Anybody here with a long term review for service life of the Liberty trans mod for the FC/FD?

 

which trans mod?

mainshaft upgrade or gearset upgrade? (or both)

 

both

 

i have been beating mine for a while and i havent had an issue for years. both street and track use.

the only thing that keeps failing is the 5th gear synchro as the 5th gear is still the oem gear .

its noisy, its loud , the changes are "violent" and the ratios are too tall so forget the 0-60 times. if you are ok with that go for it. it all depends on where you are gonna use it on

 

used for road course. Car is about 430/370 at the wheels. Im hoping the trans case will hold up as well. Cooler and billet pan may help too

 

for a road course i like the oem ratio with a 4.44 in the back. if the oem ratio works for you, you can do just the mainshaft upgrade. it will hold just fine and it will be much better for street driving assuming that the car is a street car

 

4.44 is made for the t2? Car is track only.

 

im under the impression that the FC/FD/RX8 ring and pinions are interchangeable . i have used the 4.44 and the 4.77 from an rx8 on my fd. i believe the FC is the same. the FB/SA is different i believe

 

IIRC the Turbo II uses a much longer pinion than the FD, so the gears do not interchange.

 

This +1

 

I think you'd need a pretty specific use case (and tolerance) for the dog box equivalent mods. There's a lot to live with there. I went with just their main shaft (to go along with bigger pan, and shorter 5th), which will be last things I do to make the stock trans work. Beyond that, most are likely better off pursuing the T56 or 370Z trans conversions that will still behave like a street trans.

 

Yeah im on the fence for a 370 box or something like a TTi 6 speed for another little bit of cash. Was just thinking the liberty would get me by a little longer.

 

In 2021, Liberty's Gears produced a fully faceplated stright cut gearset for me (including faceplated 5th and reverse) in custom ratios to fit in the stock FD case. This was my selected solution for a track-only FD that preserves the stock PPF. Here is a link to a video on my first test day: . I'm still learning how to drive the new trans, but I'm very favourably impressed with the performance so far. I do not have long term testing results (only 4 track days this past season), but so far, so good... I know they made several copies of the gearsets, so feel free to contact Craig Linerty at Liberty's Gears and ask for the "Jim Murray" custom gearset for the FD.

 

self-edited for being off topic

 

I wound up buying a liberty main shaft, new bearings, syncros and a ksp deep billet pan. I'll update later on with results.

 

That sounds like a good plan, Monika. I hope you have lots of fast laps in 2022!

 

just curious what the custom gear ratios are?

 

They are made to order but the highest ratio they can make for the first gear is in the mid 2.xx:1. I cant recall exact number but i was going over the options with Paul (the go to guy for Mazda transmissions at liberty's gear) because my first gear is painfully long for a street driven use. This is when i opted for the oem ratios with just the upgraded mainshaft and i have been very happy with the outcome

ON top of that, they only make straight cut gears. Straight cut gears are supercool for a racecar but for the street, in my experience, is far from ideal

 

Thanks and I get that, but was referring to the custom ratios Joe Cool mentioned on his gearset.

suppose I should just call them as he suggested, but thought he might respond
.

 

How much was the mainshaft?

 

6-700 something like that.

 

I've tried to attach my workbook for my gear ratios.

In a nutshell, the stock ratios for my 1993 R1 were:
1st 3.483
2nd 2.015
3rd 1.391
4th 1
5th 0.719
Reverse 3.288

The ratios of the custom gearset are:
1st 2.4
2nd 1.7
3rd 1.3
4th 1
5th 0.8
Reverse 3.3

Which has reduced my top speed but made all 5 gears useable on a road course with at least one low spped (40mph) turn,

 

thank you very much