I`m looking to remove some of the bracing from under my bonnet. Seems like there is some weight to be removed there The plan is to keep the area near the rear hinges and chop out just about everything else, adding a couple of aerocatches at the front to stop it flexing. Still undecided on whether to leave the centre catch and a small amount of bracing to keep the middle secured. I don`t like the look of a central aerocatch, but if it requires loads of metal has to be left to keep the catch, I may have to remove that too. What have others done for the maximum weight saving whilst still keeping the steel bonnet ? I`m thinking this kind of thing.
Toyed with the idea myself and even have a spare bonnet waiting. Feedback I have from others is that the single steel panel can flex a lot without support. Maybe put some honeycomb support in after where needed? Gurds
Yes, of course I did. But I don`t really want to start chopping the middle out and fitting aluminium sheets, its extra work, once you start on that route, you may as well fit a fibreglass one. I have a spare bonnet I picked up some time ago and keep toying with the idea of making it as light as possible. I just wondered how extreme you could be with the bracing removal. A little flex is OK, but if its wobbling all over and you get black flagged, that`s no good. Gurds, I wondered about fibreglassing some re-inforcement in to replace the steel, but I`m not sure how well I`d get the fibreglass to stick to the steel.
I actually like the ally sheet idea, although 1.5mm is too thick ... I nearly bought an ally bonnet once, but couldn't justify the cost, followed by the cost it needed to tidy it up and make it work on the car. Rivet the sheet in place every couple of inches, and don't even bother painting it, if it's on a track car... maybe some extra ventilation while you're at it. Need to make sure there are no sharp edges to catch the MOT man's attention. Bonnet is much more likely to be noticed than sunroof replacement. Replacing the bulk of the bonnet skin (and removing the bracing behind it) should get you most of the weight gain at a fraction of the cost. 30 of ally sheet and 10 of rivets, rather than 100 for the 2nd hand ally bonnet + prep and paint costs. Probably a solution for aerocatches rather than standard catches... although the rocco bonnet is fixed in 2/3 places, unlike golfs. However, the upcoming X-flow conversion means the standard slam panel on mine is in for some surgery anyway. I think by the time you've fibreglassed in some reinforcement you won't save much weight. Pressed steel isn't that heavy, as it'll be thinner than the fibreglass that replaces it. You could try fibreglassing in some ally angle, or cut some polythene pipe along its length, maybe (slightly smaller pieces than recently used for roof spoilers). I think the weight saving would be marginal. 1mm ally is definitely lighter than 1mm steel though! http://www.ebay.co.uk/itm/Aluminium...Supplies_ET&hash=item25541d9c51#ht_1626wt_942 Look at that big square section in the middle of the bonnet... just crying out for a sheet of ally... hmmmmm
not worth it, had a go at this and removed inner frame. Took hours, bonnet lost all rigidity and didn't save much weight, prob <1kg. Got composite bonnet in the end and difference is huge, even with with full frame! probably something like 4kg vs 10kg
reee,thats my pics ^^^ , weight went down from 17/18kg to about 4kg, only a slight vibration in the middle when idling, still lighter than a fiberglass bonnet and cost about 20 all in to do, hope this helps dudes,
My concern with that is any imperfections stand out on a bonnet and if it isn`t smooth, it`ll look naff. I know its a track car, but I still want it to look reasonable
I was thinking this was also a cunning way of getting rid of the dents in the bonnet, where I left a manifold on top the engine and tried to shut it I don't mind if it looks like it was put together in a barn by an eejit... why live a lie?!
