[Chris V]

Originally Posted by TrackClub

Thanks Chris. I've asked this question of Jeff Cook who posted a record lap just above. He seems to think those cars run like champs even in consecutive stints in just about any ambient. But he says G3Rs get greasy after 15mins and pace evaporates.

In any case, since John drove one and experienced reduced speed i will ask him for his thoughts directly.
He is such an amazing driver and a super helpful guy to boot!

Thanks for the source: appreciate it! Cheers!

Ps what was the the ambient at NCM when you ran there?

It was hot - last year it was Friday on One Lap. In the 80’s IIRC.

John was driving Alan’s car for reference. The data shows the increasing oil temps and corresponding lower top speeds. Maybe not exactly as slow as an SS, but a significant trail off.

[Aliveguy5]

ZL1's do heat soak after a few laps as that little blower is trying very hard. However the car still has a ton of power and grip despite the heat soak.

[TrackClub]

Generally speaking any car will be subject to slower laptimes in high vs low ambient. No motor and no tire loves excessive heat. That's a given. Even NASCAR race cars experience a fall off sometimes after a few laps.
Because of tires.

It is plausible to assume that a blown car will be more sensitive to heat: no question. But what i have heard a lot of here is 650hp/tg can fry rears after 15mins which makes perfect sense to me. And after the rears get fried exits will suffer because of loss of traction. When exits suffer so will top speed. From all accounts thus far THIS seems like the biggest culprit (based on actual feedback).

Perhaps there is an additional culprit: motor heat soak.
But this is almost never the ONLY culprit. In any case, the question then is how much power is lost. Is it 50hp or 150hp? The former would be rather mild. The latter severe and easily felt by a driver. And i would expect many threads of complaints on this forum (as it happened with a Z06), especially given the car has been out for a while now.

I also recall Motor Trend guys wasting 5 or 6 sets of rear tires without managing to overheat a ZL1. But to be fair i have no idea what they were doing exactly, or how.

Anyhow, just my musings here. I will be smarter if i manage to run a ZL1 hopefully this July.

Chris do you have actual lap times for John's run? Is Alan a forum member? Sorry cant connect the dots as to who he is. Thanks!

[Deakins]

I bet if you data logged the car you would absolutely see power being lost due to the supercharger generating heat. While the system GM uses to try and avoid many of the problems works you simply cannot avoid physics.

[TrackClub]

Originally Posted by Deakins

I bet if you data logged the car you would absolutely see power being lost due to the supercharger generating heat. While the system GM uses to try and avoid many of the problems works you simply cannot avoid physics.

Agree. I suppose physics also play a role roasting tires with 650 of torque

The question is: is the loss noticable and the car turning into an SS after 15mins, or is it mild in which case: who cares??? Just want to get to the bottom of this wrt effects specific to zl1.

[TrackClub]

FYI: i have received a response from Mr Rocket himself and he assured me that the ZL1 1LE did a good job managing heat.

He has also pointed out that ANY motor (NA, turbo, or SC) will suffer to some extent due to heat. Albeit SC will be most prone for obvious reasons.

Moreover, he rightly reminded me that pace will vary based on changing track conditions, tire wear, changing braking performance, driver fatigue and other factors - not just motor heat levels.

So now that we have feedback from an incredibly accomplished pro, perhaps we can move back to my original OP: has anyone upgraded from an SS 1LE and for whatever reason regreted it? At this stage, apart from forking out more cash, i will assume the answer is: NO.

[Mountain]

Originally Posted by TrackClub

FYI: i have received a response from Mr Rocket himself and he assured me that the ZL1 1LE did a good job managing heat.

He has also pointed out that ANY motor (NA, turbo, or SC) will suffer to some extent due to heat. Albeit SC will be most prone for obvious reasons.

Moreover, he rightly reminded me that pace will vary based on changing track conditions, tire wear, changing braking performance, driver fatigue (or error) and other factors - not just motor heat levels.

So now that we have feedback from an incredibly accomplished pro, perhaps we can move back to my original OP: has anyone upgraded from an SS 1LE and for whatever reason regreted it? At this stage, apart from forking out more cash, i will assume the answer is: NO.

I would say, these two are likely the major two to cause the most drop in lap time within a 20-25 min session in general and especially if it's hot out.

[Dave-ROR]

Originally Posted by TrackClub

FYI: i have received a response from Mr Rocket himself and he assured me that the ZL1 1LE did a good job managing heat.

He has also pointed out that ANY motor (NA, turbo, or SC) will suffer to some extent due to heat. Albeit SC will be most prone for obvious reasons.

Moreover, he rightly reminded me that pace will vary based on changing track conditions, tire wear, changing braking performance, driver fatigue and other factors - not just motor heat levels.

So now that we have feedback from an incredibly accomplished pro, perhaps we can move back to my original OP: has anyone upgraded from an SS 1LE and for whatever reason regreted it? At this stage, apart from forking out more cash, i will assume the answer is: NO.

I'm interested to hear your thoughts if you do go ZL1. I've thought about switching myself (to either a ZL1 or a ZLE).

Given that we are both track focused your feedback if you do make the switch will be interesting to read.

Once I finish these 2 salvage rebuilds (and assuming I don't buy more which is a bad bet to make), plus my champ car build/swap, plus the new HPDE BRZ build, plus the MR2 track build..

shit let me know in 2021 what you think ha

[TrackClub]

If GM doesnt change SS power for 2020MY i will likely go with a ZL1 and will defo post my impressions here.
But if they do, i will have to think about it a bit deeper, as the price difference is not insubstantial: easily $20+G where i live. So we shall see...

[Stephen12ZL1]

watch lightning lap of the ZL1 vs the SS 1LE...https://youtu.be/fOtzsKRDgCw

https://youtu.be/N-_RIatNPb0

https://youtu.be/7pzz_E9fG88

Lots of data points to see...HP matters...

[TrackClub]

Yep HP matters for sure. So do sticky tires...
It was fun to watch those vids again - thx!

[ninetres]

Every few months I find myself looking at Kyrpton Green SS 1LEs to trade my ZL1 for. Smaller payment and I just Love that damn color. And 90% as capable on track IMO.

[Badgerbimmer]

Originally Posted by ninetres

Every few months I find myself looking at Kyrpton Green SS 1LEs to trade my ZL1 for. Smaller payment and I just Love that damn color. And 90% as capable on track IMO.

Eh. Depends on the track. Road America, no. Blackhawk Farms, yes.

[Chris V]

Originally Posted by TrackClub

Generally speaking any car will be subject to slower laptimes in high vs low ambient. No motor and no tire loves excessive heat. That's a given. Even NASCAR race cars experience a fall off sometimes after a few laps.
Because of tires.

It is plausible to assume that a blown car will be more sensitive to heat: no question. But what i have heard a lot of here is 650hp/tg can fry rears after 15mins which makes perfect sense to me. And after the rears get fried exits will suffer because of loss of traction. When exits suffer so will top speed. From all accounts thus far THIS seems like the biggest culprit (based on actual feedback).

Perhaps there is an additional culprit: motor heat soak.
But this is almost never the ONLY culprit. In any case, the question then is how much power is lost. Is it 50hp or 150hp? The former would be rather mild. The latter severe and easily felt by a driver. And i would expect many threads of complaints on this forum (as it happened with a Z06), especially given the car has been out for a while now.

I also recall Motor Trend guys wasting 5 or 6 sets of rear tires without managing to overheat a ZL1. But to be fair i have no idea what they were doing exactly, or how.

Anyhow, just my musings here. I will be smarter if i manage to run a ZL1 hopefully this July.

Chris do you have actual lap times for John's run? Is Alan a forum member? Sorry cant connect the dots as to who he is. Thanks!

I don't know what the best lap time was - but the car lost 7 mph on the straight at NCM once oil temps got over 270. There was a 2:12 in one of the sessions. It doesn't overheat, or make you shut it down and limp home, but 7 mph is a significant drop off in performance.

The fastest laps will be the first two or maybe three. You'll be able to keep running it all session, but don't expect to go faster. Tires of course factor into that, as does fatigue and everything else on a track day.