I hill climb my StiV3, and it is road legal at the moment. The regs have changed and the cars in my class can be 'anything goes'.
One way to go faster is to loose weight (me and the car). The chassis is very modified, the shell is caged (6 point) and the engine gives 314 bhp.
If I strip the interior what weight is saved?
Are there carbon/fibreglass wings/doors/bonnet/bootlid manufacturers out there?
Plastic doors etc as above must save some serious weight, especially on the power window Sti's?
I still want to keep the car MoT legal so may consider plastic side 'glass' with original front rear screens.
Replace the front rear bumpers with 'shells' to remove the impact structures(?)
Remove the A/C totally will save some Kg's too etc etc.

If I do all this what is anyone's estimate on weight saving overall? Any sites I can visit for the panels? The closest I've found is Autosportif. Any in Oz or the USA?
I don't want to do all this if I only save about 100 Kg. Best tweek the engine up.
The lighter car is faster but also much more responsive in the corners.

Showing my age, but Colin Chapman used this approach!
Graham.

 

Bonnets and boots are available, aks TSL! I doubt you'd be able to do the perspex windows due to lack of a frame!
You'll lose loads if you do all that!

 

you need to find the rally guys they will do all the GF stuff ...chris

 

speak to howard at www.hdcsubaru.com

 

Thanks for the advice and contacts. I would like to know what 'you'll loose loads' adds up to!
Stuart at TEG told me last year that the max to loose is only 100Kg if you realy strip the car. I think Pavlo said once the lightest he had seen is an Impreza @ 1100kg.
In my racing class I have road going, fully trimmed EVO 5's with 480 bhp but weighing about 1400Kg = 340 bhp/tonne.
A decent Scooby with 350bhp @ 1000kg is looking good!
He won't run slicks due to his clutch/flwheel/trans, so if I add AVON slicks to the STi things look even better...
I think you can frame the 'glass' using steel frames into the doors, remember they dont have to go up and down!
Graham.

 

without going mad on GF doors and stuff, 1100kg is attainable I think. Some of which you will have with seats (major saving), but also strip out interior, racing battery, strip sound deadening, non essential stuff, wheels etc.

Paul

 

If you speak to MONEY on here or e-mail him on: frankandreas3@hotmail.com he can get you pretty much every single panel in carbon or kevlar

Good prices too

 

If the STi 5 RA was 1235kgs with rear seats, sound deadening and an interior etc., you should be able to get down to 1000kgs I would have thought without having to replace much. Remember, the dash itself weighs quite a bit, as does that passenger seat

Matt

 

I know there are about 20 Kg in the 2 front seats to be 'won', the back seat is next to nothing , so give it 5Kg. Carpet and all the trimmings are about another 20Kg. Thats about 45Kg.
The glass/power windows will be about 20Kg but the door and their bars will be a much more useful 70 Kg all up.Maybe about 130Kgs now?
The STi is heavy @ 1275 Kg.
I'm still way off the 1000Kg!Remember I've added the roll cage, so the saving is around 100kgs so far.
Maybe I'm wrong, but the interior can't weigh that much?
Graham.

 

Take it out, weigh it and find out

 

You have to weigh up the costs of stripping the interior and other bits, against getting a more powerful engine (and transmission to cope with the power), unless of course you can afford to do both.

There are carbon bonnets, boots plus perhaps some other panels available. I would have thought the rally boys would have some GF panels available as well.

You've already listed the obvious things.

Strip electric windows, relays, motors etc. Replace with manual winding mechanism from an RA if you need them still to work, otherwise simply leave them in the up position, possibly using perspex, but remember the windows aren't completely flat, but a bit curved.

Remove air-con system, plus associated piping etc. The compressor will save quite a bit of weight, say 10 Kg or so, you'll need some new belts though.

Replace front seats with light weight carbon ones, and remove carpets, rear seats, rear door panels (not sure if it's a 2 or 4 door one you have?), centre console, headlining, boot carpet etc.

Remove the fuel tank and fit a bag type device, relocate the battery (replace with a lighter version) for better weight distribution.

Bits of the dash are quite heavy, but might be limited scope for weight reduction, apart from the glove box etc.

Remove any underseal (if any) perhaps 10 - 15 Kg.

It's also possible to remove the power steering from the car, though you will need to drain the fluid from the steering rack. If it's only short sprint events, then you might be able to last the distance without needing massive arm muscles.

Remove bumper bars from inside the bumpers (ie just leave the skins), and attach using lightweight brackets.

Remove the airbag steering wheel and replace with a lighter one.

Look at fitting lighter weight brakes. Instead of getting massive brakes under big wheels, looks at smaller brakes of near enough the standard size to fit under 15 inch wheels. The cast iron standard calipers and brackets etc are quite heavy.

Look at replacing the suspension units. Some of the coil over kits can offer a weight saving over the standard units, which are quite heavy.

Fit lightweight wheels. You should be able to get suitable lightweight ones in 15 or 16 inch size from some of the rally teams suppliers etc.

I think some of the RA models, and probably rally spec cars have lighter weight/thinner glass for the windscreen and rear window.

Something more radical, is to look at all the nuts and bolts used in the car, and where possible trim them down to their minimum size/replace with lighter weight versions. I remember speaking to an Imp owner who was obsessed with weight reduction on the car, and he hacksawed everything to the absolute minimum length, re-tapped etc. Didn't save him much weight (a few pounds at most - he kept the sawn off bits and weighed them in a box), but "every bit counts"

Remove the Hi-Fi, speakers, wiring etc.

Lightweight exhuats parts (titanium etc. - very pricy though for a 5Kg saving!)

Remove the rear wiper (if you have one), plus associated wiring, relays, switches, brackets etc.

However, adding all this up I think you'll probably struggle to get the weight much below about 1150 - 100Kg, without a serious budget to buy lightweight replacement parts, and time and effort to do all the work. It probably makes more sense to do much of the easy stuff to give a reasonable weight reduction, combined with some mods to the engine etc to give a good increase in power to weight ratio. It's finding the balance that will be difficult. Over time, you can then look at the more time consuming weight reduction stuff.

I'd almost be tempted to say it might be cheaper/more cost effective to buy an older Group N rally car, which has already been stripped to the near minimum, remove the restrictor and spend a bit on engine tuning/remapping, and sell your existing car.

John

 

Thanks for that John. These are all the areas I've looked at too. I think to crack the 1000Kg mark is realy difficult, but you do gain the dynamic benefit, get weight off the front and rear extremeties and this all eases the shock on the box too!

I have to make up my mind to devalue this nice tweeked STi into a track car and just accept the loss of £££££££££.
If I can be convinced that all the effort you correctly list will realy give me a 1000Kg car, then ok, its worth it.

To get to 350 bhp/tonne needs at least a 400 bhp engine and a box to tolerate it. Easy work (in comparison to removing weight)but realy pricey, though the value is better retained.

Maybe a compromise is the carbon bonnet/boot, bumper bars.
Strip interior, RA windows (its a 4 door)racing seats.
Turbo tweek/ecu.

I wonder if this will give thw magic 350 bhp/tonne?

Graham.

 

Graham,

I know I've asked this before but what catergory are you running in ?
Also Harvey sent me some more ideas on losing weight.

Mark A

 

Graham, aren't you better off starting with an RA - perhaps an older one? My 95 weighed in at 1180kg when it was imported. The version twos are good as they have the TD05 turbos and closed deck blocks.

 

Graham,

I think you will be better by investing on a second hand LINK ECU (if it has ALS even better ) and getting some racefuel for your events. That way you can still swap to the stock ECU in case you don't find racefuel, but even with the VF23 + racefuel, with a decent ECU you will get some xtra power and torque.

Carlos H.

 

ooops also forgot about this:

get rid of the A/C !!!!!


Carlos H.

 

You lot are good at spending my money!
I made a mistake buying the STiV3 and not an RA, but 3 years ago finding an RA seemed realy hard! Bit different now....
I have about 15K in the car now. Just fitted an early RA transmission a week ago (sod of a job)and the car has a 6 point cage and very tweeked suspension. Other than the smaller bits like power windows and thin glass, it is almost an RA (sorry to over simplify)
Getting the CDB and the bigger turbo I am sure are great, but I can't justify selling the car now (about 8 K in today's world?) and buying an early RA, about the same £££ and have to start modding again!(and get my daughter through University)

I'm committed to this car, love modifying the thing, just trying to find demon ways to catch those bloody EVO's. The 480 bhp EVO 5 monster in my class has cost 44K so far......
Graham.

 

Sorry, forgot the rest of you!

Carlos: Race fuel is near none available where I race, and I drive the car to and from the events, so the tank has to have road fuel in it to get home. Race fuel is about 8 US$ a gallon here...
I like your other ideas though, and others have said much the same to me. I think this fits in with the compromise I will end up with.

Andy: I run the class in the Over 2 litre Road going Salloons class. This is usually called class C1.
The road going bit is a farce as we are supposed to run in road legal/MoT trim. But we can now run slicks!

The sports cars are in their own class, so the Morgan V8's, MG R's (do not laugh) and a killer short wheel base Audi Quattro are all away from us thank god.There is a Dax 4x4 with a 5 litre V8 there too.....
You can modify the living daylight out of the cars.

Graham.

 

Sorry Mark, been a looong bad day.....
Graham.

 

Insteady of race fuel what about using a huge slug of methanol or isopropalin ?
I read a couple of interesting threads on here about cheap fuel addatives, ? Dave Wallis or Andy F.
These are both available from work.

Mark A

 

Will the ecu 'read' these fuel changes quickly for the benefit to be realised. If you drive to the track on Optimax, then dose that fuel with whatever, and then go racing, will the ecu adapt to it, or, does it need to to get the most?
Anyway, for hill climbing you are not allowed to do it! That's why nobody runs NOX, fuel addatives are banned, maybe water injection too!
Graham.

 

I was thinking more of protection than mapping the ECU for the additive. I think the ECU would take too long to adjust.
Maybe the simplist option is to use race fuel.

Mark

 

Water Injection will help (especially if using it 50%/50% with methanol) but only if mapped for .....

Carlos H.

 

hi mate

I have a carbon bootlid i'm getting rid of. Its the same as the one TSL had fitted to their 22B ie one of the very few evocomposites ones that actually showed up. Originally they were about £500 quid and I had to spend another £150 on it to have it completely re-varnished as the finish was ****. I have a bootcatch for it, though haven't gotten round to fitting it yet.

Its apparently about 3kg iirc from speaking to TSL about theirs. Reason im selling it is i've just paid $400 and nearly $200 shipping for a double sided one from the US. My car is a show car so I needed a perfect finish.

If you're interested in pics mail me. £350 quid and its yours

Bonnnet wise Money is doing a group buy, same type I have on my car too, so I can vouch they are great.

Rally Tech do Carbon doorcards, roofscoops, rear wings and mirrors. I think they do the wings for 3 doors too

my emails is ssiwatts@aol.com, or just go through Money as hes on here much more

 

Graham, you won't be able to take advantage of the better fuel unless you have a remap to advance the ignition. You'd need two maps then - one for normal fuel, one for racing. Your car's a 97 isn't it? You should be able to get a ScoobyECU which you can then map to your race fuel and switch back to OEM.

 

Sorry to side track, but I thought the ScoobyECU was only for cars MY96 and older.

 

Really? I thought it went up to '97. Shame.

 

£600 for a carbon fibre bonnet, not sure how much lighter than the alloy one you have at present. @ 4-5 kilos total weight.

Mark A

 

take it from me up to 96 only..

if your ecu has four connectors then you may be in luck.

 

edited to say Money has put this up on for sale for me with pics

[Edited by siwrx - 1/11/2004 10:36:33 PM]