I am being totally serious here. Does anyone have before and after 2.56 to 3.42 timeslips, gears only?

 

I saw some of your posts on that 160 t-stat thread and you seemed to always want hard evidence, yes? So I would really like to see how much 3.42's drops times dramatically on the strip in the 1/4 mile for the A6. I am sure you, like I, would not be satisified with some bs "SOTP" answer without some time slips.

 

i got the gears and a spinfast a few months back at the same time, so im going to take the spinfast off and put the stock manifold back on and get my tune right because it still needs tweaked for the gears also waiting on my new tires and rims to come in. after i get everything together im going to the drag strip to get some new time slips but i already got pretty good gains with my tune being off ( i have a bad hesitation on one of my shifts as you can tell by me not gaining any mph like everyone else with the spinfast).

take my 12.18 run at 116.27 with a DA of -410 and that comes out to 12.208 at 116.05 and then take my 12.02 run at 117.4 with a DA of +1843 (had about a 10 to 15 tail wind and only difference being gears and spinfast) that comes out to be an 11.768 at 119.97 so thats a gain of .44 and thats with my tune off.

i used the dragtimes.com DA calculator for the times and calculations

the gears gain more than what everyone seems to want to think and im not trying to say they are better than a converter or anything like that because i dont have one nor have i rode in an A6 with one but i do plan on getting one some day.

dicky

 

Be sure to look at 1/8 mile results too. 0-100 is just as important to the street only guys.

 

Yes, like most engineers I do like hard, numerical evidence. In the case of the thermostat, I trusted the coolant temp readings from my DIC, and the scan data from Spin. I also relied on my very limited experience at the track, and lots of information gleaned from CF members over the years.

I would also like to see some time slips from members who have installed the 3.42 gears on stock, lightly modded, and highly modded cars who have NOT also installed a high stall converter. I think for those types of cars, the results will be very similar as for installing 3.90 or 4.10 gears on M6 gears --- a three to four tenths reduction in ETs, and higher trap speeds. As I indicated earlier, Chuck at CoW has done many of these installs, and should have some real-world experience.

Maybe I am wrong. I do have an open mind, and I think I am always willing to listen to reason.

In my opinion, the track results that I have seen posted in this thread indicate that 3.42 gears installed on a car that already has a high stall converter offers more modest gains. But I am also willing to consider that there are more gains to be had from additional tweaking, tuning, and experimenting. That's what hot rodding is all about!

 

I didnt feel disrespected so dont think we arent getting along.

Some are tired of hearing the story so I will reiterate for those that never saw it.

There is a benefit from gears that has nothing to do with getting you in the power band faster which is what gears and converters both do. For the guys that and only want that benefit, the converter is plenty although some would get the gears for that last tenth.

The benefit that gears give that a converter doesnt has to do with wheel rotation speed and traction. Converters only get you higher in rpm faster and thus more HP faster....gears doo that too. Back to gears...

When you drive a car with enough power to overwhelm your tire and you get wheel spin, only gears and not the converter can slow the rotation speed down enough to rehook faster.

How this works is at a given engine rpm you have a certain rotation speed on the tire. At 5000rpm in first gear on an M6 the speed of the rotating tire would be 35mph with 4.10's and about 42mph with the stock 3.42's. What this means is that upon launching the car's tires rotate at 42mpm with the stock gears and until the car hits 42mph, it wont hook. The 4.10 car hooks when the car gets to 35mph.

On all cars especially the A6 many looking at a calculator say....wow that gear set is like having 5.xx's in first gear so that will spin the tires all the time. Now guess what. On one of the first cars at COW that got the 3.42's we noticed that the complaint of the owner was unfounded and he was being mislead by the calculator. He had so much wheel spin in 1st that the car would be unable to rehook unless you took your foot off the gas pedal. this wasnt the case with the 3.42's on the A6. What we saw was that the car would spin for about 10 feet or so and without lifting your foot, it rehooked. Why? the rotation speed of the tire was reduced and the car caught up to the spped of the tire for two reasons:
1-the car was accelerating faster
2-the speed of the rotating tire was slower for the same engine rpm in that gear.

Converters cant do that. The more power you have, the more the effect is that come from gears.

Old story, I had a Dart (sold last year) with over 700HP and 4.30 gears. It ran 11.xx's and wouldnt hook. All of these gears swaps occured with no mods to the car. My uncle tells me that the reason it cant hook is from the rotation speed of the tire being so high that the car isnt actually catching up to the speed of the tire in time.

Gear swap 1: 4.88's.

Fighting me tooth and nail, he said go higher. I said what all people who are wrong about gears said......I already have wheel spin and it will give a TQ increase and make it worse. He said it will have an initial TQ burst that would break tires loose easier but that the gears are to rehook faster by slowing down rotation speed. The car ran a high 10 sec pass for the first time but still didnt hook in 1st or second.

Gear swap 2: 5.30's

He said not high enough and I said he was on weed. Car ran a 10.6. Immediate hook in 2nd said he was onto something.

Gear swap 3: 5.88's

He said his calculator showed my car would be able to run 6.13's and I went with the 5.88's still thinking like all vette owners do about wheel spin and gears. The car spun violently in 1st but it hooked around 8k rpms. No spin in 2nd, just a chirp as in 3rd. I could never get this thing under 10.6 but dear uncle who is coordinated takes the car down the 1320 and runs 10.22 spinning till 5k or so and it is just about getting the front off the ground.


Gear swap 4 6.13's:

The reason why I am so pro-gear is what happens next. He takes the car and runs a few shakedown passes and makes an adjust ment to the suspension. The car pulls a wheelie out of the hole and runs a 9.92 at 138. Crosses the traps at just over 10k rpms.

Im in the back washing it:


Gears make you rehook faster so as you climb in power and have the tire for it, no converter will help you like that.

Its a gear thread and I am a believer in steep gears if you have the tire for it.

3.42's for the A6. Add a converter if you want but for big power and the right tire dont fear the gear.

I run a M6 Z51 with 4.10's and have H/C/nitrous/and 12psi from a paxton with MT ET streets and it hooks.

 

i dont have an a6 but have researched it very well the thing with the a6 is the first gear ratio and 256 ratio is very close to my a4 with 373, so with that said a 3600 rpm converter feels like stock until you floor it, my a4 with 3800 rpm converter felt like you had to hit the gas harder to get to speed, but with the 373 it felt stock gears with converter brings a car back to stock like feel the a6 with 256 gears and its low 1st gear is great like stock

 

thats the funny thing with drag times it cant predict the right da you need a weather station at the track level, and the wind could have severely altered the temp at the track

 

I dont own an A6 so are you asking me to produce timeslips for cars I have owned other than an A6 corvette?

As far as comparing your car with one gear set to his car with another...just stop already its jsut getting stupid at this point. No two cars have the same power band even with the same mods. A 10 HP difference at 4000rpms could account for a tenth. Headers make a bigger difference that that brand to brand. Suspensions makes a bigger difference still.

Same car/do the swap. I offered for Mike so it would satisfy the group but it seems he isnt able to at the moment.

I dont have to own a car for the comparison, I just have to mod one and you make way too many assumptions.

One thing you gotta chill with.....dont say someone cant post on a topic if they have related experience other than ownership. If we only posted about things we own, some wouldnt be posting much. Hear me? I think peoople who worked on A6's especially the number I have should have a voice.

 

I admit your car was pretty decent in the parking lot low speed cruise but it was far from feeling stock. It didnt feel slopy. If second breaks loose on the A6 with stock gears and decent power, it isnt rehooking. Limiting the benefit of gears because 1st in the A6 is steep loses a lot.

 

yea i know but thats about the best comparison i could come up with since i dont have a weather station.

dicky

 

ever think that when people talk about racing they may be talking about something other
than drag racing???

 

there is no other is there but i dont think you would be talking roll racing because thats not really a race, no starting line or finish line its not a race, and i dont think hes talking road racing by lowering the gears or a converter maybe mud racing or sand drags or even hill climbing or the texas mile or a land speed record

 

Spin:
Did the tires remain constant through all of the gear swaps on your dart?

 

Drag Times DA does not make predictions. It takes the weather data for
a given track and a given date/time and applies the 4 components that make up DA (temp, altitude, barometer and humidity) and gives a scientific number for what has already occured. The fact that Drag Times DA (along with every other online web site and cable/TV broadcast weather) does not match to your "Atco Boys weather station" does not mean it is inaccurate.

 

Same tire model.

 

Bench racing:
These guys run 3 different cars, with 3 different cams, 3 different headers, 2 different heads at two different tracks at different altitudes, and because they are close in peak HP, they say the cars are identicle and matched making only the gears the variable???......and I'm bench racing? Any of those changes could be a tenth or more. Its an absolute joke to say they are the same as far as comparing a single variable. In fact, any of those changes could be grounds for a thread war of which was the better mod. Peak numbers are even off by 20HP.

If they arent bench/dyno racing saying those cars are all matched up then what is?

Take the same car: swap only the gears and tune for the change. Thats a test.

 

Tom, when a car spins off the line with no changes at all its MPH tend to be slightly higher. An FI car here ran a 11.8 at 138 and later with a tire swap.....no gear swap or power change resulted in a 137 and a 10.77 ET. When your 60' drops the MPH tends to also.

Example two is C6DVL's car who ran a 11.8 @128.xx. He swaped the tires, clutch and took his gears from 4.10's down to 3.90's and his MPH still dropped slightly. Less gear by your formula would acheive a higher MPH but hooking gave him the better ET and less MPH. It was only a 1/2 mph drop but if youre right then less gear should have rasied his MPH. It didnt. Hooking and better 60's lower MPH. Not hooking raises the MPH. In this case, same car, same power, he gave up 5% gearing and the MPH still didnt rise.

Dyno runs with gears show about a 10-12rwhp drop with 20% gear swaps but thats not a power drop but rather how its being read on the dyno.

 

At least we are out at the tracks racing and logging will 3 different setups including different gear ratios with these A6`s. Were not just talking on here, we are testing. If anything Subfloor has done the most testing with different gears. As a matter a fact he has run all 3 gear ratios(2.56,3.15,and 3.42`s).

Again, these aren`t opinions but more along the lines of proof.

 

Testing what? That 3 differently set up cars with different mods makes any proof for gear differences? Its not proof; its random comparisons. There are no controlled variables and the cars are way different.

TESTING INVOLVES ONE CAR WITH ONE CHANGE. TAKE THE SAME CAR AND DO A GEAR ONLY SWAP....THEN YOU HAVE PROOF.

Why isnt it the cam that made the car faster than the others? I dont get why you see a tenth change when the headers and cam on the other car may have made a difference of 2 tenths and the gears then made up 3 tenths back up? You dont know and just say the gears are 1 tenth ignoring the changes the other mods made.

Look at the cams you are comparing. Its a joke. One car even has ported heads.