T-56 dimensions, torque capacity, and gear ratios

[Bill Hincher]

I have to admit that I like the idea of being able to spool faster but I have a very difficult time with something that would require a $1,200 twin disk clutch.

 

I'm not personally concerned about the SFI but I do like having my legs. So now I think I'm going that have to find some type of daily driver scatter-shield. I remember a friend of my dads (back in 83) telling me how he was racing and had a flywheel shatter an a part went through the floor board and just barely missed taking his foot off at the ankle.

 

Here is one of Chads kits that recently sold with pics: http://www.starquestclub.com/forum/index.php?showtopic=117056. Does it have a coupler?

 

no Chad's flywheel does not have an adapter and its a very nice kit, my statement about flywheels has been way misunderstood and I have been put down many times for my opinion for why the original flywheel is the right opion to use

 

but here we go again, firstly is balance, the engine balance is in concert with the flywheel and the front vibration dampner, well everybody says that dont hold water cause the front vibration dampner is just a peice of steel,well, 'true that' but I guarentee you it makes a difference, millions of dollars are spent in the design and engineering of the balance of that engine and when you place a Chevy flywheel and clutch on the end of that crank you put it out of balance, nobody wants to hear it

second, I dont care what flywheel you run or how much horsepower, the bottom line is , you have to have a secure fit and attachment at the crankshaft/flywheel junction, end of story, no adapters or couplers, I sold a GM auto trans adapter to a guy and he is trying to put the T 56 up to the adapter using a manual flywheel on my adapter, he is what we call a 'future' organ donor

Third, cost and avilablity, yeah, you can love the car and spend lots of money on the driveline, I dont care, go to any car show and look around, it aint a car show, its a contest about who can spend the most money, trying to be 'big man on campus' just cause you got money. Big deal, I just want to help some guys build thier hot rod ata reasonable cost in a reasonable time frame.

 

Yeah you guys can go out and buy Chads idea and copy it and try to sell it off as your idea , but in the end the problem is the same, somebody has to pay for custom flywheels and try to sell them to other guys and not go broke

 

and in the end, you got an $1800 dollar car with a $3500.00 driveline

[mstieg]

A few quick thoughts:

 

1) I LOVE that so many people are embracing ideas to make these cars better. Regardless of variations on how, I'm glad we're on the same overall page.

 

2) I don't see anybody is trying to steal Chad's work. More the opposite. Austin and I are attempting to contact him about buying what he has left while he and another are willing and seemingly able to take over to keep them available if Chad does not want to make more soon. It's Chad's baby for sure =)

 

3) The T56 Fidanza was designed for the G54B to mate with a T56 using Chad's adapter plate kit. It's not a Chevy flywheel, and I would certainly agree with Bill that adapters between a crank & fly at this power level probably aren't a great idea. Granted I'm not the expert and don't have data on adapter use at the fly. QUESTION: Doesn't Fidanza balance all of their flywheels?

I know that's not quite the same as having the full assembly balanced while together. At 15 lbs, it's less than half the rotating mass as the smaller diameter stock flywheel or other. That also scares some regarding strength, but there is safety data on Fidanzas and its good.

 

4) The last run of custom flywheels cost a bit over $400 each. Now a remaining one of the last batch can be had for $300 or less. If new kits or bell housing conversions are going to be made, another run of 10 Fidanzas will be needed, so this IS something to consider. Overall, it's not going to break anybody individual buyer's bank beyond the already $300-330 for a stock 240mm Fidanza. Heck, I'll be selling my current 240 Fidanza & clutch to recoup some cost of the swap. Bill's right that SOMEBODY needs to take the lead on the next GP run of 10 however and all 10 likely won't pre-sell. It would make sense to keep that run in house with the maker of the adapter kits for buyer & seller convenience later as future conversions try to find what they need.

 

5) A used T56 can be had for $1-1.5k if patient enough, and plans don't include more hp than even they are designed for. BTW Chad notes a 20% increase in hold power for us, due to weight difference vs. the Camaro/Firebirds. We don't all need a $3000 re-manned unit. It is possible to do this conversion for $2k or less. Gotta be patient and a bit lucky in finding parts however.

 

6) Adding to the above about price... Most at the 300-400+ hp range have put in quite a bit of time & $ into their cars over the years. I LOVE that Bill still takes the approach of helping those of us who scrape to make ours cars into hot rods without breaking the bank. Even better is that he's more inclined to error on the side of caution so as to not take the "cheap" route at the expense of safety.

Edited March 22, 2011 by mstieg

[mstieg]

I'd be more inclined to get a custom bell from Bill vs. Chad's kit if the new bell replaces the kit's adapter plate and the original T56 bell. Think: added strength AND saved money by being able to sell the original bell/not buy one.

 

Granted that's if able to use the custom T56 Fidanza for many of the reasons mentioned before. I don't know of the demand or what it's worth (cost) to you Bill to make a G54B to T56 custom bell using the T56 Fidanza? Doesn't hurt to discuss at least right?

[Bill Hincher]

the critical balance of the engine flywheel doesnt mean that the engine is running smooth, it works on DE-ACCELERATION

 

when the crankshaft is loaded and stressed in its rotation its fine ( however there is a lot to know about how the inputs from each connecting rod spaced at different lengths losing torque as it reaches the flywheel) but when the engine is de-accelerated at the end of a high output period, it relaxes like and re-takes its shape , thats why flex plates are thin, the torque converter de-couples the rear wheels from the engine and the crank spins free, where as in a manual transmission with the car coasting and the clutch engaged, the rear wheels now drive the crankshaft, that all causes premature rod failure

 

as far as cost goes, the trans can be had in reconditioned condition for $1800 bucks, but then your gonna pay $500 bucks in a driveshaft, $400 on a flywheel and $400 on a clutch and you dont have an adapter for the rear end flange yet

 

plus now you gotta have the custom bellhousing or flywheel/adapter

Edited March 22, 2011 by Bill Hincher

[StarquestRescue]

You guys are also forgetting a rear gear swap is mandatory. Add $350-$600. And if you want a better spaced 5 gear and a usable 6th gear, add more bucks for the optional gear ratios. And there will be increased friction losses and additional rotating mass in the trans itself.

 

For reference. Gear ratios and calculated speeds in gears

http://www.starquestclub.com/forum/index.php?showtopic=24651&st=195

 

Pricing back when they were available.

http://www.starquestclub.com/forum/index.php?showtopic=60405&st=0&p=577843&fromsearch=1entry577843

[Chad]

Hmm, lots of interesting ideas floating arorund, some baised on opinion, some guesses, and a few facts too. Where do we start ?

 

To address the flywheel, it's essentialy no different in design from the starndard G54B replacements, except it's thicker and has more clutch area. It's only 3/4" larger in diameter, but has about twice the clutch surface area. The stock-replacement Fidanza is about 12 pounds, the T56 version is closer to 17 pounds. The mating flange at the crank is the same between them. It's no more, and no less safe to run. We told the engineers to take their CAD for the LT-1 and the G54B and graft them together, with the specified clutch surface to crank surface figure I gave them. They are SFI rated as I recall, but not balanced. I know of several that have taken them in for balance and they needed -zero- balancing, none. They are CNC made on very high end gear, so the need for balancing is very slight to none. Fidanza does reccomend balancing, but few have, and none have have realy needed it. Woudl I recommend it? sure. Did I do it? no...

 

It is true about some of the 92/93's T56's being weaker, but only the ones with the low gear set, which was an option. it has to do with the first gear beiing too low and thus weaker. The 2.66 first is the strongest, but also the least street friendly. If you want it to truly match up gearing like the stock trans, you can put in a 4.22 rear diff, then the numbers work out almost exaclty stock in 1st though 3rd, then you have 4/5 kind of overlaping where stock 4th woudl be, and the 6th is a ways past stock 5th. You still have 6 gears with the 4.22, and the top end of 6th is still quite a bit higher than stock trans/stock diff 5th gear would be. That is the combination I am going to next. I'm currently on the 3.545. It's fine 3rd 4th and 5th, but 1-2 are not quite balanced for this motors torque curve, and 6th is simply too much most of the time.

 

As for torque rating, they are basing it on the stock weight of the F-body, which is 400-500 pounds more (10-15%). You can add 10-15% to the rating if used in a lighter G54B chassis. I'm on a used bone stock 1995 T56 trans with a little over 100K on it. I've pushed a lot of torque and HP thoguh it, didn't even hicckup.

 

As to the pricing, I don't know where all these huge numbers come from, but I would say do your research before you state figures, the truth will set you free. $500 driveshaft? yes, you can spend that if you want, or you can get one for ~$200 that will still hold 500+ ft/lb. It's a simple 1350 yoke at both ends, and the tube is only ~23", any redneck driveshaft shop can build one. I got a really expensive one, but I don't recommend it for most cause it's not needed. the stock solid 1350 ujoints themselves are good for aobut 1000 ft'lb. you won't be breakign them You can get a driveshaft eaily made for this setup that will hold over 1500 ft/lb. I Know, cause I have one It's way easier and cheaper than some might think, these are Domestic parts and easily made.

 

Same for clutches, my first install of this T56 used a stock LT-1 Valeo clutch, which is rated for about 335 ft/lb, it held over 400 HP/TQ just fine. Again, these are rated for 3600 pound LT-1 cars, not 3000 pound quests. I currenlty run a $600 clutch rated at 840 ft/lb (on a 3600 pound chassis), but I can guarantee a stock $180 LT-1 clutch will do just fine for 99.5% of you guys. The really nice part? my 840 ft/lb clutch is only about 10-15% more peddal effort than the stock G54B clutch, and is almost as smooth, it's 100% street friendly. The stock LT-1 Valeo was less peddal effort compared to stock, it was actually awkward at first. Ever driven a high performance (400+ ft/lb) G54B clutch? they suck for street use ! Best part is there are dozzens and dozzens of choices, and they are all better than what is available for the G54B flywheel, at about the same price or less. The stage 4 G54B clutch costs the same as a stage 4 LT-1, but the LT-1 holds almost twice the torque. Arguing the cost of the needed clutch upgrade is stupid, you have to upgrade the stock clutch too, don't you? The LT-1 holds about 175% more torque per $$ spent.

 

Can you spend $3500 doing this swap? Sure, you can also do it for well under $2000 :

 

$450 Kit

$350 flywheel

$180 clutch

$200 driveshaft

$800 used J-yard trans

____

 

$1980

 

Then sell your old stuff:

 

$30-50 flywheel

$50-100 clutch

$50-75 driveshaft

$50-150 trans

______

 

$180-375

 

Take that off the price and you are well under $2000

 

You want to spend more and get petter parts? do it! It's just like going MPI, you can do it cheap, or go all out, all depends on the person doing the install. I'm into mine just under $3000, and have plans for a newer TR6060 upgrade (newer high performance version of the T56), which will add about another $1500 to that (after I deduct the sale of the current trans). My entire setup will be rated for ~800 ft/lb, and I expect it will hold much, much more. You can easily build this kit to hold far more than the motor will ever put out (1200 ft/lb with G-force gears). It's just how much do you want to spend... I swapped mine cause I got tired of broken transmissions, the last known-good one only lasted 7 miles

 

 

 

As for kit availability? I have 4 that are 85% complete, I just ran out of customers and shelved them. I am in the midst of moving, so my free time is limited. I still have desire to make parts, but not much time and very little demand. I will be talking to the wifew about setting aside some time to make some more kits, we could use the $$ for this move, and there is currelty some demand again. Stay tuned...

[creakyjoints]

Sweet! So, Chad can I get one for the flywheel I have collecting dust?

[SPEEDSTAR]

I have an exta t56 FIDANZA flywheel for sale, I dont think there are anymore at ULTRAREV,I purchased the last one ....325.00 plus shipping. shoot me a pm if interested...JEFF

 

Chad, I will not make or sale any copies of your adapter plate , because you are still actively doing it

Edited March 26, 2011 by SPEEDSTAR

[tkal]

I have a fidanza flywheel and was thinking about the adapter plate/bell housing that I will need. Chad, did you make a new housing or a 3/8 plate?

[Blue]

6 speed tranny behind my G54? Oh dear, yes please! That, plus plans for MPI... I can have power AND mpg's!

[mstieg]

Any word on availability of Chad's T56 kits?

[Questsi]

If I remember correctly, I spent around 3000 for the swap.

 

$400 for Chad's kit

$450 for flywheel

$500 for clutch

$500 for custom driveshaft

$1000 used T56

$100 T56 short shifter

 

Since I was one of the first to do the swap(other than Chad himself) there were a few snags along the way and I had to drop the trans twice because of a flywheel machining error. I still want to rebuild the tranny and buy a scattershield for it but for now it runs fine. Also like Chad mentioned, 422 gears would help out quite a bit down low.

[mstieg]

Yes, that issue of the "dish" the crank goes into being too shallow was resolved on the 2nd run of T56 Fidanzas. Mine checked good thankfully.

 

All I have left is the adapter kit, driveshaft, and decision on what path to take on a working speedo.

 

What other issues did you have? (I'm fine with starting a new thread separate from this topic if that's better)

 

Have you gone with either the 4.22 or 3.90 gears? The 4.22 ration look pretty good to me.

[Chad]

If I remember correctly, I spent around 3000 for the swap.

 

$400 for Chad's kit

$450 for flywheel

$500 for clutch

$500 for custom driveshaft

$1000 used T56

$100 T56 short shifter

 

Since I was one of the first to do the swap(other than Chad himself) there were a few snags along the way and I had to drop the trans twice because of a flywheel machining error. I still want to rebuild the tranny and buy a scattershield for it but for now it runs fine. Also like Chad mentioned, 422 gears would help out quite a bit down low.

 

 

You can get a steel SFI spec bell for the LT-1 now, they just came out with it about a year ago. It's about $400 I believe.

 

You can aslo get a breand new Magnum TR6060 for about ~$2400 that will hold an easy 750 ft/lb. I think they make an LT-1 version. Might be better than a rebuild given you will actually be pushing the limits with it.

 

If anyone wants a 4.22 gear set, I have the entire kit (ring/pinion/bearings/seals) new in box that I'm selling. I got a good deal on one already built and didn't want to mess with doing it myself.

[Questsi]

You can get a steel SFI spec bell for the LT-1 now, they just came out with it about a year ago. It's about $400 I believe.

 

You can aslo get a breand new Magnum TR6060 for about ~$2400 that will hold an easy 750 ft/lb. I think they make an LT-1 version. Might be better than a rebuild given you will actually be pushing the limits with it.

 

If anyone wants a 4.22 gear set, I have the entire kit (ring/pinion/bearings/seals) new in box that I'm selling. I got a good deal on one already built and didn't want to mess with doing it myself.

 

 

How much do u want for the gear set?

[Questsi]

Yes, that issue of the "dish" the crank goes into being too shallow was resolved on the 2nd run of T56 Fidanzas. Mine checked good thankfully.

 

All I have left is the adapter kit, driveshaft, and decision on what path to take on a working speedo.

 

What other issues did you have? (I'm fine with starting a new thread separate from this topic if that's better)

 

Have you gone with either the 4.22 or 3.90 gears? The 4.22 ration look pretty good to me.

 

 

Actually it was just the flywheel issue and having to massage the tunnel for a better fit.

[Funky Phil]

I wanna see how well a g54b will cruise in 6th gear with the T56. My gut says youll be in boost, about 100% of the time.

[mstieg]

You can get a steel SFI spec bell for the LT-1 now, they just came out with it about a year ago. It's about $400 I believe.

 

You can aslo get a breand new Magnum TR6060 for about ~$2400 that will hold an easy 750 ft/lb. I think they make an LT-1 version. Might be better than a rebuild given you will actually be pushing the limits with it.

 

If anyone wants a 4.22 gear set, I have the entire kit (ring/pinion/bearings/seals) new in box that I'm selling. I got a good deal on one already built and didn't want to mess with doing it myself.

 

I do, but would rather have one already built, or will have it built here. - package in with the conversion kit I need from you?

[Chad]

I wanna see how well a g54b will cruise in 6th gear with the T56. My gut says youll be in boost, about 100% of the time.

 

It's not real bad, but it lugs ofcourse. It's such a tall gear for the stock diff that the motor is at about 2000 RPM at 70, so it can't really build any boost. I've only put mine in 6th a few times. there aren't many open highways arround here, the nearest highway with a speed limit over 55 is about 60 miles away, and that is only a 65 zone.

 

5th is about perfect, seems idealy suited to a moded motor.

 

 

When I swap the 4.22 in there, that will put 6th about where the T56's 5th is now. Then it will be perfection. 1-2-3 will be almost stock, with 4-5-6 devided in the place of stock 4-5, with a little extra on the top (7000 RPM will be about 165 MPH).

[mstieg]

Chad - what are your thoughts on swapping in a better disk to the stock Veleo clutch? I got mine cleaned up for cheap and word around Camaro forums is that the PPs are mostly all the same. SPEC says otherwise (and would rather sell the entire kit w/ PP for big $$). I'd like a smooth streetable full faced setup. SPEC 3+ disk was mentioned, but SPEC also said it was thicker and not compatible with OEM PPs, however other Camaro guys seem to like them (or McLeod disks). Thoughts?

 

Clutch disk options...

[TsTKl]

smart dsm'ers don't buy fidanza...

 

http://media.photobucket.com/group/image/dsm%20fidanza%20failure/NT5TY18PDB/DSC_3993.jpg

 

http://media.photobucket.com/image/dsm%20fidanza%20failure/mitdr774/flywheel.jpg

 

http://www.dragsource.net/andrew/fidanza.jpg

 

guess whats the only flywheel I've seen or heard of failing?

 

 

 

Someone said the 17 lb fidanza has less rotational mass than a stock dsm flywheel... stock dsm flywheels are 20 lbs. Aftermarket lightweight ones are 8-11/12 lbs (fidanza-act). With how much larger the diameter of the t-56 flywheel is, I HIGHLY HIGHLY doubt it has less rotational inertia than a stock flywheel.

 

For those who don't know how a harmonic damper works: Because Combustions are not constant driving forces on the crankshaft, the crankshaft itself developes harmonic twisting forces within itself. That is to say the crankshaft itself twists during opporation, then flings back like a spring and goes the other way, coming back again after another combustion. These twisting forces are reduced by the calculated mass on the outer ring of the harmonic damper. The rubber acts as a spring allowing those forces to be dissipated through this weight. Unfortunately a harmonic damper can only work for a small range of rpms. Aftermarket harmonic dampers assume you will spend more time at a higher rpm and design their product accordingly.

 

changing the flywheel, so long as its balanced, shouldn't change this too much, although it definately will.

 

 

P.S. I'm one of the guys who bought one of bill's t-56 bell housings, although he had to modify it for the long shaft LS-1 version that I bought instead of the normal short shaft LT-1 version. The shifter is about 2-4 inches farther back than stock, but I bought a short shifter that moved it back up a little, and also I plan on moving my drivers seat back farther so my knees stop hitting the dash. I also have 4.75 montero gears for the stock rear end so that 6th gear is usable.

 

also, are you guys getting these things to fit in your stock tunnels? I had to make a new tunnel for mine. Don't see how it can be done any other way, but this adds significant time and money to the project.

Edited July 28, 2011 by TsTKl

[Bill Hincher]

thank you, thank you, thank you Tiki thank you , I have preached and preached this balance point FOREVER and no body wants to hear it

 

I might add one more very important detail

 

Think of your crankshaft as an extension on a 1/2 drive ratchet, now think of each connecting rod as a ratchet handle

 

we all know you cant use a 1/4 in drive to remove lug nuts, why? because you loose twist leverage with the diameter of the extension

 

well if you think of the front #1 connecting rod(ratchet) being further away from the flywheel ( lugnut) then you can see that # 4 connecting rod will work with more force against the flywheel then # 1 connecting rod ( thats why #4 connecting rod is usually the first to fail)

 

well you are twisting the crank front to back like a spring under compression ( when under load) but with a manual transmission, when you de-accel and leave the clutch engaged,now your rear wheel drive the crankshaft and decompress the spring tension well, take that crankshaft to an oval track like NASCAR and see how much influence the balancer has on the crankshaft

 

I try to keep this reading easy

[Bill Hincher]

well, here is the deal, the 4G63 6 bolt flywheel will fit the 4G64 6 bolt as well as the 7 bolts will all interchange, hell the EVO 4/9 7 bolt will fit the 4G63 narrow block, so you can swap and choose all over the place

 

BUT I am a big advocate of proper balance on the crankshaft

 

now the wide block R 154 I built re used the G54 b flywheel, there were two built for the G54b, I used the one that used a larger clutch

 

BUT I dont know if the flyweel for G54b is balanced to be used on the 4G64 crankshaft

 

IF I could build the wide block 4G64 and used the small FWD or AWD 4G63 flywheel I would because it would make it easier for me but because it fits does not mean it will balance properly

do you have part numbers to sort through that can help us choose?

Edited July 31, 2011 by Bill Hincher

[AustinTSI]

I'm going to throw this out there but don't shoot me if I sound like an idiot. As I understand it you have already built a t56 housing for the narrow block 4g63 buys and they tended to use the AWD flywheel since it was smaller. Since the 4g63 and the 4g64 use the same parts, why not keep things simple and just build the wideblock housing the same?

 

Wouldn't this be the easiest for you and us since people have already been running this and 4g63 AWD OEM and aftermarket options are plentiful?

[Bill Hincher]

Bellhousings kinda tend to evolve, I move to the market and what it wants, so I ask the end user what they may want and react to the input

 

as stated before, I am a big believer in the balance effects of a matched flywheel to the given crank, if you intend to destroke the wide block and use the long rod, then you may choose either the FWD ( 280mm diameter) or the AWD ( 270mm diameter) on the 2.0l crank coupled with the proper front crank balancer

 

If you intend to build a G54b or a 4G64 motor, you may choose the long stroke crankshaft and reuse the larger flywheel to accomidate a larger clutch

 

there is no need to use the 'One size fits all' rule