Drag Pak Transmission
 

Hi guys, new here. I have been talking with Mack on his car and am building one myself. I am wondering if anyone knows if any of the cars are set up with a manual transmission? The automatic seems to be the most common but I was thinking about going with the manual gears. Any thoughts on this? Thanks.

Hal Hoover

I would think that Mack would know better than most of us (definitely more so than I). I would think that you could swap in a manual though. As far as which manual trans..... I have no clue. I guess it would all depend on how many gears the auto has, how many gears do/could you shift through before the finish line, etc..

i havent seen any with a manual
it can be done, but you'd probably get better times with an auto

I think you are right. I know you can get a steel bellhousing for the hemi that fits a Tremec 5 speed and the A833 4 speed. I'm not really looking to win anything and I like a manual transmission but probably the results would be better with the automatic.

I know of only two that has plans for a straight shift.... Larry Griffith and Jerry Sheredon. Larry has put a automatic in his for testing and such. Jerry is still in the engine developement. Larry is a 6.1 and Jerry is a 5.7.... Not sure which tranny they are using or anything.. I do know that Larry Griffith had or may still have a major problem with clutch linkage and such...

I can see why the clutch could be a problem. I never even checked until today but the car came with the original style hydraulic cylinder for a hydraulic clutch. Not what I was hoping for.

Why wouldn't you want a hydralic clutch? All you would have to do is run a stainless steel braided line down to where the fork is. There is no messing with a linkage assembaly.

I have never even driven with a hydraulic clutch but I have heard there is a lag from the lines expanding slightly as you pound the pedal. A mechanical linkage is more controlable and positive in it application. In my case it may not make much of a difference but I would prefer a mechanical linkage. I am guessing that the 2 cars Mack mentioned having linkage problems are related to this. If the hydraulic was the way to go, it would be simple as you mentioned.

It looks like it would require a completely fabricated linkage which may be more trouble than it is worth.

are the hydralic lines steel braided?

Exactly right... The hydraulic works well on the street but on the track not so well... I know that Larry Griffith has made and re-made and re-re-made mechanical linkages and still not satisified with the way they are working.. Thus the reason he is now testing with an automatic....

this is a lil off topic but when you,379x or mack are racing with a manual, do you use the clutch when you shifting? or just when taking off?
i never 1/4 mile a manual but on the streats (in my younger years) i didnt use the clutch much,

I have never race a manual (on the track)... But I do know that the PS cars do not use the clutch for shifting and the new rule in SS and Stock allow a "clutchless tranny" for shifting. But I think all the old school 4 speeds still had to use the clutch... I do know that Ronnie Sox did... I was at a race in NC one Saturday and he and Jake King spent all day on adjusting the linkage so it was "just right"... Buddy Martin was tuning the Hemi and they were adjusting the linkage.. Thanks for making me remember that day!!!!!

I have a 1968 AMX set up for SS class with 4 speed and I use the clutch although the transmission is modified to allow 2nd to 3rd and 3rd to 4th gear shifts without a clutch. I still do clutch each shift as I am not a pro and don't want to break anything. You have to hit the shifts just right to do it without clutching. I had hoped to set up this drag pak in a similar way but I think the automatic will be it at least for the first running version. Maybe if somone comes up with a good linkage down the line I will switch.

if you steel braided all the lines, wouldnt that stop the expansion
isn't the same as brake line, when the rubber expands?

how long can the tranny last without using the crutch?
i have only really seen people powershift with just keeping their foot to the floor while using the clutch

In racing you go thru them so often they never wear out. You are always changing gears or ratios at almost every track... Heck, the PS guys are every round.....

Steel braid doesn't make any difference. The inner lining stretches anyway. And you are right, brakes do the same thing but it isn't that critical. Brakes work with variable pressure so the flex is compensated for by your pedal effort. A direct linkage is the only way to accurately apply the clutch.

I've only messed up one transmission clutch less shifting, bent the fork for 3rd gear in a 67 3/4 ton.
i know not a good tranny to be doing that to. it was my 1st vehicle i got after i got my license