7:22.4 ZR1 'ring time

[vetteheadracer]

according to Corvetteblogger.com Jan Magnussen set a new ZR1 ring record this week.

[JenkinsComp]

fast

[Viper]

nearly as quick as the ACR, still the current Ring record holder

(though i read this morning the vette story is a internet hoax?)

Edited by Viper on Thursday 30th October 13:23

[roughrider]

On youtube, Jim Mero did a 7'26" lap in the ZR1, while the ACR did a 7'22". Although, the onboard footage shows Jim understeering into most of the corners. So, i would guess the ZR1 would be capable of a quicker lap, especially with Jan Magnussen at the helm!!

[mitch_]

I reckon there is easily more than 10 seconds to be had out of Jim Mero's time. It was very sloppy and he was just too fast into every corner.

[Viper]

yea im sure the vette will go faster

the viper driver Tom, only had a couple of tourist laps on the day before the record attempt his first ever drive in the ACR. On the record day the ViperClub (who paid for the whole thing, dodge leant the x2 cars) hired the track for just 4 hours, Tom got in x2 sighting/set up laps then on the 3rd took the record.

He missed a couple of gear changes on the run, had a 30mph headwind down the straight and was carrying some extra weight with all the cameras/recording equipment, so some more time can be lost under better conditions. I think club has the money already to have another go if needed

[roughrider]

Yeh, Tom [won his first World Touring Car race at the weekend!] also kept forgetting to upshift! Or maybe he was trying to see if the rev-limiter vibration could reduce drag!!

[LuS1fer]

http://jalopnik.com/5070077/corvette-zr1-shaves-fo...

I think the internet hoax was about ZR1 production being cancelled which wasn't true.

Incidentally, Clarkson in the Sunday Times loved the ZR1 but claims it was falling apart after 3 days. If he tested it for Top gear, it doesn't surprise me.

Edited by LuS1fer on Thursday 30th October 16:44

[roughrider]

I think he meant HE'S falling apart........

[Godzilla]

roughrider said:

Yeh, Tom [won his first World Touring Car race at the weekend!] also kept forgetting to upshift! Or maybe he was trying to see if the rev-limiter vibration could reduce drag!!

Yes, his was the worst record-breaking Nordschleife lap I've ever seen!
It simply cannot have been faster to have run on the rev-limiter for as long as he did for the lap.
The Viper has 8.3 litres FFS, run a gear higher!

So it has to be said, that whilst the ZR1 might have a few seconds left in it, the ACR probably has more so.
But they aren't competitors, the ZR1 is very much a road car, the ACR very much a track one.

[mitch_]

Godzilla said:

roughrider said:

Yeh, Tom [won his first World Touring Car race at the weekend!] also kept forgetting to upshift! Or maybe he was trying to see if the rev-limiter vibration could reduce drag!!

Yes, his was the worst record-breaking Nordschleife lap I've ever seen!
It simply cannot have been faster to have run on the rev-limiter for as long as he did for the lap.
The Viper has 8.3 litres FFS, run a gear higher!

So it has to be said, that whilst the ZR1 might have a few seconds left in it, the ACR probably has more so.
But they aren't competitors, the ZR1 is very much a road car, the ACR very much a track one.

Whilst I agree with the gearing, the big problem in vipers is the gearbox. You can't hurry it, if you do you mis-shift all the time, particularly from 2nd to 3rd. I'm not really sure what people mean when they say he did some setup laps, sighting is one thing, but I doubt there is much room for setup adjustment on these cars, afterall they don't have adjustable brake bias, no four way adjustable shocks, I doubt there would be any wheel alignement........so other than setting tyre pressures what's left for him to change??

[roughrider]

He actually did a couple of "sober-up" laps!

The ZR1 being 50/50 weight distribution should moose the Viper. The ZR1 must also be lighter!
I took my Z06 to Silverstone GP circuit on Tuesday, & although i think its fantastic, i was surprised by the amount of understeer GM have dialled in! You have to look after Joe Public, but at this level, the cars should be more neutral, like an Aston DBS.

I have put a touch more negative camber on the front today, but if anybody has any suggestions on how to get a bit more bite out of the front tyres [without spending thousands on suspension parts that render it useless on the road], please let me know.

[JimexPL]

roughrider said:

He actually did a couple of "sober-up" laps!

The ZR1 being 50/50 weight distribution should moose the Viper. The ZR1 must also be lighter!
I took my Z06 to Silverstone GP circuit on Tuesday, & although i think its fantastic, i was surprised by the amount of understeer GM have dialled in! You have to look after Joe Public, but at this level, the cars should be more neutral, like an Aston DBS.

I have put a touch more negative camber on the front today, but if anybody has any suggestions on how to get a bit more bite out of the front tyres [without spending thousands on suspension parts that render it useless on the road], please let me know.

You just need to wear the back tyres down a bit more!

I don't know how many miles your tyres have done, but when our demo cars were new they always felt a bit understeery in extreme situations [not that I ever took a demonstrator on a track of course...]. After about 4,000 miles the balance was far more neutral.
In my brief outings as a passenger in a couple of toyo R888 equipped cars they seem to have noticably more front end bite.
Presumeably Godzilla, Jenkinscomp or lvarga have had some alignment work done at some point.

[Viper]

ill scan the 6 page article about the viper trip we got in this months glossy mag, eer..the ACR like shoebags does have x4 adjustable shocks, they describe it as adjusting the ride height a few clicks, they did this on x3 occassions on Toms word. The engineers had them set to stiff for the bumps and rough spots of the Ring

the rear wing is also adjustable to get the calculated 1000 lbs of downforce, no doubt a fine line between slowing you down to much on the couple of fast straights bits to supplying the correct amount for all the corners

here's a vid, with some of the data showing
http://www.viperclub.org/downloads/ACR_1.wmv

were getting a 2 hour DVD soon about the trip so that should be quite interesting. They are sold as a car you can drive to the track, do your thing then drive back home, there will be a couple of them over here soon
Power output is the same as the standard coupe (600bhp) but with the rear wing, front splitter and canards, adjustable shocks and stickier tyres

Edited by Viper on Thursday 30th October 18:41

[roughrider]

Thanks James.
Should've mentioned i've got Toyo R888's on. 30 profile back & front.

[JimexPL]

roughrider said:

Thanks James.
Should've mentioned i've got Toyo R888's on. 30 profile back & front.

I presume that you were also in competitive driving mode, or with it all switched off - If it's still on, you can't really hear/feel it, but it actually brakes the rear wheels quite often on the Vettes creating understeer and wearing your rear pads out quickly.

[Godzilla]

roughrider said:

He actually did a couple of "sober-up" laps!

The ZR1 being 50/50 weight distribution should moose the Viper. The ZR1 must also be lighter!
I took my Z06 to Silverstone GP circuit on Tuesday, & although i think its fantastic, i was surprised by the amount of understeer GM have dialled in! You have to look after Joe Public, but at this level, the cars should be more neutral, like an Aston DBS.

I have put a touch more negative camber on the front today, but if anybody has any suggestions on how to get a bit more bite out of the front tyres [without spending thousands on suspension parts that render it useless on the road], please let me know.

No, the ACR is a stripped-down club racer and must weigh less than the luxury-equipped ZR1 (which weighs 100kg more than the Z06).

As for handling, I can't say I've ever noticed significant understeer in my Z06, although I have had the alignment tweaked to suit the stickier R888s now.

You can take one set of shims off the front upper wishbones and that will add 0.5 degrees of negative camber which will help.
Do a search on www.corvetteforum.com in the Z06 section for a decent track alignment.

I have my car set to a good track alignment and it does not seem to incur excessive tyre wear or tramlining on the road.

[Viper]

3,454 lbs. (1567 kg) Viper Coupe

3,408 lbs. (1552 kg) ACR

3,366 lbs. (1533 kg) ACR with Hard Core Package

the optional "Hard Core" package offers maximum weight savings by deleting the audio system, underhood silencer pad, trunk carpet and tire inflator. The radio is replaced by a lightweight cover that can be configured to mount the included lap timer. The door speakers are replaced by lightweight carbon-fiber panels. The Hard Core package offers a 40 lb. weight savings and provides ultimate street-legal race-ready performance

Edited by Viper on Thursday 30th October 20:59

[Le Man]

Was it raining?

[franv8]

Either way these American interlopers must be upsetting the European and Japanese cognosetti...

(Although now there will be claims they did a shortened version, used an 'imperial' second that is longer to measure the time, or probably distorted the time space continium in a way that German manufacturers never would...)