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Discussion Starter #1
I am replacing the Tremec 3550 in my road race car. It has a high winding Dart block setup that I shift at 7000-7200 RPM. There is a lot of talk about the Tremec's not shifting that high so if I go the Tremec route, I'm going to get the upgraded one from Liberty with the Carbon synchroes ect...

After a little research, I'm also hearing of the T-56's having a hard time shifting at those RPM's too sometimes...

I was set on the T-56 before I really started researching everything. Do any of you guys have any experience with either of these transmission's on a road course?
 

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I found myself at the same crossroad a few years ago with my new high winding dart engine. My trusty old T5-Z code wasn't up to new 650 rwhp. Ultimately decided on the TKO route with the massaged internals for several reasons, mainly because it weighed less than the T56. Also I felt I did not need the second overdrive in the T56 because I no longer drove the car on the on the highway, instead trailing it to events. At first low speed shifting particularly into 1st gear from a stop was a bit too notchy for me, but it did improve as it wore in after some use. Shifts great on the track and at high rpm right out of the box. The best improvement I found for low speed shift improvement came from changing the fluid to Redline MTL 75W80 GL-4 Gear Oil, a popular replacement for syncromesh and recommended by Redline.
 

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Discussion Starter #3
Wow, from thin synchromesh fluid to a thick gear oil?
 

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i used to run my viper spec t56 in my roush for road racing. i shifted at 6200 rpms and never had any issues. i ran amsoil 75-90 for tranny fluid i believe
 

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I'm also at the same cross road... New motor is pushing the limit of the G-Force T5 straight cut dog box. Don't want the weight of the T56 but need strength. Been loosely researching this: Learn about Legend Gear & Transmission's LGT-700 Supposed to be a close 5spd cousin to the T56. There is also supposed to be a road-race close ratio box coming. Price is on the higher side of most options.

Is the only other reasonable high torque / high RPM trans a reworked TKO?
 

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Discussion Starter #8
I finally decided on the Liberty TKO and added the Carbon synchroes to the .82 fifth gear also.

I was dead set on the T-56 even though I hated adding anymore weight to my already heavy fox. Once I really started looking at things though, I realized there was no way the T-56 was going to work with my header setup as they move the clutch fork from the 9 o'clock position to the 7 o'clock position. That just wasn't going to work with my headers and I'm not interested in spending any more money for a hydraulic clutch setup.

Hopefully this Liberty shifted TKO-600 works out for me....
 

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Are the full tilt Astro A-5's not an option for you guys? Just curious.
 

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Discussion Starter #10
Nope, had my fair share of T-5 destruction with numerous iterations of T-5's. Not interested in them no matter how strong anyone claims they are....
 

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Are the full tilt Astro A-5's not an option for you guys? Just curious.
They were going to be my next play, because I keep shredding T5 3rd gears even at a measly 260 RWHP. I know the Astro's last for a lot of people in high-hp applications, OTOH there's at least one person here who's blown one up on the road course. I got an offer I couldn't refuse on a low-miles TKO and all the conversion parts to make it work, so that's what I ddi. It's not a Liberty unit and it has shown me it will occasionally balk on the high-rpm 2-3 shift if I try to rush it, but it'll have to do for now.
 

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They were going to be my next play, because I keep shredding T5 3rd gears even at a measly 260 RWHP. I know the Astro's last for a lot of people in high-hp applications, OTOH there's at least one person here who's blown one up on the road course. I got an offer I couldn't refuse on a low-miles TKO and all the conversion parts to make it work, so that's what I ddi. It's not a Liberty unit and it has shown me it will occasionally balk on the high-rpm 2-3 shift if I try to rush it, but it'll have to do for now.
Thanks Miffy. I know the drag racers swear by them but I didn't know how they would do in a lap after lap of endurance type racing application. Plus the smooth as buttah shifting I thought would be a bonus.

Yeah, rated at 650HP/575TQ with even a "Road Race" 5th gear option. I was just curious. Thanks everybody.
 

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Happy w Liberty

Using a Liberty upgraded TKO600 w RR gears in mine. It's as solid & consistent @ 6500rpm as it is at lower speeds. Synchros are good but not lightning fast. Just learned to be methodically smooth in my shifting to work within its capabilites.
 

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I haven't looked in a while...what are the T-56's going for now? It use to be about a $4500-$5000 swap by the time you did the clutch, bell housing, tranny, crossmember & driveshaft.

If anyone is willing to spend that much...& since most of you are saying you don't want the extra weight...why not go to the Jerico 5 speed road race tranny? Its about the weight of a T-5 & is stronger than the T-5, Tremec & T-56 all put together.
 

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Discussion Starter #17
It would be a fantastic choice if my car was just a race car. However, most of its time is spent on the street. Im not interested in a non-synchronized transmission for my street driving.
 

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It would be a fantastic choice if my car was just a race car. However, most of its time is spent on the street. Im not interested in a non-synchronized transmission for my street driving.
Good point! :rofl:
I forget sometimes that I'm not normal...
As far as I'm concerned, every car should come from the factory with rock hard, hiem-joint suspension, finicky triple disc clutch, non-synchro tranny's, manual steering & manual brakes. :salute: LOL!
 
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