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Mass Reduction & Acceleration Improvement:

Posted: Mon May 21, 2007 11:10 am
by ZeroK66
Hey guys,

Well... all the talk of the Pole Position seats, this weekends Santa Pod trip has got me thinking.

I would really love to break into the 11 second barrier with my car and I think with pure driving skill (Which I dont have much of) this can be done, but it could be helped with a little weight loss and a few other bits and bobs.

First things first... the seats which have been mentioned... 30kg for the Recaros and about 7-9kg for the Pole Possition Seats. That is one hell of a saving + the Pole Possition seats look gorgeous! Anyone out there who owns a set PLEASE take me for a long drive?

Secondly - a light weight flywheel. This is something my car is crying out for now. I have the standard dual mass flywheel at the moment and this cant be helping matters for me. What flywheel are you guys using out there & what are the weight savings on these?

Nex thing is brakes... I have the brembo 8-pots & 365mm RS6+ disks - all of this must weigh an absolutel tonne... surely a set of 4-pots & 330mm disks would be more than ample to stop the car with a rear brake upgrade too? This again would reduce weight.

I am happy with my 19" BS CH's - weighing about 20kg WITH tyre, they are a very light wheel & suit the car quite well.

I will be having my car's audio install re-done professionally... I may ditch my big sub box and go for something light weight that gives me more boot space. I may consider removing all the dynamat too - all I want is boom boom with fair clarity not perfection.

Then again - I have a ~12.4s / 190MPH car with 4 doors, big comfy seats fully loaded with every gadget & creature comfort in the world, why would I want to go faster? :roll:

RE: Mass Reduction & Acceleration Improvement:

Posted: Mon May 21, 2007 11:16 am
by DavidT
You just need a respray - silver is the colour I'd suggest ;) :assflash: :nodder:

Posted: Mon May 21, 2007 11:24 am
by ZeroK66
:evil: - you are an evil man! I will have you yet Mr T!

Posted: Mon May 21, 2007 11:40 am
by rikrose
I pity the fool... :D

Posted: Mon May 21, 2007 11:58 am
by clubsport
A lightweight flywheel will help the car spin up better, the downside is the increase in transmission noise as more vibrations are felt....you will save a few KG at most.

If weight saving is your goal, trim is the answer....you would need to remove, carpets, sound deadening, headlining, stereo...you could go further and remove electric window motors and either fit thinner glass or macrlon. Also remove superfluos systems like headlight wash (mot?), maybe a smaller battery & washer bottle....take out a/c???

One of my toys is a factory supplied Porsche where the only interior trim is a dashboard and door cards.......it is fine on track or short journeys,,,,,but earplugs are useful with no trim, ali bonnet, thin glass, cloth recaros, smaller battery & washer bottle it weighs about 120kg less than a fully loaded version.....makes a lot of difference, especially to the handling :)

Posted: Mon May 21, 2007 12:09 pm
by S4TAN
What about weight distribution as well as reduction ... ? Put the battery in the boot ... get a carbon fibre bonnet .... maybe?

Re: Mass Reduction & Acceleration Improvement:

Posted: Mon May 21, 2007 12:13 pm
by dodgydave
ZeroK66 wrote:
Then again - I have a ~12.4s / 190MPH car with 4 doors, big comfy seats fully loaded with every gadget & creature comfort in the world, why would I want to go faster? :roll:
Did you drive with your handbrake on ? :biggrin3:

Posted: Mon May 21, 2007 12:19 pm
by DavidT
Carbon bonnet - ?
Carbon front wings - ?
Carbon bootlid - ?
Air conditioning removal - 30kg

LWFW - 6kg saving + more 20-30 ft lbs more torque (difficult to measure from what I've read)

Recaro Pole position seats - 40kg for 2

Brakes - I guess 3kg min per side saving with a smaller brake kit.

Wheels - What do OZ Superleggera III's weigh ?

Posted: Mon May 21, 2007 12:34 pm
by Peakz
It's a well known fact that silver is a faster colour!

Keep it as it is, if you start with the weight saving scheme you'll end up with a car that is only fit for one purpose, right now it's both a smooth cruiser and a fast bruiser all-in-one.

Posted: Mon May 21, 2007 12:36 pm
by oliew
Doug knows how comfy the recaros are we did 3/4 hours in lucas's in germany and also fell asleep for a bit...
:)

Posted: Mon May 21, 2007 12:54 pm
by jeffw
The RS4 Brembo calipers weigh a ton compared with AP/HiSpec etc. I was shocked when I picked one up at MRC on how much it heavier than my HiSpec calipers it was.

Posted: Mon May 21, 2007 1:35 pm
by JonnyX
The savings from a LWFW are more to do with the reduction in rotational inertia than with it's absolute mass.

Posted: Mon May 21, 2007 1:58 pm
by Ads4
FYI : BMW discussion on launch techniques and weight reduction. Some of it may be useful? (I'm sure Woody'll appreciate it!).
http://forums.bimmerforums.com/forum/sh ... adid=47538

Posted: Mon May 21, 2007 2:17 pm
by clubsport
On Saturday I drove a '91 Audi Quattro 20V RR,,,,,it felt so light and chuckable, like being back in a mk2 Golf,,,then I got back in my standard S4 and it felt like an A8! There is a lot to be said for this weight reduction lark! ;)

Posted: Mon May 21, 2007 3:21 pm
by Paula
Is your MPH really 190mph?, If so you should have a quicker ET than 12.4. My hubby has done drag racing for a number of years, and his best time was an 11.3 @128mph. This was in a front wheel drive car though. there's a vid of him here. http://www.dragslag.com/videos/index.htm

With an MPH of 190 you theoretically should be doing 8's. What are your 60 ft times like?