Motor Trend vid: GT-R NISMO vs Z06

[GoCougs]

What about the F12?

The GT-R murders an F12 - the F12 can't really even beat the lowly base C7. M/T test of C7, F12 and 911 - Laguna Seca times:

C7:  1:38.28
F12:  1:38.04

Some of you turkeys are so riled up with yer hate to realize there ain't a factory front engine/RWD car on the planet that can touch a GT-R on the track.

[68_427]

What about the F12?

Barely quicker than a Z/28 around VIR.  It's not a very good track car from what I've seen.

[SVT666]

Barely quicker than a Z/28 around VIR.  It's not a very good track car from what I've seen.

I was just asking.  I had heard it wasn't a good track car but it has over 700 hp so I thought it might actually give it some trouble.  Apparently not.

[hotrodalex]

I forgive Ferrari for that shortcoming.

[12,000 RPM]

HP doesnt mean much if you can't put it down or stop/turn on a dime, in the context of lap times.

For whatever its worth, the C6 ZR1 was the same ~1.5 seconds off of the NISMO GT-R's time around VIR.

I would still rather have a Cayman GTS/GT4 over all of these cars. This whole lap time obsession is silly and irrelevant... 99% of enthusiasts never see a track let alone go regularly

[MX793]

They've definitely bumped the limits on their engine technology. The Z06 only makes max horsepower once a day.

Not far off.  From the article:

Add to that the Z06's tendency to get hot after one lap and the computer's decision to reduce power to compensate, and you have a lap slower than expected. "It felt faster [than the lap time], but it also didn't feel like it had 650 horsepower," Randy said. "Just not as fast as I expected."

Read more: http://www.motortrend.com/roadtests/coupes/1504_2015_chevrolet_corvette_z06_vs_2015_nissan_gt_r_nismo_comparison/#ixzz3R4GDhjkI

Nearly any road car will overheat in hard track use during extended lapping sessions, but few are spent in a single lap on a <3 mile road course, even in desert heat.  A lowly Corolla could muster more than a single lap without overheating (though it's brakes would likely be shot after two laps), and a high performance car like a Corvette (and especially the Z06) absolutely should not have issues running at least a handful of back-to-back laps on a typical road course without the engine going into limp mode.

[12,000 RPM]

The more I think about it, makes sense that the Z06 has cooling troubles. Its low cowl means its frontal area for cooling is already limited. On top of that, there are airflow requirements not just for the engine, but the intercoolers and aero. And the engine's cooling airflow requirements are probably double that of the LT1 alone. So you have about 30lb of shit in a 5lb bag. Somethin finna buss. GT-R might just have 20lb of shit in a 10lb bag, and on top of that it has a mondo traction advantage. GM painted itself into a corner. Makes sense that they want to go MR next go round, C7 is at the limits of FR street cars.

[SVT666]

They won't go MR next time Sporty. They never will.

[12,000 RPM]

But they promised

[hotrodalex]

The ZL1 has the pre-facelift front end design for more cooling, so the Z06 probably does have a harder time.

[FoMoJo]

They won't go MR next time Sporty. They never will.

Mid-engine with the same lump...so they say.  It'll be half-way there.

[GoCougs]

The more I think about it, makes sense that the Z06 has cooling troubles. Its low cowl means its frontal area for cooling is already limited. On top of that, there are airflow requirements not just for the engine, but the intercoolers and aero. And the engine's cooling airflow requirements are probably double that of the LT1 alone. So you have about 30lb of shit in a 5lb bag. Somethin finna buss. GT-R might just have 20lb of shit in a 10lb bag, and on top of that it has a mondo traction advantage. GM painted itself into a corner. Makes sense that they want to go MR next go round, C7 is at the limits of FR street cars.

It's not cooling per se but the temp of the intake charge. Roots/scroll/screw style superchargers are mounted directly on the engine. This is good for getting the compressed intake charge quickly into the combustion chamber. This is bad for independently/separately cooling the compressed intake charge like that which is typically done with turbocharged engines (i.e., intercooler mounted well away from the engine). Now add DI which forces engines to run at higher CRs and you have a recipe for having to be very careful. ALL supercharged engines suffer from notable heat soak - simply google them (ZR1, ZL1, GT500, especially).

[Eye of the Tiger]

It's not cooling per se but the temp of the intake charge. Roots/scroll/screw style superchargers are mounted directly on the engine. This is good for getting the compressed intake charge quickly into the combustion chamber. This is bad for independently/separately cooling the compressed intake charge like that which is typically done with turbocharged engines (i.e., intercooler mounted well away from the engine). Now add DI which forces engines to run at higher CRs and you have a recipe for having to be very careful. ALL supercharged engines suffer from notable heat soak - simply google them (ZR1, ZL1, GT500, especially).

Failpost. Just all of it. Failfauxinternerpersona. Why bother?

[12,000 RPM]

Failpost. Just all of it. Failfauxinternerpersona. Why bother?

Naw hes rite

Blame Joe HELOC, the driver of this market, who can only understand HP and bench racing specs

[SVT666]

It's not cooling per se but the temp of the intake charge. Roots/scroll/screw style superchargers are mounted directly on the engine. This is good for getting the compressed intake charge quickly into the combustion chamber. This is bad for independently/separately cooling the compressed intake charge like that which is typically done with turbocharged engines (i.e., intercooler mounted well away from the engine). Now add DI which forces engines to run at higher CRs and you have a recipe for having to be very careful. ALL supercharged engines suffer from notable heat soak - simply google them (ZR1, ZL1, GT500, especially).

The 662hp GT500 had no such problems.

[MX793]

The 662hp GT500 had no such problems.

Run hard enough for an extended time, yes, the GT500 would suffer from some heat soak.  I'm not aware of any production car, including the Corvette ZR-1 (running the LT-4s predecessor engine) that seems quite so prone to it as the new Z06.

[SVT666]

Run hard enough for an extended time, yes, the GT500 would suffer from some heat soak.  I'm not aware of any production car, including the Corvette ZR-1 (running the LT-4s predecessor engine) that seems quite so prone to it as the new Z06.

The 500 and 550 hp versions were very prone to heat soak, but not once did I read anything about the 662 hp version having that problem. The brakes were the problem.

[MX793]

A quick Google search was able to turn up some heat soak complaints from owners of '13-'14 GT500s.  Particularly owners in the southwestern US.  They aren't nearly as prone as the earlier models, but they are not completely immune.

[hotrodalex]

Nah Mustangs are perfect.

[GoCougs]

The 662hp GT500 had no such problems.

C'mon, man, by the very definition of how a Roots/screw/scroll supercharger works there will be heat soak issues with ANY such supercharged engine.

[GoCougs]

Run hard enough for an extended time, yes, the GT500 would suffer from some heat soak.  I'm not aware of any production car, including the Corvette ZR-1 (running the LT-4s predecessor engine) that seems quite so prone to it as the new Z06.

To be more precise, the theory is the ECU is pulling back timing (I'm still not convinced however) to prevent detonation not heat soak per se (which is a standalone/non ECU issue - power loss due to heated (and less dense = less O₂) intake charge). I also can't think of any other S/C engine that is DI - definitely not GT500 or Hellcat.

[MX793]

To be more precise, the theory is the ECU is pulling back timing (I'm still not convinced however) to prevent detonation not heat soak per se (which is a standalone/non ECU issue - power loss due to heated (and less dense = less O₂) intake charge). I also can't think of any other S/C engine that is DI - definitely not GT500 or Hellcat.

If anything, I'd expect DI to help mitigate detonation, making non-DI cars more likely to have issues.  And Audi has had a supercharged DI engine for a few years now in the S4.  There are also some DI turbocharged engines out there with top-mounted intercoolers (Mazda's DISI engine in their Mazdaspeed cars and Subaru's FA engine in the WRX).  None of these have the tendency to have their power cut after so little hard running.

[hotrodalex]

Sounds like a few aftermarket tuners have gotten rid of the issue.

[MX793]

Sounds like a few aftermarket tuners have gotten rid of the issue.

You shouldn't have to go aftermarket to get your brand new super-vette to be able to run hard for more than 2 minutes without the power being cut.

[hotrodalex]

You shouldn't have to go aftermarket to get your brand new super-vette to be able to run hard for more than 2 minutes without the power being cut.

Well hopefully GM will fix it.

[GoCougs]

Sounds like a few aftermarket tuners have gotten rid of the issue.

Just like the aftermarket "solved" the issue of putting a bigger cam into the LS7 .

GM knows more about the LT4 and its limitations esp. WRT a 10 year/100,000 warranty and emissions than all the tuners put together.

[Gotta-Qik-C7]

You shouldn't have to go aftermarket to get your brand new super-vette to be able to run hard for more than 2 minutes without the power being cut.

+1,000

[GoCougs]

If anything, I'd expect DI to help mitigate detonation, making non-DI cars more likely to have issues.  And Audi has had a supercharged DI engine for a few years now in the S4.  There are also some DI turbocharged engines out there with top-mounted intercoolers (Mazda's DISI engine in their Mazdaspeed cars and Subaru's FA engine in the WRX).  None of these have the tendency to have their power cut after so little hard running.

IMO that would only occur if CR wasn't raised along with DI. Since typically CR is raised, it decreases the "safe" operating windo, and in particular, margin of safety when something doesn't go exactly to plan.

[12,000 RPM]

Sounds like a few aftermarket tuners have gotten rid of the issue.

Yea and we will see how those tuned engines fare in the long run

[Gotta-Qik-C7]

Yea and we will see how those tuned engines fare in the long run

Well that lets GM off the hook too! Any mods void the warranty!