xstang

So power means nothing... All a C6 needs is 4.10s and I can pull C6 Z06s huh? Wow!!!! The C6 would have the gearing advantage...

k0bun

I don't think he's saying that. I don't think anyone is saying that. Don't try and tear down the argument by putting words in someone's mouth. Comparing a possible 30hp difference to a 100hp difference isn't exactly logical.


Weasel reported a .3 reduction in et going from 3.42s to 4.10s. This goes along with a few other results I have seen/read. Just because it's not on the precious C6 Fast List, doesn't mean it doesn't happen. So if we take his .3 and use the generally accepted equation of 3/10ths = 30 horsepower and cross referance that with the 30hp gained on average from a set of headers then we can intelligently come up with some type of conclusion. So let's assume that gears give the relative equivalent of 30 extra horsepower. By your own admission, gears help at the launch (not only there though) so the gear car will pull ahead immediately. Since most races are won or lost from the launch, it's safe to say the gear'd car will win. They now perform as though they have equal power however the gear'd car has the advantage off the line and retains that advantage all the way down the track.

xstang

30RWHP and 30RWTQ is significant..... You should get .3 tenths and 3MPH with headers...

SpinMonster

The problem with the trap speed emphasis is that it overlooks the simple fact that trap speeds mirror power output even on poorly set up cars. C6DVL's car ran a 128 trap speed with an 11.8 ET and the same trap speed with a 10.84 run. ET is far more important otherwise you could just run runflats at the 1/4 track and be done with trying to better your car. Why bother working on a 10 second et when every poorly set up car will run the same trap speed without any tire and suspension tweak? The bottom line is that trap speeds dont make you a winner in the 1/4. The fastest cars actually show a slight drop in trap speed when they hook and run quicker ET's. Ed's car was actually a slower trap speed by .5 MPH so by the 'trap speed is more important' mentality his car was worse after it got its clutch and better tires.

Drag racing is about ET because power output can give any car a high MPH while it loses to a car that hooks and makes it to its destination 1320 feet away faster than the higher trapping car....or the same trapping car.

As said before there are hardly any cars making it into the 10's without gears (not saying there wasnt one but it isnt the norm) so saying one is better than the other is again quite silly. Saying there is a 30HP difference is also not true. There are numerous geared 10 second H/C cars between 440and 470rwhp and yet there are hardly any stock geared 500+rwhp cars making it into the tens. 30HP doenst seem to make the difference often enough to make it statistically significant..

SpinMonster

I am guessing you have headers and dont have gears now.

Braciole

LOL! I was thinking the same thing!!!
Mike

Wicked Weasel

Better 60s means faster ETS and slower mph....

Tony B4

Here you go: C6 Z51 manual with tune,vararam,160 tstat and better 3.42 gears vs C6 A6 with Headers,tune,vararam,160 t-stat and 2.56 gears.

In the video, you will see that the guy got the jump right out of the hole but i reeled him in fast because of the power of the headers.

Also if someone says well how can you use this as a comparison, well the C6 Z51 with 3.42 gears is better gearing than a C6 with 2.56 gears.

http://www.youtube.com/watch?v=dCzySUnBfzw

He ran 12.79@113.85mph and i ran 12.522@115.26mph with a auto and less gears, but i had headers.


Also here is a chart to show the differences between 2.56 gears and 3.42 Z51 gears.



I would take power first before gears,but gears also have there place.

Just my .02

xstang

This is what I'm talking about.... Thank's for posting Tony
I will say that in the 1\4 mile with traction, the gears and Headers are a toss up... With that said, if you roll race against someone with 30rwhp, you get your tail handed to you even with the 4.10s...

See how fast the header car (Tony) yanked in the guy with gearing?

xstang

I do have experience with gearing and headers... see below...



Internal Engine Modifications

11.68 @ 122.42 - RDD41 - 06 A4 - LPE 403 package - (662)
11.76 @ 116.76 - 1955 Belair - 05 Z51 A4 - CAI, CB, conv, H&C, hdrs, intake, tune, DR
11.79 @ 120.12 - Greentank - 06 A6 - CAI, CB, 3.15, H&C, hdrs - (1821)
11.80 @ 123.50 - Xstang - 05 Z51 M6 - CAI, 4.10, H&C, hdrs, tune, DR - (1178)
11.98 @ 120.87 - Mr Z51 - 06 Z51 M6 - CAI, Cam, 4.10, hdrs, ported int, udp, DR - (1265)
12.31 @ 119.28 - Black02SS - 07 M6 - CAI, Cam, hdrs & tune


I do have a set of Headers in my garage and I'll be hitting low 11s soon with 2.73 gears and bolt-ons only on my 08...

Wicked Weasel

I would like to see more data for both cases and then we can put this to rest.

xstang

I want to state that the gears I posted in the list were actually 3.90s. With the smaller tires they were close to 4.10s

I need to pm Tommy.....

CMY SIX

GEARS, headers are a waste of money with these cars, I'm producing the same HP as header'd cars 380 rwhp/384tq on a mustang dyno

mkr3686

Tony,

did you have your 3200 stall converter in your car for this run?

GotVett?

Even though I am planning my next performance mod to be 4.10's, there is no definite hands down winner, is there? And there are some pretty knowledgable guys on both sides of this issue.

mkr3686

It's pretty close, in most cases the gears probably have a very slight edge. The gears make a better choice for some other reasons as well, like the fact that headers are a more visually obvious mod that any dealership could void parts of your warranty for. Headers could also be grounds for failing emission inspections.

catpat8000

Here are a couple of observations which I don't think will be controversial. Let's see where they take us.

1. In the 1/4 mile, trap speed is mostly a reflection of the horsepower your engine develops. If you add 100 rwhp to your car, your et may or may not improve, depending on your traction, but your trap speed will improve a lot.

2. Gears do not add hp. It doesn't matter whether you have 3.42 gears or 4.10 gears, your engine makes the same hp. Therefore, within the bounds of error, gears are not going to make a large change in your trap speed. They may improve it a little because your car may spend more of its time in a higher hp part of your engine's powerband but they won't improve it in proportion to the size of the gear change (20%, in this example).

3. Lower ets are somewhat correlated with higher trap speeds because higher power generally produces lower times but lower ets are far more directly correlated with your starting line traction. Sometimes lower ets are inversely correlated with more power, as it becomes harder and harder to launch the car well without traction mods.

4. Gears do provide significantly increased torque to the rear wheels when leaving the line. Assuming you can harness the increased rear wheel torque, you'll leave the line harder and therefore have a better et.

Conclusions from these points? Gears do help ets, assuming you have the traction. Gears won't help your trap speeds too much. Headers, because they add power, will increase your trap speed and will have some et benefit.

Which is faster? Headers will likely add more to your trap speed. Gears likely subtract more from your et, assuming you have the traction to use their potential.
Both are part of a total package for winning drag races.

All of this depends on the traction you have at the line. If you want just one mod which will lower your et the most, get a set of drag radials.

Pat

3 Z06ZR1

With what?

Tony B4

No, this run was last year(opening day 2007) after i had the headers and tune done.

This year(2008) i had the 3200 stall convertor installed with the cam.

SpinMonster

Who would win, Mighty Mouse or Underdog? I think it would be close because both only have huge upper bodies and weak small legs. If Underdog works on getting fast then his size could be an advantage after all Mighty Mouse is only a little mousey but he is fast and can duck into holes in a wall or under shorter furniture in the house. Underdog is a dog and they of course are known for being lazy and sitting around the house all day after they grow out of the puppy thing. Still both are cute. Wives are more likely to like a dog than a mouse though and this may make her help the dog in combat against the mousey.