How to widen the track on a vw?

[volksbugly]

I have a 1970 vw beetle ball joint front end. I've put wider fenders on, and I have some deep dished 8" wide wheels I want to put on. 51ET. I am wanting to do this the correct way to try and prevent any wheel bearing failures. Initially I was going to do spacers, but I really don't want to go that route, as its the worst thing I can think of doing. So my other thought was to run some wider trailing arms. Not longer ones but just wider ones. Then run some new longer tierods. Does this sound like a feasible idea? I am really not sure what to do at this moment. I want the wider track because I would like to autoX the car, and would just enjoy the better stability.

Thanks for any advice!

[Marc]

Widened control arms would be an interesting approach, since you could get a wider track width without the huge increased scrub radius caused by wider rims alone...but where are you going to get them? Not something you'd want to be of anything less than OEM quality.
I campaigned circle-track cars for many years with 10 and 11" wide rims (with backspace similar to stock at around 3½", and significant RF negative camber, around 2.5°) and never had any bearing failures - but regular inspection/adjustment was high on the routine maintenance checklist.

[Chris V]

Longer trailing arms could be built staggered to increase the KAI for the 8" wide tire...But if you'll be beating on this thing solidly, maybe go with some custom spindles first, KCW builds 'hybrid 944 drop spindles' (they put them under buses, so they're probably worthy of looking at)...With a pair of those welded spindles you'd have bigger bearings and some nice brake options...By nature they'd have some offset built into them, and that would be best to have figured out before building custom arms.

What width fenders and wheel/tire size?

[sideshow]

Widen the beam

[perrib]

Widen the beam

x2

[Chris V]

A wider beam alone is the worst thing I can imagine doing...The wheel is too wide and the offset too great for the suspension as designed. He needs to add room between the beam and the wheel mounting surface.

[Marc]

An ET51 8" rim is going to have a couple of inches more backspace than any stock rim (I estimate around 6¼") so without spacers or longer arms or modified spindles you'd need to set the steering box stops aggressively to prevent the inner sidewalls from rubbing on things at full lock - the turning circle would be ginormous. Even at straight-ahead the sidewalls would probably hit on the shock towers unless they're trimmed and rewelded.
Spacers would be the simplest, but they'll add to the scrub radius.

Widening the beam does nothing to correct any of these issues, all it'd do would be to stick the tires further out to fill the fenders.

[volksbugly]

Ahh forgot to mention the wheels are 18" so widening the beam might work. I think right now the wheels will hit the inner part of the body. I will be sticking one on soon to test fit. I also have ghia front brakes so my offset is currently pushed out 1/2 inch further than stock.

So here is what I was thinking.

I was going to get another set of trailing arms and weld them together ie right next to each other to have a nice long weld. This will push out the arms by about 2 inches or so.

||_ << that is my lame asci drawing but you get the idea.

also
I'll check out the KWC spindles

[Chris V]

For quick reference here's Dad's daily driver with 7" ET55 wheel 205/50-17 - He's got CB disc drop spindles and over an inch of bolt-on spacer...this picture shows the steering near full lock and how the tower was trimmed back lightly:



Without a spacer, and with an 8" wheel - the clearance would be about 1-1/2" less or approx none at all.

[volksbugly]

your pics above:
Without a spacer, and with an 8" wheel - the clearance would be about 1-1/2" less or approx none at all.

Awesome thanks for the excellent reference!
What sway bar is that? I like it because mine right now isn't adjustable! (I found out now I need that adjustment)

[Chris V]

It's from Whiteline of Australia...I got his through Aircooled.net. It provides lots of ground clearance and more room for the tires than the OEM bar - but the mounts could be better, though still a great deal better than stock on a lowered car with wide wheels. We did have to trim-down the lower AVIS adjuster bolt to clear the swaybar - which would snag and bounce off of it fairly often beforehand. Also the link-mounts fouled on the shocks, so they were notched and gusseted - still not ideal, but they're working.

[Marc]

With the CB spindles, 7" ET55 rims and ~1" spacers the scrub radius on my daily-driver Bug is slightly greater than on an all-stock car, but it doesn't seem to present any problems in real-world use...the car is not at all "darty" over pavement discontinuities, and low-speed steering effort isn't intolerable (I do have a full-size steering wheel; with a smaller wheel you might start to notice the increased effort).
I applaud your idea of creating the longer control arms...but considering the amount of work involved for questionable gain, I suggest you pass on this idea for now (it could maybe be something to get back to when you have money to burn, but frankly at that point I'd encourage you to go to a double-A-arm layout instead).

They're many, many more places where you could shave a few tenths off of your autocross time for a comparable investment.

A few years back my son took a Bug up to a local autocross event, entered as a novice. He turned in some impressive times, especially considering his car's low state of preparation. In this type of event, it seems that there are some kind of unscored "style" points to be gained through a smooth approach...even when more aggressive driving, although not as pretty, still results in the quicker time.
One of the seasoned competitors actually came over to me and asked where Chris' wheelbarrow was....in reference to what he must've needed to haul his balls to the track

The car's only around half of the combination, if you've got talent you can make nearly anything go fast,

[volksbugly]

Thanks everyone for your help!
I didn't really know what scrub radius is so I looked it up and found a great video explaining it:



So with a spacer at first thought I was thinking oh this is going to give me positive scrub. But then I have to remember that my wheel is also wider, so
maybe its not that big a deal. I just have to space it enough I can clear my shock tower. Also I hope that with the 18" wheel it will help.

I'll take photos above like you did when I do the switch. I'm going to get some blank rotors and have them drilled, then figure out my spacing and then get some proper spacers,
then bolt it all up and cross my fingers.

[Chris V]

Here's a cool calculator: http://www.rimsntires.com/specs.jsp

I assumed a wider-lower-profile tire, 225/40-18, on your 8's - and it came up with 1.3" (34mm) less clearance to the suspension than with the combination pictured above. If a 1" (25mm) spacer is installed I see that the result is only 9mm-less-clearance to the suspension (probably acceptable) also almost equally, it's 11mm further toward the fender-lip than the below picture, which might be acceptable, unless lowering more-aggressively (not hard to do). Car has 2.5" wider CCC fenders.

[volksbugly]

Wow 10 years later and I'm finally where I want to be with this project. So I have 11.5 inch rotors 4 pot Porsche Brembo brakes all the way around,

REAR: Porsche Twists 18x10 ET 65 in rear with 944 Porsche trailing arms, late model wider axel stubs and CCC 3 inch wider fenders and it all works nice!

In the front I have Porsche Twists 18x8 ET unkown (Will look up wheel spec later) with re-drilled hubs and custom brake mounts for 5 x 130, so I am using bug bearings and 2 inch wider CCC fenders

The front is still a work in progress as I haven't even put the new hubs on yet, but making progress!