Thread: Some contemplations on overdrive

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If it Dead Hooks that trans Could be Dust

Originally Posted by tango

If it Dead Hooks that trans Could be Dust

Not yet!!!! But with just 100 more ft. lbs. torque it would have to be a G-Force 5 speed instead of a Tremec with hardened shafts and gears!!!! (It's all in the clutch! If I were to put the old McCleod dual disc in it doubt it would live for half a dozen launches!!!!!)

Ya I have Taken Car's Of the Line with M22 4-Speeds and 4.10 Gears at 5 Grand . Man you Should have seen the Folks Running to get out of the Street

The new dual friction clutches help a lot to take out some of that initial driveline shock, especially in a well prepped chassis with slicks. Drag race only, then I use the McCleod Soft Lok....

PS--used to launch my old mini motor Maverick at 6500 and shift at 7200 with a 10.5" wide Hoosier slick!!!!! Most fun you could possibly have with your clothes on!!!!!

I ran that Borg and Beck 3 Finger Clutch set up . Yes it was hard to push Down and when you Dumped the Clutch it was very Violent all the way to the back tires . My 1965 Mustang has some Hays Clutch I can Hardly Push it Down . I know I am getting Old I will have to install a Newer Type in there .

when i get enough cash im definaly looking into a g-force 4 speed!!!!!! dave showed me them boys from g-force and now i want one !!!!

Hey Scooter I knew you could not stay Clear of any 4-Speed beat on your Car Threads

Scooter You want to Launch your Nova Like This ?

thats a bad chassis set up if i ever saw one haha. no i want to keep it wheels down just shit n get , you know me if its a stick my nose is in it learning!

Originally Posted by Dave Severson

That would be correct, but with a 2.97:1 low gear and a 4.11:1 rear gear, it launches quite well!!!! The lowest ratio low gear I know of in a stock box 4 speed would be a 2.20:1..... When you figure the ratio in low gear, then it becomes evident which rear gear will give the hardest launch and quickest 60 ft. time......a four speed with a 2.20 low gear, 1:1 top gear and a 2.54 rear gear will not launch near as hard as a 5 speed with a 2.97:1 low gear, 1:1 fourth gear, .62 overdrive 5th gear, and a 4.11:1 rear gear....(and we won't even talk about how much fun the five speed is with a 6.00:1 rear gear!!!!)

Well, my whole idea was whether a 1:1 top gear had less drag than an overdrive, or would transmit power more efficiently. To me it just seems like it would. I made an effort to try and explain it was a theoretical postulation but many people have responded with how the lower gears would now be all wrong. If you read the original thread I had made my best attempt to negate that by stating that in my theoretical transmission every gear would have the same overall ratio as it's overdrive counterpart, that is the same engine rpm to tire rpm in every comparable gear, so the launch would be the same. Maybe I need to take one of those Art Carney courses so people can understand me better. I don't know any other way to explain it any better.

a transmission is more efficient when running direct in the top gear.... but what ratio would the transmission gear sets be? I'm not saying you're wrong, just gave the example of why I like the 5 and 6 speed transmissions....

Originally Posted by Dave Severson

a transmission is more efficient when running direct in the top gear.... but what ratio would the transmission gear sets be? I'm not saying you're wrong, just gave the example of why I like the 5 and 6 speed transmissions....

The ratios would be whatever is optimal for the desired application. A drag car would be different that tow truck.
Actually it looks like the Richmond transmission attempts to do just that, allow you to tailor the ratios you want in conjunction to a 1:1 5th.

Ok, but then to equal the same overall ratio that my 5 speed has with a 4.11 rear gear, wouldn't the low tranny gear have to be so high numerically that the car would only move a few feet before shifting??

My point is, without the overdrive gear (or gears with the 6 speed) how could I still enjoy my car in the "best of both world" environment that my 4.11 rear end gear and .62 overdrive trans gear????

[QUOTE=Dave Severson;339271]Ok, but then to equal the same overall ratio that my 5 speed has with a 4.11 rear gear, wouldn't the low tranny gear have to be so high numerically that the car would only move a few feet before shifting??

My point is, without the overdrive gear (or gears with the 6 speed) how could I still enjoy my car in the "best of both world" environment that my 4.11 rear end gear and .62 overdrive trans gear????[/QUOTE
I just wrote about 2 paragraphs with examples and deleted the whole thing, if you don't understand that the total (transmission ratio and rear end ratio added together) ratio in any given gear would not change then I give up trying to explain it. It's giving me a head ache

An example of what Willowbilly is saying , My cousin has a Kenworth with a 425 Cat and 15 over trans., 4.11 gears. My Eagle has a 425 Cat and 15 direct, 3.55 gears. RPM at 60 mph is 1750 in both. Speeds in all gears is the same. The OD trans is a bit noisier in top gear, and the direct geared one seems to pull a hill better in top gear. On a long uphill grind, the Kenworth can go down to Direct and pull like crazy, quieter than the IHC in 14th (reduced gear). Once you shift them both down below that, there's no difference. Neither gets more than 5-6 MPG grossing 120,000 lbs, so I can't say if the reduced friction makes any difference in fuel consumption. Logic would say it should, but a few percent at that high rate would be awful hard to detect.