Howydo

June issue of Road and Track magazine compares Corvette ZR1 to GTR and Porsche 911 977 II twin turbo.

Results:

Lap time at Spring Mountain ZR1=1:20.1
GTR= 1:20.9
Porsche=1:21.3

0-100 7.3(ZR1),8.0(GTR),7.9(P)

Quarter mile 11.5 @ 128.7 (ZR1), 11.6 @120.4 (GTR) and 11.7@ 121.8 (Porsche)

As usual Porsche's test mule is faster then their regular production cars

I love Porsche but you can't deny power to weight ratios. Sure to 60mph they are about the same but after that it's hello ZR1!
T

Hotmetal

BUT ... Porsche Turbo with PDK transmission is much faster 0-60 in 2.9 sec

EVILNESS

But not high 120mphs as stated before...

R.

Hotmetal

You are right, but as most of the people, I do not drive 120mph on the street and honestly, i'm not often on a track. So 99.99% of the time I keep my speed under 120mph.

evoviiiyou

Lets keep in mind the test car in this comparison was a 6speed and not a PDK 997.2. Big difference is right there. Heres the link to page 3 of the test:

http://www.roadandtrack.com/tests/co...e_clash_page_3

And the fact that it actually won the comparison.

DREAMERAK

Are you filling in for notch or guibo?

Howydo

It barely won the comparison and mostly not on performance variables. Things like interior/exterior styling pushed it over the edge.

I currently have both a 911 turbo s and ZR1. They are both great cars for different reasons. When it comes to shear excitement, however, I prefer the ZR1...

Notch

I'm not sure slower 997 Turbo times in R&T means a (faster) "Porsche test mule" was used in the Car and Driver test.

As mentioned above, R&T tested the 6-speed manual 997 Turbo, which is slower in acceleration than the PDK equipped Turbo (the PDK Turbo was used in the Car and Driver article). Can the differences in acceleration times between the two magazines be completely explained by "manual" versus "PDK"? I don't know the answer. But I do know that three things combine to provide better acceleration times in a PDK Turbo...launch control, much faster gear shifts, and no break in boost between gear shifts. If for example the PDK shifts gears just 0.2 seconds faster than what a driver can do with the manual, that would be a 0.6 sec difference in trap times between the two cars (all else being equal). How much higher would the trap speed be in the PDK Turbo given that the engine remains at full boost between every shift? I don't know, but it would without question be a higher than what the 6-speed could muster. And launch control with the PDK? It makes a difference too...the PDK can launch under boost while the 6-speed can't.

tumbler05

Totally off topic but... Please inform the young lady in your avatar that I'm pretty sure I love her ... no wait.. yep, I'm sure.. I love her

EVILNESS

Not a big difference between 2.9 and 3.4 either.. the zr1 should still be faster...

Read the article and they only tested the turbo on that day the zr1 numbers they grabbed from when they tested that car in irvine. Had they tested both cars the same day belive that the zr1s trap speeds would of been in the 130s..

evoviiiyou

Well stated and much appreciated. You have a nice stable! I was merely posting what I read in the article. I love the ZR1 with out question and the factory power it produces is earth shattering. My 2010 with PDK is my third modern Porsche (the other two were 6speeds) and I can attest to its ability. I am certain that above 125ish a stock ZR1 would pull my ride quite thoroughly stock to stock...but till 100mph in a straight the ZR1 would be questioning his chances. Both great cars for very different reasons and I love both of them!

vette6799

Great post, and this debate should quietly end or it will turn into another bout of ad nauseum mine is bigger than yours, like it did the last time this topic was visited.

Futfixr

But.....mine is bigger than yours.

Tom400CFI

There is something wrong w/your math above; the manual trans car doesn't come to a dead stop, then resume its previous speed, during the .2 second difference in the two cars' shifting speed; the manual car is still moving down the track at ~60, 90, and 118 mph during that .2 second delta in shifting time frames. So it won't be slower on that merit alone. It MAY be slower, but not because .2x3=.6.

As for boost as it relates to shifting, why can't you maintain full boost by using full throttle during shifts w/the manual trans?

RichieRichZ06

Get out of here with your logic and reasonable questions.

Notch

Anytime the car isn't at full acceleration, trap time is increasing.

And I don't recall saying that the PDK would have a lower trap time based on shifting alone.

Because in the manual, boost is a function of engine load; when the clutch is depressed (or when throttle is reduced with the transmission engaged to the engine), boost immediately drops very rapidly. And when there is a load again (post gear shift with throttle application), boost is not immediately back to maximum. In the manual 996 and 997 Turbo, you can rev the engine all you want with the engine not coupled to the transmission and you wouldn't generate any boost at all. In the PDK, with launch control engaged, you can hold the brake, floor the throttle, and the ECU will allow boost. The same ECU logic also helps in maintaining full boost at each gear shift.

The bottom line is a PDK is going to have a lower trap time, and higher trap speed than a 6-speed Turbo (all else being equal). Versus the manual 997 Turbo, the PDK is going to produce lower times in many, if not all, 0-XXX accelerations .

0FORGED DST

I didn't get my issue yet........probably some Porsche or Nissan fan stole it !!

Ryan Bell

Makes perfect sense to me.

GForceSS

While I haven’t checked the boost during power shifts in my ZR1 I have done it in my old twin-turbo Camaro. Boost dropped half a pound and then spiked over half a pound. Not much loss at all.

Notch

I imagine the computer programming in the Camaro is different than what Porsche uses.