Suspension for street driven bug

[JezWest]

Apologies if this has been covered elsewhere, I took a look around and couldn't find any info.

Maybe it's me getting less tolerant as I get older (!) but I seem to have ruined the ride quality of my bug. I have a 1972 1200 bug and many suspension things are different and I suspect everything i've done has made the ride worse. So if you have any suggestions for improvements which could help whilst allowing me to retain my rims, i'd be grateful.

Front: lowered on CB Performance dropped spindles. Beam is adjustable, but wound all the way up to keep the tyres from hitting the wings. Beam is narrowed 2" to keep the 5 1/2" ARE LeMans rims sitting inside the wings. Toyo 155/70 tyres. Disc brakes. Standard Oil shocks. Since the tyres keep hitting the wings - and I can't adjust the beam any higher to stop this - I put a spare shock mounting buffer around the shock rod so it effectively makes the top buffer longer. This has stopped the tyre/wing situation, but there's so little travel now that I get a pretty hard jolt when I hit bumps (like speed bumps).

I guess the springs in the beam are a little shorter now, so the spring rate has gone up and it's stiffer? Is there a way to soften the spring rate? Do I even want to do that?

I'm thinking if I get the adjusters in the beam rotated a bit (like removed and rewelded further around, then I can raise the front a bit, remove the extra buffer on the shock and that should be a decent improvement?


Rear: stock height. ARE LeMans (6"), BF Goodrich 205/70 tyres on short axles from a '61 to get the tyres sitting nicely under the wings. Speedwell camber compensator. KYB Gas-A-Just shocks. Bus snubbers.

Feels hard over slow bumps, gets upset when hitting some bumps at speed - difficult to describe: twitchy for a second or two, then fine. I was thinking of replaing the bus snubbers with the correct ones for a bug(!) or cutting the topmost bump off the snubber. And replacing the Gas-A-Just with oil shocks.

The alignment seems just fine - my bro' went through everything front and back a few years back. Doesn't pull to either side, self-centres ok.

I read the suspension articles on aircooled.net (http://www.aircooled.net/vw-technical-articles/) - but they don't quite cover a street driven bug on grungy roads with speed bumps!

[richie]

Hi Jez


1st thing to go should be the gas rear shocks,for me they are way to stuff for a street car, koni reds would be my choice, on the front the beam mods to get more adjustment will help, I had to do that on the old cab many years ago when I put cb drop spindles on, I have koni reds on the front and it rides pretty well, stock width beam though.
I have the adjusters set up so the top one takes all the initial weight of the car and the bottom one is set up lower so its sort of like a progressive spring

cheers Richie

[Zach Gomulka]

I agree with Richie, KYB's are horrible and Koni's are magical.

I like Richie's idea with the front end adjusters. If that doesn't work, Porsche Speedster kit cars use standard width ball joint beams with removed torsions to lower the car and reduce spring rate to work with their light weight. Something along those lines may work with re clocked adjusters.

[Rocket Ron]

Narrowed beams aren't the best, IMO they make the suspension a bit harsh

[pupjoint]

Narrowed beams aren't the best, IMO they make the suspension a bit harsh

x 2. i moved from narrow to stock width beam. i changed wheels in order to make this happen.

[andy198712]

How odd, I too have a 72 1200, and have been looking for a plusher ride quality of late!
i have HD front bar, stock height and beam, KYB gr2 shocks (harsh) and 195/55/15 tyres (harsh) and camber comp

i notice you already have good depth tyres which i find helps a good amount for comfort, that extra buffer of air.


i recently put cofap stock oil shocks on the rear and that feels better, and deeper tyres on the front, again that feels better.

In the future i want Koni's front and rear, the cost is just holding me back at the min,
i've been reading Peter Nords (sp) book on tuning VW's as he has some good parts on suspension for rally beetles where they are designed to ride on rough roads and NOT super smooth tracks ect.
he does state not to remove a front torsion bar though to soften it.

I think if you had good shocks, EG the Koni's, a good tyre, good range of movement i see no reason why the font won't work as intended, reclocking your adjusters sounds like it'll be needed to get it spot on, Richie's idea to create a progressive effect sounds very interesting and i'd love to try it!
same for the rear, enough travel, correct shocks and tyres....

Thing is, being a 1200 straight line speed isn't something i can enjoy at the minute, so cornering is my "thing" and i don't want it to be too soft to ruin that, it handled great being stiff with the KYB's and HD front bar (made it very level and chuckable) BUT it was harsh and twitchy in the wet.

How does it drive at the min in terms of over or understeer?

Stiffer front increases understeer/reduces over steer
Stiffer Rear increases oversteer/reduces understeer.

and visa verser, softer rear reduces oversteer ect.

it seems the KYB's i removed, when removed they extended on there own, which will actually raise a car a tad surely? but also promote POS camber on the rear, and i think are even compression and rebound.
Where as the stock Cofaps are oil filled and will stay at a set height, but also easier to compression, and harder to extend (rebound) and this is what the KONI's do also, i forget the ratio of compression to rebound effect but it covers it in Peter's book.

Also what tyre you have in terms of grip is a good factor to consider also for cornering.

I've rambled a bit! these are my semi limited experiances and info gathered from Peter Noard's book.

Also one question to add in the pot here. when people quote, "ride height should be an inch lower at the rear then the front" Where do you measure front and rear height from??

Cheers and good luck!

[Zach Gomulka]

HD (3/4") sway bar made my old car miserable to drive...

[K-Roc]

Hi Jez


1st thing to go should be the gas rear shocks,for me they are way to stuff for a street car, koni reds would be my choice, on the front the beam mods to get more adjustment will help, I had to do that on the old cab many years ago when I put cb drop spindles on, I have koni reds on the front and it rides pretty well, stock width beam though.
I have the adjusters set up so the top one takes all the initial weight of the car and the bottom one is set up lower so its sort of like a progressive spring

cheers Richie

Hi Richie would you mind explaining how you setup the adjusters on your beam in a little more detail, I am currently tweaking with my front end, finally put dropped spindles in, seems to me the biggest problem is that all ( and I mean every shock out there made no excetions) has way to stiff of valving for the light front ends in the bug.  Bruce Tweddle used to get OEM Mexico shocks that were smooth as butter but they are no longer available, He even compared them to the OEM style Boge / Sachs shocks and the Mexi one are still way softer.  I appears that every shock manufacture thinks we have the motor in the front......
I'm looking for a soft ride with 145's on it, perhaps some old worn out original B/J shocks is what I need.....

Cheers

[andy198712]

HD (3/4") sway bar made my old car miserable to drive...

Harsh or under steer?

[Zach Gomulka]

HD (3/4") sway bar made my old car miserable to drive...

Harsh or under steer?

Both, but mostly harsh. It went away when I installed original EMPI 5/8" bars front and rear. It was a pleasure to drive! And cornered on rails. A sway bar on the rear is just as important as the front, especially on a rear engined car.
I know original EMPI bars aren't exactly common (or cheap) but Thing/Trekker/181 bars are 15mm and are much easier to source.

[richie]

Hi Darren

basically i have set it up so the top adjuster/torsion spring is set to hold the car slightly below the ride height I want with the weight of the car on it, at this point the lower adjuster does nothing,the lock nut that clamps the ally block is loose enough to allow it to move freely, then I adjust that lower adjuster up to get the ride height I want, this way the lower torsions are barely taking any of the cars weight and only start to add more spring pressure when you corner, go over a bump etc.

Something else I will add here, it[old cabrio] only has one pair of caster shims under the beam, I keep reading that you need two pairs to make a beetle safe at speed , my findings are different, to me 2 pairs makes the steering to heavy and it has no feel to it,on a street car is makes it hard work and not nice to drive, my rpm data shows I have been well over 155mph and have a timing ticket over 152mph in the old cabrio set up this way and the steering always felt good to me. Car is factory IRS with H/D torsions and QA1 rear shocks

cheers Richie

[Arnoud]

Hi!

My last Mexican bug had:stock(ball joint) beam,stock swaybar,CB-dropped spindles,Koni red all round and:quality brand tyres.Not:round and black but Goodyear 175/65/15 and 195/65/15,dropped one spline in the rear.Although swingaxle it handled pretty well.
If it bounces(too stiff)it wont grip.

Good luck!

[Lanny Hussey]

Tire pressure,
Stock AC VW's had around 18 PSI up front and 30 PSI out back. I know that works with 135's, not sure about the modern tire profile. If so, that will smooth it out a bunch. The BFG 205/70's are really bitchin looking but are pillows for that light car. As K Roc mentioned, find the softest front shocks available. My old 67 had low mileage shocks from a 66 with the dust covers cut off, then painted Koni red to match the CLF steering dampener It sound like the beam needs to come out and have the adjusters indexed.Also,  I suspect the ARE wheels have too much offset for the track to work.

[volkskris]

HD (3/4") sway bar made my old car miserable to drive...

Harsh or under steer?

Both, but mostly harsh. It went away when I installed original EMPI 5/8" bars front and rear. It was a pleasure to drive! And cornered on rails. A sway bar on the rear is just as important as the front, especially on a rear engined car.
I know original EMPI bars aren't exactly common (or cheap) but Thing/Trekker/181 bars are 15mm and are much easier to source.

Eibach makes a 15mm swaybar. Some German style guys insist on using no bigger than that.

[Eddie DVK]

I also have it set up like Richie says, only also have the bigger camber adjusters in the top arms of the beam
and also only use the front 15mm eibach swaybar.
(sorry don t know the camber degrees)

Have the empi 19mm swaybar and the cambercompensator at the rear. (165/65/15 front and 195/65/15 rear)
It corners good, a little bit of understeer, but that is a lot more predictable than sudden oversteer.. my 2 cents.
Arrow straight at highway at high speeds. (140-150km/h) ( don t know if this is high)

Oh and have the red koni s all around.

I think it is written also in this book:
'Käfer-Tuning mit Hand und Fuss Band 1. Boden-Gruppentherapie'
At least, that is where from I got my info.
 

[Zach Gomulka]

HD (3/4") sway bar made my old car miserable to drive...

Harsh or under steer?

Both, but mostly harsh. It went away when I installed original EMPI 5/8" bars front and rear. It was a pleasure to drive! And cornered on rails. A sway bar on the rear is just as important as the front, especially on a rear engined car.
I know original EMPI bars aren't exactly common (or cheap) but Thing/Trekker/181 bars are 15mm and are much easier to source.

Eibach makes a 15mm swaybar. Some German style guys insist on using no bigger than that.

I didn't know Eibach made those! Thanks. The Germans are right.

Edit: I can't find them on Eibach's website. Is this a Europe only thing?

[Eddie DVK]

HD (3/4") sway bar made my old car miserable to drive...

Harsh or under steer?

Both, but mostly harsh. It went away when I installed original EMPI 5/8" bars front and rear. It was a pleasure to drive! And cornered on rails. A sway bar on the rear is just as important as the front, especially on a rear engined car.
I know original EMPI bars aren't exactly common (or cheap) but Thing/Trekker/181 bars are 15mm and are much easier to source.

Eibach makes a 15mm swaybar. Some German style guys insist on using no bigger than that.

I didn't know Eibach made those! Thanks. The Germans are right.

Edit: I can't find them on Eibach's website. Is this a Europe only thing?

Zach,

I got him from Tafel that is a german tuner/webshop.
http://www.tafel-tuning-shop.de/cgi-bin/shop/front/eidamo.cgi?func=searchdo&sfields=&wkid=12974893218962816&rub1_search=all&sfield=1&sbeg=eibach

He is also famous for his a brake assistant kit (mechanical)
http://www.tafel-tuning-shop.de/cgi-bin/shop/front/eidamo.cgi?func=det&wkid=12974893218962816&rub1=TAFEL%2DTechnologies&rub2=Bremsanlage&artnr=1463&pn=36&sort=&partnr=01100016H00000&all=

I don t know if he ships this to usa.
Hope this helps.

[andy198712]

I can't see many options when I add it to my basket, doesn't have UK/England in the drop down menu, but I might be missing it, as I only read English sadly. 129euro for the kit

[Eddie DVK]

I can't see many options when I add it to my basket, doesn't have UK/England in the drop down menu, but I might be missing it, as I only read English sadly. 129euro for the kit

Ok I see what you mean, maybe just send them a mail, and ask if they ship to uk.
I always got good service from them.

Regards

[j-dub]

Does anyone have any additional information of the mechanical brake booster from tafel tuning? This is the first time I have seen it and am struggling to see how this helps. It seems like the same thing could be achieved with a different sized master cylinder.

A larger bore master cylinder would take less petal stroke to put the same pressure on a wheel cylinder/caliper as compared to a smaller bore master cylinder, with a larger bore you have the possibility of loosing some of the brake modulation.

At the end of the day it is about mechanical advantage. What am I missing?

[Taylor]

Does anyone have any additional information of the mechanical brake booster from tafel tuning? This is the first time I have seen it and am struggling to see how this helps. It seems like the same thing could be achieved with a different sized master cylinder.

A larger bore master cylinder would take less petal stroke to put the same pressure on a wheel cylinder/caliper as compared to a smaller bore master cylinder, with a larger bore you have the possibility of loosing some of the brake modulation.

At the end of the day it is about mechanical advantage. What am I missing?

This is not accurate.   A larger master cylinder bore will require more pedal pressure not less.

[JezWest]

Lots of useful stuff here, thanks. The Konis sound like a good step - i'll have to knuckle down at work for that pay bump 

I missed a couple of things: one set of caster shims and a 5/8 sway bar up front with urethane/stainless clamps. Urethane bushes on the rear too. I try to keep the tyres at 18/28. Not completely sure how to set the rears though as they are not the stock size - no idea how that affects things.

Seems to handle pretty well - although I never push it. Deffo not at the moment with soggy leaves everywhere.