Thinking of starting a winter project changing my speedster over to IRS from a swing axel. Has anyone done this I would like to know the Pro’s & Con’s better handling & ride or not enough to even to do?
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Handling is a hands down win for IRS although some what more maintenance intensive.... You can get advice / information from Rancho Transmission... Just have a firm idea of what you want the car to do and how long you want it to last doing that....
I've had both and really enjoyed both types once their limits were realized.....
I've done the swing to IRS conversion twice, albeit not on a speedster, but on Karmann Ghia's. I think the handling is far superior and worth the undertaking.
The pictures are from my 1958 LowLight Ghia. I also narrowed the control arms 1 5/8" per side to fit a larger tire under the fender.
I threw together a jig off a bare IRS chassis. You can buy these now from several places to make the conversion easier. A jig is absolutely necessary to get the proper orientation of the IRS bracket. Take your time when fitting the brackets to get a tight fit for clean welding.
I triangulated the rear section for strength and future attachment for a roll cage. I incorporated new shock mounts in the cross bar.
Those a type 2 CV joints, as they are larger and stronger than type 1. Axles were 16" that were narrowed 1 5/8" to fit the narrowed control arms.
This is how you fit a 205/65R15 under the fender of a Ghia. I think a 215/60 would have fit without issue.
Go for it Arden!
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That is one nice looking Ghia!!
As already said, it's worth doing, as you car with irs will be transformed. The ride will be nicer as well as handling improved, and the only extra maintenance is repacking cv's every 30,000 miles (or is it kms? I forget). Going to the extra trouble to narrow the trailing arms to fit wider tires is also worthwhile; as well as the rear of the car sticking better to the road, it will also look just that much more bad@ss!
If you can weld it'll be a great winter project. The June '94 Hot VW's magazine has a "how to narrow the trailing arms" article by my friend Bruce. He put 8" Fuchs alloys with 225/50-15's under stock fenders on his Beetle. If you're interested, I've scanned the pages and can post them here (I posted them a number of years ago).
Hope this helps. Al
PS- @LI-Rick- nicely done! (and that is 1 sharp Ghia!) A friend of mine built a similar jig and has converted a number of dune buggies to irs. The Bus reduction boxes were breaking (the new modern offroad tires are just too much for them) and Gerry has converted 4? 5? 6? buggies to bus irs transaxles and reliability has gone way up.
Another PS- @Former Member- What tires and rims are on it now? can you post a pic of your car?
I agree with all of the comments about handling improvement, but in my opinion the key thing here is: "If you can weld it'll be a great winter project. "
Getting the mounting brackets in the right place is crucial to the success of the rear wheel alignment, but as Rick mentions, there are jigs available to make the placement of the mounts really accurate. The key to success is the quality of the welds, so either you weld the brackets in or get a mobile welder to drop by and do it for you. Those guys service trucks and heavy equipment all the time so you should have one near you to google. They can weld them in, right in your garage/shop.
Once those are in and painted, assembling the diagonal arm and spring plates should be straight-forward. You can use regular VW sedan arms and hubs for a 1970 or so sedan and you can go the Type 2 (bus) route on the axles or even go nuts with modified Porsche 924/944 CV joints like I used, but for any engine under a 2,110, the stock sedan axles should be fine and you can get those anywhere, like NAPA.
I don’t think I will have to do any narrowing I have a SuperWide V/S my rims are 17x10 and my tires are 255/40 17s
I love the GHia, it's beautiful, is it finished now?
We do a lot of welding and fabrication at my shop. I’m also pretty lucky to have some Gearheads that love to work on anything with wheels.
i have a 72 coupe under my deck..pretty much rusting away...belongs to my SO(22yrs) her father left it to her oldest son,and there it rots... i am not even gonna try to get involved...,shame...
@IaM-Ray posted:I love the GHia, it's beautiful, is it finished now?
Thanks. That Ghia was sold to Pete Morley in the UK, back around 2007. He got divorced about a year after that and had to sell it. Last I heard I think it’s in Belgium. Pete gets the credit for the interior and engine, I did the rest.
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@ALB posted:If you can weld it'll be a great winter project. The June '94 Hot VW's magazine has a "how to narrow the trailing arms" article by my friend Bruce. He put 8" Fuchs alloys with 225/50-15's under stock fenders on his Beetle. If you're interested, I've scanned the pages and can post them here (I posted them a number of years ago).
PS- @LI-Rick- nicely done! (and that is 1 sharp Ghia!) A friend of mine built a similar jig and has converted a number of dune buggies to irs. The Bus reduction boxes were breaking (the new modern offroad tires are just too much for them) and Gerry has converted 4? 5? 6? buggies to bus irs transaxles and reliability has gone way up.
@ALB, that is the Hot VW’s article I followed to narrow the arms. I also used a Berg bus into bug intermediate housing, which is a nice piece of kit. Those type 2 transmissions are really tough, I used one in a drag car with a Folts swingaxle conversion years ago.
SWEET Ghia! I love it! Too bad you sold it.
Nice motor too: IDAs, Berg linkage and breather, Mallory distributor.
For some reason after @LI-Rick posted his pictures something looked familiar so I looked underneath my car and it looks like my car was an IRS switched over to a swing axel. I think it might be easier to do than I thought. I’ll get it up on jack stands and get a better look tomorrow
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It doesn't get much easier than that. Maybe.
Vintage did a lot of swingaxle conversions on the narrow bodies, it is easier for tire fitment in the wheel arches.
If it was my car, I'd buy the already narrowed(they sell them) trailing arms and install them with the widest tires I could get under there.
You may be able to only fit 165/80R15 if you change it back to stock IRS arms. Other guys who have done that can chime in here.
@DannyP I have a Superwide from V/S
Superwide? Just get stock arms and have at it.
When you go looking for the diagonal arm bolts and bushings you will probably find that everyone sells the Red Urethane bushings. Aircooled.net has both the bushings (urethane) and the special pivot bolts. It would be nice to find the German hard rubber versions, but they're exceedingly rare these days (I couldn't find any with a quick search) and the Urethane ones don't transmit too much road vibration.
Back to the question of IRS and standard bodies - unless I'm badly mistaken, if you want to run a standard rear disc brake package with this setup, you'll end up with 4-1/2" rims and you won't be able to slide a credit card between the rear tires and fender. All of the commonly available rear disc conversions (even those advertising as "zero-offset") add at least a half inch per side to track width. There may be rear disc packages that do not add width, but they won't be EMPI cheap. If you want more rubber than you can get with 4-1/2" wheels (and you would), 914 wheels provide a 5" wheel with enough backspace to work.
If you want 5-1/2" Wide 5 wheels, your options are to get steel wheels recentered, or to just get the narrowed trailing arms. As it happens, Ron Lummus Racing has them on sale right now. Figure on $1000- 1200.
Nothing pertaining to these cars is free. You don't always get what you pay for, but you always pay for what you get.
cip1.com sells an OE style trailing style bushings. These are the ones that I used when I converted over to IRS.