Talking about nuts....... 150MPH on a freeway for a long time, not a quick sprint.

http://videos.streetfire.net/video/e...aa015a7182.htm

Bill

 

I don't think he is really going 150 mph. The car wouldn't be able to switch lanes like that and slow down fast enough for the off ramp. The lines on the expressway would also look more non-existent. He probably had a gear change or a speedo box.
I had a box on my vette to correct for the 3.92 viper gears since they don't make chevy speedo gears for that ratio. All I had to do was program the box for whatever ratio I wanted and the speedo could show as fast as I wanted. I only tried it since there was a debate over how high the digitial speedo on the corvette went up to. It showed 200 mph when I was only going 67mph.

Anyway, no matter how fast he was exactly going he is obviously speeding and driving with no respect or regard for the safety of others on the road. If you want to drive like an idiot due it on a closed course so you only kill yourself.

 

Tach's only showing 3500 rpm. Not very many cars will maintain 150mph at 3500rpm.

 

Damm Al, you should be a detective............

I never noticed that.

Bill

 

The audio also indicates that he's in sixth gear.

With a 26 inch tire, a 3.42 axle ratio, and a 0.5:1 sixth gear ratio, 3500 RPM equals 156 MPH.

I believe that those two boys were doing something stupid and dangerous. They deserve a night in jail and a good caning. Too bad they didn't get a deer across the windsheild. That would have really made for an interesting video.

 

But unless you have stupid power you can NOT maintain 150mph at 3500 rpm.
A stock LS1 will pull 150 in 5th and when shifting to 6th will drop off speed.

 

have to guess that a decent H/C LS1 will maintain speed in 6th at that rpm.

Not that I have ever been that fast .

At lower boost a certain turbo f-body I know of raced a sportbike up 275 with the t-tops out, and saw 150-155 for a mile or 2. at the time I hear he was at 6-7 psi, and that would be about 450 rwhp. for the last 1/2 mile or so
he let the bike cruise ahead while lagging back in 6th.

now I know that you guys are gonna mention that TQ on a turbo Ls1 is a lot more that a H/C car, but it should still be possible.

Heck, the same owner of the above vehicle raced a couple of vette's in a 98 Z28 with a cutout, lid, and 4.10's. If he started below 50mph then the camaro would pull a length on the vette to 160. if it was a run from 60ish, the vette with 3.42's would pull a length on the camaro to 160. (assuming the accuracy of the speedo, a shift to 6th was required in the Z).

how much difference in rpm is there in 6th with 4.10's VS 3.42's at 156?

4200 vs 3500. Wouldn't an extra 125+ rwhp from a modded ls1 make up for it having to pull the taller gears?

Please discuss if you want.

 

------------4.10's------------
5th gear @ 127mph = 5,181RPM
6th gear @ 127mph = 3,501RPM

5th gear @ 147mph = 5,997RPM
6th gear @ 147mph = 4,052RPM

------------3.42's------------
5th gear @ 152mph = 5,172RPM
6th gear @ 152mph = 3,495RPM

5th gear @ 176mph = 5,989RPM
6th gear @ 176mph = 4,047RPM

Just remember, the spedometer only shows what the PCM calculates. But, RPM's never lie. Make up your own mind as to what happened. Either way, they were moving at nearly 2x the speed limit, which is a sure way to go directly to jail...do not pass go...do not collect $200.

BTW, here's a gear calculator I made a while back...

http://www.thetuningdoctor.com/Excel..._Gear_Calc.xls

 

I have always used the calc on this page: http://www.f-body.org/gears/

from every forum I had ever seen it referenced, its accuracy has never been questioned. It does generate different numbers than yours however.

Maybe different tire size input? Ws6transam listed 26.0.

The only factory sizes that I remember were:

235-55-16 = 26.177
245-50-16 = 25.645
275-40-17 = 25.661

most cars came with 245/50/16's, unless it was a "ram air" car. IE SS or WS6 or firehawk. At least in the 98+ cars. Which have an easier time making the type of power levels needed to either maintain or accelerate a car at those speeds.

minor point, I know. lol

 

Well, mine has an extra feature or two that the f-body.org didn't have. As for the tire height, these cars come with 24.9in tire heights entered into the PCM from the factory. Measure any SS rim+tire and you'll see it's only 25 inches. Not trying to be defensive...that's just what I see using EFI Live.

 

Im not taking it as you being defensive. I was just trying to get it straight for my own info, and just went by what I thought was accurate.

I see now that the numbers based on the size calculations are just generic. Which I guess I kind of knew anyway.

and thanks for the link to d/l your program. It may come in handy.

 

n/p

 

IMHO a H/C car with 3.42s will not have enough torque to hold 150 at 3500. The H/C moves the torque peak up the rpm range.

 

One other subjective thing we see in the video is how the kids pass the traffic on that interstate. If the other cars are doing the speed limit which we assume to be 70 MPH, then it sure does appear that the kids are passing these cars at a 50 to 80 MPH higher rate of speed.

Assuming that they were in fifth gear, the 3500 RPM translates to 111 MPH. My gut feeling is that they were travelng faster than 111 MPH, and that they were in sixth gear. Perhaps what we need to do is dig a little deeper into the math to see what kinds of force are necessary to push a 1998+ Camaro through 150 MPH, then determine torque requirements to see if they are realistic. Taking the mathematical model from Puma race engines out of the United Kingdom, I derived these calculations:
---
Frontal area of 1998 Camaro = 21 to 24 sq. ft
Drag Coefficient = .338
CdFA = FA * Cd = 7.1 to 8.1
Weight = 3550 lb.
Total RWHP for 150 MPH = 1.0 * ((CdFA * .00256 X MPH^3/375) + (Weight * .013 * MPH/375) = 183 to 206 RWHP.
----
Oh, it is interesting to note, that the 1984 Pontiac Trans Am, with a Cd of 0.32, only requires 173 RWHP to cruise at 150 MPH. Hmm. Is it believeable? That's something I will look at tomorrow.

 

I know of a certain group of f-bodies maintaining those kinds of speeds for a LONG LONG distance on the return trip from power tour. I have no doubt they are doing 150 at all.