Here is your C8 engine...according to GM Authority
07-10-2019, 12:38 AM
#82
Yes it is very small dimensionally and this is probably the primary reason that GM is still using it instead of a more modern engine design on its front engine Corvettes. The smaller dimensions of the LT1 enable the low hood lines of the C7 that are required to achieve the expected Corvette profile. With the C8, engine dimensions are much less critical enabling GM to use any engine design that can meet the C8's performance objectives.
07-10-2019, 12:52 AM
#83
Race Director
07-10-2019, 01:01 AM
#84
Race Director
07-10-2019, 02:15 PM
#85
07-10-2019, 02:17 PM
#86
You have to factor in the weight and volume of the turbos and intercoolers to make that power along with the engine itself.
07-10-2019, 02:36 PM
#87
True and let's not forget the engine's reliability. Porsche provides a 4 year 50K mile warranty on a GT2RS which in most cases will spend the majority of its time on the track. OTOH the cost of the power plant in a GT2RS probably costs a lot more than the MSRP of a well equipped C8. Not comparing a $75K C8 to a $300K GT2, but it is possible to get a huge amount of power out of a small power plant, provided that you have virtually unlimited money to spend.
07-10-2019, 10:57 PM
#90
Good choice, putting a V6 in there would have let down thousands of exhaust sound enthusiasts. Turbo is in the future no doubt, super charger would be easy too
I bet they added port injection to put the coking of valve business to rest
I bet they added port injection to put the coking of valve business to rest
Last edited by awright2009; 07-10-2019 at 10:58 PM.
07-11-2019, 08:04 AM
#91
This is an outstanding post. So true.
There are many of us who adore the Chevrolet V8. So entertaining to watch and listen to the semantic dance that the Euro-wennies engage in when the C7 or C8 Corvette is discussed along with the massive power that is easily realized with GM's simplistic design vs the pip squeak econo box displacement motors that Porsche employs . Seriously, who really wants a 181 cubic inch, 6 cylinder puss motor jacked up with tennie wennie air pumps to comply with European tree hugger, carbon BS mandates and sounds like the neighbors housewife in her Toyota going up the street on her way to Krogers. Forget about it. Man up and stick with a big ball V8.
There are many of us who adore the Chevrolet V8. So entertaining to watch and listen to the semantic dance that the Euro-wennies engage in when the C7 or C8 Corvette is discussed along with the massive power that is easily realized with GM's simplistic design vs the pip squeak econo box displacement motors that Porsche employs . Seriously, who really wants a 181 cubic inch, 6 cylinder puss motor jacked up with tennie wennie air pumps to comply with European tree hugger, carbon BS mandates and sounds like the neighbors housewife in her Toyota going up the street on her way to Krogers. Forget about it. Man up and stick with a big ball V8.
07-11-2019, 08:51 AM
#93
Le Mans Master
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I don't really see the advantages of a smaller displacement, but physically larger engine. While producing big power from small displacement is a fascinating engineering exercise, producing big power from a dimensionally smaller total engine package is no less so.
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07-11-2019, 09:15 AM
#94
Banned Scam/Spammer
Could you imagine owning one of those complicated nightmares outside of its warranty period? All those stats and car magazine hype sound great until you are the guy who is on the hook for the insane service costs that are a part off ownership whether the Porsche defenders of the faith like it or not. Reminds me of the oil leak I had with a 930 I owned back in the day. Estimate was "around" $7,000 to stop the leak. These ownership of this of this vehicle was the most painful financial experience of my life and was absolutely common with these cars. I've seen nothing to date that would make me believe that things are ay different now. Love the post I saw yesterday about a $27,000 Cayman replacement transmission. This is the rotten truth about Porsche ownership that always brings on a violent reaction from import boys.
07-11-2019, 09:48 AM
#95
Le Mans Master
But they are also a dimensionally larger (and probably heavier) package for the same power.
I don't really see the advantages of a smaller displacement, but physically larger engine. While producing big power from small displacement is a fascinating engineering exercise, producing big power from a dimensionally smaller total engine package is no less so.
I don't really see the advantages of a smaller displacement, but physically larger engine. While producing big power from small displacement is a fascinating engineering exercise, producing big power from a dimensionally smaller total engine package is no less so.
07-11-2019, 10:11 AM
#96
Could you imagine owning one of those complicated nightmares outside of its warranty period? All those stats and car magazine hype sound great until you are the guy who is on the hook for the insane service costs that are a part off ownership whether the Porsche defenders of the faith like it or not. Reminds me of the oil leak I had with a 930 I owned back in the day. Estimate was "around" $7,000 to stop the leak. These ownership of this of this vehicle was the most painful financial experience of my life and was absolutely common with these cars. I've seen nothing to date that would make me believe that things are ay different now. Love the post I saw yesterday about a $27,000 Cayman replacement transmission. This is the rotten truth about Porsche ownership that always brings on a violent reaction from import boys.
07-11-2019, 10:34 AM
#97
Melting Slicks
460ft*lbs near 100%volumetric efficiency
460*6000/5252=525bhp
460*7000/5252=613bhp
Every engine is only practical as a forced induction baseline. 2.0L factory engines are doing 500tire dynojet at 28-30psi of boost, thanks in part to E85 pump fuels, so a naturally aspirated engine with 450tire is not so impressive in that comparison except perhaps as a fuel savings bonus (implying that 6L owners are 'cheap' because they want an engine that will produce 450ft*lbs on cheaper 93 octane fuels)
Fuel cost aside, slap on a blower or turbo and 6L becomes more scale to the time. 800hp 1000hp is a legit target for ~6L forced induction pump E85, if only to properly compete with 500hp 2L engine. 2L torque is 450ft*lbs also at ~30psi of boost from 4700rpm to 7,000rpm, similar to 3,600-6,000rpm range 6L has. The baseline supercharged torque for tolerably low rpm is approx 2500-3500rpm, meaning you won't see many supercharger dynographs boasting their pre-2500rpm torque values. So if we take this 2500-3500 range as the "belt driven gap", that is, the difference in 'spool' between supercharged and modern turbocharged onset of boost. That is an expected trade off for not having to belt-drive the forced induction. E85 and modern tech has elevated what small displacement can do, so I only look at 2L engines and consider what 3L must be capable of. And then 4L. And by the time I get to 5L I don't even want to drive the car on the ground anymore.
460*6000/5252=525bhp
460*7000/5252=613bhp
Every engine is only practical as a forced induction baseline. 2.0L factory engines are doing 500tire dynojet at 28-30psi of boost, thanks in part to E85 pump fuels, so a naturally aspirated engine with 450tire is not so impressive in that comparison except perhaps as a fuel savings bonus (implying that 6L owners are 'cheap' because they want an engine that will produce 450ft*lbs on cheaper 93 octane fuels)
Fuel cost aside, slap on a blower or turbo and 6L becomes more scale to the time. 800hp 1000hp is a legit target for ~6L forced induction pump E85, if only to properly compete with 500hp 2L engine. 2L torque is 450ft*lbs also at ~30psi of boost from 4700rpm to 7,000rpm, similar to 3,600-6,000rpm range 6L has. The baseline supercharged torque for tolerably low rpm is approx 2500-3500rpm, meaning you won't see many supercharger dynographs boasting their pre-2500rpm torque values. So if we take this 2500-3500 range as the "belt driven gap", that is, the difference in 'spool' between supercharged and modern turbocharged onset of boost. That is an expected trade off for not having to belt-drive the forced induction. E85 and modern tech has elevated what small displacement can do, so I only look at 2L engines and consider what 3L must be capable of. And then 4L. And by the time I get to 5L I don't even want to drive the car on the ground anymore.
07-11-2019, 10:44 AM
#98
True and let's not forget the engine's reliability. Porsche provides a 4 year 50K mile warranty on a GT2RS which in most cases will spend the majority of its time on the track. OTOH the cost of the power plant in a GT2RS probably costs a lot more than the MSRP of a well equipped C8. Not comparing a $75K C8 to a $300K GT2, but it is possible to get a huge amount of power out of a small power plant, provided that you have virtually unlimited money to spend.
1. @690 SAE HP the GT2RS engine is not puny but it needs a one gallon water tank good for about a ten minute track session. Once the gallon is gone the engine safeguards itself to oblivion.
https://www.pff.de/index.php?thread/...2-rs/&pageNo=1
2. On reliability and warranty you forgot to mention the GT2RS warranty is voided once the car hits the track.
https://files1.porsche.com/filestore...nty-Manual.pdf
This Warranty Does Not Cover:
• Malfunctions in any part or system caused by misuse, modification, alteration, tampering, disconnection, improper or inadequate maintenance, fuel contamination, and, depending upon the powertrain in your Porsche vehicle, the use of gasoline which is leaded or not of the required minimum octane, or the use of diesel fuel exceeding ULSD specifications for sulfur or exceeding 5% methyl ester biodiesel.
• Damage resulting from accident, road hazards (on or off the road), track use or competitive events, acts of God, or other events beyond the control of PCNA
• Malfunctions in any part or system caused by misuse, modification, alteration, tampering, disconnection, improper or inadequate maintenance, fuel contamination, and, depending upon the powertrain in your Porsche vehicle, the use of gasoline which is leaded or not of the required minimum octane, or the use of diesel fuel exceeding ULSD specifications for sulfur or exceeding 5% methyl ester biodiesel.
• Damage resulting from accident, road hazards (on or off the road), track use or competitive events, acts of God, or other events beyond the control of PCNA
It's not unreasonable for the GT2RS engine to touch the 100K replacement mark (without labor) which brings me to a key point:
4. In light of 1. 2. & 3. most GT2RS don't spend most of their time on the track but in the garage, weekend parade or on some car sales portal waiting to be flipped...
Cheers
07-11-2019, 12:17 PM
#99
Yes it is very small dimensionally and this is probably the primary reason that GM is still using it instead of a more modern engine design on its front engine Corvettes. The smaller dimensions of the LT1 enable the low hood lines of the C7 that are required to achieve the expected Corvette profile. With the C8, engine dimensions are much less critical enabling GM to use any engine design that can meet the C8's performance objectives.
Last edited by DevonK; 07-11-2019 at 12:30 PM.
