2012 a6 are my 4.10's alittle too much?

just kinda curious as to you guys take on the whole "don't fear the gear" idea with 5.0's

I went with 4.10's thinking they would be a minimum but now I'm wondering if I'm leaving anything on the table & if something along the lines of 3.55's might not have been a better choice.

the car with the mods in my sig has went 1.85 60' & 12.10 @ 116.

In What gear and at what RPM are you crossing the line?

If you plan on staying n/a a 3.90 gear with your 28" tall tire will keep you from having to shift to 5th gear and you should cross the line around 7300rpm. This is assuming you have your rev limiter set that high. I myself would put a 3.73 gear in it as I have a friend who went 11.57 with similar mods as you cutting 1.6XX sixty foot times.

Major fail on my part.... I didn't see where you have an auto so disregard the above statement.

stkjock said:

In What gear and at what RPM are you crossing the line?

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with the tune that produced my current times, the car was shifting into 4th about 100' or so before the stripe at 7100 (it also would just touch the limiter on the 2-3 shift at 7200)

the tune I have now took 1mph from the 2-3 & added 3 to the 3-4, but I haven't ran the car with that tune yet.

I'm not trying to set any records or anything, the car is first & foremost a bracket car, I just was hoping to see if there was anything on the table I'm missing (not just et, or mabie I should say in spite of et, consistancy & track drivability are very important also).

Sounds like u have a lot of RPM left and could even use a shorter tire. Do u know what rpm in 4th u r crossing.

The 6R80 ratios are 4.17/2.34/1.52/1.14/0.87/0.69. If you are trapping 116mph with 295/45R17's and the convertor is locked, you would be crossing the finish line at about 6900 rpm in 4th gear.

Which seems like it'd be just about perfect. I'd try to improve the 60' and I think all the 6A cars should get a quality aftermarket torque convertor.

tjm73 said:

The 6R80 ratios are 4.17/2.34/1.52/1.14/0.87/0.69. If you are trapping 116mph with 295/45R17's and the convertor is locked, you would be crossing the finish line at about 6900 rpm in 4th gear.

Which seems like it'd be just about perfect. I'd try to improve the 60' and I think all the 6A cars should get a quality aftermarket torque convertor.

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Interesting, I didn't do the math, I figured if 4th is 100' before the line, there would be more rpm

3.31 with a 28" tire is what you want with the 6R80.

3.90 is the right gear for a manual trans MT-82.

Intersting, wbt has some awesome times so it would be hard to argue with him. but... I have a 28" tall tire and 4.10 gears, I think my tire is holding me back, I should run a 26" tall tire. casper is only missing a boss intake manifold for cheap/easy mods.

between cai+tune+Drag Radials only and adding 4.10s, O/R X, and boss intake manifold I dropped .5 in the 1/4 and picked up 4mph. I wish I had tested only the difference between the stock 3.15s and the 4.10s, but If you aren't running out of gear I don't see why the 4.10s would be a problem? And a taller tire effectively reduces your gear ratio, with a 28" tall tire it's like i'm running 3.90's right?

Sorry for the thread hijacking but what would you guys do with a coyote and a 3650?

My first guess was 4.10.

considering it'll rev to 7500 vs. 6500 on the 4.6, yea 4.10s would be my choice

Mishri said:

Intersting, wbt has some awesome times so it would be hard to argue with him. but... I have a 28" tall tire and 4.10 gears, I think my tire is holding me back, I should run a 26" tall tire. casper is only missing a boss intake manifold for cheap/easy mods.

between cai+tune+Drag Radials only and adding 4.10s, O/R X, and boss intake manifold I dropped .5 in the 1/4 and picked up 4mph. I wish I had tested only the difference between the stock 3.15s and the 4.10s, but If you aren't running out of gear I don't see why the 4.10s would be a problem? And a taller tire effectively reduces your gear ratio, with a 28" tall tire it's like i'm running 3.90's right?

Click to expand...

There are several things to look at.

What RPM do you think you will cross the traps at? This related to how much MPH you are looking to shoot for in the 1/4 mile.

Using a tire/gear calculator, (such as this one... http://www.modularfords.com/f259/tire-gear-spreadsheet-183536/), you can plug in tire size and RPM to determine MPH.

The 3.31 makes sense for an auto running a 28" tire because the 6R80 has a steep first gear (4.17) and it allows you to cross the traps at peak power when using the Boss intake. The next best gear would be a 4.30. The problem you run into there is blowing the tires off the car on launch. Our tracks generally aren't prepped very well when we run so this was more of a hindrance.

As you can see, there is quite a bit that goes into deciding what gear to run with what tire size. A 28" tire is not too much for the new 5.0 as they have plenty of power on tap. Moving to a 26" tire would reduce your contact patch and reduce your traction capabilities.

Set yourself some goals on what you want the car to achieve and then build a combination of parts around those goals. Otherwise you wind up throwing good money after bad chasing times.

Hope that helps.

I run at a 3900' elevation track so between that and we have good track prep, so most of the guys running under 600whp are running 26" tires, more than that and they go up to 28".

Since i'll never have any record times up here I don't really chase after that, I just figured 4.10s would help me accelerate faster than 3.73, 3.55 or 3.31.

Mishri said:

I run at a 3900' elevation track so between that and we have good track prep, so most of the guys running under 600whp are running 26" tires, more than that and they go up to 28".

Since i'll never have any record times up here I don't really chase after that, I just figured 4.10s would help me accelerate faster than 3.73, 3.55 or 3.31.

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Sounds like you have it all figured out then.....

just a small update.

tried out the 3.31's, not only lost everywhere including mph, the car also felt too flat for my tastes & certainly not something I would want to bracket race with all points season (which is the sole purpose of me owning this car, it gets no daily driving at all, only back & forth to my local track).

the 4.10's are back in along with a stepped up tune & a boss intake swap.

havent got it to the track yet (airaid cai gave me fits on fitment with the boss intake but I think it's all good now, just waiting on some couplers) & I should have some new times soon.

I do want to thank wbt for all his help thru out my debating on trying the swap, whithout his input, I wouldn't have even tried it & even though it didn't work out, I'm glad I tried it just for the advice I can give someone else if nothing else.

casper gt said:

just a small update.

tried out the 3.31's, not only lost everywhere including mph, the car also felt too flat for my tastes & certainly not something I would want to bracket race with all points season (which is the sole purpose of me owning this car, it gets no daily driving at all, only back & forth to my local track).

the 4.10's are back in along with a stepped up tune & a boss intake swap.

havent got it to the track yet (airaid cai gave me fits on fitment with the boss intake but I think it's all good now, just waiting on some couplers) & I should have some new times soon.

I do want to thank wbt for all his help thru out my debating on trying the swap, whithout his input, I wouldn't have even tried it & even though it didn't work out, I'm glad I tried it just for the advice I can give someone else if nothing else.

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Anytime!

Sorry to hear the 3.31 didn't work out. We have been pretty successful with it in 2 different A6 cars to date. The converter may be the difference on that.

I am also using the Airaid CAI with the Boss intake. This may help in the fitment:
http://www.modularfords.com/f259/boss-302-intake-airaid-fitment-171801/

wbt said:

Anytime!

Sorry to hear the 3.31 didn't work out. We have been pretty successful with it in 2 different A6 cars to date. The converter may be the difference on that.

I am also using the Airaid CAI with the Boss intake. This may help in the fitment:
http://www.modularfords.com/f259/boss-302-intake-airaid-fitment-171801/

Click to expand...

yep, I'm thinking it might have a little to do with the converter as well but for my needs, I'm a little hesitant to go with a converter just yet (while my 60's aren't the greatest at a 1.90 average, the car wouln't spin even when I try so I'm right where I need to be in that department with a bracket car).

as to the airaid kit, I tried trimming the supplied coupler & didn't care for how the tube sat, so I ordered a 45* 4"-3.5" reducer & that didn't help either, so after pulling out most of whats left of my hair, lol, I got to looking & found that if I cut the mounting boss off the fan shroud right below the tube (the one with the captive nut in it) that the tube fits almost perfect & I shouldn't even have to cut the straight reducer I have coming this week.

I'll post some picks soon.

One other thing I forgot to ask, can you post up the timeslips of the previous 4.10 best and the 3.31? I would like to compare the runs.

wbt said:

One other thing I forgot to ask, can you post up the timeslips of the previous 4.10 best and the 3.31? I would like to compare the runs.

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heres the 4.10 best so far at 12.10/116


the 3.31 slip is mia (I think I threw it out the window when I saw it, lol)

bottom line though 12.56 @ 113 with a 2.09 60'

to be fair, in the heat here lately the car has been in the 12.35ish range at 115 with a 1.90-1.92 60'.

all these times are uncorrected at a 1200 ft track.

not a big loss, the real problem I had was the way the car felt going down the track, flat is about the only way I can describe it.

I'll see about getting a copy of the 3.31 slip at the track on sat.

http://www.youtube.com/watch?v=Na6Sqh2I87k

that 12.10 run is at 1.10 in the video.

you can hear how fast it shifts with the 4.10's & thats what started all this gear swap stuff.

my old white 2000 is the first car on the video in the left lane also.