MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: Jrichards20 on September 29, 2015, 08:34

Title: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 08:34
Does anyone know the weight of the front and rear bumpers for a PFL. I check the chart and couldn't see it on there.

And does anyone know the weight for the JDL front and rear bumpers? They are fibreglass so I expect them to be lighter, but with the bigger surface area I'm not sure. Also is there any aero dynamic benefits or cooling benefits of the JDL over oem.

I want my 2 to look good. But not at the expense of performance  s:) :) s:)
Title: Re: Lightweight bumpers?
Post by: StuC on September 29, 2015, 09:29
I have a front one as home. I could try weighing it if you need Josh?
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 09:31
PFL OEM one? Only if you have time mate, I would expect someone to have the figures somewhere, but if its no hassle than at least I know the figure is reliable  s:) :) s:)
Title: Re: Lightweight bumpers?
Post by: StuC on September 29, 2015, 09:56
Yup a pfl oem. Its the original one from banana before her front end respray.
If i can get the scales working it's no dramas.
Title: Re: Lightweight bumpers?
Post by: tomaky on September 29, 2015, 10:52
The front JDL is definitely heavier than the PFL. Id say as mucha as 40-50% heavier than stock.
Title: Re: Lightweight bumpers?
Post by: Topdownman on September 29, 2015, 10:55
You might be glad of a bit more weight on the front!
Title: Re: Lightweight bumpers?
Post by: tomaky on September 29, 2015, 10:58
There is that  s;) ;) s;)
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 11:07
Quote from: "tomaky"The front JDL is definitely heavier than the PFL. Id say as mucha as 40-50% heavier than stock.

Seriously? Oh my... That's definitely given me second thoughts! I thought being fibreglass it would be lighter. Do you know about the back?  


As for more weight up the front, I want to have a 40/60 weight distribution, with a front diffuser, I'm not bothered about keeping some weight up front, would rather loose weight and increase downforce  s:) :) s:)
Title: Re: Lightweight bumpers?
Post by: JoeCool on September 29, 2015, 11:31
I've got a back bumper at home, if you mean just the plastics. And I've taken the front bumper off my car to do some work. It weighs eff all, a few Kg at most. It's the bumper bar/intrusion beam that weighs. You're on a hiding to nothing swapping plastic for fiberglass to save weight. In the interests of science, i'll weigh it when I get a moment so you know what score to beat.
Title: Re: Lightweight bumpers?
Post by: tomaky on September 29, 2015, 11:34
i know mines like hybrid JDL. Ide tp halfs stock bottom halfs fibreglass. But the JDL front is defintely a fair bit heavier. Have you weighed your JDL ones?
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 11:36
Well that's poo poo'd my idea. I guess the JDl bumpers wouldn't provide any aerodynamic improvement either?
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 11:36
Quote from: "tomaky"i know mines like hybrid JDL. Ide tp halfs stock bottom halfs fibreglass. But the JDL front is defintely a fair bit heavier. Have you weighed your JDL ones?

Get some pictures up then  s:) :) s:)  im intrigued  s:) :) s:)  

No but I can do when I get home.
Title: Re: Lightweight bumpers?
Post by: Anonymous on September 29, 2015, 12:06
Consumer Fibreglass bumpers are usually heavy because they are strengthened so much, otherwise they will be very weak and flexible and seen as poor quality.

I remember picking up some bumpers for "sadlebag" and the front fibreglass one was a lot heavier than the standard front one I picked up for myself at the same time!
Title: Re: Lightweight bumpers?
Post by: jonty on September 29, 2015, 16:53
Mark if you come to pick up those wheels from my workshop rather than house I'll show you the carbon bonnet my brother and I made for our 200sx... it weighs 7kg instead of about 15kg for a normal aftermarket one or 22kg for OEM (it's a bloody big bonnet!) , and I think we can still get about 30-40% of that weight out of it...!

Most aftermarket stuff is horrible and heavy as said by the other guys... OEM stuff is as light as you will get this side of carbon and foam/honeycomb core panels. Lucky me  s:) :) s:)

As for aero benefit, I have never yet seen any off the shelf bodykit stuff that actually improves aero in a quantified way...
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 29, 2015, 17:22
Quote from: "jonty"Mark if you come to pick up those wheels from my workshop rather than house I'll show you the carbon bonnet my brother and I made for our 200sx... it weighs 7kg instead of about 15kg for a normal aftermarket one or 22kg for OEM (it's a bloody big bonnet!) , and I think we can still get about 30-40% of that weight out of it...!

Most aftermarket stuff is horrible and heavy as said by the other guys... OEM stuff is as light as you will get this side of carbon and foam/honeycomb core panels. Lucky me  s:) :) s:)

As for aero benefit, I have never yet seen any off the shelf bodykit stuff that actually improves aero in a quantified way...

Thanks for the aero answer mate. Looks like I will be sticking to OEM bumpers then, and try and fit a splitter, flat aluminium floor and diffuser.

What did you do in regards to the bonnet?  Bet the carbon cost you a fair bit, difficult to mold into what you wanted? Great way of loosing some weight! maybe you should make a few more and sell some, il buy one  s;) ;) s;)
Title: Re: Lightweight bumpers?
Post by: jonty on September 30, 2015, 00:34
Yeah splitter, flat floor and diffuser will be awesome, it's on our to-do list too!

The bonnet is for our s14 200SX, so you would need a different car first! We made this one by wet lay, brushing resin into the fabric, but we've moved on to using prepreg. You use a vacuum to help push the fabric into shape inside the mould when using wet lay, but with prepreg you get it perfectly positioned using the tackiness of the material, and the vacuum just helps consolidate the layers together whilst you cook it.

We've had our workshop for about 18months now, and (aside from distractions like 2zz conversion) we've made door cards and air box, bumper blanking plates, bumper ducts. The amount of learning we've had to do is phenomenal, so although the actual laying up of the fabric isn't too difficult, it's all the pattern part, mould making, painting, etc that has taken so long. Here's the air box, uses an S2000 filter:

(https://farm6.staticflickr.com/5688/21832126191_fa00810ecd.jpg)
And with lid and air feed parts:
(https://farm1.staticflickr.com/450/17828585593_629acc8c07.jpg)
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 30, 2015, 08:25
Let's see some pictures of the S14?  s:) :) s:)  bet the carbon bonnet goes well on it.

Seems like a fair bit of work goes into it, but the air box looks great!! Really looks good.

does it work out a lot cheaper than buying it? I guess making the mould is costly, how is buying the materials compared to buying an actual product.
Title: Re: Lightweight bumpers?
Post by: Anonymous on September 30, 2015, 08:55
Sounds fantastic, show us more Jonty!
Title: Re: Lightweight bumpers?
Post by: jonty on September 30, 2015, 09:16
For the time, effort and money I would advise steering well clear of trying it yourself   s:lol: :lol: s:lol:

The carbon bonnet is painted body colour, but unfortunately it's a metallic and a total pain in the ass to match, so I have decided to abandon ship and wrap it in carbon vinyl. It's a cop out I know, but this one was never designed to be a visual panel..
(https://farm1.staticflickr.com/570/21643785100_ac9c698c9a.jpg)

Anyway, stuff that is more successful; here's the door card which I am in the process of fitting to the car:
(https://farm1.staticflickr.com/613/21796465686_6f6fa90f56.jpg)
Workshop clean room with door card moulds:
(https://farm8.staticflickr.com/7569/15530747599_e20ddfcfab.jpg)
On track a loooong time ago:
(https://farm5.staticflickr.com/4079/4776897997_fca7cc7aff.jpg)
And more recently after a respray and rear arches extended when we got it out for a badly needed wash:
(https://farm1.staticflickr.com/694/21644773049_80e37ea1fc.jpg)
Title: Re: Lightweight bumpers?
Post by: Anonymous on September 30, 2015, 09:29
Nice! Great stuff  s:) :) s:)
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 30, 2015, 09:32
Those door cards are a work of art! Absolutely love them! Get a set made for the 2 and il buy a pair  s:) :) s:)  

Looks really good made, I would be well chuffed if I was you!
Title: Re: Lightweight bumpers?
Post by: jonty on September 30, 2015, 10:04
Cheers for the comments chaps  s:) :) s:)

I'd love to make stuff for the MR2, but the problem is we are going to struggle to sell parts for the 200SX in a quantity and at a price that covers our costs, and the SX has a way bigger modifying scene. If it was just a hobby I would be on the case in a heartbeat and supply you guys at cost, but I plan on eventually turning this into a business, and therefore I have to be a bit ruthless and not do stuff just because it is fun, but instead because it teaches new skills or can make a few quid.

Ideally, we should be making them for high end stuff like Porsches, GTRs, etc, or even lower cost but newer cars like GT86 with a really strong modifying scene. If you look at the benefit in weight reduction we are getting twice as much improvement as most aftermarket parts, but we can't charge £1400 for a 200SX bonnet... whereas for a GTR that is the going rate for a carbon skin on GRP base (most bonnets are this) and so given that we are using prepreg and saving twice the weight we could be talking £2k, which for GTR etc, people would possibly be happy to pay.. and my career change gets a lot closer...
Title: Re: Lightweight bumpers?
Post by: Jrichards20 on September 30, 2015, 10:07
Quote from: "jonty"Cheers for the comments chaps  s:) :) s:)

I'd love to make stuff for the MR2, but the problem is we are going to struggle to sell parts for the 200SX in a quantity and at a price that covers our costs, and the SX has a way bigger modifying scene. If it was just a hobby I would be on the case in a heartbeat and supply you guys at cost, but I plan on eventually turning this into a business, and therefore I have to be a bit ruthless and not do stuff just because it is fun, but instead because it teaches new skills or can make a few quid.

Ideally, we should be making them for high end stuff like Porsches, GTRs, etc, or even lower cost but newer cars like GT86 with a really strong modifying scene. If you look at the benefit in weight reduction we are getting twice as much improvement as most aftermarket parts, but we can't charge £1400 for a 200SX bonnet... whereas for a GTR that is the going rate for a carbon skin on GRP base (most bonnets are this) and so given that we are using prepreg and saving twice the weight we could be talking £2k, which for GTR etc, people would possibly be happy to pay.. and my career change gets a lot closer...

Heartbreaking! But I understand  s:) :) s:)  I hope it all goes well! From those pictures looks like you've had a great start and can produce some great products!
Title: Re: Lightweight bumpers?
Post by: jonty on September 30, 2015, 10:40
cheers mate, maybe one day we'll be successful enough to play about again... I fancy a SuperGT MR-S as it's one of my favourite race cars of all time, so it would be cool to make bodywork for that!