Must admit, when I had my car setup at ProComp, I was slightly surprised at how much it weighed for a BEC.

I've heard of other kits specifically CEC's weighing 540kg-550kg, unless that's the unrealistic figure out of the two?

Things against getting it any lighter are:

> I have a full cage, which I believe is 2.4mm thick tubing
> Currently on 15" alloys, which aren't the light at all (think these are 16kg per wheel & tyre combo - so totalling 64kgs)
> Currently my front cycle wings & rear arches are plastic... not carbon yet...

Already have Wilwood 4-pot brakes with solid disks at the front

Here is the car for those that don't know it:







[Edited on 16/10/13 by yellowcab]

Its not unrealistic, if you've got a dry sump and oil cooler, diffuser and all these extra bits, These cars suddenly do weight that sort of amount.

Our 2ltr duratec Pulse weighs exactly the same as yours with all the extras.

I'd say your car is on the heavy side a bit but using sierra parts, im not so sure you can save much weight apart from going to 13's.

Thanks for your reply, yes I suppose I'm running dry sump system with 7.5 litres of oil now, whereas I wasn't before lol

I'll get me some 13" wheels, and see if I can keep an eye out for some carbon arches

Oh my exhaust can also is a Aprillia RSV Mille can, also known as 'the anchor' lol

Are you using a car battery or something like a Varley Red Top 25 or one of Russ's Lithium ones. Easy way to save/gain weight.
Foam and bin bags seats can also be a huge win (though you look to be on GRP or CF shells already so unless you're on steel runners you wouldn't see more than a 5kg difference for the two I'd think). Exhaust and wheels would be next on the list.

But I suspect that cage is the biggest component of your unexpected weight, for low weight once you are past the big wins needs a lot of attention to detail and lots of small reductions (for example chopping every bolt down to 2 threads past the nut can gain 1kg on some cars, going down one thickness of aluminium on the body/floor can save a surprising amount).

Also, as I think you suspect, like bhp figures without a dyno plot, weight claims without a weighbridge ticket can be treated as pub talk

Totally agree about the pub talk, and their 400kg BECs lol

Yes just fibreglass shell seats bolt directly to the floor (passenger) and on alloy runner on the drivers side.

I'm on a motorbike battery, so not a light one by any means, but lighter than a full size car battery if you get my drift

My Westfield with the blade engine weighed in at 485kg and had full MOT, Tax.

Our minimum track weight for the 'roadsports' class was 560kgs after the race, the car carried no lead and always came in on the weigh bridge at 563ish kgs.

There isnt much saving in bodywork unlesss its full of isopon, removing the reverse box & light wheels are the biggest improvements.

[Edited on 16/10/13 by Benzo]

Well currently, a single wheel & tyre weighs 16kg...

I know a 7x13 Team Dynamic Pro Race 1.2 weights 4.5kg... not sure how much the relevant tyre would be...

If you have the budget you can get 3.4kg per wheel at 7x13. See http://www.force-racing.co.uk/wheels-13/

the real weight of my fury is 430kg (live axle), this without lights, roll bar only, one foam seat and a 919cc blade.
so i think the weight of your car is in the normal range. of course you can do better ... with £££

Do what I did. Being a fat b*****d, I've dropped 27 kgs since january.
It's cheaper than C/F wings and lightweight alloys.
The gin instead of Strongbow's a dear do though.

A BUSA is fairly heavy in the bike engine stakes, add full dry sump set up and you're a long way to explaining it; At least 30 kg I guess over my R1. Cage must be 20kg. Sierra diff and bolt on shafts? That's several kilos more than my F/lander one and push ins. Then there's wheels/tyres, reverse... 60-70kg easily accounted for...

I did some sums on this a while ago, all based on toyo r888s and pro race 1.2s

6x13 185/60/13 11.7kg
7x13 205/60/13 13.1kg
7x15 195/50/15 15.2kg

So if you dropped to 6x13 it's a decent weight saving plus improved ride too.

quote:

---

Originally posted by yellowcab
Well currently, a single wheel & tyre weighs 16kg...

I know a 7x13 Team Dynamic Pro Race 1.2 weights 4.5kg... not sure how much the relevant tyre would be...

---

My Furore with ZZR1400 engine weighs in at 565kg with a car battery, just over 550kg with one of our Li Ions, so your weight's not unrealistic. The Furore is a much bigger car than a 7, & wheels aren't particularly light as we run 17" tho' I don't think quite as heavy as yours, I don't have a dirty great roll cage, heavy exhaust or extra oil, dry sump kit & oil cooler either, but I do have cast iron brakes!

As said, you could save around 4-5kg by swapping to a Li Ion battery, probably another 10 - 15 on the wheels & tyres & another few on the exhaust, after that it becomes very much a rule of diminishing returns & just how bothered can you be by it all!

Thanks for all your replies, seems about the going weight then all told

You're all right, my car is purely a bit of trackday fun, I'm not necessarily chasing 1/10ths of a second off a lap time.

If some wheels come up at the right price, and carbon bits & pieces then I'll go for them.

bobinspain - I've lost 24kgs this year already in body weight lol

I managed to knock 9kg out of the rear uprights of mine by changing from Sierra calipers to wilwoods, using lightened disc, skimming the uprights and by making some ally bearing carriers. Total cost was only £300 which I thought was pretty good for 9kg of unsprung mass.

My MNR VortX is 509kg with a full tank of fuel ( approx 8 gallons) and my 7x15 Pro race 1.2.
Ive since got some caterham R400 6x13 front, and 8x13 back. I was genuinely shocked how much lighter the 13" wheels feel compared to my 15"

so with the smaller wheels fitted, and 1/2 tank of fuel i am under 500kg

When they weighed the MK at IVA, my jaw dropped at the 615 kg on the form, the examiner explained that was with driver, and full tank (7gall) of fuel, he weighed 75kilos, so 540kg with full tank. A lot of Pub scales used for weighing cars I think

My old ZX9r haynes with 16's, reverse box etc and a full tank came in at 520kgs, god knows what it weighs now with the S2000 engine fitted well over 600 I guess.

This will make you all feel better, the kitten all running with s2000 engine and box, live axle was just tipping 700kg, but still needed glass, Perspex, lights, bonnet, big sump, heater, wiper blades and water bottle and now weighs 759kg on the road and will get heavier with fire eater when fitted, but it is what it is. I've tried to make it as light as possible as I've used alloy uprights, hubs, willwoods etc. I made a big mistake with the exhaust tubing as I could have used much lighter tube, but its always gona be around the 750-760kg.

is it a race car? if not then does it really matter? even at 600kg its still a good 1000kg lighter than your average modern eurobox!

I have a weight bridge ticket for my cvh engined narrowbody, which is 540kg, produced by the local coal merchants public bridge.

That is with the alloy bell housing, but before I fitted the 'rac style' roll over hoop. Largely standard westfield.
Don't know how much fuel was in it. 5kg race battery, live rear, M16 calipers and vented disc, 13inch ford alloys.
Think it was with the westfield flat seat panels, rather than the grp seats on runners, which are probably heavier.

I agree however, that on a road going car, 20kg is not a lot.

Also, unless the photos are lying, thats a very nice looking car.


Daniel

Olz mine was weighed at 600kg with full fuel and an 80kg driver, so mine dry was about 495kg. But then I added two extinguishers, an ATB, airbox, and a dry sump, so I bet its around 530kg now.

If I went for 13s, rear willwoods, a smaller radiator,a bike battery and a carbon exhaust it would be better, but I bet I'd need to change to soft compound tyres as I just can't get my medium compound R888s hot enough with the weight of the car as it is, let alone with it even lighter. On track days the car is ten times better without my 100kg brother as passenger but on the road I don't really notice much difference.

quote:

---

Originally posted by ashg
is it a race car? if not then does it really matter?

---

Replaced my 15" wheels & tyre combo now, for 7x13 Team Dynamic Pro Race 1.2s

15s were 16kg per wheel & tyre, totalling 64.0kg

13s now 10.2kg front & 11.6kg rear, totalling 43.6kg

Saving 20.4kg of unsprung weight

542kg - 20.4kg = New car total 521.6kg

my Indy r 1340 with car battery, 15 revolution wheels with 225 rear (very very heavy) reverse and half tank weighted 530 kg.
i hope to buy a set of 13 TD, and remove reverse this winter, to arrive at 499

a friend with indy r r1, 13 TD wheels, no reverse weighted 420

It can turn into quite a infatuation trying to reduce the weight of a 7.

Paint thickness, carbon (as been said $$), using half as many rivets in panelling especially when bonding as well, drilling everything that isnt structural, inc bolts, driveshafts can be gun drilled, diff casing fins can be reduced, thinner ali than used/ carbon sheet, using less silicone hose in cooling system minimising the over lap onto coolant pipe, wire runs kept to a minimum, battery close to the starter also to reduce wire run, ali wheel bolts (not for racing), swapping heavy materials for light weight alternatives.

Its good fun, and a a balance between lightness and operational limits/ engineering limits .............safety!!

I surprised to find my MNR CEC, with a 1.8 zetec and type 9 was 525kg at SVA. Though it would have been higher..

Then a change to ali bellhousing, Wilwood calipers and 13" wheels took it down a bit further BUT adding the front bit of the cage, which by the way I added to it, stuck 20kg back on.

The problem is why we are getting big variations in weights of cars, is not down to pub talk etc, in my opinion is how the cars are weigh, as "coozer" said above his car weigh 525kg's at SVA. At SVA they are mainly interested in total axle weights not so much overal weight, so they weigh each axle and just add these together, and some take that as the weight of your car, and it is not, my first Indy fireblade weigh something like 440kgs at IVA, but when weigh electronic scale for me by Chris Mason it weigh 496KG's.
He also weigh my ZX10R turbo MK Indy R, this came in at 486KG's if I recall, but that had Hi Spec brakes all round, light weight full cage, Raceleda alloy front uprights, race battery etc, and full Indy R spec.




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[Edited on 19/05/04 by PAUL FISHER]

Using corner weight scales has to be the most accurate, although I get the concept your aiming at, from a consistency point of view you need a single method.

My blade fisher was 420, and the caterham duratec was 515. The fisher could have been lighter and so could the caterham, it would be good to be the next build under 400!