The Official C8 Corvette Thread...

Started by Gotta-Qik-C7, April 25, 2018, 07:28:09 PM

GoCougs

Quote from: FoMoJo on October 12, 2019, 07:22:20 AM
That'd be kinda silly. :nutty:

No, not really. I mean, one wouldn't to it just because (most Ford blocks are too short for the longer Chevy rod), but using Chevy rods (or, Chevy-design) is a common thing for Ford stroker kits. 

12,000 RPM

Quote from: GoCougs on October 11, 2019, 11:59:38 PM
The Ford Voodoo is sorta interesting but still can't outperform the ancient LS7, plus the Voodoo is bigger, heavier and more complex, because it was chasing revs. IMO you have to bump up to the $190k 911 GT3 RS to find a better N/A motor (and then we'll see how durable it is) than the GM LT2.
Sure, from a pure, bench racing, engineering brief POV the SBC is superior.

But in real life, 8K+ RPMS >>>> much of what the SBC FR cars have to offer.
Protecctor of the Atmospheric Engine #TheyLiedToUs

CaminoRacer

Quote from: 12,000 RPM on October 12, 2019, 12:24:02 PM
Sure, from a pure, bench racing, engineering brief POV the SBC is superior.

But in real life, 8K+ RPMS >>>> much of what the SBC FR cars have to offer.

Get yourself a Lingenfelter destroked LS7 and enjoyed 8200 rpms all day long.
2020 BMW 330i, 1969 El Camino, 2017 Bolt EV

FoMoJo

Quote from: CaminoRacer on October 12, 2019, 12:40:20 PM
Get yourself a Lingenfelter destroked LS7 and enjoyed 8200 rpms all day long.
Or just get a GT350 :huh:.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

GoCougs

Quote from: CaminoRacer on October 12, 2019, 12:40:20 PM
Get yourself a Lingenfelter destroked LS7 and enjoyed 8200 rpms all day long.

Or, maybe just pursue performance (i.e., size, weight, simplicity, power band) rather than qualitative nonsensical metrics (like RPM).

The Ford Voodoo would've been really something had Ford invested in chasing said performance (i.e., powerband, likely via VVL) rather than RPM.

FoMoJo

Quote from: GoCougs on October 12, 2019, 02:29:48 PM
Or, maybe just pursue performance (i.e., size, weight, simplicity, power band) rather than qualitative nonsensical metrics (like RPM).

The Ford Voodoo would've been really something had Ford invested in chasing said performance (i.e., powerband, likely via VVL) rather than RPM.
You do realize that RPM is where power is, all else being equal, providing you can get there.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

MX793

Quote from: FoMoJo on October 12, 2019, 02:53:39 PM
You do realize that RPM is where power is, all else being equal, providing you can get there.

Only if you can breath at that RPM.  And breathing at that RPM with a fixed cam profile compromises power elsewhere in the RPM band.  High lift is no bueno at lower RPM.  It's why a regular Mustang GT will actually walk a GT350 in a top gear roll-on, despite the 350 having a slightly shorter effective gear ratio.

The Voodoo is a special motor, but Cougs is right.  It's compromised.  It sacrifices low and to some degree midrange power for top end.  With VVL, it would have been more than special.  It would have had power everywhere in the band.  Low end grunt, midrange punch, and top end.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

FoMoJo

Quote from: MX793 on October 12, 2019, 04:59:00 PM
Only if you can breath at that RPM.  And breathing at that RPM with a fixed cam profile compromises power elsewhere in the RPM band.  High lift is no bueno at lower RPM.  It's why a regular Mustang GT will actually walk a GT350 in a top gear roll-on, despite the 350 having a slightly shorter effective gear ratio.

The Voodoo is a special motor, but Cougs is right.  It's compromised.  It sacrifices low and to some degree midrange power for top end.  With VVL, it would have been more than special.  It would have had power everywhere in the band.  Low end grunt, midrange punch, and top end.
GT350s have, traditionally, been road racers vs stoplight racers.  Ford doesn't use VVL.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

MX793

Quote from: FoMoJo on October 12, 2019, 05:51:29 PM
GT350s have, traditionally, been road racers vs stoplight racers.  Ford doesn't use VVL.

Hence why I pointed out not that the regular GT will beat it from a stoplight, but from a roll.  Since effectively all acceleration in a road-race scenario happens from a roll (e.g. accelerating out of a corner), breadth of powerband matters.  Voodoo sacrifices low end breathing for top end, and its powerband lacks breadth as a result.  It's a very old-school solution to big NA horsepower on a limited displacement.  The kind of approach you'd have seen 30+ years ago.

Why Ford (and the rest of the Detroit automakers) seems so afraid of VVL is beyond me.  Every other major auto manufacturer has a VVL system in their parts bin.  A Voodoo fitted with a VVL system like BMW's Valvetronic would have been beyond epic.  8300 RPM and a torque curve that was a plateau from 2500 RPM to 7000 RPM.

But with everyone going to turbochargers and ultimately aiming for electrification, probably not much point investing in it at this point.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

12,000 RPM

Quote from: GoCougs on October 12, 2019, 02:29:48 PM
Or, maybe just pursue performance (i.e., size, weight, simplicity, power band) rather than qualitative nonsensical metrics (like RPM).
Yes, god forbid manufacturers actually focus on making performance cars enjoyable to drive. :rolleyes: If all that matters is performance, why bother with either? A Model 3 Performance will consistently wipe the floor with any ICE car in its price range plus 20%, at least in a straight line, and with ease. Its 2 motors are even smaller and simpler than the SBC. Tesla wins :praise:

And an engine is only one of many components in a car. The SBC is prob 20% smaller + lighter than the Coyote/Voodoo, yet the Rustang has a much lower cowl height, more practical interior/trunk and generally lower curb weights. I'd wager that's why it generally beats the Camaro in head to heads by people who have actually driven them, as well as in sales. Despite costing the same and (barely) outperforming the GT350, the ZL1 is not the performance car measuring stick in its segment; the GT350R is. So you're missing something in your assessment.
Protecctor of the Atmospheric Engine #TheyLiedToUs

FoMoJo

Quote from: MX793 on October 12, 2019, 06:01:03 PM
Hence why I pointed out not that the regular GT will beat it from a stoplight, but from a roll.  Since effectively all acceleration in a road-race scenario happens from a roll (e.g. accelerating out of a corner), breadth of powerband matters.  Voodoo sacrifices low end breathing for top end, and its powerband lacks breadth as a result.  It's a very old-school solution to big NA horsepower on a limited displacement.  The kind of approach you'd have seen 30+ years ago.

Why Ford (and the rest of the Detroit automakers) seems so afraid of VVL is beyond me.  Every other major auto manufacturer has a VVL system in their parts bin.  A Voodoo fitted with a VVL system like BMW's Valvetronic would have been beyond epic.  8300 RPM and a torque curve that was a plateau from 2500 RPM to 7000 RPM.

But with everyone going to turbochargers and ultimately aiming for electrification, probably not much point investing in it at this point.
Investment was likely a key.  Since Ford had developed  VVT, it covered a range of breathing and emissions concerns at a lesser cost than a more complex system which incorporates both VVL an VVT.  The more advanced Ti-VCT, used in the Voodoo engine helps a bit more.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

MX793

Quote from: FoMoJo on October 12, 2019, 06:11:33 PM
Investment was likely a key.  Since Ford had developed  VVT, it covered a range of breathing and emissions concerns at a lesser cost than a more complex system which incorporates both VVL an VVT.  The more advanced Ti-VCT, used in the Voodoo engine helps a bit more.

Cam phasing (VVT) has been around for ages.  Patents for it have been around since the 1920s.  It's been used in production automobiles since 1980.  Ford was using it in the 90s (and they were pretty late to the party).  It also can only do so much to broaden the powerband and optimize breathing.  At the end of the day, you need to be able to also adjust lift and duration to truly widen out the powerband.  Low RPMs prefer lower valve lift for optimal volumetric efficiency and power production.  One of the reasons why 2-valve motors actually work really well for low-RPM grunt.  Higher RPMs want higher lift cams for more valve area.  If you don't have VVL, you need to sacrifice power at one end to make power at the other.  You either have an engine that's a bit of a dog until it gets up to higher RPMs (think classic, high-output 2-stroke powerband that needs to be "on the pipe") or you get an engine that makes gobs of low end but then runs out of steam up top (most of your big-block pushrods).
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

FoMoJo

Quote from: MX793 on October 12, 2019, 06:27:09 PM
Cam phasing (VVT) has been around for ages.  Patents for it have been around since the 1920s.  It's been used in production automobiles since 1980.  Ford was using it in the 90s (and they were pretty late to the party).  It also can only do so much to broaden the powerband and optimize breathing.  At the end of the day, you need to be able to also adjust lift and duration to truly widen out the powerband.  Low RPMs prefer lower valve lift for optimal volumetric efficiency and power production.  One of the reasons why 2-valve motors actually work really well for low-RPM grunt.  Higher RPMs want higher lift cams for more valve area.  If you don't have VVL, you need to sacrifice power at one end to make power at the other.  You either have an engine that's a bit of a dog until it gets up to higher RPMs (think classic, high-output 2-stroke powerband that needs to be "on the pipe") or you get an engine that makes gobs of low end but then runs out of steam up top (most of your big-block pushrods).
If we consider steam engines, it does go back a long way.  Ford's version VCT was developed in the '90s and Ti-VCT came a bit later 2010s.  I'm not disagreeing with you.  Although the Voodoo is a great engine, it could've been better with additional technology.  For what it is, however, at it's price range, nobody's complaining that much.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

12,000 RPM

Protecctor of the Atmospheric Engine #TheyLiedToUs


FoMoJo

Quote from: 12,000 RPM on October 15, 2019, 11:04:39 AM
https://www.caranddriver.com/reviews/a29462701/2020-chevy-corvette-by-the-numbers/

Bravo GM :clap:
Ahh, they finally got it right. :ohyeah:

Anxious to see how the 'R' version does in competition.  Hopefully, they make a street version of the race car.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."

r0tor

It's interesting to see how not that much faster it is around a track... May the front engine vs mid engine vs rear engine debate live on
2011 Jeep Grand Cherokee No Speed -- 2004 Mazda RX8 6 speed -- 2018 Alfa Romeo Giulia All Speed

12,000 RPM

Quote from: r0tor on October 15, 2019, 12:42:14 PM
It's interesting to see how not that much faster it is around a track... May the front engine vs mid engine vs rear engine debate live on

According to C&D it's much, much easier to drive fast. C7 could probably match its laptimes but it's just too scary at the limit

I think the gap between the C7/C8 will grow with the special editions.
Protecctor of the Atmospheric Engine #TheyLiedToUs

GoCougs

Quote from: FoMoJo on October 12, 2019, 02:53:39 PM
You do realize that RPM is where power is, all else being equal, providing you can get there.

Sure - the world's top motor sports - Top Fuel drag racing, F1, MotoGP - begin at 10,000 RPM ;).

But there's no sense in chasing RPM in and of itself, IMO.

GoCougs

Jesus holy hell 0-60 in 2.8 sec and 11.1 sec 1/4 mile, and look at those passing times. It's probably a ringer car, but still, the production car isn't going to be super far off from that.

r0tor

Quote from: 12,000 RPM on October 15, 2019, 01:20:22 PM
According to C&D it's much, much easier to drive fast. C7 could probably match its laptimes but it's just too scary at the limit

I think the gap between the C7/C8 will grow with the special editions.

They say that, yet despite even having better tires its close to a wash.  The Vette has always been jittery from chassis flex but front engine cars are more forgivable when you overcook it so it's easier to push too far.  So now it's easier to drive fast in the C8, but is the mid engine death spin threat limiting them from pushing as hard and turning faster laps?

Is this a case where the C7 was at 10/10 but the C8 is pushed at 9/10
2011 Jeep Grand Cherokee No Speed -- 2004 Mazda RX8 6 speed -- 2018 Alfa Romeo Giulia All Speed

MX793

Quote from: r0tor on October 15, 2019, 12:42:14 PM
It's interesting to see how not that much faster it is around a track... May the front engine vs mid engine vs rear engine debate live on

Official Ring times haven't been released, but it was hinted unofficially that it was a good 20-30 seconds faster than the C7.
Needs more Jiggawatts

2016 Ford Mustang GTPP / 2011 Toyota Rav4 Base AWD / 2014 Kawasaki Ninja 1000 ABS
1992 Nissan 240SX Fastback / 2004 Mazda Mazda3s / 2011 Ford Mustang V6 Premium / 2007 Suzuki GSF1250SA Bandit / 2006 VW Jetta 2.5

12,000 RPM

Quote from: r0tor on October 15, 2019, 01:42:18 PM
They say that, yet despite even having better tires its close to a wash.  The Vette has always been jittery from chassis flex but front engine cars are more forgivable when you overcook it so it's easier to push too far.  So now it's easier to drive fast in the C8, but is the mid engine death spin threat limiting them from pushing as hard and turning faster laps?

Is this a case where the C7 was at 10/10 but the C8 is pushed at 9/10
1 second over a 90 second lap. And overcooking a ~450HP RWD car is going to be an o shit moment no matter where the engine is. The new car has a much bigger tire stagger and a lot of understeer baked into the stock suspension tune. So if they pushed any car less it would have been the C7.
Protecctor of the Atmospheric Engine #TheyLiedToUs

GoCougs

Quote from: r0tor on October 15, 2019, 12:42:14 PM
It's interesting to see how not that much faster it is around a track... May the front engine vs mid engine vs rear engine debate live on

Huh? The C8 is much more capable on a test track. C&D has a lap battle article. 1 second at those speeds on that track is ~122 feet per lab, so per the article, after but 6 laps, the C8 is more than two football fields ahead.

Payman

Quote from: GoCougs on October 15, 2019, 01:41:01 PM
Jesus holy hell 0-60 in 2.8 sec and 11.1 sec 1/4 mile, and look at those passing times. It's probably a ringer car, but still, the production car isn't going to be super far off from that.

C&D and M/T got identical times in different Z51 spec'd cars.

CaminoRacer

C&D's complaints that it's not brash enough is weird. They finally like a Corvette interior and then ding it for being too refined.
2020 BMW 330i, 1969 El Camino, 2017 Bolt EV

565

Quote from: r0tor on October 15, 2019, 01:42:18 PM
They say that, yet despite even having better tires its close to a wash.  The Vette has always been jittery from chassis flex but front engine cars are more forgivable when you overcook it so it's easier to push too far.  So now it's easier to drive fast in the C8, but is the mid engine death spin threat limiting them from pushing as hard and turning faster laps?

Is this a case where the C7 was at 10/10 but the C8 is pushed at 9/10

I'm not sure if the PS4S is actually any stickier than the PSS tires. I recently had the PSS on the G37 and just replaced them with PS4S as they are discontinuing the PSS in the G37's size, and the PSS was probably stickier and more aggressive at the limit, but the PS4S supposedly wears better and has better everyday manners (feels very similar around town). 

In addition I wouldn't be surprised if Chevy toned down the aggressiveness of the GM specific tire compounds for the new PS4s compared to the PSS for the C7s, as people experienced tire cracking in the PSS tires when moving C7s around at cold temperatures.  It is somewhat tolerated for Cup 2s for the Z06 and ZR1, but less okay for the supposedly street PSS tires for daily driver C7s.  It would explain the lower lateral G's achieved by the C8 compared to the C7.

That said, off the self, non GM OEM PSS like the one on my C5 Z06 and the G37 never experienced any cracking even down to very low temps (temps in the teens) in my experience.

I think part of the big complaints of the Z06 ZR1 C7s was their tail happy nature and inability to put their power down, while the C7 grand sport was the sweet spot in the C7 line-up.  I think GM this time shifted to optimize the chassis for the higher HP cars rather than the base cars.  Supposedly this new C8 structure feels extremely solid and stiff, and it can definitely put the power down.  Expect to see some ridiculous performance numbers with the higher HP versions.

CaminoRacer

Quote from: 565 on October 15, 2019, 02:58:17 PM
I think GM this time shifted to optimize the chassis for the higher HP cars rather than the base cars.  Supposedly this new C8 structure feels extremely solid and stiff, and it can definitely put the power down.  Expect to see some ridiculous performance numbers with the higher HP versions.

That's what I'm thinking. Base C8 might not be a huge amount faster than the C7, but I bet the Z06/ZR1 are gonna be insanely quick.
2020 BMW 330i, 1969 El Camino, 2017 Bolt EV

r0tor

Quote from: 12,000 RPM on October 15, 2019, 01:48:51 PM
1 second over a 90 second lap. And overcooking a ~450HP RWD car is going to be an o shit moment no matter where the engine is. The new car has a much bigger tire stagger and a lot of understeer baked into the stock suspension tune. So if they pushed any car less it would have been the C7.

Don't forget about the different tires

https://www.motortrend.com/cars/bmw/m2/2017/2017-bmw-m2-review-long-term-update-4/
2011 Jeep Grand Cherokee No Speed -- 2004 Mazda RX8 6 speed -- 2018 Alfa Romeo Giulia All Speed

FoMoJo

Quote from: GoCougs on October 15, 2019, 01:37:25 PM
Sure - the world's top motor sports - Top Fuel drag racing, F1, MotoGP - begin at 10,000 RPM ;).

But there's no sense in chasing RPM in and of itself, IMO.
If you're going to track it occasionally it is.  Why get a GT350 otherwise.
"The only reason for time is so that everything doesn't happen at once." ~ Albert Einstein
"As the saying goes, when you mix science and politics, you get politics."