FD transmission solution for 500+ hp
11-09-13, 03:32 PM
#126
All out Track Freak!
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I don't see why it wouldn't take drag launches just the same. I personally believe the weakness in the FD gearbox has nothing to do with the gears themselves but is actually the mainshaft flexing causing stress on the teeth from the movement. The guy who recommended the box to me originally drag races his 20b with more power then I have without issue.
thewird
thewird
All I need is the upgraded main shaft
11-09-13, 06:47 PM
#128
thewird, what would it cost to get an upgraded main shaft and dog rings?
a good friend of mine had a ls1 T56 that was modded only with dog rings, and no other upgrades.
i just want the dog rings, but i guess i wouldn't go through and not upgrade the main shaft. i definitely do not want the straight cut gears though. just dog rings.
a good friend of mine had a ls1 T56 that was modded only with dog rings, and no other upgrades.
i just want the dog rings, but i guess i wouldn't go through and not upgrade the main shaft. i definitely do not want the straight cut gears though. just dog rings.
11-09-13, 08:46 PM
#129
Cost me $1350 with apparently a perfect core that I gave them. I also asked Paul not to bother sandblasting it to make it cheaper. So that price was just the mainshaft, all their treatments on the internals, and the labor to rebuild the box.
I think I was quoted for around $2500 to get "the works" which was the additional faceplating of the gears to make it syncroless. At the time I was on a limited budget so I didn't get this option as I was on an extreme limited budget trying to spend the least amount possible to get the car to stop grenading transmissions after 3-5 laps at full power. I wish I had though.
thewird
thewird, what would it cost to get an upgraded main shaft and dog rings?
a good friend of mine had a ls1 T56 that was modded only with dog rings, and no other upgrades.
i just want the dog rings, but i guess i wouldn't go through and not upgrade the main shaft. i definitely do not want the straight cut gears though. just dog rings.
a good friend of mine had a ls1 T56 that was modded only with dog rings, and no other upgrades.
i just want the dog rings, but i guess i wouldn't go through and not upgrade the main shaft. i definitely do not want the straight cut gears though. just dog rings.
thewird
11-10-13, 12:49 PM
#132
RX 4BPT
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International calls are expensive. I'm in the uk.... But yeh a phone call is best. Thanks.
11-11-13, 01:24 PM
#134
I've run and driven many rebuilt '93-02 style Fbody LS1 T56's as well as the '04-06 GTO T56's and never really was impressed with how smooth they shift. The GTO units shift better; however I don't like their gear ratios.
I took the rebuilt Fbody T56 out of my car which I rebuilt as it was one item I felt I overlooked on finding my idea of perfection with my project..... then installed a new T56 Magnum which I sell into it. For me it was a direct fit with the trans mount needing no changes nor my exhaust. (I run an LS7).
The only changes needed to be made were to shorten the driveshaft and install a 31 spline yoke on it (I run Spicer 1350 Ujoints and a Cobra 8.8" IRS rear). It also requires a new shifter to properly position the shift handle (there are options to place it fore/aft +/- 4 inches in 1/2" increments. I run the McLeod unit with a 4" setback. The T56 Magnum is just under 2" longer than the older styles and dimensionally the same on the exterior for the most part. There is no provision for a torque arm/PPF mount anymore.
The shifting smoothness is no comparison to the older units and is awesome. The ratios are the same as the older T56; however 5th gear is now .80 ratio vs. the older .75 so you stay in your powerband better. 6th gear is .63 vs. .50 so you probably lose 1-2mpg.... no biggie.
The lighter your clutch/flywheel combo the easier of a time you will have shifting any transmission at higher RPM's. Flogging mine hard it shifts at 7400rpm without issues.
I run a 7/8" clutch MC on my setup. Routinely bleeding the clutch MC reservoir due to clutch dust contamination should be done. After 2-3K miles mine was black and glittery. Unusual... but it is a problem with this type of hydraulic slave.
I took the rebuilt Fbody T56 out of my car which I rebuilt as it was one item I felt I overlooked on finding my idea of perfection with my project..... then installed a new T56 Magnum which I sell into it. For me it was a direct fit with the trans mount needing no changes nor my exhaust. (I run an LS7).
The only changes needed to be made were to shorten the driveshaft and install a 31 spline yoke on it (I run Spicer 1350 Ujoints and a Cobra 8.8" IRS rear). It also requires a new shifter to properly position the shift handle (there are options to place it fore/aft +/- 4 inches in 1/2" increments. I run the McLeod unit with a 4" setback. The T56 Magnum is just under 2" longer than the older styles and dimensionally the same on the exterior for the most part. There is no provision for a torque arm/PPF mount anymore.
The shifting smoothness is no comparison to the older units and is awesome. The ratios are the same as the older T56; however 5th gear is now .80 ratio vs. the older .75 so you stay in your powerband better. 6th gear is .63 vs. .50 so you probably lose 1-2mpg.... no biggie.
The lighter your clutch/flywheel combo the easier of a time you will have shifting any transmission at higher RPM's. Flogging mine hard it shifts at 7400rpm without issues.
I run a 7/8" clutch MC on my setup. Routinely bleeding the clutch MC reservoir due to clutch dust contamination should be done. After 2-3K miles mine was black and glittery. Unusual... but it is a problem with this type of hydraulic slave.
11-19-13, 09:25 PM
#135
Hey gnx7, I have one of the 98-02 fbody trans and making it fit on my rotary. I usually shift at about 8k rpm. You think mine will be ok. I actually want to upgrade to a tr6060. Come from the 09+ corvettes or 2010 camaros. What do you think about them.
12-06-13, 01:31 PM
#136
The '08+ TR6060 from the Z06 is a transaxle (rear mounted) so that won't work.
The 2010+ Camaro TR6060 has funky gear ratios for a heavy car. Don't like them. They also use a 3 finger flange on the output shaft requiring a funky driveshaft/adapter piece to be used (added cost). The front bellhousing is incorporated into the front bearing plate too meaning you need a custom setup to run a traditional front bearing plate that will accept a bolt on bellhousing to adapt it to a rotary etc.
I like the new T56 Magnums (TR6060) with Fbody gear ratios (come stock with them). They suit a lighter car better with good splits thru the gears. 5th gear is .80 also keeping you better in your powerband.
The 2010+ Camaro TR6060 has funky gear ratios for a heavy car. Don't like them. They also use a 3 finger flange on the output shaft requiring a funky driveshaft/adapter piece to be used (added cost). The front bellhousing is incorporated into the front bearing plate too meaning you need a custom setup to run a traditional front bearing plate that will accept a bolt on bellhousing to adapt it to a rotary etc.
I like the new T56 Magnums (TR6060) with Fbody gear ratios (come stock with them). They suit a lighter car better with good splits thru the gears. 5th gear is .80 also keeping you better in your powerband.
12-06-13, 01:43 PM
#137
Rotor or no motor
iTrader: (24)
I ended up going with the liberty option with the straight cut dogbox and different rqtios to suit my track needs.. after a long wait I should have it by next week.. will share thoughts soon if you guys want to
12-06-13, 03:49 PM
#138
Racing Rotary Since 1983
Thread Starter
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"I have one of the 98-02 f body trans..."
so do i. 99 out of a boneyard. GTO shift mechanism. 4 years in my car.
'I usually shift at about 8k rpm."
i have no problems w the trans shifting at 9000 and love the close ratio gears..
howard
so do i. 99 out of a boneyard. GTO shift mechanism. 4 years in my car.
'I usually shift at about 8k rpm."
i have no problems w the trans shifting at 9000 and love the close ratio gears..
howard
12-06-13, 04:10 PM
#139
Junior Member
You're from wisconsin?! Where abouts?
12-06-13, 05:55 PM
#141
Its a budget game. Spend $1350 getting the stock one built and it bolts right in or spend $6000+ putting a T56 in and get another gear. Thats what the choice comes down to. No 13b is gonna break a Liberty built box so neither is better then the other other then gear ratios. My 20b with crazy torque can't even break it with 335 Hoosier slicks beating it on the track. Not to mention the T56 adds weight also.
thewird
thewird
12-10-13, 04:37 PM
#142
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No 13b you say?
You can still break the liberty, still 20yr old metal, no matter what enhancements you do to it An incredible trans none the less, but you get what you pay for it's not as strong as a t56, but for your average Fd owner a great choice
You can still break the liberty, still 20yr old metal, no matter what enhancements you do to it An incredible trans none the less, but you get what you pay for it's not as strong as a t56, but for your average Fd owner a great choice
12-10-13, 05:08 PM
#143
thewird
12-10-13, 05:16 PM
#144
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Nope, factory shaft, went 9.34 on that box
Went 9.23 on a junkyard syncro box, shock load is the main killer, case flex next
Stripping the teeth off 3rd gear, well I've heard "that shouldn't have happend" atleast 5 times lol, happened on the dyno on a boost ramp pull, well I'm getting it repaired, see how long that one lasts...
Went 9.23 on a junkyard syncro box, shock load is the main killer, case flex next
Stripping the teeth off 3rd gear, well I've heard "that shouldn't have happend" atleast 5 times lol, happened on the dyno on a boost ramp pull, well I'm getting it repaired, see how long that one lasts...
12-10-13, 06:10 PM
#145
3rd gear is the first thing to let go, it goes because its in the middle and the MAINSHAFT flexes which separates the gears and stresses the teeth. I broke 2 transmissions with my 13b and 4 transmissions (this year) with the 20b. Every time it broke it was 3rd gear. The Liberty Box hasn't broken in 2 track days with more power from the extra timing, stickier tires, and cold weather.
Stock gearbox, 5 degrees retarded timing, early in the season and I still wasn't used to the power and car wasn't setup well... gets "interesting" at 6 minutes when I let the Mclaren by intentionally lol
Liberty box and full power...
Start at 7 minutes...
I'm a scary cat in the next 2 videos, not used to that kind of speed at all. 162 mph down the UPHILL straightaway...
Porches? No Problem!
Viper Race cars? No Problem!
thewird
Stock gearbox, 5 degrees retarded timing, early in the season and I still wasn't used to the power and car wasn't setup well... gets "interesting" at 6 minutes when I let the Mclaren by intentionally lol
Liberty box and full power...
Start at 7 minutes...
I'm a scary cat in the next 2 videos, not used to that kind of speed at all. 162 mph down the UPHILL straightaway...
Porches? No Problem!
Viper Race cars? No Problem!
thewird
12-10-13, 06:45 PM
#146
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Haven't ever heard someone presenting shaft flex as the reason for faliure of 3rd, but it's plausable , as I've seen eshaft flex moretimes than most. However I know 3 other guys who stripped 3rd and all had the "upgraded" shaft
12-11-13, 01:43 PM
#148
3rd gear is the first thing to let go, it goes because its in the middle and the MAINSHAFT flexes which separates the gears and stresses the teeth. I broke 2 transmissions with my 13b and 4 transmissions (this year) with the 20b. Every time it broke it was 3rd gear. The Liberty Box hasn't broken in 2 track days with more power from the extra timing, stickier tires, and cold weather.
Stock gearbox, 5 degrees retarded timing, early in the season and I still wasn't used to the power and car wasn't setup well... gets "interesting" at 6 minutes when I let the Mclaren by intentionally lol
thewird
Stock gearbox, 5 degrees retarded timing, early in the season and I still wasn't used to the power and car wasn't setup well... gets "interesting" at 6 minutes when I let the Mclaren by intentionally lol
thewird
No doubt your car is fast. Now try hitting those apexes consistently.
