WEIGHT REDUCTION rear bumper

[nick_w]

i have already started to do a bit weight reduction to my mk1, i have done most of the interior, i was wondering if anyone has tackled the rear bumper, as it is quite heavy

i was thinking about taking most of the steel out of it but i was wondering how people mount the bumper back onto the car

[MarkySan]

What about the safety implications i.e. are there any? Even the insurance aspects.

Know what you mean about weight as I took mine off last night and I was surprised.

Maybe could cut parts of it out, whilst keep in the structure and most of the strength?

[MartG]

My trackcar has most of the bumper bar removed, just leaving a couple of sections maybe 4" wide where the mounts and towing eyes are

Rear bumper bar before....



After...approx 5.5kg lighter, and leaving the foam insert out saves another 1.5Kg





And as its mass lost at the extreme rear of the car, it'll reduce the polar moment of inertia too

[nick_w]

marky san, i reckon it would be alright there's the whole boot floor and engine compartment that sould be strong enough

Mart, cheers mate that was exactly what i was after, even better with pics

as we are on the subject of weight reduction what else have you done to yours,

ive taken out all the carpets + sund deadenig inside the cabin and fitted buckets, i did remove the spare wheel out of the front but i found it messed up the handling so i put a spacesaver back in there

[Sports Toyota Breakers]

Stick a nice little gel battery up front in place of the space saver Front bumper bar can go too, but it's more of a safety consideration on a road car.

[nick_w]

good thinking, i think i might keep the front bumper bar as it is a road car

[kaiowas]

General feeling seems to be that anything you can do to lose weight at the back of the car is a good thing.

There's plenty of scope for saving weight at the front but the CoG is already a little too far forward and as you've discovered removing weight from the front makes this more noticeable. If you can remove weight from the back however this then gives you the option of removing weight from the front as well to retain the original balance.

[Negativvv]

A chunk fell out my rear bumper on the weekend It looked a bit flakey so i smacked it with a Spanner and a bit fell out!

I drove without the spare for a while and didnt notice any real difference, mind you i wasnt going past about 40, im sure you feel the upset balance alot more nearer the limit!

Big heavy bumpers beat the putty that you get on newer cars anyway I nudged a friends Audi A3 in a work van and a dent the size of a football appeared in the plastic bumper!

Where would you tow from the rear if youve taken the eyes out tho?

[nick_w]

i don't plan on towing anyone with my 2 so i should be alright

[t-bar89]

You've probably already done this anyway but... just changing the standard exhaust to a s/s version will save loads of weight! Changed mine recently and the weight difference between new and old was huge.

[Negativvv]

You've probably already done this anyway but... just changing the standard exhaust to a s/s version will save loads of weight! Changed mine recently and the weight difference between new and old was huge.

Dammn! Ok my stock exhaust goes as soon as i pick up that Stainless ive bought

[nick_w]

You've probably already done this anyway but... just changing the standard exhaust to a s/s version will save loads of weight! Changed mine recently and the weight difference between new and old was huge.

yep done that

[un1eash]

I think this is what happens when you start to remove bumper bars....

[kevin..in]

I think this is what happens when you start to remove bumper bars....

Image Replaced With URL For Quote http://i6.photobucket.com/albums/y244/m ... une077.jpg

correct part name is "Bumper reinforcing bar" for a reason!!

[kaiowas]

I think this is what happens when you start to remove bumper bars....

There's got to be more to it than that. The chassis rail on the drivers side has collapsed which just shouldn't happen with or without a bumper bar.

[cartledge_uk]

I think this is what happens when you start to remove bumper bars....

Image Replaced With URL For Quote http://i6.photobucket.com/albums/y244/m ... une077.jpg

To add to this,

Nothing, Ie no bodywork or material of any kind encroched into the drivers or passenger compartment.


The accident was a t bone (car rolled back into his path). If the front bumper bar WAS in, there would have been the risk of MORE personal damage as the body wouldnt have crumpled absorbing the impact, causing massive shock throught the chassis and bending the chassis rails anyway. IMHO its safer without.

[Jim-SR]

I think this is what happens when you start to remove bumper bars....

Image Replaced With URL For Quote http://i6.photobucket.com/albums/y244/m ... une077.jpg

no, thats what happens in a VERY heavy accident on a RACING TRACK!!

as has been said already, and as i have observed from just looking at the picture, little or no bodywork or chassis has entered into the cockpit, meaning that the car actually held up perfectly and crumbled where it should, and didnt injure the driver. the bumper bars will make ZERO difference to that kind of impact

if you hit something hard enough to be worrying about your legs getting squashed then some 1mm thick pressed steel isnt going to help you at all. especially considering 90% of AW11's have rotten bumper bars by now anyway, so they would just crumble on impact

[un1eash]

For track, yes remove them to save as much weight as possible. For road use, i just dont see the point in losing that little bit extra weight. This is my opinion.

[millentubby]

would cutting down the rear bar affect the shape of the bumper skin much?

I'd keep the foam in there.

[Jim-SR]

For track, yes remove them to save as much weight as possible. For road use, i just dont see the point in losing that little bit extra weight. This is my opinion.

a little bit of extra weight off of multiple areas results in large savings though

its very rare on a car that you can just ditch 100kg with one item, unless you get rid of the engine and convert the car into rather a large box-cart lol. 5kg off the rear bumper, 5kg off the front, 15kg off the bonnet, 5kg off the engine cover and bootlid, 10kg out of the interior, 10kg on seats, 10kg on wheels and tyres, 15kg from spare wheel. those are all fairly small savings, yet they add up to 75kg which is the equivalent of using an average weighted person from the car (e.g. you have basically negated the drivers weight). its a significant weight saving and will undoubtedly make the car faster in terms of acceleration and corner speed

the bumper bars arent really there as crash structures. if they are then it is very clear they were devised 20+ years ago, much the same as the "side impact bars" our cars contain. back in the 80's they might have been cutting edge, but nowadays you wouldnt even register on the NCAP safety scale.

if youre not interested in losing weight from a road car then you arent really going to see the point to start with, which makes what you replied with a fairly null point. if you do see the point in losing weight then the bumper bars and other such areas of the car should be seen as prime targets