Lowering an IRS Standard Beetle

[s3racing]

I Have 2.5 inch drop spindles, but would like to go lower in the front and bring the rear down to a level. The car will be for road courses and daily driver. Any suggestions on how low to go without having to many problems of interference. I'm thinking of using a narrowed front beam (2"). and 195 or 205 rubber up front 225 rear. What else do you need to know to help me out here. I also like the look of the flared fenders on some european Käfercup cars. So using widened Fenders to gain more clearance is an option. Thinking maybe 4" up front total or is that to much or to little?
Thanks for your suggestions.
Rene

[s3racing]

Has anyone Used the Front and Rear Suspension Kits from Mendeola on there car.
If how are they for adjustability and Driving in general?
I'm contemplating using the kits for my car. Any experiences will help my decisions.

http://mendeolamotors.com/motors/index.php?option=com_content&view=article&id=147:s2-chassis&catid=1:latest-news&Itemid=110

[owdlvr]

I don't think anyone here in B.C. has used the Mendeola units, though Lorne, Gerry and I keep talking about who of the three of us will be the first to buy one. The biggest problem with the Mendeola suspension is the fact that no-one outside of their staff seems to have a car they actually use with the suspension. Lots of projects in progress which will claim they'll be using the suspension hard...but so far no one doing it. So, for the purpose of evaluation, you need to look at the systems with a critical eye.

I am not an engineer, I did work for five years in the Automotive industry designing exhaust systems and racing parts, but I'm not an engineer. Any of my suspension and design knowledge comes from a couple of courses I sat in on at UofT, and reading any and every racing design book I've been able to get my hand on. But, again, not an engineer


The FRONT suspension looks to be really well designed and well thought out. If I hadn't built the rally beetle out of a Super, I definitely would have started with a Mendeola front end. For 99% of users it's pretty much spot on and perfect. I would have used the suspension arms as a template and built my own but only because I would replace the ball-joints with rod ends. Honestly, it's a bad idea since they need to be replaced often (every 15,000km on my Audi rally car)...but I'm a bit overboard on some of my things. As far as tuning and adjustability and driving feedback, the beauty of their system is the fact that the front uses a common shock size so you can tailor the system exactly the way you want it. You can start out with a basic adjustable shock, or buy yourself some 4-way adjustable dampening units if you have the budget and know what you're doing.


The rear suspension, in my opinion, is another story. When I look at the system there are a number of engineering red-flags that scream out. A great 'beginners book' to chassis design is "Engineer to Win" by Carroll Smith. In it he highlights a number of simple mistakes that lead to failures, and in that respect the rear system by Mendeola scares the heck out of me. They have highly loaded fasteners in single shear, pre-buckled tubing and loads applied to the middle of tubes. They've tested the system up to 1G cornering loads (if I remember correctly) and claim they have no failures. But I just can't get past the fact that it's so wrongly designed.

For setup ideas and tuning of the stock Volkswagen designed systems, check out this thread: http://www.shoptalkforums.com/viewtopic.php?t=127619. These guys run a very successful Ghia which doesn't blindly follow the "advice" that's out there. I for one wouldn't narrow the front beam if your focus is on performance. I ran 195 and 205 sized tires under stock fenders with a stock width beam on my white car, though admittedly I needed 1" or 2" wider fenders. I rolled the stock ones, and rubbed the sidewalls on the tires.

Unfortunately I can't remember how much my '69 Beetle was lowered. But I think it was just 2.5" drop spindles up front and a spline or two in the rear. I'd be real careful about lowering the car too much, well depending on what tracks you plan on bringing the car to. Mission and Pacific Raceway require a higher ground height vs Portland and Pacific. http://www.airspeedparts.com/forums/index.php?topic=14769.0


-Dave

[owdlvr]

On the Salzburg bug I opted to delete the torsion bars and go with coil-over shocks in the rear. In order to get them in they required cutting out the factory lower shock mounts and fabricating my own. If I were to re-do this project, or I suppose on the next one, I won't be doing a full coil-over conversion. In future I'll retain the torsion bars, as the progressive nature of their spring rates is so key. To overcome the softness of the stock springs, I'd simply uprate the torsion bar diameter (readily available). On the dampening side, however, I would definitely install a 4-way adjustable damping unit. You can get them in *almost* the exact length needed, they'll be a little short but fine for a lowered car. Installation of limiting straps may be required though.





-Dave

[s3racing]

http://www.heidts.com/part/mustang-2-front-suspension-ifs/

What about using a kit like this for the front end. A grand cheaper than the mendoela kit, a popular proven system, and readily available parts. It would probably bring a bit more weight up to the front end. I'd use for example coil over adjustable shocks and leave away the springs that are normaly with the kit.
 Maybe even go with a power rack using an electric power steering  booster.
Makes into more of a VW rod. Bit looks to me like a similar set up as the mondeola!
Seen them used more for kit cars on VW pans or full out Hot Rods with tube chassis. That Extreame I don't want to go. My ? Is more would it handle better than the factory beam torsion bar set up?

Ren

[owdlvr]

Did you read the Shoptalk Forums thread I linked?

You can make the torsion bar front end handle very well. The Mustang kit may "look" similar, but it only looks similar due to the fact that it's a double a-arm suspension design. You're in for a whole lot of fab and debugging work, far more then that $1k in savings will garner you.

-Dave

[s3racing]

No I didn't Dave
I missed that one :-) , just looked up the others.ops
Wow what a wealth of info. Forgetting my silly ideas lol.
Thanks Dave !!!

[Bruce]

I Have 2.5 inch drop spindles, but would like to go lower in the front and bring the rear down to a level. The car will be for road courses ......

A little lower is good.  A lot low isn't.
Back in the 80s everyone lowered their cars all the way around by lots because that's what works.  I did that to mine and it didn't handle worth shit.  The problem was you must have suspension travel.  If you lower it too much, you are taking away bump travel.
My current car is a lot higher and it handles way better.
A way to lower without losing suspension travel is low profile tires.  Those will be good for 2-3", giving you 5-6" total with just your spindles.  If you have a stock height Beetle, check it's ground clearance to start with.

IMO, the Mende suspension serves only one purpose.  It's for those that want to build a garage queen so they can take it to the show and say "Look at me".  I bet you could take the VW torsion bar suspension and work it so it will outhandle the Mende.  There is a huge resource of guys that have already done it with the stock setup.
Adding to Dave's comments on the rear suspension.  Those rear TAs look really HEAVY compared to stock.  Heavy = BAD.

[s3racing]

Thanks Bruce,
I'll be staying away from the Mendeola Suspension units, and working with a version of the VW / Porsche set up.
Ev. using Coilovers or a combination of both.

Rene

[s3racing]

Got another silly ? I read two different things about suspension set on irs beetles.
One that you should lower the from and the rear of the car equally.
And on aircooled.netthat you should lower the rear 1" more than the front. Both for performance applications. Anyone can explain what is what and why. I'm sure both have their merits and justified application. By my logic I'm leaning more to equal drop front to rear. I have drop spindles front and drop plates rear.
2.5 front and 2" rear. What should go up or down. One said 2" drop is the racing and streetable max. Limit.
Me is confused on what is for what application the right way of going. Still have a chance now to call and change Tia 3" rear drop. But find that quite low ??
Thanks for your input
René

[Atomwerk]

That advice is base on a racer who had wins with a suspension set up as this. In reality he may have won just as many races with a level suspension.

[s3racing]

Front Beam weld in adjusters. Which ones to buy, which ones are better. to use and install

- EMPI from (CIP1)

or

- CSP from (CIP1)