Performance Suspension

[duesenberg1932]

Hello everyone,
I just bought a 68 auto stick IRS chassis as a basis for my project. The plan is to setup the chassis to perform as well as it can while keeping the ride height stock and the ride not incredibly stiff. I wondered onto sway away's website and was looking at different sized rear torsion bars. How big is to much? should I run a rear sway bar? Should I upgrade the front sway bar? I know very little on the practical application of beetle performance suspension parts and could use some advice. Thanks.

[dirtkeeper]

I don’t think you need any different parts. You can adjust the rear torsion bars to get back to original specs if needed. And you can replace all the rear torsion bushings, and replace tie rod ends, ball joints, steering dampner, make sure you brakes are in good working order and this will all help your handling.

The best thing you could do is get some good shocks.

I have always used KYB gas adjust and have been happy for low budget shocks.

When I upgraded to some high quality bilstein I was Blown away by how much they improved my handling. Now every time I need new shocks for one 0f my vehicles I am compelled to buy the best shocks I can afford.

[RailBoy]

Hello.. Since you want to keep the car with its original ride hight and tires, it was mentioned on some KYB Gas Shocks... The ones that upgrade from oil next step and do not ride harsh are the KYB Excell G's.

If you come across the KYB Gas Adjust, run... They are for a way heavier car or maybe an autocross car.. But as mentioned, Bilsteins are nice, but very pricey.

But as it was mentioned, check all suspension bushings, ball joints, steering stabilizer and check steering box for adjustments..

As for tires, get a nice tire, a well known company that has a rep for nice traction.. Also, on this point and if you read the threads on air pressure, you can mess with that as well. Why do I say that, well, stock tire one bugs back in the day were less than there heavy counter parts, so yes, the car's weight means you can run a lower tire pressure, just not to low to roll a tire off the rim.. Most of this will be noted in steering responsiveness, I noticed on my Super..

Ok, yea, look at the threads in the search. All kinds of info and the search can work a few ways. Once you learn that you are set, and asking questions is what thesamba is all about... RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]

[TDCTDI]

I’m running Bilsteins & just recently upgraded to 29mm rear torsion bars. The handling is incredible. However, VW did engineer the the rear to be soft to reduce the snap oversteer tendency of the rear engine car. I can, at will, lift the throttle in a corner & induce rotation, definitely not something for the inexperienced.
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Everybody born before 1975 has a story, good, bad, or indifferent, about a VW.


GOFUNDYOURSELF, quit asking everyone to do it for you!


An air cooled VW will make you a hoarder.


Do something, anything, to your project every day, and you will eventually complete it.

[modok]

With the old swingaxle larger torsion bars are THE WAY, IMO

however, with the IRS rear it's not so clear.
I suspect....you only need to match the front.
if you put a larger sway bar in front, then it would make sense to add a rear sway bar also.
If you do something to make the front stiffer, then maybe stronger torsion bars to match it. People rarely do, but...say if it you lightened the car then added weight to the rear..., then, that would result in the same thing.

[frenchroast]

I've had KYB gas adjusts on my 69 IRS for years and found them to be plenty stiff. I kept the stock front sway bar and no rear sway bar. Something you could do is change components in stages starting with shocks. Then, experiment with sway bars to find what you like best. A lot of people recommend the KYB gs or bilsteins. I've had good luck with bilsteins but have only used them on watercooleds and bmw's.

I'm bringing my bug back to original and just today swapped the KYB's for Sachs. Looking forward to that original softer ride but plan to keep the KYB's around.

[Q-Dog]

You say "project." Are you building a beetle, or a kit car? Heavier or lighter than the stock car? Same weight bias?
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Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[H2OSB]

As stated above, it's kinda important to know the eventual weight of the car to be able to suggest a particular torsion bar size, so throwing out random sizes won't be helpful

I have two full bodied, late suspension Super Beetles and one has the 23.5mm bars out of a Porsche 944 while the other car has a set of 26mm torsion bars that were meant as an upgrade for a Porsche 924. The car with the 924 bars is getting a heavier, upright converted type 4 engine, thus I went slightly heavier. Also, both of my cars are lowered, but the concept is the same.

I've only driven/raced the '73 with the 944 bars, as the other car is still in the build phase, but I can say, though the handling is "sporty", when compared to my previous cars, such as my race prepped VW GTI, or Subaru LegacyGT with race springs, it has never felt harsh or punishing.

Unfortunately, I BELIEVE your car has the intermediate length bars(24 11/16), so you cannot use direct size suggestions from me. At some point, VW went to 26 9/16 bars which is the longest length for any AC car. This length is shared by Beetles, T3 cars, and the Porsche 924/944. I THINK Notchback had 23mm bars while the Squareback had 23.5 like the 924 and 944. Beetles(even with shorter bars) always had 22mm, though I can't say that for certain on early Beetles.

Btw, the 911 bodied Porsches shared the 24 11/16 length bars, and came in various diameters over the years so there are POSSIBLE sources, however, as most VW owners know, any part with the Porsche moniker on it tends to be 2-3 times the price of an equivalent VW part.

Hope this helps
H2OSB
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(o\_i_/o) I'm not a vegetarian because I love animals, I'm a vegetarian because I hate plants.

[duesenberg1932]

My eventual plan is to put an oval window beetle shell on the IRS chassis. I wanted the better characteristics of the IRS with the older body. I was thinking run the 15% stiffer front torsion leaf pack from sway away with a larger rear torsion bars. Im just unsure what MM rear bar to run with the stiffer front leaves. Torsion bars are 26 9/16" long. I'll be sticking with a type 1 engine so weight bias will be relatively stock. Id like to upgrade the front sway bar and add a rear one as well, but there are quite a few options as far as thickness on them too.

[54bug]

Hi All

Another data point from my 1969 VW Bug. Years ago I started restoring the car, pulled the pan, sandblasted, rust repair. Paint, Interior, Engine, Trans, and Suspension.... Took a while but it's been on the street for 5 years. My goal was to improve the handling and performance in a street driven show car. I my mind I should love driving it.
The suspension was completely redone. The front received a narrowed adjustable 2" beam, Ghia spindles and discs, 3/4 inch front bar, Ball joints, steering box...) On the rear I replaced all the bushings with Urethane, used adjustable spring plates, Berg middle trans mount, 3/4" rear sway bar) Wheels are Fuchs 2 liter with 25-60-15 tires.
I started with Bilstein gas shocks on the corners, and found them to be way harsh. Changed the front to lowered oil shocks, and swapped the rears for KYB Gas adjust.
The change is great, the car still is very responsive. The original shocks were so stiff the front end transmitted every seam in the road to the frame. The rear was OK, but driving across freeway road seams was constantly jarring. I found the original shocks led me to be tired of the car after a 30 minute drive. The new combination is still very stiff, and transmit a lot of road vibration, but the compromise is great, keep in mind the seats great and take up some of the road shock. Granted I'm getting older.

My sage advice is, select the best products, and see what happens. Be ready to make changes to find what works for you. Another thought is to wait to build the stereo until after the car is running. Mine sounds great when parked, but this isn't a new quite car at highway speed. I don't use the stereo much... wasted planning and $$$

Scott

[Q-Dog]

I think heavier spring in front may be a mistake on the street, though fine for serious track days or off road. All depends on how you want to drive it.

I would probably drive the car first to find its deficiencies. You can always modify the suspension after you have driven it.
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Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[duesenberg1932]

I was hoping to do the upgrades as I was rebuilding the chassis, but i guess i will keep it stock then figure it out with trial and error once it is finished. Thanks for all the input.

[owdlvr]

A significant issue for your desire of "more performance" is the stipulation that you're keeping the car at stock height. Presuming we mean more performance in cornering, and 'at speed', my experience suggests that lowering the beetle is one of the most important changes. I could list out, and link, proven suspension setups that are used on street, and track, with well-performing cars...but each of them presume lowering will be completed in some shape or form.

If you're open to lowering your car, lots and lots of practical experience and advice can be offered.
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Instagram: @DaveHord
1971 1302s - Salzburg Tribute the #RallyBug
1958 Beetle
1975 Beetle
1973 Super Beetle
1993 C3500 with Cummins swap
1967 MGB
1963 MG Midget

[duesenberg1932]

I'd be open to lowering it slightly, but I'd like to keep the overall look fairly stock. I'm going for like 1950's factory rally car sort of vibe.

[owdlvr]

So to give you a bit of background, I run classic car tours. Three-day driving events in various parts of North America. I've coached driver training sessions in the past and taken my cars out for track days and track events. All of my cars are built to perform and handle.

Years ago I built a '69 Beetle:

I've got a '58 Beetle:

[img]https://preview.redd.it/5ox5be8vtjn31.jpg?width=1024&auto=webp&s=d083b0a35cb118956088be0611619375a3289b1e[/img]

The Rally Bug ('71 Super, shown on tarmac settings):

And just finishing my '68 German Look project:

Suspension wise, each car is modified in a slightly different manner or uses different components. Sway bars, for instance, are not a consistent choice for me across each of them. Wheel and tire choice comes into play as well.

If I’m building, or recommending a suspension setup out-of-the-box for the average person heres my suggested starting line:

- 2.5” drop spindles on the front
- Index the rear torsion bars to match. Stock torsion bars.
- Disc brakes on all four corners, Empi kits with cast brackets are perfectly fine.
- 2” narrowed beam, for tire clearance. Alternatively, 4cm wider fenders could be used up front.
- Bearings and micarta bushings in the beam. Urethane bushings for the rear trailing arms.

Sway bars, in my experience, are going to be a factor of tire size and selection. I run a rear sway bar only on the ’58, and none up front. The ’69 ran front and rear sway bars, and I’ve set my new German Look project up with front and rear sway bars. Sway bars should be used for tuning and I typically prefer to start without them and add as necessary. The German look is using 225 and 205 race rubber, so experience tells me I will likely want them. For shocks, I prefer oil shocks and not gas charged. I want maximum weight transfer under braking, to get weight moved forward onto the tires for turn-in. Later on tonight, I’ll dig up my list of links you can read for various track setups on beam Volkswagens which will help to confirm the selections I’ve suggested.

Torsion bars are naturally progressive. The more they twist, the stiffer they get.
Total brain fart. Was thinking one thing as I was typing another. I'll correct it by saying:

Torsion bars are naturally straight rate, meaning the spring action is the same regardless of how "deep into" to the compression you get. I've never felt the need for stiffer spring rates for the tracks / roads I run on, as I quite prefer the weight transfer I can work with using the stock rates. I’ve never felt the need for stiffer torsion bars in the rear of my so-equipped beetles, with the exception of two corners at one particular track where I think they could have been helpful. For street use, and I do a tonne of twisty mountain fun driving, I’ve never thought “gee, I need to up the spring rate”.
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Instagram: @DaveHord
1971 1302s - Salzburg Tribute the #RallyBug
1958 Beetle
1975 Beetle
1973 Super Beetle
1993 C3500 with Cummins swap
1967 MGB
1963 MG Midget

[modok]

[owdlvr]

[Turnswrenches]

I just ordered 7/8" front and 3/4" rear sway bars, along with a strut tower brace for my 71 Super.

I'll chime-in with results as soon as I get the car down the road with them installed.

[H2OSB]