Weight is the Enemy

[eurovintage]

An old racers wisdom. Tried to find Fiberglass or Carbon Body Panels (Hood, Trunk-Lid)
on the Net for RS 6 or S6 (C5, C6, C7), but not much luck.
Can anybody recommend vendor in North America ?
Any other Mods been tried to reduce weight without loosing everyday drivability or removing interior ?
How about looking into removing some weight from the front bumper arrangement,
as the US and Canadian spec cars have 5 mph bumpers ?
Any tips are being appreciated.
Do not have an RS6 or S6 but I am looking !
:race:

[hahnmgh63]

You might find something but the hood is Aluminum already so I don't think you're going to get much of a weight savings there. Upgrade to Forged wheels and save 10# a wheel (40lbs total), got to a lightweight dry cell battery and save 30# or go with a much more expensive Lithium and save 40#. Get rid of the whole DRC and save 10#~15#. Secondary radiators will save quite a bit off the front of the car although it is low CG weight.

[eurovintage]

Thanks Roy,
Good Info with real #'s.
My heaviest car the SHO Gen II is 3300 #
Are we close geographically ?
I am in White Rock, B. C. right near the border.
Ivan

Noble M400, 58 Austin Healey BN6, 1994 Ford Taurus SHO, Porsche racing projects

[eurovintage]

Thanks Roy,
Good Info with real #'s.
My heaviest car the SHO Gen II is 3300 #
Are we close geographically ?
I am in White Rock, B. C. right near the border.
Ivan

Noble M400, 58 Austin Healey BN6, 1994 Ford Taurus SHO, Porsche racing projects

[mrdave]

The hood, front fenders, front & rear subframes, front & rear bumper crash bars, engine block & heads, and a lot of the suspension components are already aluminum on the C5 S and RS cars.

Off the top of my head the items to reduce weight would be: interior, battery, OEM wheels (32lbs each), sunroof, A/C, emissions hardware, possibly exhaust (?), and you could save at least 150lbs by swapping in a manual trans.

[eurovintage]

Hi Dave,
Thanks, Transmission seems a very good way.
My main concern is also the heavy front weight bias.
That was has kept me so far from considering Audi's.
Spoiled by very light high hp cars.

[P1054]

Just to interject, the rear subframe on the C5 RS6 is steel, not aluminum.

Otherwise yes, going to a manual transmission is hands down the biggest weight gain, and couples with performance gain. The auto trans full of fuel is just about too heavy to lift one end by hand, much less the whole thing. The manual full of fluid is a fairly easy one man lift. The hood is already super light. Battery and wheels are good options for saving weight. I would proabably want to remove similar weight from the front anytime weight was removed from the rear (i.e. battery). SAI, aux radiators and associated plumbing, spare tire, DRC, etc are all good options. The exhaust system isn't too heavy to begin with but you could probably save a few pounds.

[eurovintage]

Thanks
Anybody try alum. or carbon fiber drive shafts ?
What source ?

[RS6 rick]

The lighter wheels are a very BIG DEAL....they represent a large decrease in rotating mass, the benefits of which, far outweighs there actual weight. You would not feel any difference with a 5 lb. lighter hood but you will feel a difference with lighter wheels. Just swing a 5 lb. barbell in a circle and then swing a 10 lb barbell and you'll get the idea.

[eurovintage]

Yes Rick,
I think the engineering book says about 3 X as much as actual weight saving when it comes to rotational mass.
On my SHO the weight saving from steel to fiberglass/carbon combo hood is about 40+ lbs.
On the AH the hood from alum versus stell, has about 10 lbs saving as it has a small shape, not covering the full front.

[nubcake]

Seats. Seriously. They're like 60 pounds each. :)

[eurovintage]

Yes inded,.
Are the Euro Spec seats lighter, and by how much ?

[nubcake]

Still quite heavy. Maybe someone else will tell the exact difference.

[mrdave]

just to interject, the rear subframe on the c5 rs6 is steel, not aluminum.

c5 4.2l:
17937

c5 rs6:
17938

[mrdave]

...and just for completeness,

c5 s6 avant:
17939

[hahnmgh63]

I'm not too far away. Just south of Tacoma by Eatonville, on the way to Mt. Rainier. I've done the wheels (BBS RS-GT's 19"), battery Odyssey 925, removed SAI and Aux radiators, even saved a few pounds by going with Miltek Catless downpipes. The wheels were the best investment, but in order to go lighter without sacrificing strength then you have to go Forged which means $$ but worth it, I run Forged wheels on all of my cars. Funny thing, even the wife's A8 came from the factory with 19" Forged wheels but not the RS6.

[eurovintage]

Thanks, forged is quite a bit stronger in general. People forget though often that going to larger diameter wheels adds weight,
not to mention wheels will be more stress on bad roads and railway crossings due to smaller section tires.
Also worse for snow driving.
Have not driven any RS6 just S4 a couple of Years back, but did not like the unresponsive steering, and the way it handled during
corner turn in due to the weight !

[Cmnair]

I am not sure if this is the car to go for if you are looking for light car/high HP. No offense but I don't see the point.

[eurovintage]

Actually I need a winter and good driver, as my SHO is getting on,
have enough light cars,
actually also building 2 more

[ttboost]

If you haven't found a car yet, this is my old 6spd car...


http://www.mjluxurycars.com/2003_Audi_RS%206_Hopewell%20Junction_NY_6208213.ve h

[Bigglezworth]

I am not sure if this is the car to go for if you are looking for light car/high HP. No offense but I don't see the point.Ditto. This car isn't a track star - although it can be fun every now and then. This is a highway bruiser and fun around town. Leave your Nobel for the track. You can waste a host of $$ trying to eek out 300-400lbs to make this a 2 ton ride. It will never be a 3200 car. It was never meant to be. It has a lot of aluminum components to aid in reducing weight (front end especially), but it will always be an AWD car with 3 differentials, 4 axles, massive brakes for stopping from high speeds, lots of sound dampening, a crap load of electronics, and creature comforts to boot. I have fast (light) cars. Didn't feel it necessary to do that to the RS. Just my $0.02.

[eurovintage]

Thanks everybody for the input. I always explore the possibilities, in this case anything which is easy and has been done,
including improvement mods. Every car has its strength and weaknesses. Not looking for tracking, although I might do
a test run at a track, as this will bring out any issues. Have been racing as an amateur since 1987, in vintage.
Some weight reduction is always good even for road cars, side effect is also better gas mileage.
The manual transmission seems to help in both ways. Drove the new Giulia Ti yesterday, feels very toss-able around 3000 lbs,
just a little bit small, also ingress for tall people like me is not perfect. As with most new cars, too many Nannies and electronics.

[Bigglezworth]

Some weight reduction is always good even for road cars, side effect is also better gas mileage.Funny quote. If you own an RS6, the last thing on your mind is gas mileage. It can consume gas faster than a fat kid can consume a Smartie....

Lots of quality rides out there and many of them in good order.

[eurovintage]

Unfortunately in B.C. we have $1.58/Liter for 91, PST (Provincial sales tax), not to mention Cost of Living considerable (Real Estate etc.).
Of course handling improvement iincl. better stopping is the most important benefit for reduced weight.
Used to live in AB, had its charms, but so has the coast.

[fbatwork]

Have to agree, the time and effort to reduce weight there are so many other options - no one has mentioned spare tire - but then you'll need a plan for flats, I think they used lead in that thing.

[hahnmgh63]

Yea, other than those items I mentioned in my threads above I will not bother with anything else. All of those things improved the car, anything further and I think you will start taking away from a great Grand Tourer.

[Turbowned]

Sounds to me what you really want is a 2010+ S4. Similar power with much less weight and sharper handling, albeit still a heavy car. The RS6 is a 4,100lb land yacht and not much you can do about it without making sacrifices. Biggest improvements would be forged wheels, 2pc brake rotors, deleting secondary radiators (if Canadian models even have them), dry cell battery, perhaps a pair of manual Recaro reclining seats. I think nearly everything else would compromise the essence of the car, which is to be a fast, comfortable, reasonably good-handling super saloon.

[lswing]

Lighter wheels, stock battery is 90lbs vs 30lbs performance battery, remove spare tire and gear, remove auxiliary radiators...drive with 1/4 tank gas:) I get 13mpg around town, 18-20 mpg highway, been that way for 5 years now...

[s8prtotype]

A few weight reduction mods and you're right around supra weight :)

[hahnmgh63]

Turbowned, I've also got a 2012 S4 with software and Supercharger pulley for somewhere claimed of over 400bhp (333bhp stock). It weights 3900lbs, my RS6 with the lightweight items above is about 4050 with 1/2 tank of fuel. The S4 would just about match the 0 to 60 but after that the RS6 would pull away easily. I would say with the light wheels and KWV3's the RS6 would match it for steering and handling too, a slightly better weight distribution in the S4, and it is slight after removing the Aux radiators from the front. The S4 with S-tronic is a great daily driver though. And I do like the S-tronic although not as good as Porsche's PDK, and not as reliable as Porsche's PDK to be sure.

[mrdave]

B8 / B8.5 S4 + the full APR package doesn't sound too bad to me.

17949

[rah]

Funny quote. If you own an RS6, the last thing on your mind is gas mileage. It can consume gas faster than a fat kid can consume a Smartie....

Lots of quality rides out there and many of them in good order.

I was dying when reading this, it is so true when it comes to gas mileage and those cars. Good fuel consumption and those cars do not mix well. Reading thru the whole post and for the fact that you love building cars, a MK2 shell paired with the quattro system is a pretty cool car in my opinion, combining lower weight, more power to the ground and quattro of course. That would also depend on the motor really

Even so not many cars compare to the RS6, if you are looking for more of a winter car with good performance and decent gas mileage, why not look into other all wheel drive VAG cars, like the golf R, R32 (even so the gas mileage is not good on those either), 1.8T Audis etc? The 1.8T can be built pretty good also. Just wondering.

Talking about weight reduction on all four corners with wheels, isn't the smallest wheel possibility with the RS6 18s due to the brakes?

[rah]

Turbowned, I've also got a 2012 S4 with software and Supercharger pulley for somewhere claimed of over 400bhp (333bhp stock). It weights 3900lbs, my RS6 with the lightweight items above is about 4050 with 1/2 tank of fuel. The S4 would just about match the 0 to 60 but after that the RS6 would pull away easily. I would say with the light wheels and KWV3's the RS6 would match it for steering and handling too, a slightly better weight distribution in the S4, and it is slight after removing the Aux radiators from the front. The S4 with S-tronic is a great daily driver though. And I do like the S-tronic although not as good as Porsche's PDK, and not as reliable as Porsche's PDK to be sure.

I would love to meet you and see that car of yours one of these days if you are up to it.

[hahnmgh63]

I'm in for it rah. I tend to be out of town a bit but I can always find a day here or there.
mrdave, you are right about the stage 2+ APR, I have the Stage 2 and it is almost a match but the 2+ is all in for an extra $1600 ($3500) and I am worried about the S-tronic. It is a great transmission but they have had their problems. I do the frequent oil & filter changes (sounds like an 5HP24 doesn't it). They don't sell rebuilt S-tronics and they are about $7k to $8k to replace, not counting labor.

[eurovintage]

Hi TT,
Sent You PM

[BradP]

So, I just have to comment on the rotating mass thing...wheels. I crunched the numbers a while back, and the rotation (modeling simply as a disc) is a 50% increase. IE, 60 pounds off your wheels gives you a 90 pound advantage (real world for these OE wheels and what you can buy at a decent price). Granted a disc isn't exact, but in the ballpark.

I'm not a fan of sunroofs, and can loose 30 pounds off the roof with a carbon filler. I used a thin layer of fiberglass to replace the interior slider as well.

52 pounds using a lithium battery. Don't use in cold climates. However, I've been down to 22 degrees without issues. CCA is simply poor for lithium. I have one the size of a cigarette pack on my snowmobile.

5 mph crash bars, headlight washers, and fog lights...35-40 pounds! Front and rear (together).

Side coolers...discussed. I figured 15-20.

Floor mats 16 pounds.

Exhaust, around 15 pounds replacing the mufflers with small resonators.

The rest, not for the faint of heart. Weight bias well, again overrated in my book. I'm about 65/35, and I'm the Audi at the track with neutral steer. Overloaded hot tires are one thing that can be helped by taking mass off anywhere on the pig, uh, I mean beast:)

Somewhere south of 3800 pounds with a third tank. It's been a couple of projects since I weighed her. I came up with 4300 on my initial weigh in.

[s8prtotype]

Convert to a manual rack Bradp! lol

[fukinavit]

On the subject of weight, I just replaced the oem battery (62lbs) with an odyssey 1200 (36lbs), and took out the spare wheel (47lbs).
I'm looking at some BBS wheels now which are 24lbs each, just wondering if anyone knows the weight of the stock rims?

[mrdave]

just wondering if anyone knows the weight of the stock rims?

http://www.rs6.com/showthread.php/33151-Stock-RS6-rim-weights-vs-aftermarket-options?p=286187&highlight=#post286187

[fukinavit]

Thanks, you made it look so easy.

[rah]

I'm in for it rah. I tend to be out of town a bit but I can always find a day here or there.

Sounds good, let me know what works for you and we will go from there. I also work quite a bit but i stay in town, so easier for me.