Ive Striped out my coupe for racing and im still a bit on the wieghty side

im converting to a light radiator

any other surgestions would be good

Im not trying to build a sports sedan I would just like to get a bit lower then the current 790kg

My L series coupe weighed in at 840 or 850kg (can't remember off the top of my head) with an extensive steel rollcage and half a tank of fuel. With a pretty big rad, 70series gearbox, and BorgWarnwer diff.
790kg is not too bad if it includes all the turbo gear I reckon. Very Light for a 2L IPRA car.

about the radiator, alloy rads can be expensive, but the heavy part is the amount of water it takes to fill it, obviously. So don't overspec the rad - just big enough to do the job and no more. ANd remember that a wider frontal area will be more efficient than a thicker core, meaning less weight for the same cooling capabilities. My L series rad was just enough - take the front spoiler off and it would overheat on the track, but it was fine with the spoiler on.

Getting the weight down once all the unnecesary stuff is removed is really about what the rules allow, and how much you are prepared to spend. It's hard to make suggestions on what to do without seeing the car...You can remove unnecesary brackets off the body under IPRA regs. That won't count for much but it all adds up, and there are a few of them on the firewall and in the back of the coupes. Call me a cynic, but there are some cars up here with holes cut in doors and trim cards apparently where speakers used to be, and are just covered over with speaker grills. I'm not suggesting you do this though - just an observation...

Dry cell batteries are nice and light, but a bit exxy. But they can also be mounted in the cabin without a vented enclosure, which saves a bit more weight.

You've obviously already got the driveline, so there's no sense telling you to stick clear of the big, heavy, overspecced H190 diff for example...

Other suspension components you add should be as light as possible too. Eg - for circuit racing there's no need to upgrade the castor rods with big heavy Torana ones as I have seen some people do. And don't add unnecesary linkages to the rear end as you are allowed - focus on setting the leaves up to handle the job themselves.

Same goes for brakes - don't go and fit the biggest thing you can squeeze in, alot of sport sedans brake absolutely fantastic with brakes that fit inside 13" wheels. And your car is quite light.

Expensive stuff can include things like chrome-moly strut legs, alloy hubs etc etc depending on how serious you want to get. I've heard that some leading RX7's use magnesium diff housings...

oh, an abvious one is the lightest seat you can afford, with the lightest mounts you can find (if side mounted). but you've probably already got a race seat in there.

Lightest, shortest exhaust you can fit. ie with the lightest, smallest muffler that does the job.

Yeah it get's hard to weight out of a race car and you can't real cut cost's.carbon fibre stuff isn't cheap.

well ive looked at two things really the diff center theres an old alloy center down the back that could be rebuilt with new ratio about three kg big wop

and the rims this is some of the problem anything lighter then hot wires is expensive

I would concentrate on unsprung wieght like the diff. I stripped my car then concentrated on get the cg lower...dropping the motor tranny and mounting things as low as possible.
Whenever trying to get a car light I always remember a story of a California GT3 team. One car was built right to the wieght limit the other was for actress Marsha Mason....she wanted the car to be safe as possible so some more tube was added. Well the go fast car breaks and Mason graciously offers up her car , so the team can get points. Well Her car turned out to be faster due to the stiffer chassis....I just keep this in mind when trying to lose another 100lbs .
Keep in mind I weigh 135lbs so my car can afford to be fat.

Tom

Take a look at this.A 592kg coupe.

http://datsun1200.com/modules/myalbum/photo.php?lid=2261

Jenny Craig? I hear that Weightwatchers is good too.

Seriously, some people could lose 20kgs of weight and improve their laptimes.

Call me now. 10kgs for $10*.

Chris

* food extra.

yeah but the tracks up here in Brissy run clockwise, so most of the turns are right-handers. I reckon my fat arse is good ballast

mmm Is that Tony Marsh coupe a fair comparison...we are talking IPRA not sports sedan.
I could drop heaps of weight by using lexan and not glass but IPRA rules dont allow it...
same with using composite doors and cutting out my engine bay and rose jointing everything, but it would be a sports sedan again...

The other thought that i had and it pretty extream was to start again

Rebuilding the car from scratch would allow me to reduce wieght in many little places

Dad always wanted to build a b310 sunny coupe with mostly alloy air craft bolts (you can get these for scrap value at the air port) and all brackets in alloy etc etc etc

The cost is the problem

Alloy brake hubs would be nice

tube sway bar and castor bars too