Weight Reduction

Jap GT300 · July 9, 2003, 14:09

A topic that has been raised a few times.
In my girlfriends 2 it has been stripped to the extreme. No roof, No storage panels at all behind seats (because of the roll cage) No stereo, No carpeting at all, No heat shielding in the engine bay, no passenger air bag, no cowling up front, No spare wheel & No tool kit (well you wont need it with the amount that has been stripped). The car does have a hard top but this won't be used for racing.

I'm going to try and get it weighed soon and post the results! What have other people removed from their roadsters?

Adam

Anonymous · July 9, 2003, 14:27

A reduced-size battery is one option I've heard of; provided you're not doing short journeys on cold winter mornings, there's just enough juice to crank the starter and get you going.

Bear in mind that changing the front-rear balance is probably something to avoid too, so be careful where you strip weight from, not just how much. Sometimes, leaving things in is better.

As a prime example, I was suffering monster understeer on-track at Keevil until I put the spare back in the front.

Anonymous · July 9, 2003, 15:15

To shift some weight from the back a lighter exhaust system (Team Moon for example) and a lighter battery are good ideas.

I have a Hawker Odyssey PC680 battery which saves about 12lbs IIRC.

Lightweight seats are a good weight saver too, if a bit expensive.

If you wanted to spend some real money you could even consider fibreglass or even carbon fibre panels!!

--H--

Anonymous · July 9, 2003, 16:22

Quote from: "Hardcore"Lightweight seats are a good weight saver too, if a bit expensive.

Not really, because they never really lose anything. The seats might weigh less but the runners etc that had to be added add the weight back up.

Also unless you have a good front strut brace and set up suspension I wouldn't remove the spare wheel, pmdye is right your just giving yourself huge amounts of understeer.

From the engine you can change - exhaust (the stock is SO heavy), battery, header and cat. A lightweight flywheel makes your car rev like a mofo.

Anonymous · July 9, 2003, 16:32

Quote from: "WoodenDummy"Also unless you have a good front strut brace and set up suspension I wouldn't remove the spare wheel, pmdye is right your just giving yourself huge amounts of understeer.

From my experience I would say "huge amounts of understeer" is a great exaggeration. I've never been on a track but I can appreciate that under extreme conditions you would experience understeer from a lack of weight up front, but on the road it is not noticable at all 99% of the time.

--H--

Anonymous · July 9, 2003, 16:59

The battery can be replaced by a Genesis G13EP which only weighs 11lbs verus stock at around 27 lbs.

See w www.spydermagazine.com/2002/Dec/genesis/genesis.htm w

UK supplier is Aesir Power in Cambridge. 01799 531152
They charge £78.33 plus VAT which comes to £92 ish and call the UK version of the battery a Red top 20. It is used a lot by aircraft apparantly. If it can fly a plane then its probably good enough to start a '2. s:lol: :lol: s:lol:

I'm picking mine up this week, as they sold 3 of them last week and had to re-order.

See disclaimer re. its not a deepcycle battery so may be issues if you leave your lights on a lot or live in Scotland or somewhere equally cold s:!: :!: s:!:

Another thought is that it is a lot smaller than stock and may give you more room or positioning options for an air intake etc.

Anonymous · July 9, 2003, 17:11

I researched and decided to go with the Hawker Oddyssey PC680 battery. It's 16Ah rather than 13Ah and is deep cycle so more suitable for a car. The Oddyssey also comes with a manufacturers warranty for automotive use which the Genesis doesn't.

The Oddyssey is a couple of lbs heiver than the Genesis (about 13.5 lbs), but worth it for the reliability IMHO.

I got mine from Knight Batteries (http://www.knightbatteries.com/). The price on their Web site for this battery is £86.58 (plus VAT I think). Knight Batteries will also sell you the battery terminal posts but I found that they were slightly too thick for the stock brackets to attach so I had to do a bodge job on the terminals to fit it.

HTH

--H--

Anonymous · July 9, 2003, 17:24

Quote from: "Hardcore"From my experience I would say "huge amounts of understeer" is a great exaggeration. I've never been on a track but I can appreciate that under extreme conditions you would experience understeer from a lack of weight up front, but on the road it is not noticable at all 99% of the time.

Trust me; on track, it was "huge" s:shock: :shock: s:shock: I don't carry the spare on-road (for space gains, not weight), and as you say, it makes little/no difference to handling. But on track (admittedly wet/damp, on near-slicks s:)

s:) ), I was all over the place without it...

Anonymous · July 9, 2003, 18:56

Quote from: "pmdye"
Quote from: "Hardcore"From my experience I would say "huge amounts of understeer" is a great exaggeration. I've never been on a track but I can appreciate that under extreme conditions you would experience understeer from a lack of weight up front, but on the road it is not noticable at all 99% of the time.

Trust me; on track, it was "huge" s:shock: :shock: s:shock: I don't carry the spare on-road (for space gains, not weight), and as you say, it makes little/no difference to handling. But on track (admittedly wet/damp, on near-slicks s:) s:) ), I was all over the place without it...

Yip the oversteer can be huge without the wheel in place, BUT it can be sorted with a suspension set up and front bar (TRD works great) and maybe playing with the psi in the front wheels.

Anonymous · July 9, 2003, 19:16

I did play with the front tyre pressures a bit when I took my spare out now you come to mention it.

--H--

Anonymous · July 9, 2003, 19:19

Dorky question but, lowering psi? s:lol: :lol: s:lol:

Anonymous · July 9, 2003, 19:25

Quote from: "ScouserDave"Dorky question but, lowering psi? s:lol: :lol: s:lol:

Yep, a little.

--H--

Jap GT300 · July 9, 2003, 22:17

Right Battery is a certanty. I know some performance products have been mentioned but i'm trying to do weight loss only.

I'm ordering a carbon bonnet from Rob at no limits. and a ppe downpipe is already on the way. I may change the exhaust (lightest possible not most bhp) possibly a single Team Moon or a custom job straight off the down pipe and out the car (no muffler). This all depends on wether the back pressure will cause a negative effect.

As for bracing it already has TRD Front and Rear although I will order an anti flexplate.

If i remove the same amount of weight from the front and rear then under steer should be unaffected dont you think?

Adam

mph · July 9, 2003, 23:44

Quote from: "Jap GT300"This all depends on wether the back pressure will cause a negative effect.

*sigh* I'd thought you'd know better. All 'back pressure' is bad, end of story. Pulse resonance frequency is another matter though. Unless you get rid of the CATs that becomes fairly irrelevant too. Presuming you do remove them (as they are both heavy and restrictive) then you're into the realms of manifold tuning. Btw, you *will* want a silencer in there, trust me!

Quote from: "Jap GT300"If i remove the same amount of weight from the front and rear then under steer should be unaffected dont you think?

You'd think it works like that, but it isn't as simple as that. Height and relative position over the wheel base is just as important.

As a side note, Sportivo, FSB, bracing and heavy 205/40R17 fronts == too *little* understeer.

Anonymous · July 10, 2003, 00:11

Quote from: "ScouserDave"Dorky question but, lowering psi? s:lol: :lol: s:lol:

Yeah, less psi puts more rubber down. Only drop it a little bit... s:? :? s:?

Anonymous · July 10, 2003, 00:17

Quote from: "mph"Btw, you *will* want a silencer in there, trust me!

You think? I've got rid of the silencer on my Tannabe Racing Medallion (so it now weighs next to nothing) and its not that bad at all, but then I can fit a plug which brings the sound down a little. You can hear it at JAE.

OH please don't fit a carbon hood, unless you spend A LOT of cash your not getting the real REAL thing and you can also very easy end up killing yourself in a front smash. Its also kinda removing weight from the wrong part of the car IMO.

Anonymous · July 10, 2003, 00:20

OH the silencer is NOT the silver max power can sticking out, it would have been hidden behind the bumper but I just have a pipe.

For anyone that was wondering.

mph · July 10, 2003, 08:02

Quote from: "WoodenDummy"
Quote from: "mph"Btw, you *will* want a silencer in there, trust me!

You think? I've got rid of the silencer on my Tannabe Racing Medallion (so it now weighs next to nothing) and its not that bad at all, but then I can fit a plug which brings the sound down a little. You can hear it at JAE.

Do you still have the CAT or pre-CATs in place? If so, they'll deaden the sound no end.

Anonymous · July 10, 2003, 09:44

Quote from: "mph"
Quote from: "WoodenDummy"
Quote from: "mph"Btw, you *will* want a silencer in there, trust me!

You think? I've got rid of the silencer on my Tannabe Racing Medallion (so it now weighs next to nothing) and its not that bad at all, but then I can fit a plug which brings the sound down a little. You can hear it at JAE.
Do you still have the CAT or pre-CATs in place? If so, they'll deaden the sound no end.

Indeed I do, and thats a very good point that I hadn't thought about... humm I was thinking about the PPE Header and performance CAT maybe this isn't a good idea...

Maybe I should just re-fit a silencer or change to a Team Moon.... humm my quest for weight savings and power goes on.

mph · July 10, 2003, 15:36

Quote from: "WoodenDummy"Maybe I should just re-fit a silencer or change to a Team Moon.... humm my quest for weight savings and power goes on.

I 'd agree - ditch the whole exhaust system for a custom job. Consider that on *my* setup, removing the primary CAT & stock silencer for a custom job released in excess of 30bhp.

Jap GT300 · July 10, 2003, 21:45

This car would be used almost certainly just for track use. So i'm not to worried about the crumple zone re: Carbon Bonnet.

I am going to rip the passenger seat out and the plastic over the gear box tunnel.

Sorry about the back pressure question

Anonymous · July 11, 2003, 02:38

Quote from: "mph"
Quote from: "WoodenDummy"Maybe I should just re-fit a silencer or change to a Team Moon.... humm my quest for weight savings and power goes on.
I 'd agree - ditch the whole exhaust system for a custom job. Consider that on *my* setup, removing the primary CAT & stock silencer for a custom job released in excess of 30bhp.

Yeah but your turbo, right?

The Tannabe how it is now with no silencer weighs next to nothing, I could get a PPE Header and keep the cats.

OR re-fit a silencer which will add weight and change to the PPE performance single cat and header which would then drop the weight with the cat change...

...I think i'd get about the same results either way s:? :? s:?

Am I making sense? s:roll: :roll: s:roll:

Tem · July 22, 2003, 14:21

Quote from: "Jap GT300"I'm going to try and get it weighed soon and post the results! What have other people removed from their roadsters?

Did you get it weighted yet? You may get some ideas and info from this table:
m http://www.spyderchat.com/technical.htm#weight m

Mine's at 929kg (without driver, with 1/4 tank of gas and a full windshield wiper tank...and a stereo system)...or 2050lbs in your scale.