Crash Box Transmission (A Cheap Legal Solution for RX7 Drag Racers)
#1
Pro-shifted Transmission MOD (A Cheap Legal Solution for RX7 Drag Racers)
Apparently, Crispeed is already using this.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
This would allow your stock 5 speed transmission to shift like a pro-shifted G-Force, Liberty etc. etc. etc.
__________________________________________________ _________________
Let me know if there is anything I am leaving out.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
This would allow your stock 5 speed transmission to shift like a pro-shifted G-Force, Liberty etc. etc. etc.
__________________________________________________ _________________
Let me know if there is anything I am leaving out.
Last edited by LUPE; 05-22-06 at 01:33 PM.
#3
Originally Posted by crispeed
Damm.
That **** been bothering you ever since I mentioned it huh?
You can also send some parts out to Liberity and have them do it for you.
That **** been bothering you ever since I mentioned it huh?
You can also send some parts out to Liberity and have them do it for you.
Can you give better instructions on how to do this?
Last edited by LUPE; 05-22-06 at 02:04 PM.
#4
Originally Posted by LUPE
Apparently, Crispeed is already using this.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
This would allow your stock 5 speed transmission to shift like a pro-shifted G-Force, Liberty etc. etc. etc.
__________________________________________________ _________________
Let me know if there is anything I am leaving out.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
This would allow your stock 5 speed transmission to shift like a pro-shifted G-Force, Liberty etc. etc. etc.
__________________________________________________ _________________
Let me know if there is anything I am leaving out.
#5
Originally Posted by crispeed
That pretty much sums it up. Once you get that done then you can install a 'Long' shifter to help eliminate any missed shifts.
Did you do your mod yourself or did you send yours off?
I'd rather do it myself
#6
Originally Posted by LUPE
how long would you reccomend?
Did you do your mod yourself or did you send yours off?
I'd rather do it myself
Did you do your mod yourself or did you send yours off?
I'd rather do it myself
#7
Originally Posted by crispeed
A 'Long' shifter is a vertigate shifter that's used on the 'G-Force' clutchless transmissions.
I looked at those G-Force long shifters. It looks like there is noway that those would work on the stock transmission. It seems a regular shifter would work. How about some pictures of yours?
Last edited by LUPE; 05-22-06 at 02:30 PM.
Trending Topics
#8
Originally Posted by LUPE
I thought you meant a pickup shifter
Do those G-Force shifters bolt up to ours or is there alot of fab work involved? How about some pictures of yours?
Do those G-Force shifters bolt up to ours or is there alot of fab work involved? How about some pictures of yours?
Plus I stopped using the stock box a long time ago. In the end you're still going to break gears once you start making some serious torque. The stock case has a lot to do with that also. It flexes too much.
The shifter is not legal for the 'street class' at NHRA but it is for everything else.
The dog gear setup is so old school that I have not done it in like 10yrs.
The new method is to machined the factory dogs off and weld on a face plate type engagement like Liberity does.
Lupe onced my last stock tranny broked on the dyno I switched over to a Richmond(Dougnash) 4+1 tranny.
#9
Originally Posted by crispeed
You need to fab. It's not bolt on. Simple explaination would be to drill three holes in the case in the area around where the rods/forks are. Remove the forks and extend the rods outwards to meet with shifter rods then you simply fab a mount on the tail shaft to mount the shifter.
Plus I stopped using the stock box a long time ago. In the end you're still going to break gears once you start making some serious torque. The stock case has a lot to do with that also. It flexes too much.
The shifter is not legal for the 'street class' at NHRA but it is for everything else.
The dog gear setup is so old school that I have not done it in like 10yrs.
The new method is to machined the factory dogs off and weld on a face plate type engagement like Liberity does.
Lupe onced my last stock tranny broked on the dyno I switched over to a Richmond(Dougnash) 4+1 tranny.
Plus I stopped using the stock box a long time ago. In the end you're still going to break gears once you start making some serious torque. The stock case has a lot to do with that also. It flexes too much.
The shifter is not legal for the 'street class' at NHRA but it is for everything else.
The dog gear setup is so old school that I have not done it in like 10yrs.
The new method is to machined the factory dogs off and weld on a face plate type engagement like Liberity does.
Lupe onced my last stock tranny broked on the dyno I switched over to a Richmond(Dougnash) 4+1 tranny.
This sounds like a great option for Schecter and whoever else plans on running the NHRA Sport RWD class. I emailed Liberty about the price of doing the pro-shifted mod and faceplate mod. Actually, found out that they only charge like $200 total if you send them your parts.
#10
Living life 9 seconds at a time
iTrader: (2)
Joined: Feb 2001
Posts: 6,541
Likes: 0
From: Abingdon, Md
Originally Posted by LUPE
This sounds like a great option for Schecter and whoever else plans on running the NHRA Sport RWD class. I emailed Liberty about the price of doing the pro-shifted mod and faceplate mod. Actually, found out that they only charge like $200 total if you send them your parts.
Last edited by ErnieT; 05-23-06 at 09:01 PM.
#11
Hey Crispeed. I don't know if you are interested but i got in touch with a guy that does all kinds of mods to the DN 4+1. He has a large selection of new and used gears and he also does face engagement conversions. He even says that they have a conversion to run a G-force gear set in a DN case.
Does your DN have the torque tube? And what ratios are you running?
Allen
Does your DN have the torque tube? And what ratios are you running?
Allen
#12
Originally Posted by ErnieT
And Paul at Liberty said it would be $4k to change it to a total dog box. BUT the problem is the main shaft will still crack. Thats the problem Ari has been fighting with.
Yep
I know exactly what he's dealing with. I give up on the stock tranny a long time ago. The cost of making the stock tranny work is not worth it. Plus in the end it still has a limit. You can have a main shaft made out of 300m but the cost is going to be very high. The next thing is going to be the gears which are available allready in straight cut design. At least the straight cut design helps with the gears trying to walk away from each other which happens to be the main cause of gear breakage.
I've seen the entire cluster gear section shoot out the bottom of the tranny behind a 600rwhp + monster. It cracked the case in two and that was on a fourth gear shift too.
#13
Originally Posted by LUPE
Apparently, Crispeed is already using this.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
(...)
Let me know if there is anything I am leaving out.
This is how you would turn your stock 5 speed Mazda transmission into a pro-shifted transmission
You take the blocking rings out or grind the teeth off them. You then grind every other tooth off the dog gear and off the inside of the slider.
(...)
Let me know if there is anything I am leaving out.
Oddly, I was *just* talking with my boss's dad about this. He used to do this for his and his customers' trannies in the 60's/70's.
This is what got me. He has no rotary experience, but he advised me to NOT take any splines off, that when they did this they had a tendency to shear the remaining ones clean off if the shifts weren't done just right and/or for big power cars, BUT they would still shift just fine with *ALL* of the teeth intact!
I have enough junk trannies that I plan on doing this, just to try it! He also said you could either take all of the teeth off of the synchros, or if the detents in the shift rails were strong enough, just remove the synchros and the keeper finger things (inside the slider) altogether. Only reason to keep the synchros is to keep the fingers in place, the fingers act as additional detents as well as keeping the synchros in sync with the sliders. Without the fingers, things can move around a bit.
*NOTE* - I'm playing with the junk smoothcase transmissions, NOT the Turbo/FD units. Minor strength difference And his idea of "big power" is somewhat higher than a rotary, for much heavier chassis...
#14
Originally Posted by 13B-RX3
Hey Crispeed. I don't know if you are interested but i got in touch with a guy that does all kinds of mods to the DN 4+1. He has a large selection of new and used gears and he also does face engagement conversions. He even says that they have a conversion to run a G-force gear set in a DN case.
Does your DN have the torque tube? And what ratios are you running?
Allen
Does your DN have the torque tube? And what ratios are you running?
Allen
The only thing I bought from Paul at Liberity would be new sliders. You have to learn to repair those trannys the hard way because parts use to be very hard to come by plus a couple of full throttle missed shifts behind a 700rwhp motor at 10k rpm would normally take out the sliders and damage the crowns.
#16
Originally Posted by 13B-RX3
This guy works out of a shop at his house and he told me that if i could break it he could fix it. How many times did you lunch your trans when it was in your car?
Probably about a 100 times! Most of them never under 9500rpm or 20psi!")
With the wrong clutch setup I've seen all-motor cars snaped the input shaft or gears of G-Force. The torque tube does take a lot of the shock out though.
#18
#20
Originally Posted by MichaelB145
Anyone have Libertys phone number or website? I need to look at a transmission option that will keep me legal for SRWD.
I just got my Liberty T56 for my LS1 FC. Its incredible!
Andrew
#21
You Must use a Mazda Trans
thats it..Does not have to be a RX-7 one
Mark's 240sx uses a early 300ZX 5 speed trans and is Legal for NHRA sport class
easy street WRX uses a subaru legacy hybrid race automatic
is there a stronger mazda 5 or 4 speed out there?
thats it..Does not have to be a RX-7 one
Mark's 240sx uses a early 300ZX 5 speed trans and is Legal for NHRA sport class
easy street WRX uses a subaru legacy hybrid race automatic
is there a stronger mazda 5 or 4 speed out there?
Last edited by kabooski; 07-10-06 at 08:53 PM.
#22
Too bad you have to use a Mazda trans. Here is an incar video of the Liberty T56 in action in my FC. The first part of the video was to show the noise driving around town using the clutch. The two power runs were clutchless with slightly lifting on the throttle between shifts.
http://video.ls1tech.com/video/65c44...0673dcf0dc.htm
Andrew
http://video.ls1tech.com/video/65c44...0673dcf0dc.htm
Andrew
#24
Pictures of Modified Mazda Trans w/Long Shifter
Crispeed, Do you have any pictures of your old setup that you mentioned using a Long Shifter with a Stock Mazda Trans? Just curious how you set it up and where you made the 3 Holes in the Tranny Case. I have a All Motor car so I am not too worried about making too much Torque to grenade a Turbo II or FD style transmission.
Any help would be greatly appreciated.
Albert
Any help would be greatly appreciated.
Albert