the (ae86) weight reduction thread

[jakel]

They should be about the same, T18 is like 98x something its like 9kgs too light or something to ba able to engineer a 1uz in it!
(and no it doesn't matter what it weighs when done they go by factory gvm I am pretty sure.

[dehney]

how much do you save on when changing the rear hatch glass and ditching the fuel tank for a fuel cell ?

[AJPS]

fuel cells weight almost the same as stock tanks

and stock tanks are mounted lower and hold more fuel

[mfxae86]

I run a decent street look oz spec 86 with what I consider to be reasonable weight reduction. I did this a while ago so im going by memory here.

My 86 came with a tow bar (yeah I know what for right?) it was ancient and incredibly over engineered at 21kg
Sound deadening was also a big one at 16kg not including the bits I had to wire wheel off or the silicone in the seams
Carpet and underlay was 5kg
ac and heating units under the dash was pretty decent as well but to be honest I can't remember the weight for those units maybe 8-9kgs
The tail end was rusted out so I body modded the panels under the rear bar a little only 1kg or so saving there but worth mentioning
frp panels - rear bar, front bar, front guards would save a bit, but probably level off when you add the side skirts and trd wing.
Under the bonnet was completely stripped and now running a 4agte with the bare essentials notable losses were alt cast iron bracket 3kg non essential wiring 2kg bonnet latch removed for bonnet pins

There is more but I can't remember, lol. and a little hard to measure out, all brackets for old hardware was drilled out, plastic liners removed... Just odds and ends I didn't need. im yet to hit a weigh bridge...

I think like most performance mods of any kind when you get started its leaps and bounds but eventually it comes to a point where the gains are minimal for the effort or cash spent.

Ok now on to the fibreglass tech bits. for those that don't know, I have worked with composites for well over 10yrs so I figure I could straighten out some of the conflicting thoughts on frp panels for you guys.
In most cases the frp gear available for most cars is NOT built to be light weight, it is purely cosmetic. Its made to be durable (usually 600gsm+) and is resin rich. Therefore its much of a muchness to have frp panels... Unless your running some thing old school like a HQ, lol.
On the other hand if the panels are built with the specific purpose of being light weight, using say 250gsm, spraying gel coat (as opposed to brushing) and using minimal resin and draining as much excess as possible or even better infusing, you can have a very light panel indeed.
The downside is that the product is flimsy and will break very easily in everyday life, taking a bump, leaning on it ect. and to top it all off it costs more to produce and buy.

I made the frp gear on my car quite a few years ago and the comparison would have only been a couple of hundred grams better on the fibreglass side outright, but if your counting every bit helps right ?

Now on to the composite roof theory, to be of similar strength as factory the weight would be similar particularly on such a flat area. it would only be viable if it were paper thin and perfectly produced in a woven strand (carbon etc.) and you would only be shaving grams... Think of it as a last resort type of thing... oh yeah and never discount cost.

just my 2 bob

[Sam-Q]

well I have to disagree with you on one point, the bonnet and fiberglass. A stock bonnet is 25kg, I have a top-stage drop vent bonnet that's 7kg. It's also so strong I can put a heavy box of crap on it without issue. I wouldn't be surprised if I could sit in the middle of it without any breakage.

[mfxae86]

I did say in most cases, lol. Keep in mind the company that manufactures the product has something to do with it also.

As a reference I have handled many 180, silvia, skyline (list goes on) composite bonnets that outweigh the factory items, some of them "carbon". This also applies for guards bars boot hatches ect.
The point I was trying to highlight was that frp does not necessarily mean its lighter, and in most cases its not... It depends on the builder.

I don't think I explained myself correctly, my comments on product strength referred to the method I briefly outlined in my post. A very under engineered part that would easily break, but would weigh sfa. I just went from one extreme to another. The middle ground is where street automotive frp parts should be if produced properly, lighter but still durable for everyday life.

Im pretty sure 86 bonnets sit at the 14-15kg ? But your right, the bonnet you have has saved you a crap load of weight. I want one... now on my list of things to do

[Sam-Q]

I am sure it was 25kg, I have one around I should put it back on the scales.

Here's the weird bit, I didn't expect there to be a difference when I put it on, however I noticed a definate change in how quick the front of the car turned into corners. It wasn't big but definately there.

[Rice86]

i second that, when i had the fiber glass vented hood, steering response was very good, and bonnet is very light, solid enough for everyday driving
put on a standard metal bonnet, straight away steering response was slower, not by a lot, but very very noticeable..

i would run fiber glass panel over metal any day of the week if i could afford to blow money on these parts (genuine parts), until then metal will do

[jakel]

Try making your own?

[Rice86]

i can make my own, but rather not for so many reasons lol