balance

[Boris]

just curious as to whether serious weight loss tactics will affect the balance of the car?

the usual: stripped interior, carbon fibre boot/bonnet etc.

i havent been able to find the front rear weight distribution of the gtr's but wouldnt massively reducing the weight of the body while leaving the engine same unbalance the car?

im guessing more torque would be taken to the front wheels more often... tho i got no idea

[MANWHOR3]

mate, your idea of "serious weight loss" is not really serious at all.

it's been covered like 100 billion times before. gtr bonnet, not heavy. carbon bonnet might save 3-4 kilos. stripped interior - might save 25 kg. boot - might save 20 kg.

that's hardly going to unbalance anything. Think about the difference between an average aussie (100kg) driving it, and a small japanese dude (60kg) driving it, and you have the difference in weight.

[Abo Bob]

Well I have driven eastern creek with full trim, subbie in the boot etc then I took the subbie, spare, jack, carpets and sundry other crap out and did some more laps. The back end was noticeably looser in braking situations both straight line and corners but it was harder to tell whether it made any difference with the power down. Perhaps that's because I don't have all that much power though.

This is with stock GTT suspension. I guess if your suspension was adjustable you could compensate.

[Boris]

see that ETC.???

that means theres more sh!t that i couldnt be bothered writing

ripping out rear and passenger seats, lexan windscreen and windows, 1 headlight buh-bye, centre console and all audio gone, all lining and soundproofing gone, digital drag spec tacho, carbon fibre boot/bonnet. HELL, carbon fibre the whole car, dash EVERYTHING. hell screw the dash who needs it.

and get the skinniest, smallest guy u can find, and starve him for 5 weeks if that makes u happy.

and fuel for one run at a time if u want!

so yeah, when i said serious weight loss, I MEANT SERIOUS WEIGHT LOSS

so do i need to go back to the word ETC.??

and if doing these things dont matter, WHY THE FARK DO THEY DO IT???

o im just talking about the gtr's btw, thats why i made a comment about the torque transfer to the front wheels

sorry to get all shitty on ya manwhor3, but ur "tone" just pissed me off

sounded to me like:

mate, ur a dum ***, i said it 100BILLION times already blah blah blah so there!

even if it only ends up being 300kg saving, a 400kw gtr full trim at around 1600kgs 4kg/kw power/weight would become 3.25kg/kw

sorry if that wasnt ur intention, it just soudned to me like u were talking to a dum noob kid who doesnt know jack sh!t

well at least now i made myself clearer, and ill remember to do that in future too

[Boris]

f-uck i was pretty harsh lol

sorry :Oops:

[Boris]

f-uck i was pretty harsh lol

sorry

[Sydneykid]

Hi Boris, there is a great disparity in knowledge on any forum, this one is no different. You really have to be quite explicit (sorry but "etc" doesn't cut it when leaving a lot to the imagination of an unknown reader).

To the questions at hand..............

The lightest GTR I have seen was 1320 kgs, lots of stuff was removed, but the sort of stuff you take out doesn't weigh much (except glass, that's heavy). The problem is the stuff you put in tends to be heavy stuff, eg; roll cage, oil cooler, extra sump capacity, larger intercooler, bigger brakes, larger wheels, bigger tyres, LSD, bigger turbo/turbos, 4" exhaust....you get the drift.

I have taken at least 200 kgs out of ours, but it only weighs 50 kgs less than a standard one. On the bright side if I hadn't taken out the 200 kgs it would be 150 kgs heavier than standard.

The next problem is weight distribution, our is around 68% front and 32% rear. The problem being most of the weight you remove affects the rear, stuff like rear seats, spare wheel, tool kit, NVH weights, rear wiper, HICAS..... But the weight you add ends up on the front, oil cooler, remote filter, larger intercooler, turbo/turbos, larger radiator.....

I have a rule, if I have to have it, is there some way I can move it towards the rear (that means anywhere past the front wheels). And can I move to somewhere lower down, in circuit racing C of G is important too.

Hope that helps:cheers:

[Boris]

thanks sydneykid ill take ur advice into accound for next time.

do u find the huge shift in weight to the front affects ur times or overall diveablilty of the car? (im thinking more circuit oriented then drag, where chassis balance is a lot more of an issue)

apart from trying to move things to the back, anything else u do?

my guess was that alot more torque would be transfered to the front wheels. (in the gtr). but i notice on the metre it only transfers uo tp 50kgm, which is only 500nm. hehe only...

would this be a problem for serious cars with over 1000bhp 1200 nm torque trying to get more power to the front wheels for grip?

in essence, would the car turn into an almost fwd, when the vast majority of torque is sent to the front?

[Sydneykid]

thanks sydneykid ill take ur advice into accound for next time.

do u find the huge shift in weight to the front affects ur times or overall diveablilty of the car? (im thinking more circuit oriented then drag, where chassis balance is a lot more of an issue)

apart from trying to move things to the back, anything else u do?

my guess was that alot more torque would be transfered to the front wheels. (in the gtr). but i notice on the metre it only transfers uo tp 50kgm, which is only 500nm. hehe only...

would this be a problem for serious cars with over 1000bhp 1200 nm torque trying to get more power to the front wheels for grip?

in essence, would the car turn into an almost fwd, when the vast majority of torque is sent to the front?

Hi Boris, I'll try and answer briefly, I have yet to see a circuit with 1000 bhp, they mostly max around the 600 to 700 bhp. This is to keep the response up, far more important on the circuit. The best the ATTESSA will do is 50% to the front, so it can never get to what I would consider the "front wheel drive" stage. We run the circuit cars around 20 to 30% front drive. If you have too much drive to the front the tyres start to overheat, from the turning, braking and powering. The rear tyres don't do any turning and 40% less braking. So you balance the tyre load out, that's why GTR's were such circuit race killers.

Hope that answered your questions:cheers:

[Boris]

Hi Boris, I'll try and answer briefly, I have yet to see a circuit with 1000 bhp, they mostly max around the 600 to 700 bhp.  This is to keep the response up, far more important on the circuit.  The best the ATTESSA will do is 50% to the front, so it can never get to what I would consider the "front wheel drive" stage.  We run the circuit cars around 20 to 30% front drive.  If you have too much drive to the front the tyres start to overheat, from the turning, braking and powering.  The rear tyres don't do any turning and 40% less braking.  So you balance the tyre load out, that's why GTR's were such circuit race killers.

Hope that answered your questions:cheers:

Great answer. although its raised another question for me.

i mentioned that attessa only maxes at 50% to the front, but i noticed on the gtr guages that the reading maxes out at 50 KGM (which is 500nm).

i had always thought the reading is just a percentage, but since seeing that i wasnt so sure (although it makes sense because there would be a max load the front wheels/drivetrain could take, and if it was 50%, and u had modified the car to produce over 1200 newtons of torque, more than 600 newtons could go to the front) which might cause problems

i only used 1000hp as an example. 1000hp is common in japanese drag circles from what ive seen but yeah u are completely right 600-800 hp would be much more suited to track

i did see however on top gear, that clarkson guy runnning the 1000hp jun r33 around a circuit. while he said that it was bloody scary when it came on boost (and at a corner!) it went around fine (although i dont know if they ran full boost)

and it was for sale at 150k pounds...

1000hp.... :flower: :jump: :burnout: