shelby gt500 12.48@110

[10.5secAWDTALON]

A 12.48 at only 110mph is good. And yes the weight, gearing, etc. will have an effect on the 60'. A 1.8 out of a 2 ton car on stock gears is respectable

12.4@110 with a 1.8~ 60 Ft and an 8.0 1/8 mile is a very typical timeslip for a car with this power to weight ratio and with some reasonable traction (ET STREETS).

Folks keep on wanting to talk about the weight of the car, but leave out the important part of the equation, the HP to weight ratio.

Oddly this timeslip of 12.4@110 1.8 60FT 8.0 1/8 mile is near identical to the timeslip I ran my Talon to with the stock 14b turbo back in the 1990's. Mods were minimal, tires were stock all seasons.

My point here folks is it's not some "great" driving, it's good driving, but the tires are basicaly doing it as witnessed by the stock ET's/MPH.

I am a bit surprised at the 5 MPH trap loss with the ET streets, are the diameters that different?:shrug:

 

[Fourcam330]

I am a bit surprised at the 5 MPH trap loss with the ET streets, are the diameters that different?:shrug:

For the third time, the launch rpm/technique needs to change to take advantage of the new tires. He's bogging bigtime on ET streets.

 

[03gobluecobra]

You will trap slightly lower with ET street over street tires. Basically, if the only difference is that you will leave the hole harder, and accelerate equally the rest of the way, the car that leaves quickest will finish in the shortest amount of time. Which leads to the conclusion that a car that doesn't have as much time to accelerate will not have enough time to trap the same speed as it would on street tires.

In this case, this guy could get up to 115 MPH in 12.7 seconds, but only 110 MPH in 12.4 seconds. Usually the difference is less than that, but things like heat, humidity, how much gas was in the tank will all play a role.

 

[10.5secAWDTALON]

For the third time, the launch rpm/technique needs to change to take advantage of the new tires. He's bogging bigtime on ET streets.

I guess the next question is can launch technique/RPM really be adjusted enough to offset that, or are gears the real answer.:shrug:

 

[Fourcam330]

I guess the next question is can launch technique/RPM really be adjusted enough to offset that, or are gears the real answer.:shrug:

Right. Even though I can't say for sure, I'm willing to bet that he didn't dump the clutch @ 6250. Over time this will defintely be answered.

 

[Fourcam330]

You will trap slightly lower with ET street over street tires. Basically, if the only difference is that you will leave the hole harder, and accelerate equally the rest of the way, the car that leaves quickest will finish in the shortest amount of time. Which leads to the conclusion that a car that doesn't have as much time to accelerate will not have enough time to trap the same speed as it would on street tires.

In this case, this guy could get up to 115 MPH in 12.7 seconds, but only 110 MPH in 12.4 seconds. Usually the difference is less than that, but things like heat, humidity, how much gas was in the tank will all play a role.

Drag racing is 90% about the launch. You not only come out of the hole harder, you don't spin during shifts, and can keep your foot planted the entire time (vs. radials). Any kind of bog whatsoever is going to hurt ET and murder trap speed.
For the last time (I'm giving up after this), if you trap lower with stickier tires something else in the setup needs to be changed to optimize what you now have.

 

[broeli]

I think that in good conditions with a good driver (Nothing at all against the driver because I dont know the conditions) this car will run 12.30's to 12.50's bone stock, tires and all. That trap speed on the vert says that it surely can with good conditions and no head wind. I have seen a 4500lb benz run 12.4 @ 111 on michelin PS2's with a 1.9 60'. This car can go 1.6x in the 60 ft. Traps speeds going down on ET's is not a new revelation. Should the coupe be faster in the quarter because of chassis rigidity?

Are you saying that the GT500 can do 1.6x 60' times on the stock tires?! Won't happen.
Mid 12's stock wouldn't be a big surprise to anyone.
With the loss in trap speed it is obvious the GT500 needs different gearing..it is definitely bogging. I'm betting the launch was plenty hard, but the gearing was killing it.

 

[AcE XBOX]

I beg to differ. 12.48@110mph in an approximately 4000lb.??? convertible is very respectable indeed. Now, this would not be the case if we were talking a 115mph trap speed like he ran with the stock tires (and on a different day if I understood him correctly).

Last a I remember a 425hp SRT8 weighing 4200lbs ran a 12.5 stock. Wtf is wrong here?

 

[dgussin1]

Last a I remember a 425hp SRT8 weighing 4200lbs ran a 12.5 stock. Wtf is wrong here?

where have you ever seen an srt 8 running a 12.5 stock?

 

[AcE XBOX]

where have you ever seen an srt 8 running a 12.5 stock?

do a search, there was a huge ****ing thread on it. a video of it as well.

 

[AcE XBOX]

where have you ever seen an srt 8 running a 12.5 stock?

Take a trip to bakersfield and make a few passes :rockon: :beer:

 

[Purvis]

I'm more impressed with a 115mph trap speed in a bone-stock, heavy 'vert into a 16mph headwind.
S.

Yeah me too. The 115mph trap sped with the vert is pretty impressive.:coolman:

 

[bad360rt]

where have you ever seen an srt 8 running a 12.5 stock?

A guy in Jersey did it last fall at Atco, great track, great weather. I'm very interested to see a GT-500 run this fall at Atco with a good driver :thumbsup:

 

[Purvis]

Again, if you run a lower trap with a stickier tire something needs to be adjusted to make the most of the new meats--launch rpm, gearing, suspension. Rolling resistance doesn't factor into the equation much if at all--you're accelerating down the track, not coasting. The only thing skinnies really do is remove weight from the front of the car.

Fourcam,
I dont understand how you can believe that rolling resistance is not a factor with tires in drag racing. Why do you think people blow up their front radials with extra air??

Beyond a doubt, a barely inflated ET street tire (with like 12-15lbs of air) is going to be generating much more friction while turning at 120mph (hundreds of revolutions pers second) than a radial tire with 40lbs of air. This is known as rolling resistance. And it is one of the reasons why "skinnies" allow cars to go faster. (As you mentioned, weight is also a large factor, but not the only factor). Rolling resistance also is why radials tires that are over inflated are easier to "turn" (create less drag/friction) than normally inflated radial tires.

I would not presume to EVER lecture you on :bowdown: engines, however, when it comes to racing I do have a bit of experience. :beer: Im not trying to be smartass or a know it all.. This is just information generally excepted as fact.

 

[ON D BIT]

Fourcam,
I dont understand how you can believe that rolling resistance is not a factor with tires in drag racing. Why do you think people blow up their front radials with extra air??

Beyond a doubt, a barely inflated ET street tire (with like 12-15lbs of air) is going to be generating much more friction while turning at 120mph (hundreds of revolutions pers second) than a radial tire with 40lbs of air. This is known as rolling resistance. And it is one of the reasons why "skinnies" allow cars to go faster. (As you mentioned, weight is also a large factor, but not the only factor). Rolling resistance also is why radials tires that are over inflated are easier to "turn" (create less drag/friction) than normally inflated radial tires.

I would not presume to EVER lecture you on :bowdown: engines, however, when it comes to racing I do have a bit of experience. :beer: Im not trying to be smartass or a know it all.. This is just information generally excepted as fact.

i would think the air pressure would be much higher in the et street at the end of the track than before the run. with all that heat surrounding the burnout, and takeoff created on the rubber the air pressure might be as high 5-10lbs higher.

 

[Purvis]

i would think the air pressure would be much higher in the et street at the end of the track than before the run. with all that heat surrounding the burnout, and takeoff created on the rubber the air pressure might be as high 5-10lbs higher.

Same goes for the radial tire.

 

[ON D BIT]

Same goes for the radial tire.

so what you are saying is that a radial will have statistically significant less rolling mass at 50lbs of pressure than at 40lbs of pressure?

 

[Fourcam330]

Fourcam,
I dont understand how you can believe that rolling resistance is not a factor with tires in drag racing. Why do you think people blow up their front radials with extra air??

Not a shot at you....but LMAO. I see people shoving 50psi into their stock front tires at the track all the time, ****ing hillarious. :lol:

Beyond a doubt, a barely inflated ET street tire (with like 12-15lbs of air) is going to be generating much more friction while turning at 120mph (hundreds of revolutions pers second) than a radial tire with 40lbs of air.

In a car with any real power (say one that can light them up in 4th gear on a non prepped track like most are) that deflated slick is also still going to be transmitting all of it to the ground vs. a street radial.

This is known as rolling resistance. And it is one of the reasons why "skinnies" allow cars to go faster. (As you mentioned, weight is also a large factor, but not the only factor). Rolling resistance also is why radials tires that are over inflated are easier to "turn" (create less drag/friction) than normally inflated radial tires.

Again, the only benefits to running skinnies are less overall weight and weight transfer. I guess you could throw smaller frontal area (wind resistance) in there too.

I would not presume to EVER lecture you on :bowdown: engines, however, when it comes to racing I do have a bit of experience. :beer: Im not trying to be smartass or a know it all.. This is just information generally excepted as fact.

Accepted as fact to you. Most of "facts" that you read on the net are BS, for instance the 4v head tick being a coolant flow problem--it's actually a guide issue. I've also been drag racing for some time. What I've posted is a collaboration of what I've personally experienced along with guys that make hundreds of passes per year. :beer:

Bottom line. If you follow the same launch procedure you always have when switching to a real tire then you will lose mph. You have to reoptimize your setup when making any significant change. Once that happens your traps will increase. I've seen it happen more times than I can count.

 

[broeli]

I can't believe something that is common knowledge and so simple is being debated here. Go try to push a car with the tires half flat..then go and push it with them aired up. You will find it MUCH easier to push the car with high inflated tires. The same goes for tire width. Not only do skinny tires weigh less they also have less rolling resisitance due to less contact patch. A tire with more contact patch will have a higher roll resistance. The contact patch becomes less when they are overinflated. That's is why many people will overinflate the fronts at the drag strip and turn slightly better times. All simple, well known, tricks of the trade.
A slick or Et Street type tire will expand when the car accelerates creating less resistance than it would if it was pushed at a slow pace..but there is still some increased roll resistance. The air inside will expand causing higher tire pressure during the run but it won't be anymore than about 5psi.

 

[P49Y-CY]

do a search, there was a huge ****ing thread on it. a video of it as well.

if you are talking about this one, it was determined to be a fake (?). really ran a 13.46. i don't think that famoso would have helped too much, might have even run slower there

http://www.svtperformance.com/forums/showthread.php?t=314693&page=3