhp in stock form, a GT500 will make about ~440rwhp. No matter what the gearing is in that situation, it's just not going to be a close race with the car with less power carrying 500 more pounds, mostly on the wrong end.

The math just wouldn't add up.

 

[dbk]

... but even if I were talking 1/4 mile, MM&FF got low 12's in a stock GT500 ... and predicts 11's with gears alone.

I'll stand by my prediction ... especially on the street :thumbsup

'

Evan Smith drove the 12.2@117. Same guy who put an 03 Cobra to a 12.4, and a Ford GT to an 11.0@130mph with a 4mm smaller pulley. Let's say it does get 11's, even miraculously shaves a 1/2 second off what one of the best drivers in the world can get and goes 11.7, stock GT's from forum members have done much better. It just doesn't add up to handing anyone their asses.

 

[Townshend]

And even if it did, just wait until a turn or two....

 

[werewolf]

By street racing, I refer to speeds less than 1/4 mile speeds ... the weight disadvantage is understood. But you can't swap a pulley in the GT, without also doing the same in the Shelby for a direct comparison. MM&FF also precits 10's in the Shelby with simple bolt-ons :wink

I'll do the detailed math in a bit ... but in first & second gear, I'd still put my money on the GT500 with 4.30's, compared to the extremely tall-geared GT.

 

[werewolf]

A quick analysis of second gear acceleration ... a good indicator in my experience for street performance, as well as seat-of-the pants "feel" ... the subject of this thread :biggrin

Let's compare the Ford GT to a Shelby GT500 with 4.10's swapped in :

Motor Torque : Ford GT = 500 lb-ft, Shelby GT500 = 480 lb-ft
2nd Gear Ratio : Ford GT = 1.71, Shelby GT500 = 1.78
Final Drive Ratio : Ford GT = 3.36, Shelby GT500 = 4.10 (swap)
Tire Diameter : Ford GT = 1.21 ft, Shelby GT500 = 1.12 ft
Weight : Ford GT = ~3500, Shelby GT500 = ~3900

Accelerating force at road/tire interface is found by mulitplying motor torque by gear ratios (selected gear and final drive), and dividing by tire diameter :

Accelerating Force : Ford GT = 2374 lbs, Shelby GT500 = 3128 lbs

Including vehicle weight, the resulting acceleration numbers (strange units, because I'm using pounds for mass rather than slugs):

Acceleration : Ford GT = 0.678, Shelby GT500 = 0.802

So ... there's no question that the GT500 with 4.10's will pull much harder than the GT in second gear (assuming no traction limits, of course).

But what will the top speed be, in second gear for the GT500 with 4.10's? With a redline of 6250 rpm, the top speed should be about 69mph (tire circumference of 7.1 feet).

Now the GT will obviously pull harder in first gear, than the GT500 will pull in second gear. And the GT500 will spend first pretty quickly with 4.10's swapped in, whereas the GT takes first all the way to 60 mph.

More to follow ...