I am preparing my Beach buggy for trialling and am having trouble designing an engine cage/wheel holder for the back. Can anyone give me some ideas on attachment points.
The only strength is the original beetle floor/chassis. Is it necessary to build up a steel frame internally to brace a rear frame?
Difficult. The arms that hold the shocks are nice and solid so you can
ReplyDeleteattach to them. At a guess your tub is probably bolted to them already.
Another good attachment point is the frame horns. These are the two bars
underneath that support the engine/gearbox. Your framework would need to
go around the bell housing. Have you got a bash plate under the
engine/gearbox? If not you need to consider fitting one. If you attach
it to the frame horns you could incorporate your cage into it as well.
Just to complicate the issue a rear towing point is a good idea. It
would need to be strong enough to withstand a good solid tug from
another vehicle.
Whatever you do, consider how you will get the engine out afterwards.
Clutches tend to die quite quickly so you want to be able to get the
engine out fairly easily.
Les
juslade wrote:
> New Message on Classical Gas, For Trials enthusiasts
>
>
>
> *Ideas for a VW Beach Buggy engine cage/tyre rack please*
>
>
> *Reply*
>
>
> *Reply to Sender*
>
> *Recommend*
>
> Message 1 in Discussion
>
> From: juslade
>
>
>
> I am preparing my Beach buggy for trialling and am having trouble
> designing an engine cage/wheel holder for the back. Can anyone
> give me some ideas on attachment points.
> The only strength is the original beetle floor/chassis. Is it
> necessary to build up a steel frame internally to brace a rear frame?
>
>
> View other groups in this category.
>
>
>
> To stop getting this e-mail, or change how often it arrives, go to
> your E-mail Settings
> .
>
>
> Need help? If you've forgotten your password, please go to
> Passport Member Services
> .
> For other questions or feedback, go to our Contact Us
> page.
>
> If you do not want to receive future e-mail from this MSN group,
> or if you received this message by mistake, please click the
> "Remove" link below. On the pre-addressed e-mail message that
> opens, simply click "Send". Your e-mail address will be deleted
> from this group's mailing list.
> Remove my e-mail address from Classical Gas, For Trials
> enthusiasts.
>
>
</mailto:classicalgasfort
Have a look at the engine cage in the "Street Style & Power" catalogue.
ReplyDeletehttp://www.vwheritage.com/ssp/_rfx/?sku=AC7073105&src=rfx&&rfx_page=42&RFX_PassBack=&rfx_catalogname=SSP_0708&rfx_catalog=1&&rfx_spread=42&rfx_gid=2818256&rfx_pageid=null&rfx_catalog=1&rfx_passback=&rfx_base=http%3a%2f%2fvwheritage.richfx.com.edgesuite.net%2fcatalog_vwheritage%2fSSP_0708%2f&rfx_catalog_base=http%3a%2f%2fwww.streetstyleandpower.com%2f%3f&rfx_omni=1&rfx_OmniPageName=p42-43&rfx_OmniCatalogName=spring2007&rfx_OmniClientID=vwheritage This item fits to the top shock mounts, and the engine mounting brackets at the end of the gearbox frame horns. If you buy this item from SSP, note that in standard form it hangs down below the engine in a manner that's not conducive to good trialling, but is not beyond modifying/encouraging into place with the aid of a lever and a big hammer. However, you are spending money with SSP a set of "solid mounts" is a good idea, as they come with the lower cage mount already moved to the right place and include a mount for your bash-plate. Not to mention stopping the car from jumping out of gear. SSP part no AC3019530 (without straps)
Fit the cage to the car, then drop a spare wheel over the cage and see where it lies, then you should be able to see where to weld up a bracket to hold two wheels one on top of the other. The wheels should not project beyond the back of the cage, or you will probably break the one-third overhang rule.
The system I designed for VW Shorty (which is basically a shortened Baja body mounted on a Buggy length chassis) is as follows: Two mountings welded to the outside edges of the transaxle yokes just behind the line of the front transaxle mounting, these are drilled and tapped to take sumpguard fixing bolts, and are flush with the bottom of the yoke tubes. A 13mm solid steel square bar stitch welded across the bottom of the rear transaxle mount carrying yoke, again drilled and tapped to take sumpgaurd fixing bolts. The sumpguard is a full length 5mm steel plate 340mm wide stretching from the front transaxle mount to the rear of the engine sump where a vertical 40mm cross plate comes up behind the engine sump, this is drilled to take bolts from the end plates of the spare wheel carrier/engine crash bar. The sumpguard plate has been flame cut to create cooling slots in the areas in front and behind the reinforced rear transaxle yoke (very important in order to avoid cooking the engine). The two wider, outer slots each have a longtitudinal 13mm square section reinforcing bar welded in the centre to take load from the spare wheel carrier. A 40mm o/d steel tube crash bar surrounds the engine and bolts-in to captive mountings welded inboard of the engine bay on either side at the level of the normal horizontal tinware. Two further angled 40mm tubes extend down from short vertical tube stubs, to meet the vertical plate on the end of the sumpgaurd where they are bolted through. This creates a suitably steep departure angle at the back end of the car without infringing the permitted overhang regulations. A square registration plate fits neatly centred on these tubes. The spare wheel carrier mounts on horizontal swivel pins mounted on the top of the engine crash tube and has a top, truck dropside body snap pin type, mounting on the bodywork grille just below the rear window. This allows the carrier to be lowered to access the engine without having to resort to unbolting etc. The carrier is designed for two spare wheels mounted one on top of the other and the whole structure is easily capable of supporting the weight of the spares when the frame is subjected to extreme loading on rough sections. The whole assembly is very neat, not over-engineered, and follows closely the contours of the car. The sumpgaurd is easily removed to facilitate oil/filter changing by releasing the various plate securing bolts. After spending a little time thinking about what this structure was required to do. worst case loadings etc, and taking the various measurements physically from the car, just an hour on the drawing board was all I needed to make the working sketches, it could just as easily be done by measuring and cutting in situ once you're clear on the design. I know that Shorty is not quite a Buggy but you can easily adapt my design to work on your new trials car. E-mail me if you need a sketch. David Alderson
ReplyDeleteThe upper shock mounts are not as strong as they look, especially if you hang 3-4 foot of tubing off the back of them. They will bend about unless secured to something stiffer than a plastic buggy body. Ideally you need to connect them up to your roll bar. This will have the added benefit of adding some triangulation to your rollbar. If you are planning to trial your buggy for some time rather than as a one-off you should also consider a cross-brace between the shock towers and some struts up from the ends of the frame horns to the cross-brace or the shock towers to reduce flex in the frame horns. Otherwise the frame horns will eventually crack. Let me know if seeing some pix would help.
ReplyDeleteThanks for the responses regarding the cage. Most helpful. Back to the drawing board now. Julien
ReplyDeleteNo worries, let me know if you need some pix. Were you out on the exeter at all?
ReplyDeleteIt is possibly a bit late now but here are some pics of the cage I built for my car over Christmas. It probably doesn't help you all that much because it uses the roll bar as the main support.
ReplyDeleteThe original cage was an overweight mess. I estimate I have saved in the region of 40kg with this version. Some of you my recognise the car. It is Ed Nikel's old buggy, now fuel injected and with air suspension on the rear.
Attachment: rear1.jpg