Quarter mile times for bone stock LS1/A4

[DRTH VTR]

Len
I thought about the hybrid cars and how this same discussion applies to them. Most cars get better gas mileage on the highway and poorer gas mileage around town. The reverse is true for the hybrid cars. The difference, it seems to me, is that the kinetic energy converted to heat in the brakes of the standard car is converted back to kinetic energy in the hybrid car. That takes some of the other variables out and enables us to compare mileage at lower speed and mileage at higher speed. Interesting, no?
Jim

 

[C5Richard]

Len
I thought about the hybrid cars and how this same discussion applies to them. Most cars get better gas mileage on the highway and poorer gas mileage around town. The reverse is true for the hybrid cars. The difference, it seems to me, is that the kinetic energy converted to heat in the brakes of the standard car is converted back to kinetic energy in the hybrid car. That takes some of the other variables out and enables us to compare mileage at lower speed and mileage at higher speed. Interesting, no?
Jim

Hybrids get great gas mileage in the city because the gas engine isn't even on for the most part. There is seemless operation between the electric motor and the gas engine. It uses the electric motor to launch the car and the gas engine for higher speeds.

Richard.

 

[tipcapman]

Len
I thought about the hybrid cars and how this same discussion applies to them. Most cars get better gas mileage on the highway and poorer gas mileage around town. The reverse is true for the hybrid cars. The difference, it seems to me, is that the kinetic energy converted to heat in the brakes of the standard car is converted back to kinetic energy in the hybrid car. That takes some of the other variables out and enables us to compare mileage at lower speed and mileage at higher speed. Interesting, no?
Jim

Interesting observation. I don't know a lot about hybrids, but I offer the following...

The regenerative braking you refer to converts the kinetic energy back to (chemical) potential energy, in the form of battery charge. Very elegant and efficient!!!!

A hybrid car has the advantage that excess power required for acceleration, climbing hills, etc, can be supplied by the electric motor. This allows the gasoline engine to be reduced in size, even smaller than an equivalent economy car. At cruise, the gasoline engine operates closer to wide open throttle than, say, your Z06, so guess what... those nasty pumping losses are minimized!!!!!

By the way... if you've ever heard of these vehicles specifically designed to break fuel mileage records, many have a tiny engine designed to run at wide open throttle which accelerates the vehicle to an optimum speed... the engine is then turned off, and the vehicle coasts to begin another cycle. Low pumping and friction losses.

The C5 is of course the opposite... it has all sorts of excess engine displacement to support acceleration and high speeds, so uses an extreme overdrive to lower engine revs.

L

 

[DRTH VTR]

Hybrids get great gas mileage in the city because the gas engine isn't even on for the most part. There is seemless operation between the electric motor and the gas engine. It uses the electric motor to launch the car and the gas engine for higher speeds.

Richard.

I understand that. I believe that both the gas engine and electric motor accelerate the car. However, once again, nothing is free. The electric power must come from somewhere. Much of it is gained from the conversion of the electric motors to generators, recharging the battery. But you can't get back as much as you put in, so additional charging is also required, I suspect. The gasoline engine has to do it. There is no external source of energy, beyond the gasoline. So one way or another the gasoline engine supplies the power.

 

[tipcapman]

DRTH... that book is either gonna edumacate you, or give you the best sleep of your life! I bet its the former!!!!

I read a bit about the Prius in Car and Driver... they said the power management scheme between the gas engine and the electric motor is so complicated they didn't dare try to explain it! As Richard said, it covers 3.6 miles of the 11.0 mile Federal emissions and MPG road test with the gas engine off. So you're robbing from Peter Highway to pay Paul City.

They didn't mention the effect of regenerative braking, but you are right, it is a contributor.

Prius also has an aerodynamic drag coefficient better than the C5... .26 versus .29.

 

[Edmond]

Prius also has an aerodynamic drag coefficient better than the C5... .26 versus .29.

Not too many people consider aerodynamics in calculating mileage and speed. Theoretically, if a car has to work harder by cutting through the wind, it would get poorer mileage, right?

 

[tipcapman]

Not too many people consider aerodynamics in calculating mileage and speed. Theoretically, if a car has to work harder by cutting through the wind, it would get poorer mileage, right?

Correct. Actually, vehicle weight is the biggest factor in obtaining good fuel economy, and aerodynamics is second. Come to think of it.... those are critical for high performance vehicles as well.... hmmmmmmm

L

 

[Patman]

I don't know if GM was wrong or not but, I will tell you this. I was on a long 550 mile trip about a month ago and I tried using 5th and not 6th and my gas milage did not change much at all. If there was a 1 mpg change, that was it. So, I think going to say a 4:10 from a 3:42 in a 6sp will not change the MPG much at all based on what Ii did..

You are correct. I had a 98 Firebird Formula six speed and went from 3.42s to 4.10s. My best highway MPG with the 3.42s was 31.0 and my best MPG with the 4.10s was 30.0. Around town it did not change, I still got 20-21 MPG average with the 4.10s. Best bang for the buck mod I did on that car too!

 

['04 Torch Red]

How do you figure, "better gas mileage" with the 3.15's? It would seem to me that the more times the motor turns over at a given speed, the more fuel it is going to use, all things otherwise being equal.

A 3.15 equipped LS1 is certainly going to have more rpm's at 70mph that a 2.73 equipped LS1 at the same speed.

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

I agree...I think he meant less gas milage with a 3.15...because that is what it gets...less gas milage with a 3.15 as opposed to a 2.73

 

['04 Torch Red]

[QUOTE=DRTH VTR.............."Place your hand against your pants and slowly move the hand back and forth. Note any warm sensation. Now repeat, but move the hand much faster. I suspect that it will be warmer, no?" ....

==========================================================

OK, thats it!....you are grossing a lot of us out...us a different example please..this is getting too weird...

 

[DRTH VTR]

[QUOTE='04 Torch Red]

OK, thats it!....you are grossing a lot of us out...us a different example please..this is getting too weird...[/QUOTE]I didn't even think of that, even with my twisted and deviant brain!

 

[tipcapman]

I didn't even think of that, even with my twisted and deviant brain!

Jim...

Enough of the deviant brain... let's see last weekend's times... after all, that is the general subject of this thread!!!!

L

 

[donnyonee]

0-60 time

ive got a 0-60 time of 4.95 on my gt2.
99 vert auto 3.42 bwing caimaf magnaflow, sometimes at a constant speed it feels like it "surging" . this might be the maf. i'll have shorties on next wk and soon a ls6 intake. then a good dyno tune. how much does a tune cost and who in so cal is good?.
thanks,
don

 

[DRTH VTR]

Jim...

Enough of the deviant brain... let's see last weekend's times... after all, that is the general subject of this thread!!!!

L

I am not very proud of them. I had good trap speeds, but did not launch aggressively enough. I bogged a little on two of the runs. I only got three altogether. The temperature was about 80 degrees, and the elevation is 2600 ft.

1: Beat a Buick turbo (Grand National 13.622 MOV 0.5625))
RT- a lifetime- forget it
60' 1.967
330' 5.454
1/8 8.229
MPH 86.48
1000 10.706
1/4 12.732
MPH 112.76

2: Lost to a modded Evo (12.697- MOV 0.1147 should have beaten him!!!)
RT 0.030
60' 2.113 (bogged badly)
330' 5.696
1/8 8.530
MPH 87.42
1000 10.940
1/4 12.967
MPH 113.33

3: Beat a neon turbo (13.481 MOV 0.6273)
RT 0.061
60' 2.046 (bogged)
330' 5.578
1/8 8.414
MPH 87.66
1000 10.816
1/4 12.837
MPH 113.40 (fastest trap I have ever run)

I have not raced for about a month, and I seem to lose my launch touch if it is too long between track sessions. My best ET's are 12.42 and 12.47. The last 2 runs were my fastest trap speeds.

 

[tipcapman]

U R D man!!!!!


L