ThatGuyEG8

So I have been researching different transmissions offered for the ecotec engines and a couple of randoms and did a top speed per gear. Now to start off this more so for drag racing but can be used for whatever. What I have notice about the ecotec transmissions is the gearing is very long.

Now obviously this is just calculations and no your car will not go 200 mph. This just a calculation of tire size, RPM and final drive.

cw383

iTrader: (6)

Very good work. I remember sitting at work figuring a bunch of these out at work once, but I never recorded or saved my info. On the F35 section, the low gear one should be 4.45. I said I wouldnt doo anything else to my car after last motor, but that Saab trans is looking so tempting.

zeeky420

Depending on f40 you have mine is 3.55fd

Sharkey

iTrader: (1)

there are far more ratios out there than what is listed. the f23 has 5 different final drive ratios (3.63, 3.94, 3.84, 4.17, and 4.41) and a couple different 5th gear ratios. the f40 has a couple different gear sets and between the 2 all the ratios are different.

in both the 4t40/4t45e and 4t65e the differential can be changes as well as the chain sprockets, so both transmission types have a large number of possible final drive gear ratios. the 4t65e is the descendant of the 4t60e, 4t60 and 440-t4 transmissions that date back to the early 80s and they share a lot of parts. this transmission family was used in midsize and larger cars with engines ranging from the 2.8l all the way up to a 5.3l. because of this, the list of possible gear ratios is huge. the 4t40e/4t45e wasnt used in near as many cars, it came out in 1995 in small and midsize cars, mostly behind 4 cylinders but they did offer some v6 engines with them (3.1, 3.4 and 3.5l). the possible final drive ratio list isnt nearly as long on these transmissions, but there are still plenty.

ThatGuyEG8

4.45 FD for the F35 (very hard to find) Came in the L-Seires Saturns and I have been considering getting that final drive also.

3.545 FD F40 also had different gearing compared to the 3.7 FD F40
F40
3.545 FD
1st 2nd 3rd 4th 5th 6th
3.77 2.04 1.32 0.95 0.76 0.62
43 mph 80 mph 123 mph 172 mph 214 mph 263 mph

Highway Cruising @ 75 mph
2150 RPM

Sharkey you are absolutely right but for time and space i didn't list all of them i guess i could list them but for me personally for drag race use i would try to get the lowest FD possible.For the 4t40/45e came with quite a few FD from Wikipedia:

The "MN4" 4T40E is able to handle vehicles up to 4000 lb (1814 kg) GVWR. The final drive ratio can vary depending on the car's curb weight and engine power output. 3.91, 3.63, 3.29, 3.05, 3.69, and 3.42 are all of the available ratios used in the 4T40 (and 4T45) transmission; Made possible by using combinations selected from 3 different sprocket combinations (32/38, 35/35, 33/37) and 2 differentials (3.29, 3.05). It is designed for 1.5–3.1 L engines producing up to 190 ft·lbf (258 N·m) of torque.

Minor design changes provided the 4T40E an increased torque capacity, producing the 4T45E. The "MN5" 4T45E is able to handle vehicles up to 4,500 lb (2,041 kg) GVWR. Final drive ratios include 3.63, 3.29, 3.05, and 3.91. This same transmission is used in the Saturn Vue Green Linehybrid vehicle with the addition of an auxiliary oil pump and hybrid-aware electronics. It is designed for 3.0–3.5 L engines producing up to 205 ft·lbf (278 N·m) of torque, but was also commonly mated to some versions of GM's 4-cylinder Ecotec line.

As for the 4t60/65 they are a ton of different final drives for these transmissions as you stated and the came in almost every FWD gm car with V6/V8 engine from 1991-2007.