hey...anyone know if the Vette pulls in 6th?

Since its more aerodynamic and a little lighter.....

EDIT:

Just one more reason to hurry up and do that cam swap

 

Weight will not affect top speed, just how quickly you get there. Better aerodynamics are the key to that one and I suspect that even the Vettes slightly more slippery shape will not be enough to pull 6th. 6th gear is just too tall for that at stock power levels.

 

$50 + shipping if that is all you need done.
118 MPH is the speed limiter for non z-rated tire equipped cars.

 

Weight does have an effect on top speed, simply called engine load, the less weight the lighter the engine load, will pull more speed.

As to 6th gear that depends on what the final gear ratio is, where a 2.73 will get more top end speed but 6th gear is useless but try it with a 4.10 gear and 6th becomes useable but less overall top end.

As to the Corvette, my '99 has pulled 194 MPH and with a bit less angle on rear wing I suspect to spike the 200, this is in open road racing, 100 miles of a public road are used.

 

Hey Guys,
This is my first post over here but FWIW I bought my car brand new A4 w/2:73's and the P245/50/ZR16 Good Year GSC's. Had it up to 125 walkin' a 'Stang up I-75 with alot more to go. Mine was a unique build though (I think)

Again FWIW audiopro at a minimum go with a Predator. If you have the time to learn, then HP Tuner. If you get a Hypertech you'll just end up wanting to go further with PCM mod's. I know first-hand!

 

Air drag affects top speed. based on what you are telling me, if you made it lighter, it would also go faster? Or, I believe that is what you said here:

So, by taking wing out of your car....or making it lighter, it would go faster? I don't think that is what you said. You said:

Even you didn't mention weight in that case. Because, aerodynamics are the key to top speed.

Otherwise, I'd think you are trying to say that if I could drive a vehicle in a vacuum (with no air drag) it would still have a top speed limit based on weight? Where is the physics behind that one? I'm asking, because I've never seen a top speed calculation that involved weight. The top speed of an object (such as a vehicle) in a vacuum with no air drag would be essentially "infinite" (ok, gear limited and/or we break into Einstiens realm). Weight would only affect the rate of acceleration, not the maximum velocity. Right?

The rate of acceleration has to account for weight, but not top speed.

And, I'm not trying to start an arguement, I just wanted clarification of your thoughts on this one.

 

Weight has ZERO effect on top speed. Why do you think salt flat car very commonly weigh in at over 5-6 thousand pounds. Weight has EVERYTHING to do with acceleration. NASCAR rigs weigh in at 4K and will exceed 200mph. BUT they sure dont pull a quick 1/4 mile given the hp of the car.

AERODYNAMIC DRAG is the limiting factor when it comes to top speed. Actually its a combonation of HP and Aero drag. HP and speed are inverse square of each other. In laymans terms, it takes 4x's as much HP to go twice as fast. The load on the engine is created from the aerodynamic drag on the car. You can make changes to rear wings, air dams etc to increase your top speed but at the same time you are making the car less stable at those speeds by DECREASING THE AERODYNAMIC DRAG. You are NOT decreasing the weight of the vehicle. The NEGATIVE LIFT (see: DOWNFORCE) will cause increased PRESSURE on the car BUT THERE IS NO PHYSICAL WEIGHT CHANGE of the vehicle itself.

Take a given vehicle on a given chassis combo at say 3500lbs. Get it to TERMINAL VELOCITY, say for talking purposes 200mph . NOW, go and remove 1000lbs from the vehicle. The vehicle now weighs in at a scant 2500lbs. Now get it to 200mph.....The car will still NOT exceed 200mph without AERODYNAMIC changes to the car that DECREASE the amount of resistance and/or DRAG. The drag on the car will be the limiting factor NOT the weight of the vehicle.

Example: Todd Carpenters UNL. Class camaro. This car has seen sustained speeds of 215mph. When he went hunting for another 5mph he DID NOT start yanking weight out of the vehicle. He started by pulling the rearview mirros, taping body seems, removed his rear spoiler (which he almost regreted) and added MORE HP. Weight isnt his problem, even at a lofty 4200lbs, it is the drag that his car is creating at high speeds when it punches a big hole through the air.

If your concerned about the weight of your car........go drag racing. In ORR weight doesnt mean ****. The only thing weight will effect is response time on your suspension. BUT IF you took this into consideration PRIOR to building the car, its not even a concern.

The concerns you need to have for running at top speed is finding the perfect balance between drag and downforce. Then you throw the HP in the mix to get it up there.

In a reletively stock C5/Fbod, 6th gear is USELESS. As a matter of fact its not even recommended that you use 6th gear at all when you are trying to go REAL fast (over 165mph). The amont generated inside your trans (even with a cooler) is astronomical when trying to pull 6th gear at speeds over 165mph.

To be able to pull with a 2.73 rear gear you better have a TRAIN LOAD and I mean a fricken TRAIN LOAD of hp. I know guys in the ORR world make WELL in excess of 650rwhp and fight to pull 210+mph with a 3.08 rear gear.

Making a high speed pass with gearing as deep as 4.10 is just plain ignorant. You are risking serious engine and drive train failure by doing it. Not even mentioning the critical driveshaft speed will go WELL beyond what just about any driveshaft is capable of handling.

At what event did you do that?

 

Weight has ZERO to do with top speed, WOW,
you would be correct if you had unlimited distance to prove that but in all other cases you would lose.

If the engine had 400 HP and car weighted 3300 lbs that would equal 8.25 lbs per HP.
If the car weighted only 2300 lbs then that would be only 5.75 lbs each HP had to support.

If I now added a rear wing and for each 1 degree of upward angle it was set to would equal another 100 POUNDS of weight onto the car, thus 5 degrees, 500 lbs, you add that to the rolling resistance and the lighter car will have the top end speed, not the heavy one.

Salt flats, the cara are heavy, but they also have tons more HP for the sole purpose is to use that weight to reduce lift and maintain traction.

If I took a Corvette that weighted 3300 and another exactly the same EXCEPT it weights 2300 lbs the following simulator results would happen in the real world and as can be seen the vette weighing 3300 lbs loses not only in elapsed time but also distance it took to get to the same speed and if a rear wing was used it would be worse.

If the distance, IE was salt flats was 3 miles the heavier car would not get to the top speed as lighter car did since it would take about another mile to get to the same speed, if the engine was able to with added wind resistance.

Vette on left is 2300 lbs and vette on right is 3300 lbs



As another example I custom tuned a airplane that had two props, the engine is a C5R with a turbo, it required at least 600 HP to stay in the air, the 1st tests and the plane was a bit shy in HP at the rotor tips and the only way they got it to work correctly was to reduce the weight to HP ratio.

As to ORRing we do not reduce the weight for nothing and I have done every ORR event in Nv and Tx, Silver state, PE100, Big Bend, Gamblers run, etc.

My GM/Mobil I Snakeskinner ZR-1 went from 3.600 lbs to 2,600 lbs and
thanks but I'll keep the weight off.

 

When did we put a restriction on the distance. Top speed = terminal velocity. And yeah, your right if we were talking a drag race or a 1 mile shoot out, weight would be an issue. But were not talking a 1/4 or mile drag race. Those are pure tests of ACCELERATION, NOT top speed.

Those are accurate #'s. Only when you are worried about 0-60, 0-100 times. Regardless of weight, 400hp is 400hp. The lighter car WILL get there faster but the aerodynamic drag created will limit it to the exact same speed of the heavier car.

It doesnt matter how much or how little downforce, using an identical wing on identical cars, one being heavier than the other, changes nothing in top speed. The aerodynamic resistance is the MAJOR contributor to terminal velocity. Both cars would have the exact same amount of frontal area and drag CD. Therfore they would both hit a "wall" at the exact same speed if all variables are the same. Rolling resistance is the only negligable arguing point.

Doesnt matter how much they weigh, Once at speed aero is what makes or breaks them for the extra mph, they use the HP and aerodynamics of the vehicle to combat the resistance at speed.

I learned a LONG time ago that what goes on paper and "simulators" doesnt mean poop when the rubber meets the road.

The only reason I will even remotely concede to the above statement is because in a plane you are trying to achieve LIFT. And light does make might in relation to trying to get a plane off the ground in a GIVEN DISTANCE. There we are again, covering a distance ina given time, not on the top speed.

I didnt ask what events you have done, I asked which one you did 194mph? I'll bet the saved weight helps alot around a road course, but doesnt help you on the big end.

 

This has gotten way off course.