Z28 vs. ZL1 quarter mile?

[Skylane765]

I heard the Z28 will run 12.7 in 1/4. The ZL1 is the one for drag racing, not the Z28.

[McRat]

If I only run 12.7 first pass, I'm going to cry.

2002 Z06, Motor Trend. Spends all day long to get a 12.85 @117.
2002 Z06, McRat. First pass, no changes at all (baseline) 12.40 @ 110 at Carlsbad.
Shortly afterwards, wifey runs 11.95@117 at California Speedway.

Yes, I'm going to do drag testing and dyno testing. They said it was Blasphemy with the Z06, and I imagine I'll get the same with Z/28.

[Skylane765]

Do not cry I remember somewhere it said 12.7

[DRKS1D3]

The Z/28 is not meant to be a 1/4 mile car. It was engineered to be a track monster. If you're a 1/4 mile warrior, buy a ZL1.

[McRat]

Originally Posted by DRKS1D3

The Z/28 is not meant to be a 1/4 mile car. It was engineered to be a track monster. If you're a 1/4 mile warrior, buy a ZL1.

Dude. I've run 9's/10's in cars, bikes and trucks. I hold a NHRA SuperGas license. I've exploded an engine at Bonneville at over 200mph. Nothing the ZL-1 or Z/28 does stock in a straight line is going to blow wind up my skirt.

Besides, I already have a CTS-V. The ZL-1's Daddy.

[LINMUP]

Originally Posted by Skylane765

Do not cry I remember somewhere it said 12.7

In the comparison between the Z28 and the GTR it ran 12.3

[Skylane765]

Originally Posted by LINMUP

In the comparison between the Z28 and the GTR it ran 12.3

That may be true. I have seen one that says 12.1 rolling start also. I do not remember where I even read it.

[McRat]

ET's can be all over the place. It's the trap speed that is significant. It doesn't change much except for wind direction and density altitude.

Trap speeds on a clean run (shift it like you mean it) at a known weight are as good as a dyno, perhaps better, for indicating tuning changes to an engine. They are the only way to evaluate CAI changes since dynos don't have 100mph wind blowing at a closed hood.

[newmoon]

12:30s from what I have seen published in testing which is not bad. I'm sure in good conditions on a prepped track this car should be able to run 12:00s-12:20s. That being said under those same conditions a ZL1 can dip well into the 11s.

[SGOS252382]

Originally Posted by McRat

ET's can be all over the place. It's the trap speed that is significant. It doesn't change much except for wind direction and density altitude.

Trap speeds on a clean run (shift it like you mean it) at a known weight are as good as a dyno, perhaps better, for indicating tuning changes to an engine. They are the only way to evaluate CAI changes since dynos don't have 100mph wind blowing at a closed hood.

You are very correct.
The Z28's trap speed is around 117 mph (give or take a few MPH) on average (based on several magazine testing).

117 mph trap speed is good for low 12s (stock tires) and high 11s (drag radials). But the Z28 (from what I've been reading) is pretty hard to launch without breaking the tires loose. The Z28 has steeper gearing and a stiffer suspension.
12.3s - 12.7s is the range most magazines have tested the Z28 in the 1/4 mile.

The Z28s road course suspension makes it harder to launch smoothly without wheel spin.

[Xlr8ion]

If your drag racing the z you wasted your money.Chevy had 0 interest in making it for that.

[McRat]

Which Z? They said that about Z06 too.

Here's what's odd.

The top speed of the Track Car Z06 was 175mph. This also happens to redline in 5th.

The top speed of the Track Car Z/28 is 175mph, aero limited. The redline is 186mph.

The Z06 had equal gear spacing (WR) for road racing. The Z/28 doesn't, it's a close ratio box akin to drag cars.

If they had no intention of you modifying the car or occasionaly visiting the strip, then they missed the trans spacing and axle ratio big time. The rear should have been about ~4, and the spacing should have been WR.

[Dropspeed]

Originally Posted by McRat

Which Z? They said that about Z06 too.

Here's what's odd.

The top speed of the Track Car Z06 was 175mph. This also happens to redline in 5th.

The top speed of the Track Car Z/28 is 175mph, aero limited. The redline is 186mph.

The Z06 had equal gear spacing (WR) for road racing. The Z/28 doesn't, it's a close ratio box akin to drag cars.

If they had no intention of you modifying the car or occasionaly visiting the strip, then they missed the trans spacing and axle ratio big time. The rear should have been about ~4, and the spacing should have been WR.

Ratios for C6 Z06 and the 1LE/Z/28 below:

1LE & Z/28 w/3.91
1st: 2.66 10.42
2nd: 1.78 6.97
3rd: 1.30 5.09
4th: 1.00 3.91
5th: 0.74 2.90
6th: 0.50 1.96

C5 Z06 w/3.42
1st: 2.97 10.16
2nd: 2.07 7.08
3rd: 1.43 4.89
4th: 1.00 3.42
5th: 0.84 2.87
6th: 0.56 1.92

-Matt

[McRat]

Originally Posted by 130R

You seem to know what you're talking about drag racing. I'm a road course guy, but I did do a 1/4 mile run once just out of curiosity. Unfortunately, unknown to me, someone (one of the tuners) had disabled the TC and I was spinning all the way through 3rd. I pedaled as much as I could, and managed a 12.7 on street tires, but the trap speed was 121 MPH.

What kind of number does a 121 MPH trap speed equate to?

122 in a Z06 is 11.3x ET. Need your weight to figure out HP.