Help! I'm bottoming out! :(

[Merlin]

Hi all,

I have a '67 Euro bug, which has been converted to dual-springplate IRS.

* Urethane bushings
* Kafer Cup Brace
* 3/4" sway bar
* Dropped 1 spline
* TYPE 3 torsion bars

The bug is running a deep sump, and external oil filter, and this coupled with the exhaust mean that cutting/removing the bumpstops is a monumentally stupid idea.

The car hits the rear snubbers on most bumps in the road and if I have a friend in the car with me it'll bottom out on almost anything.

Let alone putting anything in the car.

Short of raising this car back up, which I'd really prefer not to do, what's recommended to cure this problem?

I've had a look at the Sway-a-way website, for their torsion bars, but to be honest, their prices are way out of my budget.

Any ideas?

Many thanks, Nic

[FJCamper]

Hi Merlin,

You've discovered the main problem in even a little lowering -- quick bottoming out. Cosmetic lowerng and street survivability don't co-exist well.

However, the least expensive route is cut-down coilovers on the rear. Not the high-price stuff - the cheaper coilover shocks used on dune buggies. The trick is to cut the spring so you get no suspension lift out of them, but plenty resistance as you compress the suspension.

The only drawback in this is the ride is going to be rough.

FJC

[Merlin]

Hey FJC,

Thanks for the info'.

I've been chatting to a few people here and I'm come to the logical conclusion which is simply to raise it to stock again.

I also think I need to brush up on my torsion bar theory as I seem to understand how it all works rather incorrectly. I expected things to be a lot stiffer with the Type 3 bars.

Hopefully it'll get a nice rake and not look completely daft.

With my deep sump and external filter, a higher rear does make sense.

I'm refuse to notch my 'plates as that puts the sump and filter further into danger territory, and I just can't accept the idea that it's safe to drive like that.

I'll start a new thread here soon too, which I'd appreciate your input on too if you don't mind...setting up front sway bars.

Thanks, Nic.

[Brent Bousman]

Not sure what length bars you need since you changed to IRS but a set of used torsion bars will stop the bottoming out along with some shocks.

$50 http://www.thesamba.com/vw/classifieds/ ... ?id=747215

$50 http://www.thesamba.com/vw/classifieds/ ... ?id=752080

It will be tough to find a fix that costs less...

[Merlin]

Hey Brent,

Brilliant! Thanks. I never even thought to check the TS classifieds.

Any idea if they will actually cure my problen though, and what size bars to buy?

Thanks, Nic

[Brent Bousman]

I'm not sure of the proper length of torsion bar for your car but this is the proper way to fix your problem.

I would start with the skinnier torsion bar and a gas shock in the rear. It will be stiffer ride but it should hold your weight (with passenger) over bumps as long as you don't have it slammed on the ground already. If you are a couple of big guys and need that added protection try the larger bar and a skid plate.

Question- why don't you use a skinny sump on the street? The clearance is much better. Do you really need the extra capacity? I don't recommend deep sumps unless you have a special application such as drag racing.

[Merlin]

Well I'm on 22mm Type bars already...

My bug builder says he dropped the rear 8 degrees (1 spline).

I tend to drive my bug like an absolute Hooligan and more often than not I'm racing it around non-stop, and getting it sideways...oil starvation is a problem - plus the extra oil does tend to help cooling just that little bit extra.

Shipping such heavy bars to South Africa will cost me a boatload of cash so I'd like to get a clearer answer as to what size to look for first.

Thanks, Nic

[Brent Bousman]

OK I see you push the car with weight. I do also as I drive my street legal SCCA Rallycross RP Ghia to the track and back.

8 degrees is about 5cm. It is OK to drop the rear that far but not with a stock bars as you will quickly bottom out. I would go with a larger 27 or 28 bars at the same -5cm height that you have it currently.

I highly recommend you go with the skinny sump and extended pushrod tubes. I have raced with the skinny sump in autocross sucessfully since 1980 and never starved a motor for oil using large race slicks generating big Gs. With the skinny sump you will gain extra clearance behind the rear tires which will be a big help.

[Merlin]

Hey Brent,

I drool over the toys some of your chaps have...

Thanks for the info on the torsion bars. I'll drop the seller on the TS a message about his 28mm bars.

Due to location and exchange rate we pay around 4-5x for parts what you guys do, and we have to import everything, so it really adds up.

I don't know anything about extended PR tubes...I'll do some reading up.

Cheers, N.

[Bruce2]

Got any auto wreckers in your area that deal in Porsches?

Stock IRS bars are 676mm long. I don't know what that is in obsolete units.

Porsche 924s and 944s used a 676mm long bar. Their diameters are bigger than VWs. There are also optional suspension packages that have different diameter bars in the same year and model, so you will have to open up every car to find the bars you want.

[sideshow]

Spring rate and free lowering. While I always have just reset the torsion bars to change ride height I have been wondering if that is the best way. This strikes me as old technology, but aside from IRS bus boomerang plates I have not seen this on any ACVWs.

http://vwrepublic.com/forums/index.php? ... view;id=22


While the vendor looks rather sketchy (per samba threads) the concept looks very simple, make a block to keep the swing plate pre-load stock and hang the tire up a little. Stock spring rate, sane lower ride?

[Merlin]

Porsche scrapyards? Not a chance...but I might know someone able to help - I'll drop him a line.

Thanks for the tip.

No idea what bus boomerany plates are, sideshow, but I got the idea of those brackets after reading the description a few times.

Definately also an option...

Thanks, N.

[sideshow]

The picture next to the phrase "Rear Lowering Plates (Boomerangs)" is how it has been done on IRS buses.
http://www.bus-boys.com/bbsusp.htm
Named after the shape I assume

[Merlin]

Thanks, sideshow.

[volkdent]

I didn't see this mentioned, but they have Z shaped spring plates so you get the drop without grinding or bottoming out, but that is still not going to take care of your sump clearance. You can have one or the other, not both unless you're ready for a really harsh ride. You could just do a full flow oil system for your extra volume and ditch the sump to create more clearance, then you can go a lot lower. Plus you could add an external filter, and cooler if that's an issue.

Jason