How to improve? .. - Perth-WRX.com

Evidencee · #1 31-10-2007, 10:43 PM

Hey,

Took my car down the the motorplex tonight with the new clutch (worn in about 3,000kms) to see how ide go.
My car is a 03 wrx running the stock wrx 5 speed with a HD organic by ross at autoclutch and with 200kw(TD05-16G) atw tuned with verso.

I got the times of:

1st: 13.598
2nd: 13.495
3rd 13.020

I was launching at 5000-5500rpm.
Call me noob but the first thing i did when lining up was deflate my tyres to 20psi (normally at 32) as i was told by my mate that it helps with traction.
Should i have done this? I also did the runs with a sub in the back .. would it have any effect if i removed the doof doof?

What could you guys suggest to make me run into that 12 i want?
would removing the sub be significant? would having harder tyres be better?

Suggest me!

Cheers
-Nick

Adz · #2 31-10-2007, 10:48 PM

firstly - theres a big variation in your times

Deflating the tires help

And remove the subs.. less weight to push!

Id be more concerned about getting your times consistent.. at the moment it sounds like the car definitely has a 12 sec pass in it - but comes down to driver error - You not doing consistent run times means you're still not getting the potential out of the car on each and every run.

Load up the box before a launch - a simple pull of the handbrake - bring up some rpm - and find that friction point before a launch always helps - and somewhat lessons the brutality of a launch (not that much tho :P ).

Find optimum shift rpm for you car - this is only something ur gonna feel for

Try things out - sit back - look at the times - and work out what works best

12 will come.. the car has it in it.

Evidencee · #3 31-10-2007, 10:58 PM

i dont use the handbrake to launch, i just have the clutch fully in and rev around 5.5 then when i see the green light, i ride the clutch ever so slightly until i feel its properly engaged then give it full throttle.
Is this an alright launch method?
is 20psi tyres on an awd car too soft?
the sub is coming out next run!

I think also i was shifting at the wrong points, i have a habit of taking it into 6.5, nearly 7 then shift. My dyno graph shows my peak power at ~5,600 rpm ..

BOMB3R · #4 31-10-2007, 11:13 PM

Quote:

Originally Posted by Evidencee

i dont use the handbrake to launch, i just have the clutch fully in and rev around 5.5 then when i see the green light, i ride the clutch ever so slightly until i feel its properly engaged then give it full throttle.
Is this an alright launch method?
is 20psi tyres on an awd car too soft?
the sub is coming out next run!

I think also i was shifting at the wrong points, i have a habit of taking it into 6.5, nearly 7 then shift. My dyno graph shows my peak power at ~5,600 rpm ..

You seem to be on the right track mate! I ride the clutch because theres always torque steer and you want to have the tyres engaged with the road as well as the clutch engaged fully at the right point. I launch from 6-6.5 though. Clutch is a massive part of the 1/4 mile but as ADZ said driver skill is the most crucial part.

I always have the car go to 6.7-7k as well as even though your peak torque is down the less RPM's you use getting it back to peak torque the better. Some people would disagree with good reason but the more RPM's you gain the less you lose on the next change to a certain extent.

Darken · #5 01-11-2007, 08:24 AM

Practice, practrice, practice but be prepared to have to start fixing things!

Chrus · #6 01-11-2007, 09:03 AM

Quote:

Originally Posted by Evidencee

i dont use the handbrake to launch, i just have the clutch fully in and rev around 5.5 then when i see the green light, i ride the clutch ever so slightly until i feel its properly engaged then give it full throttle.
......

Dont wait for the green light to illuminate before burying your clutch (try to pre-empt if possible). Its hard but a good reaction time will count for a lot of the seconds lost.

BOMB3R · #7 01-11-2007, 09:05 AM

Quote:

Originally Posted by BugeyeSti

Dont wait for the green light to illuminate before burying your clutch (try to pre-empt if possible). Its hard but a good reaction time will count for a lot of the seconds lost.

Your reaction time does not affect your 1/4 time at all...... You could wait for 2 seconds after the green and still run a 12.

The clock dosen't start until you start moving.

Chrus · #8 01-11-2007, 09:06 AM

Quote:

Originally Posted by PIGSTi

Your reaction time does not affect your 1/4 time at all...... You could wait for 2 seconds after the green and still run a 12

Yeah true that (my bad).....but ideally you dont want to wait for green light ---right

BOMB3R · #9 01-11-2007, 09:44 AM

For a good reaction time as soon as you see the second orange GO, do not wait for the green.

mr_psi · #10 31-10-2007, 11:06 PM

as adz said... main thing is just dont be nervous on the line....

bring the clutch up slowly just to the point the car starts edging forward.... handbrake up.....ride the clutch out and dont dump it and the rest is normal driving just shifting a bit quicker....

i wouldnt really worry bout sub unless its greater then 50L box ...

With tyres its one of them things where to much is bad because you got greater tyre surface on the road meaning more friction which interms mean lesser speed at top end and pumped at 34psi means wheels spin... personnally on your car i would be looking at ~25psi which is just a guess.... just have a couple goes and diflate them little by little and get a feel for it....

also revs i aint really sure about but in my car (which had the same clutch) i liked the 4500rpm rev range for a launch

with 200kw atw you should be able to make 12.5 sec passes