Yes I did a 2nd gear burnout then left the line dumping the clucth a 4500rpm which produced a big bang ( which I was used to in my 05 GT)this car is gonna need some serious trailing arms & a 3rd link.14.5# of air in ET streets.
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shelby gt500 12.48@110
- Thread starter dohc32v
- Start date
try it
You dont know what your missing launching a car on slicks is awsome talk about being put back in the seat:bowdown:.The bad thing is that it very hard on your drivetrain and suspension if its not set up right.:rockon:
Formula51 said:
You dont know what your missing launching a car on slicks is awsome talk about being put back in the seat:bowdown:.The bad thing is that it very hard on your drivetrain and suspension if its not set up right.:rockon:
lower you pressure
You have to much air pressure in your tires:nonono: run them at about 9psi and after your do a burn out they will inflate to about 9.5 or 10 psi and for sure you will go into the 1.49 60fts:thumbsup: .I personaly run my et streets at 8.5 and it seams to work the best for me.And my car does weigh about 3300lbs with me in it and a full tank of gas.
MD03SVT said:
You have to much air pressure in your tires:nonono: run them at about 9psi and after your do a burn out they will inflate to about 9.5 or 10 psi and for sure you will go into the 1.49 60fts:thumbsup: .I personaly run my et streets at 8.5 and it seams to work the best for me.And my car does weigh about 3300lbs with me in it and a full tank of gas.
MD03SVT said:
Gotcha. You're definitely leaving some on the table leaving at 4500rpm. I've personally found best results using 11-12psi cold pressure fwiw.
Any chance you'll leave at redline next time out? ;-)
Please! :rockon: Get it on video too!Fourcam330 said:
XtremeBuford
Banned
I did 12.45 at 110 with under 300hp, 1.78 60. Not impressed to say the least
was that with the stock suspension at 3200#, your first time out to the track with the car? Oh, I didn't think so.XtremeBuford said:
XtremeBuford said:
op:1st of all the track prep was extremly great Billy Glidden went 7.02 back to back & Chuck Samuels went 6.44 so with a 4300 pound car & 3.31 gears I had absolutly no tires spin at 14.5 pounds so why lower the pressure & if you have ever driven a 4300 pound car with only 9 pounds in your slicks you know that it is a scary feeling at the top end.I only got 2 practice runs & 1 round of elimination.I plan on raising the launch RPM on my next time out this weekend.
My buddy had his 248.8rwhp 02 GT there & ran 12.67 @ 109mph with a 1.66 60 '.
My buddy had his 248.8rwhp 02 GT there & ran 12.67 @ 109mph with a 1.66 60 '.
Above all raise your launch rpm. 4500rpm with a dump and those gears is instant death. You may spin them if you launch higher on a day when the track isn't so well prepped, try dropping the pressure and see what happens.
spoiler
Hey bro don't come on here and spoil the mans thread.And BTW wheres your GT500? just what we all thought you dont have one.:shrug:
XtremeBuford said:
Hey bro don't come on here and spoil the mans thread.And BTW wheres your GT500? just what we all thought you dont have one.:shrug:
spoiler
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MD03SVT said:
I know a car can get scary on the top end with low pressure
, but trust me with a good track prep like you stated it will stick to the groud and it run as smooth as if you had 12-13 psi but you will go faster because of the quicker 60ft;-) .Iam not telling you to run 9psi Iam only suggesting what works for me and Billy Glidden and Chuck Samuels cars are set up differant then yours so its hard to compare track prep and stickness with them.But still you are the one having the awsome time.So be safe and you will be there.:rockon:I ran 11.23 @ 124mph with a 1.57 60' in my 04 cobra coupe & 11.43 @ 122mph with a 1.65 60' in my cobra vert & 12.48 @ 111mph with a 1.67 60' in my 05 GT so I think I have a pretty good idea of what I am doing.This was my first time out with the shelby & I was feeling things out,the reference to billy & chuck was not to compare me or my car but that the track prep was the best I have ever run on as our track here in montreal is considered an icy track where many times my cobra's have broken loose in 3rd gear.Here anything over a 5000rpm launch will get you nowhere real quick.last weekend onthe ET streets I had no tire spin what so ever but broke loose on every shift on the stock goodyears even with the traction control on.
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understand
now I understand your reasoning thanks for the in put.epper:
MD03SVT said:
now I understand your reasoning thanks for the in put.
epper:
As far as the question about the relationship between the 60 foot time and weight, the short time goes as the square root of race weight and is inversely proportional to the square root of rear-wheel torque.
“It can be shown that” a decent estimate of the 60-foot time is given by the expression,
60’ time = 0.397*[(w*Dtire)/(TQ*GR)]^0.5
where w = race weight in pounds, Dtire = tire diameter in inches, TQ = engine torque in lb-ft as meas'd on a chassis dyno (use peak for best-case estimate), and GR = total gear ratio. For the Shelby, GR = 3.31*2.97 = 9.83. In deriving the formula, I assumed a roll out of 12 inches. A little more or less won’t change the answer much. The derivation also assumes PERFECT traction! TQ can be corrected for ambient conditions.
“It can be shown that” a decent estimate of the 60-foot time is given by the expression,
60’ time = 0.397*[(w*Dtire)/(TQ*GR)]^0.5
where w = race weight in pounds, Dtire = tire diameter in inches, TQ = engine torque in lb-ft as meas'd on a chassis dyno (use peak for best-case estimate), and GR = total gear ratio. For the Shelby, GR = 3.31*2.97 = 9.83. In deriving the formula, I assumed a roll out of 12 inches. A little more or less won’t change the answer much. The derivation also assumes PERFECT traction! TQ can be corrected for ambient conditions.
Slicks > *
Black2003Cobra said:
Is there any way to account for the energy stored in the rotating parts on the flywheel side of the drivetrain?
I guess you would need to know the mass moment of inertia of the various parts.
Probably a tough calculation to figure what happens when that energy "hits" the non rotating parts from the imput shaft of the trans back.
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Very good point JT. Yeah, there would be some guess work there for sure! Although I haven't worked through it, I would treat it as an inelastic collision. But yeah...that's exactly why I made the point to mention that the above formula is only an estimate! It does tell one how the numbers would scale with weight, etc.jtfx6552 said:
et streets own any DR. preiod.. anyone who thinks otherwise.. hasnt been to the track with both tires..
on my old cobra.. bfg's to nittos.. wouldnt hook like my mt et streets.. AT ALLLL.. et streets area whole other world.
on my old cobra.. bfg's to nittos.. wouldnt hook like my mt et streets.. AT ALLLL.. et streets area whole other world.
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