The Z/28 Thread You've All Been Waiting For/Dreading
#212
#213
Rennlist Member
#214
Thanks.
If you come across a Camaro at Mosport, capture some video and for gods sakes, MAKE SURE that you ask him if he went WOT on the straight and didn't short shift. Get some SOLID proof of that. Don't forget to take a picture of his face when you ask those questions too.
That camera view was a screw up. I forgot to switch the camera back to wide view mode. This is the normal 'setup':
If you come across a Camaro at Mosport, capture some video and for gods sakes, MAKE SURE that you ask him if he went WOT on the straight and didn't short shift. Get some SOLID proof of that. Don't forget to take a picture of his face when you ask those questions too.
That camera view was a screw up. I forgot to switch the camera back to wide view mode. This is the normal 'setup':
What I have done of late, you may also want to try, is alternating the views.
I promise to record the driver after a session at Mosport. I'm just not sure
he'd be amenable to an interview by someone that just passed him...
Link to a short clip taken last week with a few automatics that were definitely broken in and were WOT. I hope my rear Go Pro was on.
https://vimeo.com/104116825
#216
unless you're actually driving both cars yourself, doing comparos on which car is faster even on straight-line is pointless. drive both then do a review.
anyways, 996flt6 did gave pointby when he had 6gt3 even though he faster driver than me but his car was down 80hp!
anyways, 996flt6 did gave pointby when he had 6gt3 even though he faster driver than me but his car was down 80hp!
#218
Nordschleife Master
#219
Drifting
Not gonna deny it. I'm not convinced the z/28 is all it's been marketed to be. I knew people would disagree.
Your scenario is possible. I'll buy that he could have been in 3rd instead of 2nd going through turn 11. If you're focused on braking zone/turn in/carrying speed through a corner, though, I'd think you want to be in the right gear to exit properly. Maybe I'm giving the z/28 driver more credit than is due, or maybe I'm right that the heat was slowing the car down. It was hot that day, last session, and at the back 1/2 of the session as well. Is the heat proposition that unreasonable?
Your scenario is possible. I'll buy that he could have been in 3rd instead of 2nd going through turn 11. If you're focused on braking zone/turn in/carrying speed through a corner, though, I'd think you want to be in the right gear to exit properly. Maybe I'm giving the z/28 driver more credit than is due, or maybe I'm right that the heat was slowing the car down. It was hot that day, last session, and at the back 1/2 of the session as well. Is the heat proposition that unreasonable?
I would say yes to your assumption on heat taking a toll of over 100 hp is far fetch. I had a Porsche Turbo. No matter the heat, I would never - ever lose significant power that was noticeable drastic. 110+ degrees at thill and i would still pull in .2 GT3 RS in the straight line, even after 20 / 25 min sessions back to back.
#220
I've seen tons of guys use higher gears at the track because they can ride the torque curve (and learn the proper lines before adding more up/down shifts).
Now, don't want to offend anyone but the Z/28 with the LS7 would absolutely stomp a boxter s/spyder/Cayman R in a straight line.
The torque from down low out of that engine is utterly ridiculous. Top gear did a test on the c6Z back when it was launched (same engine with a few small tweaks). It started from a stop and launched in 6th gear and can accelerate to top speed in 1 gear!!.... If that's not a statement I don't know what is.
Steve
Now, don't want to offend anyone but the Z/28 with the LS7 would absolutely stomp a boxter s/spyder/Cayman R in a straight line.
The torque from down low out of that engine is utterly ridiculous. Top gear did a test on the c6Z back when it was launched (same engine with a few small tweaks). It started from a stop and launched in 6th gear and can accelerate to top speed in 1 gear!!.... If that's not a statement I don't know what is.
Steve
#221
Nordschleife Master
#222
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The kool-aid is 9 years old, the LS7 platform is well proven and refined in the Z06 chassis. Tons of data there to look at and heat soak isn't a substantive issue. Sure, the LS7 is now in a new chassis and will continue to be refined, nut the platform hasn't changed.
#223
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LS7 engine in stock form will overheat if driven hard on the track after couple laps. This is a well known issue in Z06 and all the fast guys watch their engine temp like a hawk and wisely pull in to paddock when water temp reach above 240F. The same engine with added cooling tricks borrowed from ZR1 as seen in my Z06 carbon and new Z28 also suffer the same fate when driven hard. The few Z28 I seen so far at the track is worst than my Z06 in stock form as far as overheat goes and they were not driven hard. It make sense since Z28 is 700+ lbs heavier than my Z06
This issue can be reduced by using water wetter, lower temp thermostat, reprogram fan to engage at lower temp and better hood ventilation to allow trapped heat to escape. I done all of the above and was able to reduce engine temp by 20+F compare with stock but still not great. My friend Ron has one of the best LS7 engine build by Katech with aggressive racing dry sump system, vented hood and upgrade radiator and he is able to maintain engine temp below 210F consistently - that's after spending enough time and money on engine mod to buy a Porsche Spyder.
Here is my write up and video of my Z06's oil pressure measurement at Thunderhill
http://www.corvetteforum.com/forums/...rack-test.html
As you can see by graph below my engine water temp climb up to 230F after 6 lap running in the 1:57-1:53 lap time at Thunderhill with ambient temp of 73F which is cool for Thunderhill standard
Recently I cut the hood insulator to allow more trapped heat to escape as shown below which help reduce temp by 5-10 degrees (how did black sheep racing logo got on my windshield?)
Overheat engine will produce less horsepower and keeping it as cool as possible under hot lap condition is crucial to maintain Hp and Tq. I see this heat soak condition all the time when I run with my ZR1 friends. They will keep up with my Z06 on the straight for 1-2 laps then fall badly behind when their supercharged engine suffer from heat soak. I won't be surprised if the Z28 in orthojoe's video experience the same over heat issue
This issue can be reduced by using water wetter, lower temp thermostat, reprogram fan to engage at lower temp and better hood ventilation to allow trapped heat to escape. I done all of the above and was able to reduce engine temp by 20+F compare with stock but still not great. My friend Ron has one of the best LS7 engine build by Katech with aggressive racing dry sump system, vented hood and upgrade radiator and he is able to maintain engine temp below 210F consistently - that's after spending enough time and money on engine mod to buy a Porsche Spyder.
Here is my write up and video of my Z06's oil pressure measurement at Thunderhill
http://www.corvetteforum.com/forums/...rack-test.html
As you can see by graph below my engine water temp climb up to 230F after 6 lap running in the 1:57-1:53 lap time at Thunderhill with ambient temp of 73F which is cool for Thunderhill standard
Recently I cut the hood insulator to allow more trapped heat to escape as shown below which help reduce temp by 5-10 degrees (how did black sheep racing logo got on my windshield?)
Overheat engine will produce less horsepower and keeping it as cool as possible under hot lap condition is crucial to maintain Hp and Tq. I see this heat soak condition all the time when I run with my ZR1 friends. They will keep up with my Z06 on the straight for 1-2 laps then fall badly behind when their supercharged engine suffer from heat soak. I won't be surprised if the Z28 in orthojoe's video experience the same over heat issue