Orr89rocz said:its not a half second difference on the 1/4 mile.
Force4.6 said:Doesn't matter how much time the GT won by on a road course it was still a little quicker, the time adds up lap after lap.
LMAOFormula51 said:So, the Viper has the MUCH better overall gearing for gas mileage (city and highway) with a final drive ratio of 3.07 vs. 3.42 and the same tranny gearing as the Z06 yet it gets FAR worse gas mileage!
Remeber that on the highway the weight difference (270lbs) is minimal because the objects are in motion. Also, rolling resistance is relatively insignificant with both cars having the same front tires and the rears of the Viper are only 20mm or about 3/4" wider than the Z06. Without knowing the details of each tires compound we cannot accurately calculate their respective rolling resistances, but from my past analysis I am confident that the difference is negligable.
Based on the numbers posted, the Viper should achieve equal to better mileage than the Z06 but that is not the case. The reason is the LS7.
E
Orr89rocz said:come on man, i never driven a stick and i could do better than that.
they are easy 11.7 car at 123-124 with a decent driver. car n driver or motor trend did 11.7 at 126.6mph.
E. Green Cobra said:So the Viper has heavier rotating parts, heavier in general, slightly better gearing, more power and larger tires,
While the vette has less power, slightly more gearing,less overal weight and less frictional losses, and YOU still THINK its because of the Ls7?!!?!?!?!
the difference in gearing is what 10%? Thats MUCH?
You've never driven a stick?!? But you're confident you could run better? I've never driven a GT but I'm confident I could run 10.9999 @132 in 104* heat @ 3000 ft elevation into a 30knot headwind on cold tires, with no track prep on the FIRST pass
E. Green Cobra said:LMAO
the difference in gearing is what 10%? Thats MUCH?
E. Green Cobra said:Furthermore about the tires,the Viper rears are about 3% larger an ASTRONOMICAL difference... :lol1:
E. Green Cobra said:(like you said compounds are likely pretty close the Mich PS is rated 220, while Good years Supercar tire is also a 220)
Back to those wheels, the viper wears 18x10 fronts and 19x13 rears, the Z 18x9.5F and 19x12R, who wants to guess the Viper has the heavier wheels? Who also wants to guess that a 335 tire is heavier than a 325 tire?
E. Green Cobra said:Now who wants to bet that having heavier parts a) slows you down, and b) increase fuel consumption
Add to the fact that these parts are in fact rotating parts adds significantly to the effects.
E. Green Cobra said:So the Viper has heavier rotating parts, heavier in general, slightly better gearing, more power and larger tires,
While the vette has less power, slightly more gearing,less overal weight and less frictional losses, and YOU still THINK its because of the Ls7?!!?!?!?!?
E. Green Cobra said:So then let me ask you if you strap the Z with the larger wheels, tires AND the additional weight do you possibly believe that the car will produce the same EPA numbers???? Will it produce better numbers than the Viper?
Conversly- take out that POS Viper engine and stick God's, I mean an LS7 in the viper, do you believe the Viper will suddenly increase its EPA ratings to 16/26 ???
E. Green Cobra said:Again I'll say, weight, gearing, and frictional losses combined play a larger role than the Ls7. You could put anything in GM's lineup in this thing and it would still make awesome (EPA) numbers
fordification said:even thought the 5.4 has a better torque curve, the smaller displacement has to work a little bit harder to move extra weight, increasing the average rpms, which in turn increases that much more boost. Case in point, Ferrari F430. 4.3L, 493hp, 3100+lbs, 12mpg.
300lbs would make up the 2mpg difference.
fordification said:so is GM taking in Z's to replace the rightside rotors?
4.10's from 3.27's is about 25%, most 4.6L cobra guys do a minumum of 4.10's, with a fair majority up into .30's and .56's. More on this in a momentFormula51 said:A 3.07 rear gear vs. a 3.42 rear gear is a SIGNIFICANT difference. You know this, admit it. This is very significant compared to the other differences.
Sarcasm yes, I believe that little piece of rubber does do something, why else would Dodge use it? Or Why wouldn't GM? I love how your so quick to discount such small differences we're debating a few miles per gallon here, small things DO add up, extra weight, heavier rotating parts- all add up, look at the effect of changing a dirty air filter, or properly inflating ones tires on gas mileage...Formula51 said:I think you are being sarcastic here and if you are I agree with you, 3% larger or about 3/4 of an inch wider is insignificant.
First of all the Viper has a 345 tire and it will be heavier than the Z's 325 tire by what ounces? maybe a pound? It is a 3/4" strip of rubber, it will have an insignificant impact on the rolling resistance. It seems logical that the Viper would have slightly heavier wheels because they are larger, but that is not necessarily the case and is worth looking into. Again, you make statements without facts.
Imagine a new Z add 80lb wheels HELLO 35MPG (hwy) epper:Formula51 said:You are reaching here. We are talking about a likely very small difference in rotating mass here. Not to mention that the heavier rotating assemblies will have greater inertia at a given speed and thus will not "slow you down" at highway speeds. It will actually be beneficial at highway speeds. During city driving, acclerating and deccelerating the "potentially" heavier rotating assemblies will have more of an effect. Again, we are probably talking about a very small difference in weight.
Formula51 said:Absolutely, but you are very good at choosing your words! According to you, the Viper has "heavier rotating parts", "more power", and "larger tires". But in reality it has "SLIGHTLY heavier rotating parts" (unconfirmed by either of us!), "SLIGHTLY more power", and "VERY SLIGHTLY larger tires REAR TIRES ONLY'. YET, its most significant difference, the gearing is only "slightly better"! You crack me up.
I guess thats usually how things work out :shrug:Formula51 said:You my friend need to become a statistician as you are very good at making things say what you want them to say.
Sure at highway speeds, but the weight had to GET to highway speeds... a simple experiment should clear that up...throw a 270lb body in the trunk of the vette, (or you'r own vehicle if it helps) we'll see how that extra ballast effects accel,decel, and mpg....Formula51 said:Myself and others have explained that the weight difference is insignificant at highway speeds. Let it sink in....... now get with the program please.
Tuning? I didn't ask if you could optimize the setup- I wanted to switch the one variable that you are claiming as the most important one, i.e the engine... my point was to add the larger wheels, and extra "insignificant" weight to the vette to see what it put up for numbers.....Formula51 said:I can not say what the LS7 would do in the Viper chassis, but from what I have seen so far I think if the LS7 was put in the Viper and tuned for the different gearing then it absolutely would achieve better mileage than the Viper does. Would it achieve better than the Z06 does? I just dont know, but I think it is possible.
Without a doubt huh? from before I mentioned all of those 4.6L cobra owners and they're fascinations with gear changes.... a very large percentage report BETTER mileage with 4.10, 4.30, and 4.56 gears over the stock 3.27's (over 25% difference) and it usually amounts to about 4-500 rpm "cruising"Formula51 said:Well you have yet to show me how and we have already PROVEN WITHOUT A DOUBT that the Viper has the more fuel efficient gearing.
You do realize that the rpm difference between a 3.07 and 3.42 gear @70 in 6th gear amounts to ~200rpm :bored:Formula51 said:You severly underestimate the benefit of those 3.07 gears.
Because you've produced what exactly to prove the LS7 is the SOLE reason the Z06 gets 16/26? I'd like numbers, btw I'd also like an independent party to watch all testing .... :banana:Formula51 said:So that leaves you with "frictional losses". So I say go find me some numbers for once and back up your statements. Who knew "frictional losses" could be responsible for 6mpg on the highway!?!
Maybe we should all wear loffers because walking in these tennis shoes is requiring some serious energy here, sticky compound and all, you know, the frictional losses.