Fibreglass (grp) Bonnets (std & Auto)

[mattbenselin 0]

Hi everybody...

 

As the title goes I will be making myself an auto bonnet out of fibreglass in the coming weeks. This will be done around other projects one of which is making all the body panels for this years Formula Student project.

 

I have both standard and auto bonnets in perfect condition to use to make moulds from and will be making a couple of 'test' skins to see what works best. A friend and I made a bonnet for a gen2 rx-7 and if anyone knows what these are like they are big enough to park a 205 on! We made it quite thin to keep the weight down but it flapped in the wind and we felt it needed to be either thicker or have bracing. The same will apply with the 205 bonnet in that we will make a bare skin and see how well that works, we will also try making one with built in bracing but in both cases with the intention of keeping weight to a minimum.

 

Once we are satisfied with the results and feel confident to produce more I will post a topic and see if I can make some peoples bonnet dreams come true! Options should include either a bonnet suitable for attaching using bonnet pins or similar and also bonnets with standard mounts for the hinges and standard bonnet release mechanism. I will make moulds for both standard and auto style which will more than likely be light grey in colour (depends on resin colours) and we will sand them down ready for priming and painting by you.

 

I will see how much interest I get on this and go from there I guess but I asked a while back at it seemed quite a few of you would be very interested. The main issue with anything like this is of course cost. Now at the moment I am not in a position to be quoting costs but lets say they will be very competitive and fair. That's not to say the product will be of a poor standard, I am making this primarily for myself and I always demand the highest quality. Everyone I make will be done to the same standards and finish.

 

Again depending on interest and requests other options may become available, personally I would like to make some from carbon fibre but once I am happy with the GRP ones I will look into this and again costing it.

 

This is just a enquiry really into who might be interested and any comments people have about it. The more demand there is the quicker I will try and get it ready.

 

Thanks and enjoy the new year,

 

Matt Benselin

[Peetypug 5]

i'd consider an auto one depending on price

[Tesstuff 222]

I am also interested in an auto one

[Baz 421]

Again, dependant on quality and price.

[All Praise The GTI 3]

as said above dependent on quality n price id have an auto one

[Cameron 16]

I've made a couple of these now, you'll definitely need to have built-in bracing unless you make the skin uber-thick. The biggest problem is being able to make the leading edge stiff enough, you'll soon find out.

[mattbenselin 0]

Cheers Cameron, this is the same problem we had with the rx-7 bonnet in that when at highish speeds the air would squeeze between the panel gaps esp. near the headlights and warp the bonnet. As a quick fix we blocked all the panel gaps and this worked but it wasn't permanent. We started to make another with bracing across the front and rear and cross-bracing to try and fix this but the car got written off in an accident so we never found out if it worked.

As you said things like should become apparent when we test them and I fully plan on resolving anything like to make sure they will work well.

Out of interest what did you use to brace it?

[BusEngineer 7]

as said above, im interested dependent on quality n price id have an auto one

[Tandoh 17]

As everyone else, intrested depending on quality and price =]

Cheers

Luke

[gizzmo 3 1 Cars]

i would take an auto depending on price

[MerlinGTI 3]

Im very intrested in an Auto one, with framework, as long as the quality and finish is second to none inside and out!

[Cameron 16]

I basically used a bit of trial and error. The first one I made flapped like a biatch over about 50mph, then I replaced it with a carbon / kevlar one with a slightly better bracing design and some ribs to support the front. Like so:

 

 

Its unbelievably light (sub 2kg) and very stiff. It does still flap over about 80mph though so the bracing design isn't perfect.

 

I was planning to make them to sell, the carbon / kevlar one was advertised for £300 but no takers so I kept it.

If you want to make any money I'd definitely recommend making an auto bonnet, nobody seems to want standard ones.

Making some carbon doors now, hopefully there's a bit more demand for those! Plus I want some.

[Batfink 201]

is it a trick of the light or is your bonnet lumpy? looks like there are trapped flies in it

[Cameron 16]

its no trick of the light, but that's the underside. Its lumpy from the gel-coat, as its difficult to get a smooth layer without spraying. The lumps are then exaggerated by each layer of cloth. It's ok though, the front is silky smooth.

 

[mattbenselin 0]

That looks great Cameron, well the topside anyway The bracing you used there is similar to the design we were thinking but ours would run around the edge and link across the middle. We had thought of either building up the fibres in these areas creating thicker 'bands', or building shaped braces from fibre beforehand then laminating them into the bonnet skin as we build it, or using a different material altogether such as stainless sheet cut and laminated. What did you use?

 

I was talking with my friend today and he has been asked by someone else if will do him a show bonnet which would be simply a thin skin which could be applied to a standard metal bonnet or a GRP one made from carbon fibre. This is obviously more show than go but we will never the less look into it.

 

I think from the interest shown already there is the market there for these, and if we can make a quality product which meets expectations and comes in at a good price there's no reason not to. An auto style one will be done first and tested then a std one after if there is enough interest.

 

Thanks for the interest and keep advice coming! I will keep this thread updated with info and the progress once its underway.

 

Cheers, Matt Benselin

[swordfish210 20]

I'd be tempted with an auto one.

[tagy 1]

would be interested in one depending on price.

[Cameron 16]

I wouldn't use any steel to be honest, it kind of defeats the point. There are all sorts of foam core materials you can use that weigh nothing, that's how I made mine, or you can make a separate mould for the bracing and then bond it on afterwards. The next one I make I think I'll either be taking a mould of the standard bracing, or copying its layout as some extra support is needed across the back to stop the skin sagging from the heat of the exhaust manifold and wind pressure.

 

Have you done much composite work before?

[daveyboyblack 1]

I'd also be interested in an auto version... price dependant etc

 

On a slight hijack note.....Are you doing formula student this year? This was by far the best thing I did at uni and enjoyed every minute of it! On a somewhat connected note, we built our front carbon tub using internal bracing that was then backfilled with foam (can't remember which sort). This method should give you decent rigidity so long as you use a good U shape for the cross section profile.

 

Here's a couple of pics.... ahh the memories!!

 

 

 

 

Dave

[benlilly 0]

There are all sorts of foam core materials you can use that weigh nothing

 

These guys make loads of the core foams for composites Lantor Coremat

 

Helps alot to create a stiff panel by increasing the thickness but without lots of heavy resin.

[Paul_13 212 1 Cars]

I'd be after an auto one depending on price, any idea when they'll be done?

[mattbenselin 0]

Hi,

 

I have been having a good old think, getting the cogs turning, and will be trying 2 methods to begin with.

 

First, I will try to make a skin which has thicker sections to improve strength, for example across the front, back and ribs to create rigidity. I have a few ideas up my sleeve to keep the use of glass fibre and resin to a minimum to conserve low weight but ensure strength. The standard bonnet comes in at around 12-13Kgs, I hope to have something which weighs around half this.

Second, I will make a mould of the underside of the bonnet as well as the top creating a similar structure to the standard underside out of fibre glass. This will then be bonded onto the bonnet skin. This method will also provide me with connection points for the hinges, stay and release/clamp mechanism.

 

If I think of another better way to do things I wil try this also. I have been doing a lot of researh into how other people make bonnets and body panels in general. As far as Peugeot 205's are concerned there are not many options:

 

1) You can get plenty of bonnets which make chavs go weak at the knees with F50 style vents! Not good and not what I am after at all, they also do not seem to be made well, just a thin skin.

 

2) Spoox Motorsport: Spoox will make you a non-auto bonnet (total cost inclusive of postage and surcharge £220.50) but they do not offer auto ones (according to their website). You can also have one made from carbon fibre which looks great but again in non-auto (total cost inclusive of postage and surcharge £467.25)

 

3) Magnum Motorsport: Magnum will make you a non-auto bonnet in fibre glass (£79.90 NOT inclusive of postage or other charges) and a raised bonnet to accomodate a large carb airfilter though this is NOT an auto bonnet (£88.13 NOT inclusive of postage or other charges).

 

4) Ecosse-Peugeot: Ecosse have a few bonnet options on their website from full panels to bond-on bulges/vents. They do NOT make or sell directly an auto bonnet. Instead you can get an auto bonnet with integrated Renault Clio 16v vent (£316.25 inclusive of VAT and postage), I presume this to be fibre glass but it does not say on the website. You can also get a bond-on auto-ish bulge with a vent but this would need to be bonded to either a standard fibre glass bonnet or standard metal one, neither solving our requirements.

 

5) If anyone knows of other companies or individuals who make fibre glass auto bonnets I would be greatful for information. This is not so I can copy but take forward what other people have tried and improve the concept.

 

 

So...what I have found so far is that no one appears to directly make and sell auto bonnets from fibre glass. You may be able to get one made specifically for you on a one-off basis but this would be at great cost.

I hope within the next 2 weeks to have made the primary moulds and sourced the materials for the first few bonnets. Please bare in mind I am a very busy person, aren't we all, and this is at the moment a side project. From what I can gather these companies I have mentioned above will take anywhere from 2-6 weeks or more to make a single bonnet for you. Once each bonnet is finished I will test it for strength/rigidity, it's tolerances to heat/cold on long runs (ie: extended time in proximity to extreme heat (exhaust manifold)) and of course its quality and fit. I hope to have all this done asap as I want one to! From there I will assess the frequency with which they can be made and the total cost per item and begin to take orders. I will do my best to keep costs down and competitive but I will only sell a quality product and the price will relfect this and the time put into it.

 

Stay tuned for updates and I will document all stages of the process and post so people can see the progress.

Thank you and enjoy your weekend,

Matt Benselin

[Guest Jamie1986]

Just thought i'd add my interest in one as well

[pdd144c 0]

I've got an auto bonnet mould, just the outer skin though, laying the first one up as we speak.

 

Paul.

Edited January 20, 2009 by pdd144c

[rally_kid 0]

so how much are we looking for then for one of these? i would also be interested in an auto one f the price was right.