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Just saying, the difference between the current stock Sting Ray & the z51 Sting Ray diff's is small : 2.41 vs 2.73 (Z51). This small difference in the ratios results in slightly better performance for the z51 & but 2-3 mpg less, with the same trans ratios.
I suspect the trans ratios for the stock vs z51 Ray will be the same so a much higher (numerically) rear end on the z51 c-8. could result in a slightly quicker car than the stock version,
For the C8 the difference is 3.62 vs 3.80, giving the Z51 pkg. equipped car a very minute 0.18 mechanical advantage which is so small that it is barely worth mentioning.
^^
If you were right it would be a significant difference. BUT at Carlisle there was a GM sign saying the dif ratio was 5.17:1! I have said in a number of posts why that could make sense! It depends on the Trans gear ratios!
Our Nissan Murano had the same dif ratio, 5.17:1! That was for their CVT trans! For the C8 could be related to the GM DCT patent that says it uses fewer gear pairs than a conventional 8 speed DCT would require!
^^
If you were right it would be a significant difference. BUT at Carlisle there was a GM sign saying the dif ratio was 5.17:1! I have said in a number of posts why that could make sense! It depends on the Trans gear ratios!
Our Nissan Murano had the same dif ratio, 5.17:1! That was for their CVT trans! For the C8 could be related to the GM DCT patent that says it uses fewer gear pairs than a conventional 8 speed DCT would require!
A 0.18 ratio difference is what we know at this point and is not even in the realm of being "significant". Transmission gear ratios are not a factor if they are the same which is obvious.
^^^
We DON'T know the values you state. When I asked where they came from on another thread was told that was "just a guess!" Folks at Carlisle said they saw a sign! Quoting (there was another similar post
On the c7, the rear ratio difference between the stock Ray vs the z51 is 2.41 vs 2.73. Not a big difference, However, jumping to 5.17 for the c8 z51 is a huge change. As others have said it'll be interesting to see what the stock diff ratio is & what the trans ratios are.
A 0.18 ratio difference is what we know at this point and is not even in the realm of being "significant". Transmission gear ratios are not a factor if they are the same which is obvious.
We don’t know know anything for sure at this point! IMO a sign saying 5.17:1 in a Chevy tent means more than someone’s guess!!
For the C7 the base M7 had the same differential ratio as the Z51. It had different 1st gear. Easy to change the diameter (teeth) on two gears in a trans and keep the same dif!
We’ll see when GM decides to divulge trans gears as well as dif ratios in both base and Z51.
PS: IF the 3.62 and 3.80 were correct The difference in torque multiplication would be = (3.80 -3.62)/3.62 = 5% more. That extra torque would equate to 5% x 495 hp = 25 hp. Nothing to sneeze at! PS: to PS:
The #'s are in! Z51 = 5.17 Base 4.89 dif ratio's
As above = (5.17-4.89) /4.48 = 5.7% As above the extra torque multiplication as equivalent hp increase = 5.7% X 495 = 28 hp increase!
We don’t know know anything for sure at this point! IMO a sign saying 5.17:1 in a Chevy tent means more than someone’s guess!!
For the C7 the base M7 had the same differential ratio as the Z51. It had different 1st gear. Easy to change the diameter (teeth) on two gears in a trans and keep the same dif!
We’ll see when GM decides to divulge trans gears as well as dif ratios in both base and Z51.
PS: IF the 3.62 and 3.80 were correct The difference in torque multiplication would be = (3.80 -3.62)/3.62 = 5% more. That extra torque would equate to 5% x 495 hp = 25 hp. Nothing to sneeze at! PS: to PS:
The #'s are in! Z51 = 5.17 Base 4.89 dif ratio's
As above = (5.17-4.89) /4.48 = 5.7% As above the extra torque multiplication as equivalent hp increase = 5.7% X 495 = 28 hp increase!
So a gear ratio change actually creates horsepower? 5% ratio change=5% more HP, simple as that?
Wow, this means that a guy who has 460HP and goes from 3.27 gears to 4.11s makes himself 120 more HP. Who knew?
You should call John Force right away and enlighten him on your insights.
When you think you've heard it all, a post like this comes along.
^^^
Hmm, that is what gears are all about! Torque multiplication. Could of used torque and hp equation but didn't want to confuse you!
OK 5% more torque would be 5% X C8 max toque of 479 ft-lbs = 24 more foot lbs.
Now: HP = Torque x RPM ÷ 5252 I'd go through the derivation but don't want to lose you! We'll use the gain at max torque rpm which is @ 5150 RPM
So extra hp (a derived value) is 24 ft-lbs = 23.5 hp!
Yep John Force (who is almost as old as I am) knew that when he was a Freshman in High School! By the way he is well aware he can only use a 3.20:1 dif ratio by rules. He doesn't use any gears! Now his tires do grown ~13% at 320 mph so could consider that a gear!
PS: Yep next to Paul Newman who won an SCCA race at ~81 John Force is one of my hero's. Of course the best is Kris Karamesines who went over 300 mph in his 10,000 hp plus AA Fuel Dragster at a National Meet this year at 87!
^^^ This is new to me.
Help me understand how different gearing increases MAXIMUM HP. Different gearing just means you achieve MAXIMUM HP at a different speed. You're correct, HP = lb-ft at 5,252 RPM (it's simple math).
^^^
Since the torque does increase it's "like a hp increase" at launch BUT it's at a lower engine rpm. Since hp is a derived value of torque and rpm and rpm is reduced the actual "power" does not! Think of it as a Torque increase, which it is AND understand it's a simple Math equation that defines hp. Dyno's measure torque and convert to hp.
If you don't accept that the torque increase in lower gears and have a M7 in a C7, start in 7th gear and with the engine revved high and see what happens. Only used the "HP equivalent" to "make it easier to understand" that a small change in dif ratio will create a faster launch!
Very good to now know that one can add 25, 50, 150HP with just a gear change. All news to me and I'm sure to quite a few others.
Read the post above yours. IT’S a torque increase. HP is a derived value from torque and rpm. Dyno’s Measure torque.
Only used hp because it appears you cannot understand torque!
James Watt in the 1700reds undersold folks could only relate to what they knew. Although an excellent engineer and mathematician he used the equivalent power of a horse to derive the mathematical term.
Read the post above yours. IT’S a torque increase. HP is a derived value from torque and rpm. Dyno’s Measure torque.
Only used hp because it appears you cannot understand torque!
James Watt in the 1700reds undersold folks could only relate to what they knew. Although an excellent engineer and mathematician he used the equivalent power of a horse to derive the mathematical term.
HP=TQ X RPM/5250
Yes, the dyno measures TQ. HP is a mathematical derivative of TQ.
You are calculating the percentage difference in gear ratio then directly equating that to an increase in HP per the above equation.
The guy with 500 rwhp goes from 3.27 to 4.11 gear set which is a 26% change and according to your mistaken perception would then read a peak of 128 additional HP on the dyno at the wheels(500 vs 628). This does not happen with only a gear change.
You should just stop now as you are only creating gross misconceptions here.
^^
Started this dialog because of your foolish statement made several times that a 5% differential ratio makes no difference in launch time.
Yep, it is a torque increase that makes a significant decrease in launch time.
Will leave discussing this subject with you following the classic suggestion:
“Never argue with a fool. The will bring you down to their level and beet you with experience!”
Yeah, OK Dude, I just showed you how idiotic your HP increase projections with only a gear change are and now you pick up your marbles and run home like a puss. You are a well demonstrated "fool" here Pal. You don't have a clue about this stuff.
This might have already been answered but with the Z51 package what exactly are the performance suspension changes? Did not know about the added cooling inlets either.
I am repeating myself...VERY COOL C2 ! Poorhousenext....Bavo!!!
A 0.18 ratio difference is what we know at this point and is not even in the realm of being "significant". Transmission gear ratios are not a factor if they are the same which is obvious.
Jesus, there you go again. Get an engineering degree. I’ve got one, you’re wrong...
A 0.18 ratio difference is what we know at this point and is not even in the realm of being "significant". Transmission gear ratios are not a factor if they are the same which is obvious.
Jesus, there you go again. Get an engineering degree. I’ve got one, you’re wrong...
Jesus, there you go again. Get an engineering degree. I’ve got one, you’re wrong...
Oh, OK. So 3.62 vs 3.80 delta in dif. ratio is a big change and would make a sig. difference in acceleration? If you think that it is your are totally clueless, "engineering degree" or not.
The c8 is beautiful but what’s a muscle car with no muscle.
