davepl

Roll race is no different than a dyno pull. No driver involvement, really only useful in 1:1 gearing to prove anything, generally boring, and sometimes something goes spectacularly wrong.

The part that most annoys me is that 95% of the time one car jumps and seems to win. At least from the videos. Remember at 90mph a quarter of a second is a BIG distance. With a big power delta the jumper will still get run down, but with close cars it's often too much to overcome.

At 70mph you cover over 102 feet per second. A quarter second jump is over 25 feet of advantage, and a lot of those "races" are closer than that and have a bigger jump. (I know the -delta- in speeds is not 70 mph, I'm just talking about leaving early).

3 Z06ZR1

Your facts are backward? In a roll race the other car is moving at the same rate when you start your pull.
Even 2-3 tenths off the line is getting left in a 1/4 race. Because 1 is sitting still. So head starts are part of the race in the 1/4. Roll racing is much more even starting with your car doing the work

Snorman

It's not the distance gained if one car gets a jump, it's where both cars end up on the acceleration curve.
A .3-.4 interval really isn't much at all. However, cars at this level will accelerate 4-5 mph in that interval. So if we run from 60 mph and I jump, in ~.3-.4 seconds I already have a 5 mph advantage before you even go WOT and am pulling. By the time you go WOT, ~.3-.4 seconds later you're going 65 mph...but I'm now going 70 mph pulling away and will continue to do so unless the "chasing" car has a steep enough acceleration curve to overcome the deficit.

So yeah...the majority of these roll races are largely useless unless done the right way...with vBox in both cars ran at same time side by side under exact same conditions to determine which one truly is faster.
S.

0NORCAL-SS

More you talk more you are lost. Trap speed on theboard says a lot. I can see I'm dealing with someone that does not understand trap speed at track. I give up

3 Z06ZR1

This thread was not about the track or 1/4 mile to start with so thanks for bowing out.
Since you didn't read it to start with.

It is about the gearing differences to help some understand the differences between the two.

The low 10.99 vs .7.83 is like a 3.42 racing a 4.11. The 4.11 wins the 60ft the traction and the thus the 1/4 race.

The thread is about how the M7 matches up better in a roll contest.
Where it carries the advantage with a proper driver. The manual
is very driver dependant. One driver can clearly use skill than another and get more out of the same car.

The M7 has the roll race advantage with the closer gear spreads and less drive losses. Thus why a A8 dyno's about 25-40 less from what I've seen.

3 Z06ZR1

I agree the race must be started evenly to be fair not really rocket science.
You just restart again until it 's even. You pull an even roll race with both having traction you drive away end of story you have the faster car.


That's what I like!

Snorman

I agree. But it's pretty difficult to get the cars to start at exactly the same time. Even if you 'think' they started evenly.
Even a few tenths is more than people think.
S.

RBK

Unless I am misunderstanding something a 2:41 at VIR would be considered slow. My reference point is driving a SCCA T-1 Car in 2005 and turning 2:05 (for those who do not know, the T-1 was a C6 LS3 with stock motor). Best

Snorman

You're comparing two different VIR layouts. Mero ran the VIR Grand West Course.
S.

0NORCAL-SS

This is why drag strip puts it all there with legit times. Trap mph proves a lot also

Time doesn't start till you move even if someone takes off on first yellow 1/4 mile time won't be faster.

L Duncan

Remember shift times WILL be faster in the A8 as well...autos NEVER miss a shift in 1/4 mile or roll races.

Snorman

Yep. It's a real number, not some unknown with no data to support it.
S.

3 Z06ZR1

yep .2 of a second makes no difference except the drag strip.
So 99.9999999 percent of the time my car IS else where.

So I remember how much more enjoyment I get driving a manual.
Then I remember other auto purchases that were quickly sold because of no involvement other than a gas and brake. I like the control and the A8 guys are missing GM's best manual EVER the M7 with a MGW pure driving joy teamed with the best car.

davepl

Whatever helps you sleep at night. The difference between 3.2 and 3.0 is significant. It's not linear - it's not like the difference between 6.2 and 6.0

By that logic why paint the outside since you sit inside the car anyway 99.99% of the time?

Keep in mind also that most of us (I think, anyway) have had stick Corvettes in the past. I just spent 8 years with a C6Z06, it's not like I don't know what a manual trans is...

3 Z06ZR1

I sleep great so if you needed to respond I hope it helped. The manual is was the better choice.
But the paint logic is way off you could do better!
Ready and waiting for roll races from the A8's!

TripleBlack99

strange, mine came with a wheel thingy for steering

davepl

The A8's what?

b4i4getit

The number one reason the M7 is preferred over the A8. It does not go into limp mode when it gets hot outside.

L Duncan

Lol here is a guy that really wishes he had bought the faster A8. If your a good boy I'll let you drive mine sometime.

mookiec

In the big picture does it really matter if one car is a tenth or two faster? If I am spending 100k on a car I am going to buy the car with the trans that I want to drive even if it is slower and that is an M7, end of story. Comparing digs and roll races is also a great deal to do with the driver so even if specs say the A8 is quicker I am quite sure many "wheel men" can beat it all day driving a stick.