Drag race: MMamdouh vs. Zikas

[MMamdouh]

ultimate cause of this problem was leaky injectors... they were sending uneven amounts of fuel to cylinders thus the idle was erratic and the performance is downgraded... car felt much more responsive and powerful after replacing injectors

MMamdouh

[benzino]

wow did it take that long?
does the car feel better now?

[MMamdouh]

well... the feedback is the one that came late... the resolution didn't take that long

i just reviewed my old threads and added feedback to the ones that didn't have one

MMamdouh

[ICEMAN_08]

a cold air intake would be worth looking at. i have one on my 98 1.5l lanos and it gained low and top end power

[MMamdouh]

my car got a cold air intake, Bob's car got an SRI

MMamdouh

[Fltofancy]

Guys, your really overthinking this, and the answer is much simpler than you think. Lets review
Both cars have similiar engines with similiar horsepower and the cars have similiar weights.

Mr. Newton said:

Force = mass * acceleration

So with similiar masses (car weight) we "see" more acceleration in the one car than the other.
Which means a greater Force is being exerted on the faster car.

How can this be if they are similiar in all other respects?

MMamdouh said the faster car had 13" diameter wheels and his had 14" diameter wheels...remember this fact.

Torque = Force * distance

If the engines put out similiar torques then the one with the smaller wheel diameter (distance in the above equation) will have a resulting Force which is greater (the same Force in the first equation, just to connect the dots).

So a smaller wheel diameter will result in a greater force applied by the wheel to the ground (motive force) resulting in a greater acceleration.

Fltofancy

[Daniel]

Guys, your really overthinking this, and the answer is much simpler than you think. Lets review
Both cars have similiar engines with similiar horsepower and the cars have similiar weights.

Mr. Newton said:

Force = mass * acceleration

So with similiar masses (car weight) we "see" more acceleration in the one car than the other.
Which means a greater Force is being exerted on the faster car.

How can this be if they are similiar in all other respects?

MMamdouh said the faster car had 13" diameter wheels and his had 14" diameter wheels...remember this fact.

Torque = Force * distance

If the engines put out similiar torques then the one with the smaller wheel diameter (distance in the above equation) will have a resulting Force which is greater (the same Force in the first equation, just to connect the dots).

So a smaller wheel diameter will result in a greater force applied by the wheel to the ground (motive force) resulting in a greater acceleration.

Fltofancy

Hi,
Not sure that this make the difference.
14" MM's rims wear 185/60/14 tires ===> ((60% of 185mm) x 2)) + (14 x 25,4mm) = 577,6mm dia.
13" Mika's rims wear 175/70/13 tires ==> ((70% of 175mm) x 2)) + (13 x 25,4mm) = 575,2mm dia.
The difference in diameter is only ~0,4%.

[Fltofancy]

Daniel,
Your math appears correct, and certainly two or three millimeters isnt enough to make a difference.
The theory is still correct, but obviously assumes the tires have the same aspect ratio and therfore a significant difference in overall wheel/tire combo diameter.
I stand corrected.

Fltofancy.