Vauxhall's V8s compared.
Discussion
Hello. This is my first post. The table compares the key features of Vauxhall's V8 equipped cars:
||=Model=||=Power=||=Torque=||=Weight=||=Gears=||=Diff=||=List=||=Qty=||=Accel'=||=Value=||
||= =||=PS=||=Nm=||=Kg=||= =||= =||=£=||= =||= =||= =||
|| 04 CV8 || 333 || 475 || 1658 || MM6 || 3.46 || 28,650 || 250 || 1.00 || 1.00 ||
|| 04 VXR || 387 || 510 || 1658 || MM6 || 3.70 || 35,995 || 50 || 1.15 || 0.91 ||
|| 05 CV8 || 354 || 500 || 1695 || MM6 || 3.46 || 29,895 || 100 || 1.03 || 0.99 ||
|| 05 CV8 || 354 || 500 || 1695 || M12 || 3.46 || 29,895 || 0 || 1.20 || 1.15 ||
|| 05 VXR || 398 || 530 || 1688 || M12 || 3.46 || 36,995 || 650 || 1.27 || 0.99 ||
|| VXR500 || 500 || 677 || 1688 || M12 || 3.46 || 35,995 || 50 || 1.63 || 1.30 ||
|| VXR8 || 417 || 550 || 1812 || M12 || 3.70 || 35,105 || 250 || 1.32 || 1.08 ||
From this we can calculate a "figure of merit" acceleration, which compares the car's mid range acceleration or "shove in the back". This is calculated from (Torque x 2nd gear)/Weight. Further, we can calculate a value for money figure of merit from (Torque x 2nd gear)/(Weight x price). Both are "normalised" to the figures for the original 04 CV8 Monaro. Final drives have been further added to the equations. So both figures indicate how much better or how much better value for money the cars are compared to the 04 CV8.
The 05 CV8 appears twice with the two different ratio sets. The MM6 is what actually has been supplied in the UK and M12 is what the UK brochure quoted and was sold in Australia. These are the under bonnet VIN plate transmission codes. Many in this forum appear unaware of this difference which makes a big difference to how the cars perform. 2nd gear is chosen as this is the most different between the sets and the most useful gear on the road, roughly spanning the legal limit and free from the transient effects of 1st gear:
||=GM Vin=||=GM=||=Tremec=||=Ratios=||= =||= =||= =||= =||= =||
||=Designation=||=Part no=||=Part no=||=1=||=2=||=3=||=4=||=5=||=6=||
|| MM6 || 92067136 || TUET2100 || 2.66 || 1.78 || 1.30 || 1.0 || 0.74 || 0.50 ||
|| M12 || 92155485 || TUET2066 || 2.97 || 2.07 || 1.43 || 1.0 || 0.84 || 0.57 ||
The VXR8 may have a different code as 1st is 3.01. Other ratios as above.
Not surprisingly the VXR500 is the clear winner in terms of both outright performance and value for money. Behind this the cars are much more grouped together and the difference the gearbox makes to the CV8 is clear. The 05 Ozy cars are actually quicker than the 04 VXR in the low to middling speed ranges where torque is important. Only at high revs does power matter and the 04 VXR would claw back ground. The Ozy CV8 is much closer to the 05 VXR.
In terms of value for money the 05 CV8 is significantly lifted with the M12 ratio set. The VXR would then be only 6% quicker but cost 24% more. Also long term maintenance costs appear a lot higher with the VXR due to the much higher spec cycle parts. The 04 VXR is the clear looser.
Pitty the 05 CV8 didn't get the improvement the Oz cars did. So as usual in the UK we pay more and get an inferior product....
Please correct me on any errors in the data.
||=Model=||=Power=||=Torque=||=Weight=||=Gears=||=Diff=||=List=||=Qty=||=Accel'=||=Value=||
||= =||=PS=||=Nm=||=Kg=||= =||= =||=£=||= =||= =||= =||
|| 04 CV8 || 333 || 475 || 1658 || MM6 || 3.46 || 28,650 || 250 || 1.00 || 1.00 ||
|| 04 VXR || 387 || 510 || 1658 || MM6 || 3.70 || 35,995 || 50 || 1.15 || 0.91 ||
|| 05 CV8 || 354 || 500 || 1695 || MM6 || 3.46 || 29,895 || 100 || 1.03 || 0.99 ||
|| 05 CV8 || 354 || 500 || 1695 || M12 || 3.46 || 29,895 || 0 || 1.20 || 1.15 ||
|| 05 VXR || 398 || 530 || 1688 || M12 || 3.46 || 36,995 || 650 || 1.27 || 0.99 ||
|| VXR500 || 500 || 677 || 1688 || M12 || 3.46 || 35,995 || 50 || 1.63 || 1.30 ||
|| VXR8 || 417 || 550 || 1812 || M12 || 3.70 || 35,105 || 250 || 1.32 || 1.08 ||
From this we can calculate a "figure of merit" acceleration, which compares the car's mid range acceleration or "shove in the back". This is calculated from (Torque x 2nd gear)/Weight. Further, we can calculate a value for money figure of merit from (Torque x 2nd gear)/(Weight x price). Both are "normalised" to the figures for the original 04 CV8 Monaro. Final drives have been further added to the equations. So both figures indicate how much better or how much better value for money the cars are compared to the 04 CV8.
The 05 CV8 appears twice with the two different ratio sets. The MM6 is what actually has been supplied in the UK and M12 is what the UK brochure quoted and was sold in Australia. These are the under bonnet VIN plate transmission codes. Many in this forum appear unaware of this difference which makes a big difference to how the cars perform. 2nd gear is chosen as this is the most different between the sets and the most useful gear on the road, roughly spanning the legal limit and free from the transient effects of 1st gear:
||=GM Vin=||=GM=||=Tremec=||=Ratios=||= =||= =||= =||= =||= =||
||=Designation=||=Part no=||=Part no=||=1=||=2=||=3=||=4=||=5=||=6=||
|| MM6 || 92067136 || TUET2100 || 2.66 || 1.78 || 1.30 || 1.0 || 0.74 || 0.50 ||
|| M12 || 92155485 || TUET2066 || 2.97 || 2.07 || 1.43 || 1.0 || 0.84 || 0.57 ||
The VXR8 may have a different code as 1st is 3.01. Other ratios as above.
Not surprisingly the VXR500 is the clear winner in terms of both outright performance and value for money. Behind this the cars are much more grouped together and the difference the gearbox makes to the CV8 is clear. The 05 Ozy cars are actually quicker than the 04 VXR in the low to middling speed ranges where torque is important. Only at high revs does power matter and the 04 VXR would claw back ground. The Ozy CV8 is much closer to the 05 VXR.
In terms of value for money the 05 CV8 is significantly lifted with the M12 ratio set. The VXR would then be only 6% quicker but cost 24% more. Also long term maintenance costs appear a lot higher with the VXR due to the much higher spec cycle parts. The 04 VXR is the clear looser.
Pitty the 05 CV8 didn't get the improvement the Oz cars did. So as usual in the UK we pay more and get an inferior product....
Please correct me on any errors in the data.
Edited by granada203028 on Sunday 1st February 17:02
Edited by granada203028 on Sunday 1st February 17:02
granada203028 said:
Pitty the 05 CV8 didn't get the improvement the Oz cars did. So as usual in the UK we pay more and get an inferior product....
Welcome. I trust all your facts are accurate. It's just that I've been under the impression that there were only 15 VXR 500's produced. If I had known they were that common..... 
Still at least I got VFM.
I wonder, are you the sort of chap who could answer this. Who makes the best power to weight production engine? Actually anyone can answer it. I was just thinking that an all alloy V8 might not weigh a lot more than some smaller capacity iron blocks. Forget FI for this.
Still at least I got VFM. I wonder, are you the sort of chap who could answer this. Who makes the best power to weight production engine? Actually anyone can answer it. I was just thinking that an all alloy V8 might not weigh a lot more than some smaller capacity iron blocks. Forget FI for this.
broadslide said:
Welcome. I trust all your facts are accurate. It's just that I've been under the impression that there were only 15 VXR 500's produced. If I had known they were that common..... Still at least I got VFM.
I wonder, are you the sort of chap who could answer this. Who makes the best power to weight production engine? Actually anyone can answer it. I was just thinking that an all alloy V8 might not weigh a lot more than some smaller capacity iron blocks. Forget FI for this.
Still at least I got VFM. I wonder, are you the sort of chap who could answer this. Who makes the best power to weight production engine? Actually anyone can answer it. I was just thinking that an all alloy V8 might not weigh a lot more than some smaller capacity iron blocks. Forget FI for this.
There were only 15 'official' cars, yes.
gsxr750steve said:
If only I was clever enough to work that out I'd be able to show that since I only paid £26,995 for my 05 VXR and not £36,995 that I win the smiles per £ calculation.....(and since mine is Red then it also would prove that Red is the fastest colour as asked above....)
Feel a bit sorry for the poor sods who paid circa £37k for theirs. Heard VX jobbed off all remaining VXR stock to the trade for £25k meaning used values have nosedived. Just steeling myself for when they shaft me and do likewise to the VXR8. Must confess I suspected it would happen when I bought the thing but not regretted it one iota.
broadslide said:
I wonder, are you the sort of chap who could answer this. Who makes the best power to weight production engine? Actually anyone can answer it. I was just thinking that an all alloy V8 might not weigh a lot more than some smaller capacity iron blocks. Forget FI for this.
In this case you'll be looking towards bike based engines or manufacturers. Honda and Yamaha make some storming engines - the 2litre unit from the current Civic type R is stunning (when kept on cam). these engines have very short (relatively speaking) strokes that reduces torque output but makes it considerably easier to rev higher. On an N/A engine to get power you need to rev.
Although far from a production engine, my last car had a 1.8 engine chucking out about 220-230 bhp N/A. It actually had a noticably lower torque output than the production cars producing 120bhp but it could produce this lower torque at 9k rpm v's 6.5k red line in the production units.
Problem is that power is used on the track and torque is used on the road
My only problem with this type of analysis is although it's fun, it's also based on peak figures which are pretty meaningless.
Normally the higher powered BHP car would be the one to go for but what this doesn't tell you is how peaky the power curve is as often happens with funky aggressive cams.
Also, as soon as you compare a N/A car and a FI car things get even more complex - esp when considering turbocharged installs. The FI car will generally produce a distorted power curve when compared with the N/A as the FI engine will more often than not perform much better when at lower RPM which isn't alway clear from the peak figures.
The only way you can compare two completely different setups is really look at the area under the torque/power graph between the engine RPM's in the gear you are evaluating.
Normally the higher powered BHP car would be the one to go for but what this doesn't tell you is how peaky the power curve is as often happens with funky aggressive cams.
Also, as soon as you compare a N/A car and a FI car things get even more complex - esp when considering turbocharged installs. The FI car will generally produce a distorted power curve when compared with the N/A as the FI engine will more often than not perform much better when at lower RPM which isn't alway clear from the peak figures.
The only way you can compare two completely different setups is really look at the area under the torque/power graph between the engine RPM's in the gear you are evaluating.
Thanks guys for your comments. I will post another discussion shortly with the story of how I came to know about the CV8 differences, the hard way. For the record here is the VXR8 auto and the Australian spec 05 CV8 auto.
Model____Power__Torque__Weight__Gears__Diff____List__Qty__Accel'__Value
VXR8_auto_417____550____1850______?____3.27__36,505_?___1.30____1.02
CV8_auto__354____500____1698______?____3.46__29,895_0___0.94____0.91
Obviously if you bought a later car and got a decent discount this effects the comparisons hugely. When the 05s were launched 04 CV8s were discounted 2K. When the VXR500 came out both the 05 CV8 and VXR were discounted 6K. Presumably if there is any left they are giving them away now...
The drive by noise test is the reason I have been told to.
In relative terms the LS1 and LS2 engines are pretty flexible without strong power bands or caminess. So peak torque is a good guide to road performance magnified of course by the gear ratios. The LS2 specific power is higher and peak torque occurs at 4400 rpm rather than 4000. So at low revs you might expect the engines to be even closer.
What are the VXR8 autos like? Is it a proper torque converter/epicyclic transmission? Presumably not a robotised T56. Even a T1000 might struggle...
I think the VFM calculation for all cars would put modern turbo diesels at the top. Half the price of the Monaro, lighter, many making 300 - 400Nm.
Model____Power__Torque__Weight__Gears__Diff____List__Qty__Accel'__Value
VXR8_auto_417____550____1850______?____3.27__36,505_?___1.30____1.02
CV8_auto__354____500____1698______?____3.46__29,895_0___0.94____0.91
Obviously if you bought a later car and got a decent discount this effects the comparisons hugely. When the 05s were launched 04 CV8s were discounted 2K. When the VXR500 came out both the 05 CV8 and VXR were discounted 6K. Presumably if there is any left they are giving them away now...
The drive by noise test is the reason I have been told to.
In relative terms the LS1 and LS2 engines are pretty flexible without strong power bands or caminess. So peak torque is a good guide to road performance magnified of course by the gear ratios. The LS2 specific power is higher and peak torque occurs at 4400 rpm rather than 4000. So at low revs you might expect the engines to be even closer.
What are the VXR8 autos like? Is it a proper torque converter/epicyclic transmission? Presumably not a robotised T56. Even a T1000 might struggle...
I think the VFM calculation for all cars would put modern turbo diesels at the top. Half the price of the Monaro, lighter, many making 300 - 400Nm.
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