5thGear

We had the chance to join Porsche club at Spring Mountain this past weekend on the Mansell 3.4 mile course. We had three Z06’s in our group. Mine is the 2017 Z07 M7 joined by two of my friends that had 2015 Z07A8 and 2016 Z06 M7. All stock expect Ron Davis radiator on the 2015 Z07 A8.
Ambient was just shy of 90F although it felt even warmer. Ambient reached 99F just 10 miles outside of the track and we could feel a hot air blowing around the track. Each session was 30 minutes which is pretty long.We decided to compare cooling’s between the 3 cars since we were running within a second of each other. All on the fast side of advance group. We observed the following:
2015 Z07 A8 (with Ron Davis radiator)

• As expected, the A8 engine was the first to overheat and it also lost power steering within 5 to 6 laps.
• In order to complete 5 laps. It needed to run in manual and shift at no more than 5K rpms.
• After 15 minutes oil went pass 300F, coolant 260F, and it goes to limp mode.

2016 Z06 (stock cooling)

• It did complete 20 minutes but eventually did overheat.
• Oil 300F and water 260F.
• It did lose some power as the temps started to climb. Earlier in the session it would stay close to my 2017 but later it didn’t have the same power on the straight.

2017 Z07 (stock cooling which included secondary radiator/updated supercharger cooling)

• It completed all 30 minutes sessions all day.
• Coolant mostly stayed around the 225F and oil around 275 at the end of the session shifting just shy or red line.
• The car pulled strong even on the last lap of 30 minutes session. No power loss.
• It didn’t overheat and it didn’t lose power steering as occurred in the 2015 and 2016 Z06’s. I don’t know if there is any change that is preventing power steering from overheating on 2017.

We ran into one of Spring mountain instructors and he stayed with us for some tips. He also advised my friends to run the heater at full blast and point the vents towards the open windows to extract hot air out of the engine. This actually helped and my friends were able to push the cars more and stay a little longer in the sessions. Here is the data from all 3 cars. The instructor also advised me to hold second gear through the technical sector which was hard acceleration in second, braking lightly to point the car then again hard acceleration. Still my car didn’t overheat. My temps reach 239 coolant at the end of 30 minutes session with holding the 2nd gear for longer times and oil 280F. I could run 3rd gear in the technical sector and keep my temp at 225F/270 without losing much on lap times.
It seems that the 2017 updates are legit. No power loss, no limp mode, no overheating, and no power steering loss in comparison with 2015 Z06 and 2016 Z06 same day, same session and within a second of each other. I cannot make a general statement since driving style, tracks and ambient could have different results but these were my observations for this comparison.
Both my friends will be installing GM power steering ducts and my friend with 2016 M7 will be ordering the secondary radiator. Not sure if they would do the supercharger updates since cost is high.
Below data starting with 2015 that managed 4 laps followed by 2016 which ran a little over 20 minutes then my 2017 the full 30 minutes.

rw99

Great post, thanks for sharing.


Rich

Fastmikefree

Excellent! Very instructive. Got my second radiator installed under warranty on my 2016. Waiting for summer to see if that improve the situation and by how much since no update on the SC compare to 2017 models.

2017ZO6

I trust GM and the improved cooling on the 2017. I own a 2017 ZO6 and couldn't be happier.

davepl

So far as I can tell, then, the only cooling improvements are actually the aux cooling and the revised timing tables that pull less timing. Another potential piece of evidence for my "timing retard exacerbates the overheating" theory.

Too bad the 2016 didn't have the aux cooler, that'd be a revealing comparison too.

BMadden

Glad to hear this. My '17 Z06 will be here in mid-April and I can't wait.

5thGear

I am sure that the revised intercooler bricks and taller lid is a big factor for maintaining power through out the complete session.


I have a feeling that more things were addressed in 2017 than we know. After all, there was never an official release detailing everything that was addressed in MY 2017

JoesC5

I know that you said the 2015 and the 2017 were Z07's and the 2016 was a Z06. Looking at the photo, I see that all three have the Z07 rear spoiler with the clear center.

spearfish25

Thanks for the info. Very worthwhile comparison. I agree that a 2016 M7 with aux radiator vs a 2017 M7 would be particularly interesting to see how SC changes alone play a role.

All the same guys will eventually post here. I'll go first. My 2016 M7 with aux radiator has never overheated. In 94F ambients at Sebring, I've never seen a coolant temp above 230F or oil above 260F. My power steering has never overheated and my car has never had noticeable power loss by the end of a session. It just runs very low on fuel .

JoesC5

So, you are saying that the GM engineers had no idea what they were doing when they added the tilted bricks and the taller lid on the 2017's as there is no problem with the 2015's and 2016's requiring that particular change be done for the 2017's.

dar02081961

Hugh? How did you get that from what he said?

fleming23

Just ignore him, he is still salty over his C6Z valve guide issue.

5thGear

Thats correct. The two white cars are Z07. The silver is stage 2 Z06 and added clear center.

5thGear

This was a positive experience for all three of us that were out there. We all enjoyed our cars and even my friends learned how to manage the heat better based on what we learned from Spring mountain instructor. Obviously the 2017 handled the heat issue better but there are fixes that can improve 2015 and 2016 cars if needed.

TXshaggy

How did you get the aux radiator installed under warranty? I've got a 2016 and have been considering an install and it'd be great to have the warranty take care of it!

dar02081961

Great comparison and much appreciated.

Does the 2017 come stock with the aux radiator? or is it an option?

Wondering how the 17 and 16 compare when both have the aux radiator? Or when both are without the aux radiator (if 17's normally come that way).

Patastic

this, how did you get 2nd rad under warranty?

5thGear

All 17's M7 come stock with secondary radiator and upgraded intercoolers bricks as well as the tall supercharger lid.
There is no doubt that the secondary radiator is very effective. Another friend of mine with 2016 added a secondary radiator and his coolant temps at the track dropped and ran almost same temp as my 2017.
Still mine seems to have a little more power at the end of session most likely due to supercharger updates on 2017.

spearfish25

It's unfortunate the ignore list doesn't work on my mobile tapatalk app.

CFHay

If I recall correctly Tadge said that some 15 & 16 cars would run a couple cylinders hotter and overheat so the updated 2017 cars with the better intercooler would prevent that from happening. If it weren't for that damn pedestrian **** for the EU market the cars would have had these from the beginning lol.