olddude

Handsome as well as f'n smart, anyway, if you bothered to read my post (#6), you would have your answer. If you are pulling, say 3500 RPM, your motor is pushing out 80 (crude estimate) horses or so. Top speed with 80(again, crude estimate) horsepower in a Cobalt would be drag limited to 98 MPH (per your experience). Wind resistance goes up as a cubic function, meaning that to increase your speed from 98 MPH to 120 MPH would take 147 horsepower (the calculation is correct, just the starting numbers were estimated, thus the end numbers are a guess, but used to show the math results in that it would take roughly 80% more power to go from 98 to 120.)

Your engine does not make 147 horsepower (yes, I know, higher than rated, but that is the way the math worked on my crude estimate) until probably 6000 RPM. So, unless you are spinning the motor that fast, you won't have enough power to get to the actual top speed of the vehicle.

DoNtGeTdUnNuP

im not totally positive cuz i wasnt staring at the rpm guage the whole time, but i really think that 3500rpm's is a bit underestimated considering they are around 2500 when im going 60ish in 5th gear.. it just doesnt make sense to me that there is no force to push the car in 5th gear

Cobalt30

im at 4 grand at 105 mph in 5th gear. or i believe its 5250ish in 4th gear at 105 mph.

olddude

fine, you were pushing 4000 RPM at 100, whatever, it makes no difference, READ my post above, your engine is not making much power at the lower
RPM that 5th gear gives you at 100 MPH. If you spin if faster (using 4th), your engine puts out more horsepower at the same speed and it will go faster.


Somebody please post a dyno chart so he can see how the motor puts out more power at higher RPM's

IonNinja

i can hit 100 in 5th gear

cobaltss12

I usually can get up to 125 in top 4th gear... then 5th... the highest was 144. it was damn fast... and scared me a little lol

05sedan

DoNtGeTdUnNuP
listen to olddude he is right....our cars dont produce enough power at low rpms in 5th to pull against the wind around that speed....just drop to 4th so it puts u back in the powerband and it will go past 98mph

Lhs_Raider

Umm yeah you should be able to do more than 98 cause i also have a 2005 Cobalt Ls and have got it to 115 today like it was nothing

redlineblueline

Today I was racing a 240sx on the interstate and i was pushing the 105 limit as i have done before and it did the die down-pick up one time then it started gaining speed again and i got it up near 110 and there was some wierd smell, dont know if it was my car or the surrounding because it didnt smell mechanical. does anyone know of this happening and if so how did it happen?