Do you think benefit would be had by removing the spare wheel, having a dribble of petrol not a full tank, and removing the rear seats, in terms of launching the car up a 1/4 mile strip?

 

The back of the rear seat weighs a lot, as does the spare wheel, and I guess petrol weighs near 1kg per litre. I reckon these would total over 60kg.

 

Now would the reduced weight over the rears benefit the car or would it reduce grip enough to make it not worth it over a 1/4 mile? :confused:

 

I guess something like letting a little pressure out of the rears might help improve grip ;)

 

Cheers

 

Pete

Removing weight nearer the front would obviously be best but I'm damned if I can be arsed removing the passenger seat lol :D

you could relocate the battery to the rear, that would help

get a midget to drive it weight loss and no work

get a midget to drive it weight loss and no work

:rofl::rofl: i was going to say get someone else to drive it :x: :x:

what suspension are you running? if its adjustable drop the rear a little to throw the weight balance back to normal. if not i would still presume that weight loss would benefit. even if you have less traction the tyres have less work to do. take out the pass seat. its worth it - they weigh a tonne. and the carpets. and the dash. and the doors. and the boot. should be at around 1100kg by then ;o)

petrol ia about .73kg/litre.

 

however it's something I've always wondered about, going to move the battery to the boot (so I can move my ABS to where the battery is to get my big turbo in)

 

Not sure what the F/R distrobution in on the Zed, but the S13 is 53/47 so needs weight at the back.

 

You struggle to get an S13 to 1100kg stripping it and removing all of the sound proofing etc, would be a miracle to get a Zed to 1100kg.

 

Take a big crap. :)

remove the anti roll bars, get a decent diff, and soften the suspension, and use a subframe spacer kit to induce more squat.

 

Oh, your old 16" wheels with drag tyres at low pressure. :)

Just get TC :rolleyes:

Just get TC :rolleyes:

 

Why? It ruins a good car infact IMHO It is a complete load of crap and I hate it :o

LOL Cheers boys, all good, but I was kind of thinking of stuff I can remove on a Saturday afternoon then replace on the Sunday evening ;) I've removed the rear seats, spare wheel and boot crap, the passenger seat will have to stay in cos I'm taking a passenger :rolleyes:

 

Traction Control - people already rib auto owners saying theres no skill in drag racing. The launch is the only skill part lol ;)

 

I've got stock Nissan suspension, i had thought of drag radials once but never got round to finding anything out about them.

 

I will take a big crap ;)

 

Cheers

 

Pete

I read somewhere that to get optimum tyre pressure for dragging, you should do a series of burnouts. Inbetween each burnout you should drop the pressure in each tyre until you get the widest tread mark!

 

Pete

TC & LC doesn't help really unless you spend a LOT of time setting it up.

Although once set up it's probably pretty damn good, or at least repeatable.

Probably the same argument as ABS, you can outbrake it if you are shit hot, but probably not as consistantly.

 

Drag radials...

http://www.sxoc.com/vbb/showthread.php?t=86824&highlight=drag+tyres

Incidentally, what is the general concensus for the best way to launch a zed (without launch control of course!) - What revs give the best balance between traction and torque and do you just drop the clutch or slip it?

 

I have to admit that I'm not really a standing start expert - never really found the need.

drop the clutch, it's just a matter of getting the right revs to drop it from LOL.

Too much, spinny spinny, not enough, boggy boggy.

 

I reckon between 3000 and 3200 should do it. :)

This is for 1/4 mile and a std Zed.

 

Interesting - thanks,

 

I pressume that the reason the clutch dump method is slower at higher revs is simply down to traction loss at the very start?

yeah, you just wheelspin so takes longer to get off the line.

 

the only prob with dumping the clutch (apart from the mechanical stress) is that if you too few revs you'll feck it right up LOL.

Why? It ruins a good car infact IMHO It is a complete load of crap and I hate it :o

 

Opinions Vary Iain

you going to need it mac, cos when your car comes on boost at 5.5k rpm, you're going wish you'd go it. :)

 

It's great fun actually, and you can just turn it off.

And the noises it makes are just awesome, I shit everyone up at intepro last week when I went for a boost controller setup run. :D :D

For the quickest start, you should let clutch out as you let throttle in.. so as your left foot comes up your right foot is going down... thereby feeding torque to the rear wheels gradually. I say gradually, but you do all that pretty quickly! I seem to get better launches if I don't use WOT until everything's settled down a bit, ie just before time for 2nd gear...

 

I'm also assuming that launches that feel better to me are actually better, given that I have yet to do a proper timed run!

 

The problem is engine peak torque is 3500-4000 revs, so ideally you don't ever want the engine running below that speed, but the output shaft is doing zero revs when you start, by definition. So you've got to let something slip. If you dump the clutch you'll probably find tyre slips unto road rather than friction plate slips unto flywheel, but there's always the danger something else will slip catastrophically instead!

 

In a Z you KNOW that all the torque arriving suddenly at low speed will be too much, so you can choose to start the whole process a bit further down the dyno chart. You know you haven't got all the go you could have right off the line, but you also know it'd just spin the wheels if you did, so no great loss. Hence why doing this at 3000 revs seems to work better - it's easier to feed the clutch in slowly enough. If you go too low the turbos won't be spooled up by the time the tyres have enough grip to handle full bore, so you have grip you're not using.

 

None of this is good for the clutch (or the diff) of course, but that's the nature of standing starts!

 

In an R34 I'm told you can just dump the clutch as hard as you like and the multiple plates just take it all up smoothly for long enough to get to 4000 revs without destroying anything... (and of course less chance of wheelspin anyway)

 

In an auto, everything's slipping until you get to 4000 revs, like it or not!

 

How does the RaceLogic actually cut power when it needs to anyway?

 

It's a bloody site easier to get right in a Z than it is in a Leon TDI, anyway. :rofl: