Dang, busted again. Stupid bablefish. Guess I should get my eyes checked.

 

D'accord is actually one of the very few French phrases I understand.

D'acura

 

Yes, I am quite familiar with those "official" performance figures as I myself have posted them here as well.

But there would seem to be some discrepancy between the "official" and the actual "practical" numbers obtained, and made widely available so far. That is the bone of contention.

The real world results obtained so far are inconsistent with the "official" numbers in that they indicate that the discrepancy is wider than the "official" company line. That is all that I have said.

I offer in support of my statement, that in order to obtain the same gearing in a non Z51 manual, as found in the Z51 manual, one would have to go to near 3.90 gears to get the same 1st gear gearing seen in the Z51. (Well, 3.8185 to be exact). 3.977 second gear, 3.762.

I suspect that if one went from 3.42 gears in a base car. Skipped 3.73s and went to near 3.90s and a better performing tire, that they would pick up at least one tenth improvement in the quarter, all else equal.

I'll ask it a different way. Any of you who drag race. If you were to go from 3.42 gears, in your base car, to 3.85 gears (effectively 3.90) and with equal traction, pick up only a tenth...... would that be the gain that you would expect?

One could actually take the time to calculate it out and obtain an "expected gain", but as I said before, the practical results seem to have, at least so far, demonstrated that what I said is valid. So there is really no need to go to the trouble to calculate it out.

So if one says: "forget the calculations, just drive." my response would be: "Many have. And the results seem to support that which I am saying". The difference is "at least" a tenth and probably more.

Now I know that you see this as a "pissing match", but I assure you that it is not. I am merely pointing to that which we already know, with regard to gearing and it's impact on quarter mile times, and to that which we have already seen.

 

You're a good man, Ops...keep tryin'



Harry

PS-I came by my French honestly, 4 yrs high school, 4 yrs college and a French GF for 3 years who spoke no Anglais and refused to learn. I now get it regularly reinforced in Montreal (La Nouvelle Paris), Paris and Brussells.

H

 

Let me see if I'm interpreting your answer correctly.

You would rather believe information taken from different drivers - of unknown skill level, and different tracks around the country, and unknown weather conditions, rather than the information obtained from the same driver at the same track at the same time of year (similar weather conditions). And this driver is, in effect, a professional driver who's job is to run the car enough to get a representative sampling of the times.

Is that correct?

 

No, that is not what I am saying.

I am saying that the gearing difference between the cars indicates that "at least" a tenths difference in quarter mile results is to be expected and likely more.

And furthermore, that the results that we have seen from around the country, coupled with that which we already know about gearing and its effect on quarter mile times, seem so far to bear this out.

In short, if that gearing is correct, it is unlikely, that traction equal, that the discrepancy is only a tenth. The numbers simply do not work out. Practical experience does not support it.

How does one go from 3.42 gears to near 3.90 gears and with equal traction, and everything else equal, even better tires, only pick up a tenth?

Thats what I am saying.

 

I think you are over rating the effect of gearing. Lower gearing has both positive and negative effects on 1/4 mile times. It makes the car harder to launch cleanly - a Corvette on stock tires cannot use all the power it has coming off the line as it is. Also, sometimes the gear ratios are actually detrimental to keeping the car in it's power band. There are several people on this forum who believe the spacing of the non-Z51 gears are actually better matched than the Z51. (I must go on record and say that I really don't claim to know this myself).

But I have to go back to what I said - you ARE saying you don't believe in the factory driver's results. How else can you say you don't believe there is only 1/10 difference, when that's what he came up with in actual testing?

 

Well, I would respectfully ask again,.....who? Where are his results?

But I wonder.......you would seemingly chide me for "not believing" the results of your professional driver,........ yet at the same time, refer to those "forum experts" who think that Chevy's engineers got the gearing wrong in the Z51 C6 and by extension the C5 Z06??????

Again, lest you accuse me of starting a "pissing match" FORGIVE ME, but talk about a double standard.

I would say again, if one were to make a gear swap of that magnitude in the same car, and keep the same 60ft times, there would be "at least" a tenth improvement in quarter mile times expected by whomever did it.

The fact that actual real world reports are supporting that which we really should already know, based on any rudimentary understanding of gearing and its effects on quarter mile times and acceleration, assuming equal traction,... further back this up.

I am saying that I don't believe the company line because I have personally witnessed the effect of gearing in my own cars.

If the two cars have the gearing difference which they describe, then it is not likely, that all else equal, the performance difference is only a tenth.

The fact that Z51 was and has been on constraint for most of it's existence offers incentive for Chevy to stick to the company line. Whether they are or not is beyond the scope of this post.

 

Took the Vette to the garage and tech done a check and it had a programing error in the trans. Thanks for all the feedback. I know that some of you do not care for my choice of vehicle, but I have been driving these cars since 1958 and with a little time and money, they can all be made to run satisfactory.
Thanks for all your input. In my late 60's is what made me choose the F55 for the comfort mode but I still enjoy the performance.

 

HELLO! Is anybody home??? He's not "my" professional driver. Hell, you're the one who posted the page from the Corvette broshure that listed "my" professional drivers results!

 

Maybe we should have a forum poll?

Something like: Which poster is on the most Corvette forum members' ignore list....

 

I like the jelly donut comment!

 

I don't remember why it was dynoed in 2nd. and 3rd. and he did not have the program yet to do a tune on it until next week so that the trans and ls2 edit can be done but I am going to put Ram-air and LG long-tubes on it to start with and will go from there but I will post what the difference is then and thanks for your interest.
As I said later I had it check at the shop and they had to do an update to the transmission and it seems great now.

 

 

Sure. I'll remember that the next time you start talking about "pissing contests."

You be sure to remember it too.

And thats "brochure".

@BlackOps

So much for altering my "delivery" huh?

 

Hopefully that takes care of it Diamond Dave. Heres to hoping that you have no further problems with it.

 

Is that what all this Z51 elitism is all about??? Being able to outrun Fords? Let them pass me! I could care less! That stuff hasn't bothered me since way back when I was a kid. I know they would swap their Rustang for my Vette in a heartbeat.

 

"Rustang"??? Now who is being "elitist"?

 

that sounds like a pretty weak vette you got there, maybe a lemon.