what are some advantages of sticking with the c4 or going with the aod. i have a 302 that came with the aod but im not sure if i should replace the c4 with the aod.. what do you think?
i'd say stick with the aod, you get an overdrive gear. Can run 4:10 or 3:70's and still cruise down the highway with your rpm's at a decent level unlike a c4 also goes in with minor modification. It has been done on here by a few members, think there might even be a tech article done as well
The C-4 has a better gear spread...The AODs' gear ratios are not the best if you plan on doing alot of drag racing. For a street car though with taller gears for fun...AOD
? I see how do you figure that the gear ratio's are so close most people could not tell the difference c4 gear ratio's C4 first gear 2.46, second gear 1.46, third gear 1.00 AOD gear ratio's AOD first gear 2.40, second gear 1.47, third gear 1.00, fourth gear 0.67 so knowing that if you were running 3.55 gears and 265/40/18 tires (like on some of the mustang gt's) C4 AOD RPM-- MPH...... RPM-- MPH 500 4.3............500 4.4 1000 8.7..........1000 8.9 1500 13.0........1500 13.3 2000 17.3........2000 17.8 2500 21.7........2500 22.2 so honestly looking at the data generated by the gear ratio's and the numbers that would mean that an AOD is actually better transmission for drag racing then the C4 just basing my answers of the first gear. Oh and if you want to check my data go ahead (the tire diamater ends up being 26.35 inches) http://wahiduddin.net/calc/calc_speed_rpm.htm It is also a similar story with second gear also if you want I can go and figure that one out for you too.... and third does not matter because they are both 1:1 gear ratio's
I stand corrected... Just going on personal experience here... The C-4 shift points feel better to me. The AOD feels soft and slow. Even in the gt stangs. Overdrive and stock 2:79 or 3:00 gears in a Mav at 43 MPH...LOL... You are correct the difference between the gear sets is practically nill(but certainly "feels" poor compared to the C-4 to me) In that vein... A few tenths of a MPH will only count on the strip. The numbers speak for themselves. I thank you for the impromptu education on the subject. I dont need you to run the calculations for second gear. Nor do I need to check your data...I have nothing to prove to anyone.I am also quite aware that 1:1 is 1:1 wherever it applies (pound of feathers/pound of lead) its still a pound. I am thick skinned and not an argumentative sort and never conduct myself with any one here in such a fashion but, I find your tone less than personable on this matter and dont appreciate it. I will chalk it up to "it's late and were just cranky and tired" and leave it at that and, bid you a good night and thank you again for the enlightening information you have provided... Pete
I'm doing the mod right now....of course my Mav has been a project since I bought it and have never driven it more than 2 miles. I made my own crossmember and got a custom flexplate for the application.
No I was on break and at work and trying to be as helpful as possible I didnt mean to come off in a condescending tone. But looking back yes I was somewhat, sorry about that.. I was just trying to help LOL.
Steve, You will want to get different rear gears - 4:11 is ideal - or the engine will be turning so slowly that it will be in the idle circuit of your carb which has an air fuel ratio of around 13.5:1 instead of the cruise circuit that is 14.7:1 and any movement of the throttle will engage the power valve which will further richen the mixture. (gas mileage will suffer) You may need to have your drive shaft shortened (and balanced) You will need a throttle valve cable and it will have to be adjusted before you drive the AOD or it is possible that the AOD will burn up in as few as five miles. Your gain in mileage will be very little compared to the expense of the installation. Since I build both transmissions for performance I agre that properly set up the AOD is a good transmission almost as good as the C4 but for street use only and with stock gearing or up to about 3.5:1 the C4 is the better alternative. If you like the acceleration of the lower gears then you can use them and the AOD very well on the street. It is also a good choice if you will be running a late model engine with EFI and EEM. The EFI can be tuned to make the AOD work well with the stock ratio in our Mavericks and Comets. Note: the reason I say the AOD is almost as good as the C4 is that above 500 hp the AOD must use a solid input shaft which does away with the locking converter. You end up with a very loose converter (because of the high stall speed) that generates much more heat than the C4 (2 - 3 times as much) because of the OD.
Ain't no thang my friend. Happens to us all, Work tends to amplify moods at times,(theres a reason its a four letter word) I know I am guilty of it sometimes too.(just ask my wife... LOL)...You definitely helped me with the gear spread issue...:Handshake Pete
I'll only be running about 270hp...maybe. I don't drive at the track. I DON'T have a C4....I DO have a rebuilt AOD. I've already made my own crossmemeber. So, so far, the expense of the installation is limited to the correct flexplate, the driveshaft stuff, the throttle cable and related brackets. The custom flexplate I got didn't work.(good thing I didn't install it) The studs from the converter aren't long enough. Not sure what I'm going to do until monday.
Time to replace C4 Original C4 in 72 Comet GT appears to be leaking from front main seal. Doing a resto-mod street/strip with 302 (original), Headers, 3.89 rear with traction bars. Hurst floor shifter just installed. Should I be looking at a stall convertor, shift kit, etc for my application while things are apart? Thanks. Gary
The C4 responds very well to a good shift kit - I recommend the TransGo 40-2 reprogramming kit. I have seen too many problems with the B&M kits and nobody stands behind the kits like TransGo - they are - in my opinion - the best engineered commercial kit available for the C4.
Thanks Paul. It is things like this that are only learned from experience and I appreciate you sharing yours. Would you have any recommendations on torque convertors and who is an honest broker. I have had pretty good luck with Summit for smaller stuff.
Stavro- looks like the beach, beer, and a bike with the AOD. Kinda steering toward the C4 to be less of a migraine. Good luck on yours. Gary
