Well we finally got the 4:11's installed and decided to test her out................WTF! Man these gears are a good match for the cam, stall, etc. I would never ever have imagined what going from 2:79 to 4:11 would do, it gets into the meat of the power band immediately, slam 2nd and it's right back up there. So far we have only pushed it hard through 1st and 2nd, when I shifted into 3rd at about 6400 rpm give or take 100 rpm it was still pulling hard, I have no doubt 7k rpm will be a non issue........NOW, does anybody have a good AOD for sale cheap cause this will be a problem, it loves some petro
Also the son is having a grand time, we have been doing a good bit of back road driving and he is very comfortable with the car and I feel he is going to be a courteous safe driver, his biggest worry and exact word's were "Dad I'm worried about gas money"!
3:55s would be gas money in the pocket...tell him..."you have to pay to play"... with the 4:11s I don't think the AOD will make that much difference in mileage...JMO
The AOD has a 0.667 final gear, that's a 33% drop in rpm, so say turning 3500 x .667 = 2,334, that's almost 1200 rpm drop if I'm calculating correctly.....that seems like a good bit, is it? or do we need to just hunt down a 6 speed manual?
I have read about those before and they seen really cool, the splitting of the gears so to speak, seems really really cool...just not $3000 cool IMO
And yes we would rather stay with the 4:11's and go with a 6 speed manual, I have a friend in the transmission/rear end business (started on class 8 equipment only) but they have a boneyard of trannies I could choose from then have him build it up for low $$, example of what he charged to do the rear end $0, I assume I could get a 6 speed built to take a hard punch for a few hundred dollars at most.........of course I'm guessing there may be way more to building that tranny than the rear end
Also...Most 6 speeds still only have 1 overdrive gear...Also, with the 4.11s, final cruise RPM at say 65 mph, will depend on tire diameter as well. A larger diameter tire will effectively lower your cruise rpm along with the OD gear.
actually the popular over dive that is most commonly available is the tremic t56. it has 2 overdrive gears. its a big transmission. i believe that some transmission tunnel modifications will be necessary. a t5 will help a lot with keeping the rpms down. the ones in the fox mustangs have a really short 1st gear and combined with 4.10s its almost useless. the z spec t5 which is the one that was used in the 93 cobra and is what is sold new all over the internet has a taller 1st gear and would work much better with 4.10s. the aod also has a reall short 1st gear but has a really deep over drive and will work well with the 4.10s. also rear tire height really factors in. i always run around a 28-29" tall rear tire. if your running closer to a 25" tire then the 4.10s will still be screeming the rpms with the overdrive transmissions. so consider trying to get the tallest tire you can on the rear.
Theirs absolutly no point in purchaseing a Gear vendors unit unless you litally just spent a wad of cash on a fully built non O/D trans..if you have the cash for a gears vendor you can just buy a build overdrive for around same price and less install headaches the coolest manual trans out there would be the legend gt700 http://legendgt.com/Products/lgt-700-transmission/ a built ford AOD would do well
Bryant how is the AOD's 2.40 1st considered real short? A T5(.68) or AOD(.67) in overdrive will bring the cruise rpms of the 4.11s back very close to stock 2.79s. Off topic, my car has the exact opposite issue as the OP: 2.79s x AOD 4th of 0.67= a 1.87 Final drive(I have no idea why the PO thought an overdrive was useful with 2.79s).
honestly i havent messed with aods in a long time. i remember on fox mustangs early on the gears to run was 3.55s with a t5 and 3.73s with an aod. then people got more about race and each recommendation stepped up a 1/4 point. i remember putting 4.10s in aod cars and thinking they drove like that was too much gear. my first suggestion is to convert to a t5. its way more fun to shift on the streets than to let an auto do its thing. if doing the t5 conversion is to much then the aod is the next best option.
