That is done on Road Racing gearboxes where you downshift into 1st at 50 mph. Road Racing gearboxes are usually "Face Plated" instead of pro-shifted [ face plate dog box seen below ] They are quite loose and are easier to downshift In a drag racing gearbox you only need to upshift so they only "pro-shift" 2nd , 3rd , & 4th gears If you really want to have "Ronnie Sox" style FUN you can modify your gearbox to do "FULL THROTTLE CLUTCHLESS UPSHIFTS" quite easily. What you do is get all 4 gears pro-shifted and 4 sliders pro-shifted also. Then you grind the dog rings and sliders on an angle so they jump out of gear on "over-run" [ deccelaration ], Now the fun part! You need to make 2 "Split Sliders" out of the 4 so when you upshift 1/2 the slider upshifts while the other 1/2 stays in the lower gear [ for a nano-second ] When the dog ring engages in the upshifted gear , the lower gear goes instantly into overrun so it spits out the slider. What really slows down shifting is Torque holding the slider in the lower gear [ preventing it going into neutral ]
Please understand when I wrote this ! I don't think Ronnie Sox ever used these mods, he was way more talented than this! It is a simple procedure to give us mere mortals a fighting chance when competing against the "Shift Lever Gods" 1 :You need to get the gears Pro-shift modified in all 4 gears [ 4 speed ] Don't waste your time grinding off teeth on the dog-rings ,you need them to be coarse and chunky with a lot of freeplay 2 :You need to get 4 sliders Pro-shift modified 3 :You need to cut down the sliders in a lathe in the dead center of the groove where the shift forks go. When you hold two cut down sliders together they should measure the exactly same as one slider [ but with a split in the middle ] That is why you need 4 sliders to make 2 4 : On each gear [ all 4 ] AND on each slider you need to grind an angle on the dog ring teeth and the slider teeth on the "over-run side" of the teeth so that the gearbox jumps into neutral when the gas pedal is lifted. You have to do all 4 gears because you cannot pull the gearbox into neutral with split sliders [ you just rock the car forward and it jumps out ] It pays to dummy assemble the gearbox and mark the sides of the teeth you grind off at this stage Three things slow down /or prevent full throttle upshifts 1. The speed differential between the two gears [ the loose pro-shift "dog rings" remedies this ] 2. The spike in RPM going through neutral between gears [ the split sliders remedies this ] 3. The torque of the engine holding against the gear you're trying to shift out of ."hanging in gear" [ the split sliders and the angle cuts remedy this ] If you're slightly less tatented with your shift lever speed , Dont worry! When you partially pull into a higher gear, the overrun of the lower gear jumps the slider out and "assists" the slider into the next gear [ only on the 1-2 or 3-4 shifts ] ps: Don't tell anybody about these mods, So when somebody spies an old OEM gearbox in your race car you should be able to enjoy your new found "shift lever guru" status
Yes, right where the shift fork goes. But you lose a bit of material when you part it off in a lathe so you need 2 to make 1 to keep it the same width Here's a pic of a stock slider compared to a pro-shifted slider combine that with a pro-shifted gear and you'll see that it will be loose [ you can rock the car back and forth ] Here's a piece from "G-Forces" website [ they tie the two 1/2 sliders together with springs that stretch momentarily as you upshift ] Clutchless Engagement: With clutchless gearbox, it isn't necessary to back off the gas pedal or release the clutch even for a split second - when making a gear change. The GF-5R clutchless transmission utilizes split, spring-loaded sliders. The engagement lugs on each half are ramped on the deceleration side. When the shift lever is pulled into first gear, both slider halves move to engage the first gear faceplate. When the shift lever is moved to the second gear position, only the slider half-facing second gear moves to engage that gear. At this time, both gears are engaged momentarily, but second gear causes the main shaft to increase its rotational speed. This speed difference kicks the first gear side of the slider out of engagement, (hence the need for the ramped engagement lugs). Subsequent gear changes operate the same way. All shifts are made at full throttle, without the use of the clutch, just as they are with a planetary transmission.
I see. Not really a back yard modification but I understand. Depends on the slider moving off the gear when power is removed.
I heard a rumor that the Sox and Martin Hemi Pro stock had a Ford toploader 4 speed transmission, because it would hold up better than the Chrysler. They didn't admit it because they were sponsored by Chrysler Ago
They were marketed in the NW called a bang bang. When I worked for Coletti Chrysler plymouth you could buy a new MOPAR with one in it. People tried to drive them on the street. I never could figure out whay someone would want one to drive to the grocery store.
As I said, we ran a mopar slick shift box until the Lenco came out, we got number six production trans, flew out to get it, broke it down and carried it on the airplane. Stored in overhead bins. Try that with the TSA today. A racer buddy has run a Jerico in a 9 second street/strip car for years, and its kinda driveable on the street. Dog type trans, like a harley. Faster you pull the shifter, the nicer it shifts. Gotta double clutch downshifts. Heres a link, fyi...http://www.jericoperformance.com/cl4.htm
Problem with the Harleys was always bent shift forks. Maybe not on the new bikes. This sounds nuts but I have wanted to run a Lenco in a driver for years. my wallet has always prohibited that but one of these days.
I have a spare toploader setting under the bench. Makes me want to do this so I can put in my 56 F100. Have some fun at rhe dragstrip. What is the life on the street ? Only abuse would be at the strip.
Back in about '05, Ronnie was at Fred Engleharts car show in Elkton, MN. There was a big crowd around him all day, getting autographs, etc. Late in the day when the crowd had dwindled, Ronnie and another guy were sitting alone in the shade of a tree. I asked if I could sit down in the empty chair and he said "sure, sit down" I introduded myself, we shook hands, and started talking 4 speeds, talking like we knew each other even though we just met. I had heard the rumor about him using toploader transmissions as well, so I asked him about it. Well, that ruffled his feathers a bit, like he was tired of hearing about it. He said "No, why would we?" and went on to tell how the mopar 4 speed was the strongest tranny available at the time, that they could get as many trannys and parts as they needed for free, and he told me how they modified them, and how they adjusted the linkage to pre-load 3rd, stuff like that. So I heard it straight from the horses mouth, the rumor is not true. Joel
The Jalopy Journal
