# GT-R does 7:29 around nurburgring.

**URL:** <https://forums.speedlife.net/t/gt-r-does-7-29-around-nurburgring/197592>\
**Category:** PittSpeed Automotive\
**Created:** [May 22, 2008, 4:42am UTC](https://forums.speedlife.net/t/gt-r-does-7-29-around-nurburgring/197592 "2008-05-22T04:42:21Z")\
**Posts on this page:** 1\
**Showing post:** 58

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**Author:** ![tjZ28](https://avatars.discourse-cdn.com/v4/letter/t/9de0a6/32.png) [@tjZ28](https://forums.speedlife.net/u/tjZ28)\
**Post date:** [July 1, 2008, 6:08pm UTC](https://forums.speedlife.net/t/gt-r-does-7-29-around-nurburgring/197592/58 "2008-07-01T18:08:34Z")

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> [@Roadmaster progress](https://forums.speedlife.net/t/roadmaster-progress/36856/6):
>
> Im not sure if that 100% accurate, but the GTR vspec is supposedly doing laps in 7:25.

I’d be surprised if it’s “only” a few seconds faster than the current model. But if 7.25 holds true you can bet GM will re-run the ZR1 on a day w/ less wind and a pro driver. With lap times in the 7 minute range being just 1% slow means nearly 5 seconds. It’s not hard to imagine a GM engineer being a few % off what a true ring-seasoned profesional could do. But perhaps time will tell.

> [@TwinTurbo grandprixGT deep8's FWD build](https://forums.speedlife.net/t/twinturbo-grandprixgt-deep8s-fwd-build/34410/23):
>
> the ring testing is shady… you never know if the car was hopped up or not or what tires they used, etc
> 
> I do know the Z06 did 7:42 on run flats which is damn impressive. I bet it had mid 7 30’s easily on good tires or low 30’s on race R compounds

Just for the fun of bench-racing, a good “street tire” is probably 5% faster than a run flat. A true R-compound is at least 5% better yet, probably closer to 10%. So just assuming an overall advantage of 10% going to an R-compound a C6Z06 could shave more than 40 seconds off its ring time… dropping it into race car sub-7 minute territory.

Obviously that’s just pure speculation and nothing but empty bench-racing, but I think most seasoned track drivers would agree that 10% reduction in lap times going from any “true” street tire, particularly run flats, to an R-compound (something on the order of a Hoosier R6 would probably be appropriate for the 'ring) is conservative, very conservative.

However, since the 'ring has long sections of flat out high-speed running where there’s little/no advantage to the R-compounds perhaps typical gains wouldn’t hold true. Still, even a 5% improvement would have the C6 Z06 in the high 7-teens.

For an example of the extreme differences between street tires and R-compound; my car has stock C5 Z06 suspension other than alignment and front sway bar (T1). I hit 1.39Gs on flat ground on Hoosier A6s. Stock C5Zs are rated at around what .98 on Supercars (better tires than run-flats)?

-TJ

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