4.10's in a4 question
11-02-2011, 11:46 PM
#1
4.10's in a4 question Next week im swapping out my 2.73 for a 4.10 rear end. I hate the 2.73's and am not worried about gas mileage as car is just a weekend cruiser. What i was wondering is---- I know its not good to shift into 4th at wot, So will i be able to run the 1/4 without shifting into 4th? Whats the max speed at 6k in 3rd gear with 4.10s?
11-03-2011, 11:18 PM
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"...not good to shift into 4th at wot, So will i be able to run the 1/4 without shifting into 4th? Whats the max speed at 6k in 3rd gear with 4.10s?"
111.06 mph @6k rpm @4.10 gear@ 25.5 dia tire@ 3rd gear
go below, figure
http://wallaceracing.com/calcmph.php
Johnny
111.06 mph @6k rpm @4.10 gear@ 25.5 dia tire@ 3rd gear
go below, figure
http://wallaceracing.com/calcmph.php
Johnny
11-04-2011, 04:39 PM
#6
Wow- i looked at that, then also found fbody.gears.org. Its says about 112 mph at 6k in 3rd. So i guess thats gonna make running the 1/4 a little tricky? 112 would put you no faster than a high 12 i guess. O well im already swapping the rear and i dont race much any way. Should be fun on the streets with the 4.10's - even more so coming from the 2.73 i have now 
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11-04-2011, 06:30 PM
#8
No thats my next big mod- My trans has quite a bit of miles, so i dont want to add a stall untill i do a trans rebuild. Im afraid if i add a stall now it would just ruin the trans and then risk ruining the new stall too. Im working on it tho- Id love a good 3600 stall in it
11-04-2011, 06:35 PM
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No thats my next big mod- My trans has quite a bit of miles, so i dont want to add a stall untill i do a trans rebuild. Im afraid if i add a stall now it would just ruin the trans and then risk ruining the new stall too. Im working on it tho- Id love a good 3600 stall in it
For sure, my last TA was an a-4 stalled with stock gear. It was fun as could be to drive around town.. Good luck with your swap man.
11-04-2011, 08:19 PM
#10
My A4/TCI2800/4.56s' required going into 4th to finish the 1/4. My current setup is YankSS3600/4.56s'. Haven't run that combo,but that shouldn't change the necessity to shift to 4th because of the 4.56s'. The 4.56s' were put into a spare rearend I had. I'm currently rebuilding my OEM 3.23 rearend to put back in. The 4.56 rearend is gonna get 3.73s'.
11-04-2011, 10:55 PM
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26" dia tire x 6400 ( OP is winding to 6k)( is it safe to wind the OE top end to 6400?) X 4.10 x 1.1( 3rd- no OD ) =120MPH
AS I just install 9" with 4.10 I also need to know answer, may I please ask access to the progrom which is stating the above combo will =130 mph
again please forgive if I differ
Johnny
11-05-2011, 02:18 PM
#14
LEMONS, Please do not think I am only tring to create a problem as I may have the wrong info I was told the OE tire 275/40/17 is about 25.5 in dia and the on line programs which I find calulate if useing
26" dia tire x 6400 ( OP is winding to 6k)( is it safe to wind the OE top end to 6400?) X 4.10 x 1.1( 3rd- no OD ) =120MPH
AS I just install 9" with 4.10 I also need to know answer, may I please ask access to the progrom which is stating the above combo will =130 mph
again please forgive if I differ
Johnny
26" dia tire x 6400 ( OP is winding to 6k)( is it safe to wind the OE top end to 6400?) X 4.10 x 1.1( 3rd- no OD ) =120MPH
AS I just install 9" with 4.10 I also need to know answer, may I please ask access to the progrom which is stating the above combo will =130 mph
again please forgive if I differ
Johnny
I have no idea how tall his tires are, if that's the case it will be lower obviously. And iirc it may have been high 120s, this has been about 3 years sice I ran that setup... Tires were specd at 26" but I'm sure could have been a 26.5".. Which means mine would have just been a hair more. I know for a fact it cleared 120mph.
Over the years, I have never heard of people having a problem in the 1/4 with 410s.. This is kind of where I'm coming from it being much higher than 110 as these are head cam cars. I am not using a calculator so I would assume your estimates are spot on.. I'm just going from experience.
A stock bottom is good to spin to 6500... After that you're pushing your luck.6200 is playing it safe.
Replace the rod bolts and spin it to 7000-7200.
What size tire are you running and how high are you spinning 3rd?
11-05-2011, 11:55 PM
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http://www.f-body.org/gears/ try that site for figuring out mph and gears for your a4. I run 4.10's behind a a4. On a stock cammed lt1 I shift at 6k. Last night I was trapping 109 with mid 12's and a best of 12.4x's. Under wot you shouldn't be shifting into 4th anyway, I dont believe the pcm will allow it. I have mine tuned that way but I think factor is the same
11-06-2011, 10:05 PM
#16
http://www.f-body.org/gears/ try that site for figuring out mph and gears for your a4. I run 4.10's behind a a4. On a stock cammed lt1 I shift at 6k. Last night I was trapping 109 with mid 12's and a best of 12.4x's. Under wot you shouldn't be shifting into 4th anyway, I dont believe the pcm will allow it. I have mine tuned that way but I think factor is the same
11-13-2011, 09:57 AM
#18
First of all there are so many factors when determining this equation. As of now you have the stock converter. If you only change the gear, then the fbody.org calculation is great. If you ever put a converter in, then at that point you will have to factor in converter slip and a few more. Put it in and have fun, like you said it's not like you wanna be racing every weekend.
