Jump to content
HybridZ

T56 improvement?


heavy85

Recommended Posts

T56 behind LS1. Currently 365 whp and dont expect to ever go over 400. All came from '02 Camaro and the flywheel, clutch, and transmission are factory originals from the Camaro donor. About 50k street miles and somewhere north of 50 track days on it. 2700 lb car for time trial, autox, and hill climb action. This transmission combo has served me well for several years and even today still works great. However it shifts sooo slow so I know its holding me back on lap times plus it weighs a bunch. 4 speed dog box would be great but more I look more confused I get and concerned it would cost many, many thousand $$. Can you modify T56 to get better shifting and possibly reduce weight? Is there a reasonably priced light & fast 4 speed? Other options? So whats the best bang for buck options in the following order:

 

1) reduce shift time

2) reduce weight

3) not cost arm and leg

 

Thanks

Link to comment
Share on other sites

The nascar takeoff trannys will run you in the 2500 range and you need a bellhousing.  You can do all manner of things with the gears including overdrive in case you think you're stuck to 1:1 for fourth.  You can add a cheap low ground clearance bellhousing usually for around 200 and a tri-lite style throw out bearing for around 150.  Reverse rotation starter is around 100.   Then a 3 disk 7.25 clutch, which you can convert to a 2-disk rally style for a little more slip (if needed).  All said that's probably 40 to 50 pounds less than the T-56 but you're looking at around $3K.  

 

For the T-56 you can have it faceplated, which is the same thing as dog ring engagement.  I think they are around 1K for 1 to 4 and leave 5th and 6th with synchro for street drive.  Dog engagement can be shifted as fast as you can move the lever and only takes a small breathe off the gas to reduce torque.  There are some fancy bits that can be added for no-lift-shift using a load cell shifter and interface box.  That's double the cost of the gearbox mods.  You can also do the mutli-diks behind the T-56 using a flexplate for ring gear, button flywheel, and clutch.  I think Ron Tyler found it was 38 pounds less weight than the Corvette flywheel and clutch combo.

 

Unless you plan to go all out and want to dry sump the motor and lower it I'd probably lean more towards face plating what you have.  

 

Cary

Link to comment
Share on other sites

Thanks Cary thats just the info I was looking for. Several follow in questions:

 

- Why faceplate 1st since you need a synchro to get started?

- Any idea if $1k for face plating includes going through the rest of the trans? I assume any general maintnance would add to that?

- You have any more details on the flexplate/button/clutch as I've never heard if it. Starting to google now.

Link to comment
Share on other sites

I can help a bit with the button clutch. You've got 2 diameter options, regular diameter flexplate or the smaller stuff. The smaller stuff reduces the OD of the bellhousing and allows you to mount the engine and trans lower in the chassis. I don't know if you are looking at new drivetrain mounts at this point, but that's what it would take. The oil pan hangs down lower than the bell housing, so you'd need to do something about that too if you really wanted to get the thing lower.

 

For just a button clutch, you can run a flexplate from an auto and then a button clutch. I bought an ACE 7.25" dual clutch and found that it did not work with the stock flexplate off of a 5.3, so I had to get another flexplate from Quicktime which had a flat mounting surface. I also got the wrong throwout bearing from QM and had to return it and get the Tri-Lite that Cary mentioned. There are always multi-plate clutches on ebay. You can get NASCAR takeoff triple clutches from Tilton for about the same price that I bought the ACE. I got a double because supposedly you can slip it "a little bit." Really though, these clutches are pretty digital and not meant to slip at all, and things like pulling the car onto the trailer are going to ruin the clutch. You will HAVE to winch it on the trailer regardless. I just figured that a double might be a little bit easier to get the car from the grid to the starting line when autoxing.

 

I think just going to a plain 'ol light flywheel would help the shift speed, but doing the flexplate button clutch should enable the engine to wind down MUCH faster which should improve the shift speed a lot (I know going to a light flywheel on the L series helps quite a bit). 

 

Related thread here: http://www.corner-carvers.com/forums/showthread.php?t=47895

Edited by JMortensen
Link to comment
Share on other sites

Anything special you have to do when down-shifting a faceplated or dog ring tranny?

 

Not really.  Ideally you rev match and either double clutch or drop it in.  With dogs when the gears come together they engage.  It doesn't matter if your doing 100 and select first it will go in.  I like to left foot brake and you can drop down a gear by a simple blip on the throttle and pull it in.  For up shift you let off a smidge and select the gear.  Dog ring/face plate trannies require fast shifts to survive.  If you granny shift it cause a lot of damage.  

Link to comment
Share on other sites

Thanks Cary thats just the info I was looking for. Several follow in questions:

 

- Why faceplate 1st since you need a synchro to get started?

- Any idea if $1k for face plating includes going through the rest of the trans? I assume any general maintnance would add to that?

- You have any more details on the flexplate/button/clutch as I've never heard if it. Starting to google now.

 

Good point on 1st.  I'd do it for the gears you plan to use.  I'd call Liberty gear for actual prices.  I was throwing around what I have heard but I haven't talked to them directly.   G-force used to do T-5 straight cut gear conversions with dogs too.  Not sure if those are still around.  

 

Download the Wilwood, Tilton, and Power Train technologies catalogs.  They will have the part numbers you need for everything.  The idea of using a 3-disk converted to a 2-disk rally clutch is so you can slip it a little more.  I drove a corvette a few times that had a Tilton 3-disk and button setup and it wasn't too hard to get used to.  You bring the revs up and quickly let it out to get going.  You can go a lot deeper into corners under braking with these compared to a normal clutch setup.  And you can't shift faster than the dogs engage.  Just be accurate because if you're not it's still going in.  Until you get good I'd recommend always using the clutch across gates and throttle lift when inline.  

 

The next step for hillclimbs is an auto clutch where you use a restrictor to simulate dropping the clutch at a certain rate.  You set that with the bleed hole, and then determine RPM, and push the button to go.  Something for well down the line but to keep in mind.  I've been trying where possible to come up with ideas to eliminate inconsistency on launches.

 

Cary

Link to comment
Share on other sites

Dont like the sounds of these clutches. A guy I work with swapped an LS into a 350Z and I drove it once. The clutch was touchy and very hard to use. Made it unfun to drive. Plus dealing with winch and standing starting, getting around pits, etc. Sounds like a PITA. Cant you just use a regular clutch - I've been and continue to use the factory original Camaro clutch and it works great? Faceplate + lightweight flywheel + stock clutch?

Link to comment
Share on other sites

Another option is a Ford Toploader, stronger than the T5, Muncie, or Super T-10. 

 

I bought a Toploader 4 spd off craigslist for $275, looked rough and the front collar was broken.

 

(3) faceplates- $65/ea

(2) faceplate slider- $100/ea

input shaft- $150

master rebuild kit- $175

hyd t-bearing- $150

RAM clutch disc- $225

 

I have a lathe, so i installed the 2/3/4 gear faceplates myself, and modified the 1/2 slider for 2nd gear faceplate / 1st gear synchro. Also turned down the front collar to allow using a Chevy hyd t-brg.

 

shopmuletoploader1.jpg

 

In your case, you would also need...

...bellhousing

...driveshaft

...shifter mods

 

You could probably sell the T56 for enough to finance most of the swap.

 

Shifting is foolproof. If the engine even slightly coughs and the shifter has any preload at all, it's instantly into the next gear even without the clutch. I faceplated 2nd gear in a Saginaw once, when 1st gear broke, the trans instantly short-shifted into 2nd gear before i even knew what happened. 

 

TNT32314.jpg

 

 I use mine for drag racing, but it's been bulletproof for 2 years at about 700rwhp...

  • Like 1
Link to comment
Share on other sites

The next step for hillclimbs is an auto clutch where you use a restrictor to simulate dropping the clutch at a certain rate.  You set that with the bleed hole, and then determine RPM, and push the button to go.  Something for well down the line but to keep in mind.  I've been trying where possible to come up with ideas to eliminate inconsistency on launches.

 

Cary

 

Here's a link to the clutch slipper setup i designed... http://grannys.tripod.com/hillbillyclutchslipper.html 

used on this car... http://tntrc.com

 

If your clutch is hydraulic, a line-lock solenoid could be used to make it button-release on launch.

Link to comment
Share on other sites

They are "road race style" with a back cut angle of a few degrees to keep it from popping out of gear.

 

The "drag only style" have little back cut angle on the engaged faces and a ramp angle on the trailing side to kick the slider out of gear when the force thru the gearset reverses. If the slider is split, you actually engage the next gear before the current gear dis-engages. Definately drag only, kicks out of gear on decel.

Link to comment
Share on other sites

When i made mine, Liberty did not offer a 1st gear synchro option when they did a faceplate conversion on a Toploader, but i hear that they do now.

It's a busy time of year for them, might not be very quick on service, but you can give them a call at 313-278-4040, email is libertysgears@aol.com

Link to comment
Share on other sites

  • Administrators

Something else that may help speed up your shifts is reprogramming the ECU. The OE programming is intentionally designed to keep the RPM's up between shifts and these can be nulled with HPTuners, etc.

 

 I think Ron Tyler found it was 38 pounds less weight than the Corvette flywheel and clutch combo.

 


 

Yup. Sort of. 38lbs less than a Monster Stage II clutch with 18lb flywheel. But I believe that package is nearly identical in weight to the stock stuff.

Link to comment
Share on other sites

Yup. Sort of. 38lbs less than a Monster Stage II clutch with 18lb flywheel. But I believe that package is nearly identical in weight to the stock stuff.

Ls1tech.com says 28 for the Camaro too, so that's even more weight savings. Wonder what the difference is between your tiny flywheel and my flexplate. Guess I'll just figure it at about 40-45 lbs for my setup.

Link to comment
Share on other sites

Something else that may help speed up your shifts is reprogramming the ECU. The OE programming is intentionally designed to keep the RPM's up between shifts and these can be nulled with HPTuners, etc.

 

 

 

 

Yup. Sort of. 38lbs less than a Monster Stage II clutch with 18lb flywheel. But I believe that package is nearly identical in weight to the stock stuff.

Interesting about the tune. I have noticed it takes a lot longer to get back to idle than it takes to close the butterflies. You have any details of this clutch set-up like brand, part numbers, etc?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...