Pic of that black 68 Charger that ran 200MPH....

[Highbanked Hauler]

Right with just pure math of gear ratio's and horsepower, now factor in the drag for the car and I"m sure you looking at a much higher RPM. The 68 Chargers weren't known for   their aerodynamics, hince the reason they built a 500 and a Daytona in 69 to compete on the larger tracks in nascar.

I just read an interview with Charley Glotzbach(sp) that said they were turning the cars up to 7200 at times.

[chargervert]

7000 plus RPM is not a stretch for a race prepped Hemi,but thats a lot of revs for a 440! The Hemi heads flow much better than the wedge heads!

[69_500]

For those of you interested we have the Charlie Glotzbach interview on DVD. It will be available here in the next few days. The same interview that Highbanked Hauler is refering too.

[Blakcharger440]

Yep,Thats the one I am talking about!  Wish I had video of that car hauling a$$ down a Nevada Open road race! Too cool!!!! Thanks for posting the pics!

[69_500]

by the way HighbankHauler, are you going to have your 69-500 clone car done soon? Or is that still a few years off? And when you get it done is the real 500 going to go back to stock appearance?

[Blusmbl]

Right with just pure math of gear ratio's and horsepower, now factor in the drag for the car and I"m sure you looking at a much higher RPM. The 68 Chargers weren't known for   their aerodynamics, hince the reason they built a 500 and a Daytona in 69 to compete on the larger tracks in nascar.

Drag has nothing to do with RPM required for a given speed.  Tire size, axle ratio, and final drive in the trans.  That's it... nothing more.  Horsepower yes, RPM no.

BTW- those are my scans of the Hot Rod article posted at the top of this page. 

[69_500]

I guess I'm still confused here. Are these formula's meant for like say a vacuum or something? Because to me my brain is saying that the weight of the car, and the aerodynamics of the car will also factor in as to what RPM you would need to be pulling to get a car up to a set speed. I mean say the car is a 1957 Chrysler 300C, or a 1983 Dodge Charger. Now obvious differences in aerodynamics, and obvious differences in weight and size. So are you guys saying it would take the same horsepower with the same axle ratio, same trans ratio, to get to the same top speed?

[Troy]

No, the horsepower is what overcomes the air resistance. The calculated top speed is wholly dependent on the engine RPM, trans gearing, and axle ratio. If the car has unlimited HP then it still has a max RPM so a change in gearing is the only way to adjust top speed. In the real world, engines don't have unlimited HP so the engine can only do so much work (pushing air). When the resistance (friction of all the moving parts plus the air) becomes equal to the max power then you are at top speed. If you want to go faster than that you either have to become more aerodynamic or add more power. No matter what, you still can't go faster than the parts will spin (usually slower).

Troy

[69_500]

I get that much of it, but the size of the vehicle has to come into factor somewhere. I get that the RPM is the limiting factor for what your saying. I understand that concept of it. That is why I was saying the origional part that he would do better with a flush rear window, because it is more aerodynamic. He must have already taken into thought some of that as he has the flush front grille, and A Pillar moldings already. I was just trying to say you can take a car that weighs the same, with the identical driveline, and engine, and go faster with say a Daytona than you could with a 59 Cadalac. Even if they weighted the same amount.

[Ghoste]

Yes, because it would take less horsepower to achieve the same rpm.

[69_500]

Now I think I have it all understood.

sorry for the hijack of the thread to edumacate this here hillbilli