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4/01/2013 8:28 am  #1


Narrowing a Toyota Supra IRS

Hello All - first time poster, occasional lurker.  My current project is to somehow get a MK3 Toyota Supra narrowed and stuffed into my 1966 Volvo 122.  The rear of the Volvo is quite narrow and will require shortening a few things (6" total).  This presents any number of problems and I am appealing to your collective wisdom to help me out in this uncharted territory. 


 

 

4/01/2013 8:32 am  #2


Re: Narrowing a Toyota Supra IRS

Here's post number 2...I'm a moderator on another board and love the spam bots as much as you do...

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4/01/2013 8:40 am  #3


Re: Narrowing a Toyota Supra IRS

Here's the start point:



I built a frame to copy the suspension articulation points.



Then remove the jig from the frame and draw it in to the required width.



I have started to fabricate the subframe to fit this all up under the Volvo.  So I bolted the hub and upper A-arm onto a wheel and tossed it under the car.



From the inside...just enough clearance for the arm (the spring perches will have to be removed).



Beginnings of the subframe - looking OK so far.  Space is too tight for the A-arm to get fancy curves, so a simple cut and welded 2 X 3 120 wall tube frame at the top will suffice.



Then BANG - there's a suspension arm that is right in the way of the subframe.  A few hours later and I find myself registering for you forum and collective wisdom.  The curve on the frame matches the rear seat pan.

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4/01/2013 1:13 pm  #4


Re: Narrowing a Toyota Supra IRS

Canuck, nice package, phantomjock will be jelous of your upper A arms I'm sure.

And welcome!

Ralphy

 

4/01/2013 2:55 pm  #5


Re: Narrowing a Toyota Supra IRS

Welcome aboard - and yes nice works going on there!

Cheers - Jim


UNDERCONSTRUCTION! Highly Modified C3 Corvette
         Dual Wishbone IRS w Subframe + Custom Uprights
 

4/01/2013 7:21 pm  #6


Re: Narrowing a Toyota Supra IRS

Thanks guys - any thoughts on what I've got to do?  I'm thinking that the only solution is to just fabricate the fram to the minimum dimensions and then fit it into the car.  There doesn't seem to be any point to trying to fabricate around the existing sheetmetal.  It's not what I was thinking, but it does seem to be the only solution. 

Any sources of companies that will shorten my drive shafts?

Craig

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4/02/2013 2:28 am  #7


Re: Narrowing a Toyota Supra IRS

Craig -
You oughtto be able to find a local drive shaft companyto do that for you .  I will need to shorten mine when I move the engine aft - and it seems my local shop has a good reputation.  You could getthe parts and build one up - but I want mine spun in a lathe to check for balance.    OTOH, they did say they'd check - but didn't say what next...hmmm I'd better do more research.  But that is a few weeks away.  On-line shops?

Cheers- Jim


UNDERCONSTRUCTION! Highly Modified C3 Corvette
         Dual Wishbone IRS w Subframe + Custom Uprights
 

4/02/2013 7:12 am  #8


Re: Narrowing a Toyota Supra IRS

Canuck - Welcome.
I would think if you lived near a decent sized city there would be a couple of driveshaft shops.  I know of one or two around Denver that even dealerships contract out to because they can have a one day or less turn around, even with balancing.
For online shops you could out Randy's Off Road or most any big off road site is likely to have references.  When my '59 is more complete, I plan on dragging it down to a local shop and having one built.
Good luck with your build!

 

4/02/2013 7:37 am  #9


Re: Narrowing a Toyota Supra IRS

Thanks guys - by drive shafts I meant the half shafts with the CV boots.  I've sent in a few web forms for companies that say they do these things but have had no response.  Typical...I'll have to call and talk to them directly.  I don't think there is anyway to shorten these shafts that doesn't involve cutting and remachnining the spline.  I'm going to try to get more of the frame member tacked up tonight.

     Thread Starter
 

4/02/2013 6:06 pm  #10


Re: Narrowing a Toyota Supra IRS

I'm not at all familiar with that breed, but it looks like it would be no different than shortening the jag halfshafts? Can they be disassembled to the bare shaft and stuck in a lathe?

 

4/03/2013 11:00 am  #11


Re: Narrowing a Toyota Supra IRS

     Pretty much all OEM half shafts and axle shafts can be annealed and resplined providing there is sufficient metal where it is required.  Heat treating after the machine work was finished obviously would be required
   When you decide you want to shorten a half shaft the first thing you must do is determine if it is possible. Tear down one half shaft until you have the raw shaft.  You said you need to narrow your IRS 6 inches so measure in 3 inches from one end and mark it. measure the diameter with a good caliper or a micrometer at the 3 inch mark. then measure the major diameter of the splines. If the area you want splines is the same or larger diameter than the splines for the length of where you need to have splines. Then your in luck. Rarely is this the case. Most half shafts are necked down in that general area so the small end of the grease boot has a place to seat. I have yet to see a OEM  CV type half shaft that did not have this feature.  If both ends of the half shaft are the same and have this reduced diameter where the splines would be required, your only options would be to have a machine shop make new shafts, go narrower providing a sufficient diameter exists there  or cut a segment out of the center so you can weld and sleve it to the desired width.  Welding half shafts is tricky business since they are technically very similar to torsion bars. The elasticity is where they get their toughness.  Unlike most larger diameter half shafts ie. Jag units that are forged and by design flex very little,  most smaller half shafts are designed to flex torsionally to absorb shock loads.  Welding a sleve on them will usually result in a shear where the weld stops due to the change in metalurgy and the change from a flexable shaft to a ridgid sleve.    Pre heating and post heating can help some but will not fix the non flexing nature of the sleeve and the enormas stress riser it creates..   I am guessing that wheels with a 3 inch negative backspace isnt an option.

Last edited by tyrellracing (4/03/2013 11:57 am)

 

4/03/2013 8:45 pm  #12


Re: Narrowing a Toyota Supra IRS

This was what I understood.  There is suffecient material to do the respline.  I'll have to call around and find out who'll do this sort of work.  Welding is out of the question - there's lots of room for machning.  



 

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4/05/2013 5:25 pm  #13


Re: Narrowing a Toyota Supra IRS

Perhapse I didnt quite make my point.  Where the boot is clamped to the shaft is aprox. where your 3 inch dimention will land.  usually this area is smaller in diameter than the splines.  The only way to determine this is to remove the CV, and boot from the splined shaft. With out doing this to one end of one half shaft you are opperating on wishful thinking.  99% of the half shafts I have seen have larger diameter splines than the diameter of the exposed portion of the shaft. The closest thing to a supra I have had apart is my Tacoma 4x4 pickups front half shafts. It has been too long since I put the electric lockers in it to recall any of the pertainate information.  I do believe they are of the same design as the supra's half shafts but shorter in length. If you call a toyota parts dept. they would be capable of looking up the 4x4 half shafts to see if they share the same spline size as Supra.  I am sure they are at least 3-4 inches shorter because the front diff is aprox. 10 inches wider than the supra's diff.  Just a thought.

 

4/06/2013 5:10 am  #14


Re: Narrowing a Toyota Supra IRS

Canuck, went thru your posts. I don't see any mention of width difference?

Ralphy  CTRL + Q to Enable/Disable GoPhoto.it

 

4/07/2013 9:58 am  #15


Re: Narrowing a Toyota Supra IRS

I mentioned the width change it in my first post.  I've got to go 6" shorter.  I'll take one apart this afternoon and confirm the shaft size.  There's a company in Portland that advertises shortening http://www.dutchmanaxles.com/services

As it happens, I'll be in Portland in late May.  So once I get the frame done I can double check the dimensions and send them down for machining and pick them up on my way by.

Spent some time cleaning things up yesterday.  It's now all bead blasted and ready to go...but unfortunately, the axles are as Tyrellracing described and quite complex.  We'll have to see if Dutchman can just make a set that are shorter as I don't really want welded axles.

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4/07/2013 4:00 pm  #16


Re: Narrowing a Toyota Supra IRS

I missed it! I was just wondering if the difference weren't much you could squeek a little here and there. What about your wheels can you bring them inward much?

Ralphy

 

4/07/2013 5:08 pm  #17


Re: Narrowing a Toyota Supra IRS

No way to get it shoehorned in there without shortening it.  The tracks are totally different and even with FWD offset (say -45mm) the wheels would overhang the finders significantly.  I knew this going in - so it wasn't a surprise.  I was surprised that I couldn't get a reasonable subframe stuck up under the car.  I've got room behind the back seat and will make the frame work.  Getting the shafts made is not inconsequential, but not that difficult either.

     Thread Starter
 

4/08/2013 3:05 am  #18


Re: Narrowing a Toyota Supra IRS

Too bad.  I have tried all kinds of tricks to shorten half shafts and can confirm none of them worked for me. Welding up the diameter with special wire, rod, pre, post heating heat treating and carburising the welded area after cutting splines. Ect.  I wound up with stripped splines every time.  The only time I had any luck resplining an oem half shaft was when I found larger shafts I could cut splines on both ends to get the length I wanted. Even that proved difficult due to an unusual alloy that did not anneal well enough to remove sufficient hardness to enable me to cut the new splines at a realistic rate with a high speed steel cutter.  Normally I will sharpen the tool before starting and it will last for 28 to 31 splines before the bottom of the spline became unacceptably rounded . On that job I had to re sharpen the cutter every fifth spline.  In a nut shell, paying someone else to make a pair of new ones has to be a better way to go.

 

4/10/2013 6:41 pm  #19


Re: Narrowing a Toyota Supra IRS

Quick update - Dutchman got back to me promptly (very rare these days) and they will make new chromoly axles starting at $495 if you send them a sample.  Looks like I'd better get out to the garage and get that frame done so I can double check the measurement and get these sent.

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4/12/2013 12:17 am  #20


Re: Narrowing a Toyota Supra IRS

You gotta be able to discover a regional generate base company to do that for you. I will need to reduce my own when I shift the motor aft - and it seems my regional store has a strong popularity.  You could get the areas and develop one up - but I want my own unique in a lathe to examine for stability. .. . . .  .

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Last edited by JimpetRICia (4/12/2013 11:41 pm)

 

4/12/2013 7:38 am  #21


Re: Narrowing a Toyota Supra IRS

JimpetRICia wrote:

You gotta be able to discover a regional generate base company to do that for you. I will need to reduce my own when I shift the motor aft - and it seems my regional store has a strong popularity.  You could get the areas and develop one up - but I want my own unique in a lathe to examine for stability. .. . . .  .

I'm going to assume Google translate wasn't doing you any favours .  While this company is located in the US, their shop is south west of where I live and I consider them to be in my "region".  Fact of life for a Canadian. 

I also have no faith that people that have a lathe can make an axle...what I mean is, sure they can turn it and put a spline on it, but they have to be heat treated and we'll assume that companies that do this as part of their core business will have the experience to not make a set of axles that fail.  I usually look for things like race governing body certification or ISO standards or some sort of history.

Craig 

     Thread Starter
 

4/13/2013 2:22 am  #22


Re: Narrowing a Toyota Supra IRS

Craig, maybe this guy can do you up?




Here's a good video showing some pros and cons of three types of couplers. U joint, CV joint and Thompson CV joint. I'll add it to my videos. What he doesn't mention is the CV's ability to slide and change length.






Ralphy

Last edited by Ralphy (4/13/2013 2:46 am)

 

4/13/2013 8:03 am  #23


Re: Narrowing a Toyota Supra IRS

I have herd of people cutting splines with cut off wheels too. I have yet to see a succsessful splined shaft using this method.  Its hard enough to cut splines using a deviding head that fit properly let alone doing it free hand and getting the correct spacing, spline count and depth.  My only thought seeing vidios of home cut splines made free hand is "You cannot be serious"   It would require a great deal of luck for that method to work.

 

4/13/2013 3:53 pm  #24


Re: Narrowing a Toyota Supra IRS

tyrellracing wrote:

I have herd of people cutting splines with cut off wheels too. I have yet to see a succsessful splined shaft using this method.  Its hard enough to cut splines using a deviding head that fit properly let alone doing it free hand and getting the correct spacing, spline count and depth.  My only thought seeing vidios of home cut splines made free hand is "You cannot be serious"   It would require a great deal of luck for that method to work.

Ya, yikes!  My family used to own a large machine shop...I always marvel at the ingenuity of people that need to get things done.  We all do the best we can with what we have and at least he has a shield!  I do my best to build cars that are safe, fast, and reliable.

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4/14/2013 1:10 pm  #25


Re: Narrowing a Toyota Supra IRS

Necessity is the mother of many improbable tequnics that with enough patients and determination will some times succeede.  .  I liked the shield too. I just hope the opperator had on a good pair of safety glasses on as well   Speaking of necessity, Years ago some buddies and I were riding dirt bikes on the trask trail to the coast when I lost my master link. More than 35 miles from no where I was screwed. none of us had a rope or a spare link and I could not leave my bike behind. The vultures would get it! We were near a stripped car that happened to have some coat hangers in it. I bent a segment of wire to make a crude link, twisted the ends together and cut off the excess with a small pair of vise grips I carried in my bikes tool pouch. My friends laughed their asses off saying it would never work. well it did. I carried all the hangers that I found for replacements.  Each link would get me about five miles before breaking.  I could not go fast but I was mobile just as long as I got off and idled up the steeper hills.  That was a classic case of making do with what you have where you have to make use of it.   

 

5/21/2013 5:43 pm  #26


Re: Narrowing a Toyota Supra IRS

Hi Guys,

I've been making progress...albeit slow.  I've had to cut and reposition the brackets on the parts as the clearances were too loose and I didn't want to cause a stress crack from having the mounting tab bent.  As usual, I'm worried about powder coat thickness we'll hope for the best and adjust the bushings as needed.  

Anyway, here's what I've done.

The back plane (at least that's what I'm calling it) was cut and I added in support by creating a rather curvy "tube" out of 16 ga.  There was no way anything straight was going to work properly or look cool.



It's TIG welded all the way around - fully boxed.  Strong as heck.



The brackets that hold the lateral link were fabricated using 3/16" steel and TIG'ed in place. 



Then to get the axle measurement, I mocked up the rear using the differential and the hub.  No binding (mind you I'm two links short of a suspension at this point).  




The axles worked out to be 3" shorter (which is good as I narrowed the rear 6" overall!).  You can see the upper strut mount point on the upright.  My current plan is to work out a pushrod system for an inboard mounted coil over.  I still have to fabricate the front crossmember and rework the arms and make adjusters.  Should keep me out of trouble for a bit.

Craig
 

     Thread Starter
 

2/27/2014 6:49 pm  #27


Re: Narrowing a Toyota Supra IRS

I have a 65 fairlane 500 wagon the front sub fram is rusted out. Im going to install a supra front and rear suspension under it. I have got alot of fabrication to figure out on the rear suspension any suggestions  or feed back would be appreciated.

 

2/28/2014 8:29 am  #28


Re: Narrowing a Toyota Supra IRS

I haven't forgotten about you guys.  I've been busy on a number of projects and have now got back to this one.  If your frame is rusted out...start with a new frame and design around the parts...here's where I'm at now.

I've run into a few problems.  At first glance the Volvo frame notch appears to be centralized in the fender opening.



But it's around 1" biased towards the front of the car...this caused the upper control arm (UCA) to hit the back of the frame when Matt and I finally got the sub-frame mounted and tacked in place.  So I took a week off and made a few parts like bushing holders etc.







I then attacked the back of the car with my trusty sawsall and removed large sections of the trunk.  It's just easier to start from a "clean slate" - the replacement rear frame rails are being tacked up this week and should be in stalled over the weekend.  I actually cut the frame back further than is shown in these photos...but you get the idea.  The entire section of frame that sits parallel to the ground was removed and will be replaced by 3" X 2" 3/16" wall steel tube with provision for a coil over.  Then it will be recovered with sheet metal and finished.  The idea is to create a rear frame that is able to handle all the associated loads that the IRS brings to the table instead of what Volvo had in mind which was a frame to handle your luggage.





There should be lots of room to still use the spare tire well...if it's about 2" shorter in length.  My spare seems to fit just fine.  That's a relief.



The rear seat/trunk closing panel was also removed instead of hacked to get access to back side areas that need welding and reinforcing.  This needed to happen anyway as I've got a new parcel shelf that doesn't have enormous holes hacked into it for speakers.



The subframe has gone in and out of the car numerous times and I was finally comfortable with the modifications to the rear structure that I was able to remove large parts of the car to get this done.  You've seen what had to happen to the spare tire well...and here it is going back in last night.

A little welding along the seam (after I put in a filler strip) and it's now installed.



Spare tire just fits with the addition of the 2 X 3 - I've had to wrap the structural member around the tire well to join into the frame rail.  All fabricated with 10 gauge steel.



Shrinking the radius on the well required some pie cutting and careful fitting.



Here we are tacked up and ready to weld.



And welded in place and ground...welded inside and out just to ensure strength and prevent pin holes.



The original subframe used eccentric adjusters to alter the toe and camber of the rear wheels.  I didn't allow for this provision in my subframe as it's difficult to fabricate and I'd rather just complicate my life.  So, I decided to go with adjustable suspension links in all positions (including traction bar).  This will allow for complete control of the suspension adjustment within the stock geometry.

So we start with fabricating a very precise jig using the old arms as reference points.



Side registration - sides are clamped and this register picks up the busing and allows you to get the arm out of the jig post weld.



Cut and re-weld tube to make very tight fits to the arm brackets which will be reused instead of bending up new ones.  The old ones are perfect and should save some fabrication time.



Grind off the old welds very carefully and then cut the old bars off...seamed tube - wasn't expecting that.



Bushing holders are then cleaned and blasted and fitted with 3/4-16 adjuster bolts.  Bigger is better with suspensions as far as I'm concerned.



Careful fitting (this takes the time) before welding makes sure everything is going to come up roses.  



All TIG'ed and ready to party.



Cut and thread the DOM structural tube...didn't take pictures.  Then carefully prep the area for weld with a good weld prep zone and use a little emery on the tube to remove any contaminants - these welds have to be flawless.



And bang - done.



Each set of arms took a day to fabricate (about 4 hours - I have a job people).





All welded parts are allowed to cool very slowly (about 1 hour or so) in my sand pit.



The camber links are next.

First fill a few holes.





Build a long threaded sleeve.  I would have used nuts...but I had the tap and more threads are better - actually this allowed for the taper that I wanted.



Tight fit into the tube.



Plug welds and pie cuts.



And done.



For the toe adjuster, I stubbed the end of the original ball joint link with a steel shaft and fit it into the end of the tube.  Followed by a good root weld and a cap with the TIG and it's strong as hell.  No pictures for some reason.



Here are all the links installed.  I had to modify the frame to accommodate the poly bushings as the originals were used for fabrication and the poly adds about 60 thou of width.  Total PITA, but it's done.  Next time I'll remember to fabricate WITH THE PARTS I'M GOING TO RUN - rookie mistake #-o .


 

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