Weight Reduction in 32 GTR

[«Cyph3r»]

Hi,

Basically looking towards ways of removing weight from a 32 gtr.

I had a couple of things planned but am open to any comments/suggestions about cutting down the weight of the car.

1. Was looking at removing hicas system completely if possible. I read in another thread somewhere "sydneykid" mentioned by removing all the hicas related parts you can save up to 20kg i think. Anyone seen any list of parts needed to do so or a tutorial on what to remove and where?

2. Titanium cat-back exhaust system. Is this going to make a worthwhile difference. The system i was looking at is custom made and section welded and the ss version weighed only 6kg so the ti system i would guess would weigh in at ~4kg or less.

As these are quite expensive though was just working out whether be better off getting one made in australia or trying to find one 2nd hand over here?

3. Are the standard seats much heavier then say recaro, sparco or bride fibreglass fixed back seats?

Most of the other weight savings i can think of are allready done. But still any suggestions would be appreciated. BTW this will not be a daily driver so all the creature comforts are not looking to be retained.

Cheers

Jamie

[BigMicky]

I dismantled a GTR last week and weighed a few things as they cam off for interest sake.

The complete wiring loom weighed about 20kg's

ABS unit was 8kg's.

The seats are heavy compared to some of the aftermarket ones.

My suggestion is to remove everything, then only put back what you absolutely need.

Saving 2kg's on exhaust seems like a bit of a waste of time.

I know where I could easily get 25kg's out of a GTR I was driving..

I could go on a diet!!!!

Little Micky

[«Cyph3r»]

I dismantled a GTR last week and weighed a few things as they cam off for interest sake.

The complete wiring loom weighed about 20kg's

ABS unit was 8kg's.

The seats are heavy compared to some of the aftermarket ones.

My suggestion is to remove everything, then only put back what you absolutely need.

Saving 2kg's on exhaust seems like a bit of a waste of time.

I know where I could easily get 25kg's out of a GTR I was driving..

I could go on a diet!!!!

Little Micky

Sorry should have let people know whats allready gone. :Oops:

Aircon has been removed

ABS has been removed

Carpet has been removed

Sound Deadening has been removed

Rear Seats and trim have been removed from centre pillars back

Boot is completely stripped

Drivers seat is changed allready but passenger side is stock gtr

Lightweight wheels

Lightweight coilovers

No stereo although will probably have an easily removable one put in

I have a<2kg titanium front pipe on the way (why i was looking at ti cat back aswell)

And i am underweight as well

Battery is downsized and relocated

Don't really want to go as far as removing loom and getting a new one made up though.... i never reallly thought that the wiring alone would weigh that much.

Also thought about carbon fibre bonnet (a proper dry carbon one, not just frp bonnet with cf skin but are they really that much lighter then the aluminium one and where can you get them from?

[Sydneykid]

The exhaust system confuses me, I just replaced a 3.25" mild steel cat back that weighed 22kgs with a titanium 4" that weighs 5kgs. I don't see how a stainless system could weigh 6kgs, the old centre muffler weighs more than that on its own.

Alloy wheel nuts are good for 600 grams, not good weight for dollar.

Alloy brake rotor hats, saved 1.5kgs each, not bad value. And the backing plates, not much weight but better cooling as well. The one piece braided hoses were lighter than the 2 piece rubber ones, mostly because of the heavy steel fitings.

I have weighed a carbon fibre bonnet and there was barely 1kg in it compared to the alloy GTR one, not very good value.

Removing the HICAS is definitely worth it, saves weight and handles better, very good value for money. There are no tricks here, just take it all off, start at the rear rack and work through to the front, follow the hydraulic lines, removing as you go.

Engine fan and clutch, the electric one was a kilo or 2 lighter.

Loose the HVAC, the air con compressor weighs heaps.

All alloy radiator, the PWR one was noticeably ligher, I didn't compare the weights though.

Rear wiper, I haven't removed ours yet, glad I reminded myself.

Seat belts, those retractors are heavy.

The NVH weights around the rear supension are remarkably heavy, around 6kgs all up if I remember rightly.

I have changed a few bolts to alloy, been doing it one sizes at a time, they are expensive so not great value per kg

Next on my list is a one piece alloy/carbon fibre tailshaft, the 2 piece steel and centre bearing are heavy. It's a flywheel (like the wheels) so it counts twice.

Engine pulleys, I haven't found a full set that I like yet, still looking.

Glass is very heavy, I wish I could swap it for plastic but the class regs don't allow it.

Moving stuff is always good value, GTR's have terrible weight distribution. Moving stuff into the boot or from the driver side to the passengers side are both worthwhile. Battery in the boot is the most obvious, power steering reservoir to the boot, fuel pressure regulator to the boot, remote oil filter rearwards, catch can in the boot, etc etc

[T88 ON BOARD]

I currently have just stripped my gtr r32 interior makes it easier to do before the cage was going in...

Anyways....

Under the Dash/Consol there is alot of Sh*t That doesn't need to be there...Mainly got to do with the A/C such as heater box etc....

as Gary said the seat belts were Surprisingly heavy..The retractors and the thick bolts are really noticable...

Jamie...I managed to almost close another sponsorship deal With a carbon fibre Company...Pm me if your interested in any panels to be done...

cheers

[MANWHORE]

How about the rest of the interior? The door trims, centre console - take the dash out etc.

Have you got the roof trim yet?

Since you've removed all the stuff at the back such as speakers, etc, have you removed the wiring? helped strip my friend's 180sx, and you'll be suprised how much the wiring weighs and it won't It won't cost you anything. Especially all the wiring under the dash. what I did was started to unrol the electrical tape that's wrapped around everything and start tracing back stuff you dont' need e.g. interior lighting, speakers, hicas wiring, etc. Trace it back to as far as you can, then just cut it.

Light weight steering wheel

rear window wiper motor and wiper itself weigh almost 2kg!!!

Hi Sydneykid

I have a question for you

how did you get the catch can and oil filter relocator into the boot?

isn't that an awfully long path for oil to travel?

Cheers fellars

[Sydneykid]

Hi Sydneykid

I have a question for you

how did you get the catch can and oil filter relocator into the boot?

isn't that an awfully long path for oil to travel?

Cheers fellars

remote oil filter rearwards

Note "rearwards", not "in the boot". I see too many with the remote filter mounted just behind the headlight. At least mount it BEHIND the front wheels. It will fit next to the brake master cylinder, with a bit of a fiddle. Or where the ABS unit was, if there isn't one. In a 2wd we mount it where the front tailshaft goes, that's both rear and low.

Catch can, it matters not how long the pipework is, it is only a breather after all. In fact the longer run allows time for the oil to condense out of the airflow. Plus it keeps the engine bay oil mist free.

In the V8 Supercars the brake and clutch reservoirs are in the boot. Every little bit helps.

[dangerous_daveo]

I havent really got anything to add to taking stuff out, but a few questions.

Not so much why take it all out, as that is fairly obvious. But HOW much difference does it make. I was once told every 200kgs = about 30hp, but no one ever mentioned how much difference it made to handeling, and braking distances etc. Going by the 200kgs = 30hp thing changing all the bolts etc would actually seem cheap to some power mods.

But! While I think about it, Im not 100% sure on what you can rip out, but say light globes? wiring to those globes etc? If you dont need it, get rid of it.

[Sydneykid]

I havent really got anything to add to taking stuff out, but a few questions.

Not so much why take it all out, as that is fairly obvious.  But HOW much difference does it make.  I was once told every 200kgs = about 30hp, but no one ever mentioned how much difference it made to handeling, and braking distances etc.  Going by the 200kgs = 30hp thing changing all the bolts etc would actually seem cheap to some power mods.

But!  While I think about it, Im not 100% sure on what you can rip out, but say light globes? wiring to those globes etc?  If you dont need it, get rid of it.

You can do the straight power to weigh calculation.

600 bhp / 1400 kgs = 2.33 kgs per bhp

600 bhp / 1200 kgs = 2kgs per bhp

So to get the same power to weight ratio at 1400 kgs you would need 700 bhp

We tend to look at it more in lap times, say 20 kgs = 0.1 seconds per lap.

So if we take out 200 kgs = 1 second per lap.

That means in a 30 minute race we would be the length of the main straight at Oran Park (or the back straight at Sandown) faster. That's a big winning margin.

[«Cyph3r»]

Sydneykid.... reread through the translation... seems the other system was in fact ti and not ss, my mistake. So given the weight saving ti cat back is def worth it.

I also allready have all aluminium radiator and piping etc....

I will look into legalities of removing retractable seatbelts and running only harnesses up front in qld... rear belts have allready been removed as have the rear wiper and wiper motor assembly.

What are the NVH weights that were mentioned earlier in the thread?

Cheers Tony... will let you know if i'm after any trims redone in cf or panels.

Thanks everyone for the ideas so far.

[dangerous_daveo]

You can do the straight power to weigh calculation.

600 bhp / 1400 kgs = 2.33 kgs per bhp

600 bhp / 1200 kgs = 2kgs per bhp

So to get the same power to weight ratio at 1400 kgs you would need 700 bhp

We tend to look at it more in lap times, say 20 kgs = 0.1 seconds per lap.

So if we take out 200 kgs = 1 second per lap.

That means in a 30 minute race we would be the length of the main straight at Oran Park (or the back straight at Sandown) faster.  That's a big winning margin.  

Thanks! And yeah 1 sec a lap is a wee bit of a difference

[Duncan]

re the wiper blade and motor, how did you plug the hole in the rear windscreen?

[«Cyph3r»]

re the wiper blade and motor, how did you plug the hole in the rear windscreen?

Will have a closer look but there is a sticker over where the assembly normally is.

Wasn't the rear wiper an option though or not?

[Sydneykid]

re the wiper blade and motor, how did you plug the hole in the rear windscreen?

Easy;

1. Race tape aluminium plate under holes (on the inside)

2. Fill holes with Selleys crystal clear Araldyte (great stuff)

3. Smooth over with flat scraper

4. Remove the aluminium plate and race tape

5. Trim any excess Araldyte off with a razor blade

6. Cover with sticker of choice, 100% invisible

[lwells]

Next on my list is a one piece alloy/carbon fibre tailshaft, the 2 piece steel and centre bearing are heavy.   It's a flywheel (like the wheels) so it counts twice.

I'll be fascinated to see what difference that makes, both in terms of reducing outright weight, but also in terms of decreasing rotating mass. Please keep SAU updated on that one

Lucien.

[Sydneykid]

I'll be fascinated to see what difference that makes, both in terms of reducing outright weight, but also in terms of decreasing rotating mass.  Please keep SAU updated on that one

Lucien.

Hi Lucien, we are trying one in the RX7 over the next couple of race meetings. So that will give me some confidence in spending the money on a Skyline one.

[predator]

re the wiper blade and motor, how did you plug the hole in the rear windscreen?

wiper assembly is 2kg.. I used a rubber bung.. looks the goods, although mind you a sticker was the next option. get them out of the boot wells . I think mine came out of the R31, or was it the r33.. anyhow. one of them, I had a few sitting around - perfect fit.

wasn't so much for weight reduction in my case, wiper was borked.

You'll find the heater box is around 5kg.. probably the fan another couple of kg.. Compressor is 9kg, and a few other aircon bits probably pull that up to around 15kg. I'm not sure whether you can nick the side mirrors off for racing - but they are 2kg each. They dash mould itself is about 8kg..

[«Cyph3r»]

I just replaced a 3.25" mild steel cat back that weighed 22kgs with a titanium 4" that weighs 5kgs.

Sydneykid, do you get your titanium exhausts made in australia or get japanese made ones? I was looking at getting a section welded ti cat back brought in but if i can get one made of same quality here i would do that.

[Sydneykid]

Sydneykid, do you get your titanium exhausts made in australia or get japanese made ones? I was looking at getting a section welded ti cat back brought in but if i can get one made of same quality here i would do that.

The new one is an Apexi, it was at a good price as it is a bit LOUD for a road car. I haven't found anyone who does reasonably priced titanium welding in Australia. The aircraft guys charge aircraft prices.

You can't weld titanium in atmosphere, it absorbs oxygen, nitrogen and hydrogen and gets brittle. If you are Tig welding it, you have to have an inert gas (eg; argon) surrounding the weld, both on the outside and the inside. And it must be maintained while the joint cools. This is not easy with pipe, you can use the usual shield on the outside but the inside would need to be sealed and filled with argon. Plus you have to use low moisture content argon.

If anyone has found a good, reasonably priced titanium welder then please post them up. They will get some business.

[Roy]

You can't weld titanium in atmosphere, it absorbs oxygen, nitrogen and hydrogen and gets brittle. If you are Tig welding it, you have to have an inert gas (eg; argon) surrounding the weld, both on the outside and the inside.  And it must be maintained while the joint cools.  This is not easy with pipe, you can use the usual shield on the outside but the inside would need to be sealed and filled with argon. Plus you have to use low moisture content argon.

If anyone has found a good, reasonably priced titanium welder then please post them up.  They will get some business.

LOL...thats how TIG welding should always be done:( The biggest problems with titanium is the cost of material, the cutting and fitting of the material, and then frequency/amps required to TIG weld it. Basically the little $800 caddy isnt going to do the job:( Works great for stainless and mild steel but not dont even consider alloys with a cheap TIG,

At least titanium does not require post weld het treatment like chrome-moly (if its used in critical/pressure applicatio) etc:(

Instead of goign OS im considering buying a TIG, have to think carefully about whether it has the ability to pay itself off though.:confused: