ooldguy93

had this subject on the C7 Z06 forum, just looking for any additional info

Road America post event update :

Quick review -

My 3rd track day with car ( 50+ yrs. of W2W and open track experience ) was at Autobahn Country Club on the full course config. ( 3.5 mi. )
In the AM ( 65 deg. ) car ran well. felt normally strong
In the PM ( 90 deg. ) car went " flat " with 240 water and 320 oil temps. Could, barely, catch a friends well driven STOCK C5 Z06 with 355whp
No msgs. on dash

After that and this forum conversation :
Installed the GM 2nd radiator
Installed the DEI cat convertor wrap
Had a Corvette dealer that's actually familiar with C7 Z's " vacuum " the I.C.

Next test day @ Blackhawk Farms was rained out so on to Road America with the following results :
Session 1 - 78 deg. / 25 min. = water - 220 / oil - 240
Session 2 - 83 deg. / 25 min. = water - 220 / oil - 250
Session 3 - 86 deg. / 25 min. = water - 220 / oil - 250
Session 4 - 90 deg. / 25 min. = water - 220 / oil - 260
Session 5 - 86 deg. / 25 min. = water - 220 / oil - 250 and appeared to run strong / normal all day

It appears that the additions actually made a positive difference although the C7's speed at the end of the 3, rather, long straights was the same as my, also, stock '13 C6 Z06

Just some RA end of straight speeds from some previous vehicles :
'94 and '99 stock Mustang GT's = 120
'08 Turbo Cobalt SS and a '96 LT4 = 130 ( both stock )
'03 Z06 ( stock ) = 140
'13 Z06 ( stock ) = almost 150
'16 Z06 ( stock ) = almost 150

Socko

My 17 gs was regularly getting very close to redline at 151 into 1 whenever i wanted to stay in the throttle till i was scared I was going to hit the redline. (I am pretty sure this is what caused lifter failure on my c5z ls6 so I am just avoiding it in this car) So almost 150 with 200 more hp doesn't seem right.

Mind you i was seeing 217 water and 262 oil with 200 less hp, so may be something there. It didn't seem to matter what ambient was the car stabalized at 217/262 peaks each lap in every session from low 70's to low 90's ambient. The one exception was in the session i ran a split of 233, I saw a 264 oil temp on my faster lap, but at that pace there was too much traffic to really keep the car running at that level.

fleming23

Do you have a Z07, or full stage 3 aero, on the car? The C7 rear wicker and front side splitter extensions create a decent amount of drag, particularly when compared to a stock C6Z. Viper ACR seems to experience same thing with it's massive downforce as it hits an aero wall around 140-150.

What sort of lap times did you run (kink or no kink), how did those compare to those prior cars (especially the C6)? Looking at my data, I touched 153 going into T1 and 152 into T5 with a mostly stock engine (Halltech and x-pipe, but detuned slightly to run a little richer A/F on track).

Bill Dearborn

It sounds like the car ran fine. However, as for top speed at the end of the straights you have to remember the C7Z is carrying around 300 lbs more weight accelerating off the corner which tends to slow the acceleration to some degree and once you get above 100 mph the Stage 3 Aero really starts holding the car back. With my car I feel the acceleration level drop off a fair amount above 140 mph where I didn't notice the same thing with the C6Z. Basically, at the end of long straights I find the C7Z hitting about the same or even lower speeds than the C6Z did on the same straights. For instance, running the uphill Esses and the back straight at Watkins Glen. I can enter at the same speed as I did with the C6Z, can carry the same speeds all the way to the track out point of Turn 4 and be right at the same 142 mph speed as I ran with the C6Z but then the car doesn't accelerate as well going up the back straight. I could hit 158 mph in the C6Z if I tracked out of 4 at 142 but I can only squeeze 151 out of the C7Z. However, overall I have turned a 3 second faster lap running the C7Z than I did running the C6Z.
Bill

ooldguy93

I have no additional OEM / aftermarket aero

The C7 Z feels stronger coming off the corner's than the C6Z

I don't have any comparative lap times as 50 years of being timed was enough. Now its just for " fun " and to run with other as fast or faster cars

Next event is INDY ( same speeds on the straights as Road America ) and then the Arkansas Mile

C5ZEE06

Bill Dearborn

When you say you have no additional OEM Aero do you mean your car is a basic Stage 1 Car with no front splitter and no side skirts?
Bill

ooldguy93

Yes, just a base 1LZ / Stage 1 / M7