GenVibe - Community for Pontiac Vibe Enthusiasts

Can someone calculate what 6th gear would theoretically top out at if power, drag, speed governor, etc were out of the question?Just curious...it's not like I'll ever try .

I would be curious to know that also...

In http://forums.genvibe.com/zerothread?id=9053 MadBill did the math and calculated 6000 RPMs in 6th gear would be 134.4 mph. If redline is 8200, then the calculated speed at that RPM in 6th would be 134.4 * (8200 / 6000) = 183.7. Good luck!

I'm not a car guy, but it seems pretty straightforward if you ignore power. drag, etc:Sometime when you're driving, note the RPM and matching speed in 6th gear: (Doesn't matter what speed, just in 6th gear)RPM6 = The RPM you notedSpeed6 = The matching speed you noted.RPMRL = Redline RPM (forget what it is for GT)TopSpeed = (RPMRL * Speed6) / RPM6EDIT Joatmon beat me to it - posted while I was writing my post!

Thanks. You jump started my brain and I now remember some of the jr high math I used to do. Here's the math for using the 8350rpm fuel cut off.IF:134.4mph/6000rpm = x/8350rpmThen:6000x = 1,122,240/6000x = 187.4mph/301.6kphhmm....

Quote, originally posted by Mase »Thanks. You jump started my brain and I now remember some of the jr high math I used to do. Here's the math for using the 8350rpm fuel cut off.IF:134.4mph/6000rpm = x/8350rpmThen:6000x = 1,122,240/6000x = 187.4mph/301.6kphhmm....Hmmm...so if we were on the moon...imagine the possibilities

Quote, originally posted by Mase »Thanks. You jump started my brain and I now remember some of the jr high math I used to do. Here's the math for using the 8350rpm fuel cut off.tks, I couldn't remember the max rpmsanother inch or two in tire diamter would push the number over 200 mph

That's pretty close to what i've had....the other day i had my GT up to a buck 40 and i was runnin just over 6000 rpm's...these things a pretty quick!

Quote, originally posted by WickidWeazel »That's pretty close to what i've had....the other day i had my GT up to a buck 40 and i was runnin just over 6000 rpm's...these things a pretty quick!Not something to be proud of!!!

Quote, originally posted by ragingfish »Not something to be proud of!!! aww... come on whats the point of having a fast car with out testing it out once in awhile... Granted being safe about it...

Hey, I hit 102 on I-95 after nearly sandwiching between an RV and a Dodge 1500. If anything, the car can sure hold it's own.And c'mon Mike, you liked me taking that offramp at 60 the other day..

i have the PROPERGear ratios and speeds on my cardomain page, its in my signature.

At one time I worked on the design of the Dynamometers used by most of the auto companies in the world and know that the problem with not including the wind resistance is that it is increased by the square so it takes much more power to run at higher speeds. The idea of just extending the gear ratios only works if the hp can push the car to that speed. The Vibe is a tall car so it may not go as fast as the numbers would suggest. That being said, the early 2003 stock GT that I purchased new, is the fastest car I have ever owned. That includes my 327 69 Camaro with oversized pistons built for drag racing which would run out of gas when I hit second gear. (it needed an electric fuel pump but I never got around to it) and every other car I have owned or driven. I have driven many cars over the years and nothing has been a quick as this car. I know that many cars with go faster but not for the price I paid for this one. I have hit 130 in fifth so I figure 150 would be no problem but I am not going to try it. You can see the dyno’s at http://www.bepco.com

...try using this equation:MPH = [60/(G×A)]×[RPM/rpm]...where:MPH = vehicle speed, miles-per-hourRPM = engine speed, revolutions-per-minuterpm = tire speed, revolutions-per-mile60 = conversion constant, minutes-per-hourG = gear ratio, ie: 2.47:1, etc.A = axle ratio, ie: 3.55:1, etc....you get the tire revolutions-per-mile (rpm) value from your tire-store, or calculate it from the tires' diameter; but assume only 97% of it's unloaded (round) diameter to be more accurate.

its about 4100 at 90 mph in 6th so x by 2 180 mph on paper anyway

LOL, holy thread revival!

Car limited by drag around 138mph...trust me