R35 Weight Saving Options

[LSX-438]

After ideas for relatively easy reversible weight saving options for our R35's...

Thus far i've replaced the mid-pipe (probably five to ten kg saving there) track rims/tyres (about 40kg saving) removed passenger seats, front and back (about 25kg) rear seats and seatbelts (maybe 4kg ~ 5kg).

Thinking to put a race seat in (probably another 20kg saving)

The door trims look to weigh a LOT (anyone know if there are any carbon door trims replacements available?)

So that leaves exhaust (catback) i suppose

Also i usually run low fuel (say 1/4 tank)

Any other ideas?

I dont fancy removing carpet or sound deadening as i would like the option to put back to road car status if possible (although would be interested to know how much all that carpet etc. weighs if anyone knows!).

[writeoff]

For carbon door trims you might want to search for any German GTR specialists. In a rule that I find bizarre they can legally strip their cars of practically everything but must have door trim on the front doors. As a consequence a lot of carbon door trims are made in Germany for all sorts of models. Of course it may be difficult to find a German GTR specialists - perhaps they can help more at GTROC UK.

[Priestley]

Would carbon fiber doors, bonnet and boot lid save much?

Carbon doors from Made in China, wonder what the quality is like:

http://www.made-in-china.com/showroom/zhch...haker-Gift.html

http://www.f1carbon.co.uk/carbon-carbon-do...9774c2300f9c1d3

[Munro]

Hey Duncan, are you still driving the GTR as your daily vehicle as well? Or has it been relegated to

"toy" for occasional street use & mainly track work?

I have been down this path years ago with more than one of my cars & once you get past the

"I'll just pull out the other seats & put them back later" stage it is unlikely that car will see much

more regular street duty. Been there, done that.

My opinion is that you are doing so well as it is, continuing to strip the car will defeat the purpose

of what these R35 GTRs are supposed to be in the first place.

You may find that pulling further weight out of the car doesnt make it that much faster anyway.

One thing is for sure. If you keep going, you will destroy it as a street car.

Then you may as well just build up a full race car weighing under 1300 kg & join the ranks of trailer sailors.

I have a purpose built R33 GTR race car (that is only slightly faster than my full weight R35 so far!!!)

but at 1300kg it is much more fun to fling around than the R35.

You could keep going & be a pioneer but my 2c is cool it for a while, enjoy it as it is & see how you feel

about it "down the track".

I love what you are doing, & wish I had the time to do the same thing. Not trying to stop you.

Just know that I have destroyed some very nice street cars over the years & in hindsight I wished I hadn't.

Keep up the good work.

Cheers.

[TheTunersGroup]

After ideas for relatively easy reversible weight saving options for our R35's...

Thus far i've replaced the mid-pipe (probably five to ten kg saving there) track rims/tyres (about 40kg saving) removed passenger seats, front and back (about 25kg) rear seats and seatbelts (maybe 4kg ~ 5kg).

Thinking to put a race seat in (probably another 20kg saving)

The door trims look to weigh a LOT (anyone know if there are any carbon door trims replacements available?)

So that leaves exhaust (catback) i suppose

Also i usually run low fuel (say 1/4 tank)

Any other ideas?

Hi Duncan,

If your car is road registered you'll need to check with an engineer about what can be done while keeping it road registerable.

The Supercharged 911 is a very interesting example of how to take weight out of a car for track use ...

It weighs 1124 kg.

It runs a fibreglass bonnet and engine lid, fibreglass bumpers, carbon fibre doors, lightweight door trims, light seats, and even perspex moulded headlight covers instead of glass. The carpet is a lightweight carpet.

So all those things are bolt ons that can be reverted back to stock if necessary.

More info on it here ...

http://www.tunersgroup.com/supercharged_911.html

Continuing on that theme of focussing on power to weight ratio, I was very interested in this post on The Real JDM blog about the Lotus Exige 300R titled "The Car That Beat HKS’s Carbon Time Attack Evo - A Lotus" ...

http://www.bespokeventures.com/blog/?p=1027

You're right that the seats can save a lot of weight. Many cars have very heavy factory seats.

As an example of how much weight lightweight seats can save, the OMP WRC seats above in fibreglass weigh 8.8kg each. OMP also make a carbon version of them that is lighter still.

How light you want to go seatwise depends on your budget of course.

These Recaro's are about the lightest seats I've ever seen.

They are a very special lightweight carbon kevlar version of the Recaro Profi SPA seat that were built for use in the V8 Supercars and rallying. These two are new old stock that have been sitting in a warehouse. They weigh approx 2.6 kg each.

You've got to love the way Recaro weigh their seats to the gram

To put that into perspective, the standard Recaro Profi SPA seat weighs 8.8 lbs (3.99 kg).

Your best friend when taking weight out of a car is a set of digital bathroom scales - the guy who owns the supercharged 911 is constantly weighing parts on bathroom scales and then finding lighter alternatives - plus it's great to know how much weight you've taken out of the car

Go much beyond bolt ons and you can end up with a car with no alternator etc, which isn't much fun and can be pretty impractical.

Some batteries can be pretty heavy, so it might be worth checking out lightweight batteries like the Optima racing batteries - a lot of the 911 guys in the US run them.

There are also mounting kits available for them ...

http://www.allzim.com/acatalog/Steel_Optim...unting_Box.html

There is a thread here about Optima battery weight savings ...

http://forums.rennlist.com/rennforums/996-...ma-battery.html

If you get to the point where you're weighing your wiring harness and trying to figure out which wiring circuits you can do without, you've probably gone too far for a car you ever want to use as a roadcar again

How much do you like your air conditioning ?

- The Tuners Group

[Martin Donnon]

You could keep going & be a pioneer but my 2c is cool it for a while, enjoy it as it is & see how you feel about it "down the track".

Dont listen to the 33 drivers Dunc....they are only trying to slow you down

33 GTR - 100kg = FUN

[LSX-438]

Hey Duncan, are you still driving the GTR as your daily vehicle as well? Or has it been relegated to

"toy" for occasional street use & mainly track work?

I have been down this path years ago with more than one of my cars & once you get past the

"I'll just pull out the other seats & put them back later" stage it is unlikely that car will see much

more regular street duty. Been there, done that.

My opinion is that you are doing so well as it is, continuing to strip the car will defeat the purpose

of what these R35 GTRs are supposed to be in the first place.

You may find that pulling further weight out of the car doesnt make it that much faster anyway.

One thing is for sure. If you keep going, you will destroy it as a street car.

Then you may as well just build up a full race car weighing under 1300 kg & join the ranks of trailer sailors.

I have a purpose built R33 GTR race car (that is only slightly faster than my full weight R35 so far!!!)

but at 1300kg it is much more fun to fling around than the R35.

You could keep going & be a pioneer but my 2c is cool it for a while, enjoy it as it is & see how you feel

about it "down the track".

I love what you are doing, & wish I had the time to do the same thing. Not trying to stop you.

Just know that I have destroyed some very nice street cars over the years & in hindsight I wished I hadn't.

Keep up the good work.

Cheers.

I hear you. It's a good point about compromising an otherwise completely good road car (I've done that before too). I'm in two minds about it. I haven't decided which direction to go in, which is part of the reason for this thread. I don't drive the car daily, however I still need to drive to and from the track, and have the car APPEAR somewhat legal from a distance... I don't want extra attention (from the law). Re-installing factory seats, door trims, speakers and what-not shouldnt be too much drama should it? Yes it destroys the DD aspect of the car for sure, but I probably don’t care about that, as long as it yields results and I can reverse it. But, I know you are right about this.. It's a slippery slope!

[iplen]

From a report I read in HP, CroMo tubular subframes.... But again, Carbon Body panels

[Modena]

Hit the gym... and lay off the junk food.