light weight car
Discussion
I am thinking off cuttting the skin from the bonnet and use bonnet pins do the same with the boot lid and remove the inside of the door and removing the dash, is this a good idea ?
Also if any one else has any weight saving tips please let me know. Already done lexan window remove most of the interior and fitted light weight wheels.
Also if any one else has any weight saving tips please let me know. Already done lexan window remove most of the interior and fitted light weight wheels.
weight saving is usually dictated by the race series rules. if the reges allow, few ideas. remove std washer bottle and replace with small bag type (modern cars especially german cars have 5 gallon drums!), ally fuel tank, smallest capacity your usage gets away with. remove all carpet, sound deadening, air con. ally brake calipers help unsprung weight too which is a win, win. remove all excess wiring (stereo, leccy windows mirrors etc). all trim if regs allow, rera wash/wipe motor and mech, remove heater and fit 12v caravan blower/hairdryer to screen ducts. single wiper conversion etc etc
as for bonnet/bootlid, are they steel or fibreglass? (dont know what car...) if steel single skinning can reduce weight but can leave them floppy if unsupported. a lightweight fibreglass version is usually stiffer and lighter than the steel equiv. lose the hinges though and use bonnet pins.
lose dash as is probably heavy moulded affair. GRP universal or mini dash pods are available
as for bonnet/bootlid, are they steel or fibreglass? (dont know what car...) if steel single skinning can reduce weight but can leave them floppy if unsupported. a lightweight fibreglass version is usually stiffer and lighter than the steel equiv. lose the hinges though and use bonnet pins.
lose dash as is probably heavy moulded affair. GRP universal or mini dash pods are available
Edited by CNHSS1 on Tuesday 27th May 11:19
marT350T said:
I use my car for drag racing so there arent that many rules.
All my body panels are steel at the moment as I find fibre glass items for a mk 3 polo coupe hard to come buy.
worlds ya oysetr thenAll my body panels are steel at the moment as I find fibre glass items for a mk 3 polo coupe hard to come buy.
if it doesnt need it, bin it!!as for glass panels, if you are looking for 'race weight and finish' ie not concours, making your own fibreglass panels isnt hugely difficult although smelly and time consuming. getting a OEM finish a la Lotus/TVR etc takes much more time and adds weight too. can give you a few pointers if you fancy having a bash at mould and panel making
OK this is what i did.
take a std panel in as good a condition as poss as any dents/damage will be replicated in the mould and subsequent moulding. add 'skirts' to the panel so that the moulding will release. these can be thin tin, hardboard, plasti-card etc, hot melt glued in place or screwed. these ought to be painted to give a smooth surface to release from.
once the 'buck' is made, coat with release wax. i was taught that 6 good coats is enough, so do 8! allow to dry thoroughly each one and buff off, before applying next.
once the bucks completed, cut 1 layer of surface tissue, then use 450gm chop strand mat (CSM)and cut enough pieces to shape to do 6-8 layers. bit of overkill for a one off, but will ensure that should you damage a bonnet, you can easily re-use the mould to make another few. dont worry if it requires each layer to be in a few parts, better to get a decent fit, than all ruckled up. each layer should be slightly oversize too.
for the mould use a generous coating of gelcoat, apply liberally and try not to re-brush, just let it settle straight from the brush. leave until tacky (couple of hours generally), then apply a layer of resin and then the tissue. its worth trying paint rollers for the tissue as it tends to get snagged with a brush and ruckles up. once the tissues down, wet out the 1st layer of CSM on a seperate bench/board/floor. the CSM will go translucent within a couple of mins as its saturated with the resin, and then lift of the wet board and onto the buck. stipple down with a bruch and then use a ally paddle roller (from grp suppliers) to squeeze out and air bubbles. lay up 2 more layers in the same way, ensuring theres a good coverage of resin and no air bubbles. then leave to cure.
once cured, add 2-3 more layers and cure, then add some bits of old timber across the buck to act as stiffners (keeps the mould stiff and allows the buck and final mould to be prised away). cover these with a couple more layers of csm to complete the mould. leave to cure for at least 2 days, preferably 3-4. trim the excess off with and then prise the original bonnet from the mould. often a sod of a job to be honest. i use plastic door wedges to sqeeze the two apart, oh and lots of swearing! often once the edges are parted, a kettle of hot water poured in between the two halves will help release. it takes a lot of brute force and ignorance and patience, and of course swearing. when it does release its usually with an almighty crack and youre convinced youve broken it!
once released, check the mould for damage or flaws. these can be filled with car body filler if minor, sanded and then re waxed up. again another 6-8 layers of wax is good house keeping.
laying up the panel moulding , is similar to making the mould, but less layers. for say a Polo bonnet, gelcoat, surface tissue and 3 layers of 450 csm would give a light panel, which may need bracing glassing in afterwards (id try it first). easy enough to put the completed panel back into the mould and adding extra bracing to keep it square. for ultra light panels, use a paint roller to apply the gel coat (gels heavy) but try and get an even coat (helps with final finish). 1 x layer of tissue, 1 x 450csm, then a layer of 3mm foam core, then 1 x more 450csm. panel wont be factory, but itll blow away in the wind when not pinned to the car! cheap too compared with carbon. with the foam core try not to saturate it, just cover both upper and lower surfaces, again paint rollers tend to use less resin (resins the heaviest component of the panel). dont take the foam core to the very edges of the panel, about 2" from each edge is ideal.
to make the panel more resilient to usage, an extra layer 2" wide all around the edges of 450gm csm will toughen them up no end.
all of the above is relatively cheap, for better finish or stronger or carbon (bling) panels, the cost tends to go up exponentially. get hold of Simon McBeaths Competition Composites book from Haynes, very good and far better explained than i ever could, best £15ish you will spend on the subject
hope that helps,
CNH
take a std panel in as good a condition as poss as any dents/damage will be replicated in the mould and subsequent moulding. add 'skirts' to the panel so that the moulding will release. these can be thin tin, hardboard, plasti-card etc, hot melt glued in place or screwed. these ought to be painted to give a smooth surface to release from.
once the 'buck' is made, coat with release wax. i was taught that 6 good coats is enough, so do 8! allow to dry thoroughly each one and buff off, before applying next.
once the bucks completed, cut 1 layer of surface tissue, then use 450gm chop strand mat (CSM)and cut enough pieces to shape to do 6-8 layers. bit of overkill for a one off, but will ensure that should you damage a bonnet, you can easily re-use the mould to make another few. dont worry if it requires each layer to be in a few parts, better to get a decent fit, than all ruckled up. each layer should be slightly oversize too.
for the mould use a generous coating of gelcoat, apply liberally and try not to re-brush, just let it settle straight from the brush. leave until tacky (couple of hours generally), then apply a layer of resin and then the tissue. its worth trying paint rollers for the tissue as it tends to get snagged with a brush and ruckles up. once the tissues down, wet out the 1st layer of CSM on a seperate bench/board/floor. the CSM will go translucent within a couple of mins as its saturated with the resin, and then lift of the wet board and onto the buck. stipple down with a bruch and then use a ally paddle roller (from grp suppliers) to squeeze out and air bubbles. lay up 2 more layers in the same way, ensuring theres a good coverage of resin and no air bubbles. then leave to cure.
once cured, add 2-3 more layers and cure, then add some bits of old timber across the buck to act as stiffners (keeps the mould stiff and allows the buck and final mould to be prised away). cover these with a couple more layers of csm to complete the mould. leave to cure for at least 2 days, preferably 3-4. trim the excess off with and then prise the original bonnet from the mould. often a sod of a job to be honest. i use plastic door wedges to sqeeze the two apart, oh and lots of swearing! often once the edges are parted, a kettle of hot water poured in between the two halves will help release. it takes a lot of brute force and ignorance and patience, and of course swearing. when it does release its usually with an almighty crack and youre convinced youve broken it!
once released, check the mould for damage or flaws. these can be filled with car body filler if minor, sanded and then re waxed up. again another 6-8 layers of wax is good house keeping.
laying up the panel moulding , is similar to making the mould, but less layers. for say a Polo bonnet, gelcoat, surface tissue and 3 layers of 450 csm would give a light panel, which may need bracing glassing in afterwards (id try it first). easy enough to put the completed panel back into the mould and adding extra bracing to keep it square. for ultra light panels, use a paint roller to apply the gel coat (gels heavy) but try and get an even coat (helps with final finish). 1 x layer of tissue, 1 x 450csm, then a layer of 3mm foam core, then 1 x more 450csm. panel wont be factory, but itll blow away in the wind when not pinned to the car! cheap too compared with carbon. with the foam core try not to saturate it, just cover both upper and lower surfaces, again paint rollers tend to use less resin (resins the heaviest component of the panel). dont take the foam core to the very edges of the panel, about 2" from each edge is ideal.
to make the panel more resilient to usage, an extra layer 2" wide all around the edges of 450gm csm will toughen them up no end.
all of the above is relatively cheap, for better finish or stronger or carbon (bling) panels, the cost tends to go up exponentially. get hold of Simon McBeaths Competition Composites book from Haynes, very good and far better explained than i ever could, best £15ish you will spend on the subject
hope that helps,
CNH
Edited by CNHSS1 on Wednesday 28th May 09:25
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