V8 Supra Builder

iTrader: (37)

I'm stumped on my Supra swap for what to do as far as a clutch:
I have a 2003 5.3 LM7 motor, 1986 350 truck bellhousing w/ bracket for slave cylinder. I can order an adapter from Novak that will allow the BH to bolt to the Supra trans (I know what you're thinking, and a T56 won't fit). I have a stock LS1 flywheel, Ram LS1 clutch disk & PP. The problem is the disk is 11.5" and has a 26 spline center, and the Toyota trans has a 21 spline input. The largest available 21 spline disk is 10.5".

I'm sending out inquiries to clutch companies for an 11.5" disk with a 21 spline hub, but maybe it would be easier to run a 10.5" PP. To do so, I'd need the smaller 153 tooth flywheel.

So here is the issue- can I use an '86 up 153 tooth flywheel on this Gen III motor? Any clearance or balance issues? I'd like to find out now before I spend more $.

Andy1

Two companies I would suggest first: Clutch Masters, and South Bend Clutch. Call them and tell them what you are doing; they may be able to help. I would be inclined not to worry so much about the diameter, as recent clutch technology seems provide excellent performance. OTOH. if you are going to drag race it, then perhaps you need the largest you can get. If you don't get what you want, try Quarter Master. They are a race clutch manufacturer (NASCAR, IRL, etc), but if you call them you'll find them surprisingly accomodating. I got them to configure an 8 1/2" button flywheel, single disc, & PP good for 450+HP for my mid engined application. Basically they can make a disc with any spline.

I don't believe the GEN I and GEN II flywheels interchange with the GEN II LSX motors. Bolt patterns are different as are the bolts.......M11x1.5, a Chevy invention!!!

Andy1

V8 Supra Builder

iTrader: (37)

Thanks for the info, I didn't figure they would interchange. I'll contact the clutch companies.

Project GatTagO

iTrader: (7)

The problem with getting a 153 tooth flywheel for a Gen III is that the starter will not engage. So you will need a custom nose as well. Quarter Master can indeed be very accomodating and offers just about every spline known to man, but I can tell you they are swamped now since it NASCAR and all types of other circle track and road racing is in full swing. Not likely you will be able to get a disk made. Try Spec too. I bet they make a Supra clutch and they should be able to make you a "hybrid" disk. Its not a big deal.

Andrew

Andy1

I simply used the stock 168T flex plate and stock starter. It took Quarter Master 4-5 weeks to make up my parts. Just received them Friday. This is definately their busy season.

Andy1

Project GatTagO

iTrader: (7)

Your setup is what is commonly called a button flywheel. The automatic trans flexplate is sandwiched between the crank and button flywheel. The flexplate is used strictly for starter engagement. The friction surface of the clutch is provided by the button flywheel. Andy, I know you know all this, I am just posting for the benefit of others. Post up some pictures!

I have attached a picture of a button flywheel for a 5.5" diameter clutch. The one for the 8.5" clutch is very similar, just bigger.

Andrew

V8 Supra Builder

iTrader: (37)

That "button" seup looks nice.... and expensive, which exceeds the project's budget.

I'm waiting to hear from the clutch companies on this issue.

Project GatTagO

iTrader: (7)

See my first post regarding having Spec or Clutch Net making you a hybrid disk.

Andrew

V8 Supra Builder

iTrader: (37)

I should probably contact the clutch companies you mentioned, and await a response from them.

Sabre002

iTrader: (7)

would drilling the LS1 flywheel so you can bolt the Supra pressure plate to it not work. That way you just use all supra parts for the clutch, and just bolted to a LS1 flywheel

V8 Supra Builder

iTrader: (37)

I hadn't thought of doing that- I'm curious what the cost would be vs. having a disk made. I sent info to Clutch Net & have called South Bend Clutch twice now (the "guy" is never available & I missed his return call ) and have not heard anything.

The issue with using the Supra PP is that the Novak bellhousing adapter I'm looking at uses GM clutch parts. I'm not sure how the throw out bearing would work on this setup, but this may be easier to adapt than other stuff. The nice thing about using OEM stuff would be easy parts replacement.

Project GatTagO

iTrader: (7)

Do you have pictures of any of these parts? Specifically the bellhousing that you want to use, the adapter plate and the front of the Toyota trans.

My initial feeling is that by the time you do all this and coble the parts together, you would have been better off modifying the Supra trans tunnel and putting a T56 in it. That would be WAY simpler and more durable.

Andrew

V8 Supra Builder

iTrader: (37)

The bellhousing is in my shop (haven't taken a pic yet)- it is from a mid 80's GM truck, the trans is in PA, and the adapter is at Novak:

I considered the T56, which was my initial intent, but the cons outweighted the pros:
Modify tunnel (?)
New driveshaft (300)
Adapt speedo cable or electronic speedo (200-300)
Cost of T56 (1000)
Crossmember (60)

By sticking with the Toyota setup:
Used R154 trans (225 shipped)
Bellhousing (75)
Used LS1 clutch & flywheel (80)
Retain speedo cable, driveshaft, and crossmember

Of note here as well is the financial environment- I'm finishing up the LT1/T56 280Z (a car I bought with only 2 wheels, no motor or trans) and were I to lay out the $ on something of this scale again, while I'd have another great car I'd have no great wife . I've already heard "You could have bought a complete car for what you've spent on putting this one back together!" a few times, but like others, sometimes I repeat my mistakes, plus tinkering with cars is what I enjoy doing and I take pride in the construction/fabrication vs. buying someone else's work. I was really happy (Ok, and a little surprised) to see my old LT1 start right up in the 280 after I had "re-wired" the harness and spliced it into the Datsun one (see attached jpg for this wiring diagram). I just finished one for the Supra and need to scan it. Sorry.

I love the T56- I have two of them, and were I able to do so for this car, I'd pickup an all forged 6.0 with a T56 and even upgrade the diff to a Vette IRS setup. I'd even like to put a C5 transaxle in my Corvair for the overdrive if it could be done . I'm not looking to build a 10 second drag racer. I want the car to be a daily driver with everything working- AC, cruise, etc. I beleive the choices are the best available for my needs based on my finances.

Andy1

Here you go

Andy1

Project GatTagO

iTrader: (7)

V8 Supra...(I wish people would post their first names....)

Your pictures are exactly what I was looking for. Your using a GM truck bellhousing that uses an external hydraulic slave cylinder right? The slave cylinder probably look ssomething like this:



So the external slave pushes on the clutch fork, which in turn moves the TOB and presses on the fingers. All you need to do is use the TOB from the same GM truck that you got the bellhousing from. It will be a standard GM style bearing and will look something like this:



The ID of that bearing will be 1.375". If you measure the bearing retainer on that adapter I bet it will be right around 1.370". The only thing you might have to measure is how far away from the TOB the fingers of the clutch are. When all is said and done, you want about .250" between the face of the TOB and the fingers. If you TOB is too tall or too short, GM made several different heights, and all will work with that bearing retainer and clutch fork.

The other thing to keep in mind is the stroke of the slave. You want to make sure it moves the fingers of the clutch spring to release it fully. I don't think there will be a problem, because the LS1 clutch and the truck clutch are similar in design and will require roughly the same TOB travel.

Clear as mud?

Andrew

V8 Supra Builder

iTrader: (37)

Andrew,
Thanks for the info. I received the slave cyl today & it looks just like that one. I'm holding off on a TOB until I get the rest of the stuff in place so as not to have excessive excess parts that I can't use.


What did you say your name was?


I said...


IT DOESN'T MATTER WHAT YOUR NAME IS!!!

Sorry, couldn't resist that one.

LS1MCSS

iTrader: (18)

Supra, do you have your cable-x box yet? If not, I have one I will sell you. I used it for about 100 miles and decided to swap to Autometer electric speedo and tach. I also have a tach signal conversion box that I removed.

V8 Supra Builder

iTrader: (37)

I ended up deviating from that diagram on the 280Z. I used a reverse-wind Cobra electronic speedo via a Dakota adapter box, so I never bougt the Cable-X. On the Supra, I'm planning on hooking a Stealth Conversions pulse generator into the speedo cable so as to use the regular speedo. I will need an adapter for the tach. Do you have the Dakota SGI-5? This is what I was planning on buying.

Link to new diagram (56K warning, 1.6 MB).