08-19-2012, 08:17 PM | #1 |
v It bites.
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A6 gears for FI
I am attempting to build a foundation for my auto to go FI in the next year or so... Obviously, many of you have experience with this so my question asthe subject suggests is what ratio is best for not only an A6 but to build me the foundation to eventually go FI.
I was set on the 3.70-3.73 but it is hard to ignore the 3.91 I have heard rumored that is being offered by GM due to the 1LE... And that the cost of parts may come in around 300 without install kit. That is substantially less than aftermarket, but if LPE makes OEM then quality wont be an issue. Is the 3.91 too much for a street car when coupled with cam and blower? By the way I have narrowed it to Maggie or whipple if that matters.... |
08-19-2012, 08:37 PM | #2 |
Drives: the wife crazy talking Camaros Join Date: Aug 2010
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3.91 is way too much for the A6, the A6 has a very tall 1st gear vs. M6. Go with 3.45 or 3.7x. 3.45 should cost the same as 3.91. If you are going big cam and big F/I go with 3.45 because you do not want to be shifting into 5th on the 1/4 track. 5th is a weak overdrive only gear. 1/8 track is okay for 3.7x
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08-19-2012, 09:12 PM | #3 |
3.70 gear + 720rwhp + Slicks = NO Traction. That being said, it really depends on type of FI you are going with and power level you end up with. But topically the more hp the higher the gear...
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08-19-2012, 09:18 PM | #4 |
I Wanna Go Faster!!
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Pick up a diff from an M6 car...3.45...perfect.
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08-19-2012, 09:43 PM | #5 |
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08-19-2012, 09:57 PM | #6 |
v It bites.
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My power level will probably top off around 560rwhp... With the future mods I'm mind I never expect 600.
Is there a seat of the pants difference with the 3.45 in a A6? I want to have a lil fun while I save up for the blower |
08-19-2012, 10:02 PM | #7 |
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3.70s are fun...I have a feeling however that 3.45 may be faster at the track. If you can hook some 3.70s though. Bam. Our local track is 1k feet. Thus I went for fun street factor and figured I would try to hook some 3.70s.
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08-19-2012, 10:12 PM | #8 |
10.11 @ 136.32
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I have 737 rwhp + 3.70's + slicks and with proper coil over settings I have no problem hooking. Runs about a 1.5x - 60 foot. The problem is I trap at 5200 rpm in 5th gear at the track. Going to change to an LPE 9.5" rear end this winter with their 3.42 gears. As the fellows have said above the 3.45's from a manual trans is your answer.
Bryan
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08-19-2012, 10:15 PM | #9 |
3.27 to 3.45 has a real noticeable difference - I think you would be happy and save some money in the long run. Just my 2 cents...
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08-19-2012, 11:04 PM | #10 |
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3.45
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08-19-2012, 11:07 PM | #11 |
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From a drag racing standpoint you'd look at shifting rpms, max rpm, tire size, rear gear and trans gearing.
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08-20-2012, 12:57 AM | #12 |
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Andy of ADM installed me the 3.45's on my 617rwhp whipple car.
I love it.
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08-20-2012, 08:50 AM | #13 |
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Conventional wisdom will tell you 3.73. If your building a strip car, 3.45s may be even better depending on how high you will go in power.
My car is a street only car. So most of my aggressive driving is on the roll so my 3.91 are exactly what I want and I could not be happier with them. Just comes down to what you want to do with your car.
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08-20-2012, 09:50 AM | #14 | |
v It bites.
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Quote:
If it was a weekend or even monthly strip car I would have done 3.45s without asking. Do I launch from a stop on the street at 3 am? Sure... that is where this is becoming a hell of a decision.
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