1/4 mile launching
15 August 2006, 06:06 PM
#1
Scooby Regular
Thread Starter
1/4 mile launching
i've got a uk classic decated and remapped runing 260bhp and 280ftlb of torque. its still got standard clutch but i have got kyb adjustable shocks amongst other suspension mods.
first question,
whats the best way to launch it off the line, while i want a resonable time i'm looking for it being fairly gentle (although i realise nothing gonna be gentle on it) on the clutch so i don't kill it.
second
is it worth adjusting the suspension stiffness for it? i currently run it on setting 4 at back 2 at front.
first question,
whats the best way to launch it off the line, while i want a resonable time i'm looking for it being fairly gentle (although i realise nothing gonna be gentle on it) on the clutch so i don't kill it.
second
is it worth adjusting the suspension stiffness for it? i currently run it on setting 4 at back 2 at front.
15 August 2006, 08:44 PM
#2
Tidgy,
I was launching by reving to 5.5k and then as quick as possible feeding the clutch in, which ultimately gave me a 60ft of 1.6s at TOTB V. I havent done drag or standing starts for some years and will be trying to perfect the launch further if possible.
Using this method I never smoked the clutch once in 4 of my 5 runs, but the timing is so crucial between coordination of both your feet. The 1st run I did smoke the clutch when side stepping the clutch though.
Of course to get a good time as possible you need to make gear changes as quick as possible and also pick the right revs to change.
As regards to the suspension, i would tend to go softer rather than harder. Also the same with tyre pressures. Exactly what to go for I have no idea, but I will certainly try several combinations later in the year.
IMHO you have to be fairly brutal, but key is speed of action and smoothness.
Practice makes perfect..... or sit should do!
Good luck!
Regards,
Shaun.
I was launching by reving to 5.5k and then as quick as possible feeding the clutch in, which ultimately gave me a 60ft of 1.6s at TOTB V. I havent done drag or standing starts for some years and will be trying to perfect the launch further if possible.
Using this method I never smoked the clutch once in 4 of my 5 runs, but the timing is so crucial between coordination of both your feet. The 1st run I did smoke the clutch when side stepping the clutch though.
Of course to get a good time as possible you need to make gear changes as quick as possible and also pick the right revs to change.
As regards to the suspension, i would tend to go softer rather than harder. Also the same with tyre pressures. Exactly what to go for I have no idea, but I will certainly try several combinations later in the year.
IMHO you have to be fairly brutal, but key is speed of action and smoothness.
Practice makes perfect..... or sit should do!
Good luck!
Regards,
Shaun.
16 August 2006, 09:29 PM
#4
Scooby Regular
Join Date: May 2004
Location: Ascended to the next level
Posts: 7,498
Likes: 0
Received 0 Likes
on
0 Posts
Yup feed in the clutch 'til the boost is starting to kick in, too quick it'll bog down, too slow and it'll smoke and smell. You need to get a feel for it, generally you need to give it roughly a second of slip to get the turbo spinning.
Revs? depends on your turbo (td04 or td05 etc) and state of tune 4.5K is a minimum. I find the turbo spools better if you do rapid full throttle blips as opposed to holding steady high revs with a nearly closed throttle. Although I noted many people don't do this, so maybe its just works for me LOL
Gearchages, again depends on the turbo, state of tune and gearing (5speed/6speed). The td04 will drop off before the redline, so I find there is little point in taking past 6.5K in 1st or 2nd but I usually hold it in 3rd. Don't worry about short shifting in 1st gear, it doesn't make too much difference IMO but it certainly is better than redlining it and hitting the limiter, as things happen pretty quick once the cluth had bit.
Revs? depends on your turbo (td04 or td05 etc) and state of tune 4.5K is a minimum. I find the turbo spools better if you do rapid full throttle blips as opposed to holding steady high revs with a nearly closed throttle. Although I noted many people don't do this, so maybe its just works for me LOL
Gearchages, again depends on the turbo, state of tune and gearing (5speed/6speed). The td04 will drop off before the redline, so I find there is little point in taking past 6.5K in 1st or 2nd but I usually hold it in 3rd. Don't worry about short shifting in 1st gear, it doesn't make too much difference IMO but it certainly is better than redlining it and hitting the limiter, as things happen pretty quick once the cluth had bit.
17 August 2006, 01:12 AM
#5
Best time i got was with revs at 5.5-6k clutch slightly slipping pulling against handbrake, when the lights go, dump hand brake, dump clutch and nail accelerator.
Think there are so many variations tho, sum never use hand brake sum (ignore who you're racing against) blip throttle and then let go of clutch, sum, do fullbore clutch dumps etc
I've had diferences of 1.7 secs in 1/4 mile time but only 6 mph in terminal speeds, as they say its all in the launch
Think there are so many variations tho, sum never use hand brake sum (ignore who you're racing against) blip throttle and then let go of clutch, sum, do fullbore clutch dumps etc
I've had diferences of 1.7 secs in 1/4 mile time but only 6 mph in terminal speeds, as they say its all in the launch
17 August 2006, 11:19 AM
#6
Moderator
iTrader: (4)
Join Date: Jul 2004
Location: The Terry Crews of moderation. P P P P P P POWER!!
Posts: 18,687
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Shark Man
Don't worry about short shifting in 1st gear, it doesn't make too much difference IMO but it certainly is better than redlining it and hitting the limiter, as things happen pretty quick once the cluth had bit.
Ns04
17 August 2006, 01:24 PM
#7
Scooby Regular
Join Date: Jul 2006
Location: Ibiza
Posts: 597
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Shark Man
Revs? depends on your turbo (td04 or td05 etc) and state of tune 4.5K is a minimum. I find the turbo spools better if you do rapid full throttle blips as opposed to holding steady high revs with a nearly closed throttle. Although I noted many people don't do this, so maybe its just works for me LOL
Trending Topics
17 August 2006, 03:11 PM
#9
Scooby Regular
Thread Starter
forgot to mention its a my00 uk classic so its got a td04
cheers for the replies guys i shall have to give it a go, not able to at the min cos i've got tonsilitus
so stuck in the house
cheers for the replies guys i shall have to give it a go, not able to at the min cos i've got tonsilitus
so stuck in the house
18 August 2006, 08:54 AM
#11
Scooby Regular
iTrader: (1)
Join Date: Jan 1999
Location: UK
Posts: 15,271
Likes: 0
Received 0 Likes
on
0 Posts
I am interested in the number "clutch slip" techniques here - feeding it in until the boost comes up.
Personally I think that will do far more damage to your clutch in terms of wear, heat and possibly glazing it (which I managed to do on my Sti V!).
I suggest the Shaun technique. Maybe not side step but certainly lift sharply as you foot pushed the accelerator to the floor. You need to start with between 5,500 and 6,000 rpm. This way you are more likely to break tyre traction which is far better for your car.
Nail it with 1st banging the rev limiter for two second then into second. Too early it will bog, too late and you are losing time.
With this approach I consistently got 1.6-1.7s 60ft times, irrespective of spec , tyre and suspension set up; from standard right up to huge power and massive turbo.
Rannoch
Personally I think that will do far more damage to your clutch in terms of wear, heat and possibly glazing it (which I managed to do on my Sti V!).
I suggest the Shaun technique. Maybe not side step but certainly lift sharply as you foot pushed the accelerator to the floor. You need to start with between 5,500 and 6,000 rpm. This way you are more likely to break tyre traction which is far better for your car.
Nail it with 1st banging the rev limiter for two second then into second. Too early it will bog, too late and you are losing time.
With this approach I consistently got 1.6-1.7s 60ft times, irrespective of spec , tyre and suspension set up; from standard right up to huge power and massive turbo.
Rannoch
18 August 2006, 10:42 AM
#12
Scooby Regular
Join Date: May 2004
Location: Ascended to the next level
Posts: 7,498
Likes: 0
Received 0 Likes
on
0 Posts
My clutch is over 10years old now...care to say anthing about that?
Before any launching or abuse it judders, like they all do as stock, and has done so from new, as per all Imprezas of that era, regardless of how its driven (dealer comment - "they all do that sir"). Launch it a few times and it works perfect for months after. So your glazing theory is infact reversed.
More likely to kill the clucth by holding it on a hill at red traffic lights instead of using the handbrake - which many car drivers do through pure lazy ignorance and lack of mechanical sympathy. Which explain why IMprezas that have never seen a "hard" launch have only managed 40-50K before frying the clucth.
Hitting the rev limiter in 1st will give you a slower time. Better to short shift.
Before any launching or abuse it judders, like they all do as stock, and has done so from new, as per all Imprezas of that era, regardless of how its driven (dealer comment - "they all do that sir"). Launch it a few times and it works perfect for months after. So your glazing theory is infact reversed.
More likely to kill the clucth by holding it on a hill at red traffic lights instead of using the handbrake - which many car drivers do through pure lazy ignorance and lack of mechanical sympathy. Which explain why IMprezas that have never seen a "hard" launch have only managed 40-50K before frying the clucth.
Hitting the rev limiter in 1st will give you a slower time. Better to short shift.
Last edited by Shark Man; 18 August 2006 at 10:50 AM.
18 August 2006, 10:42 AM
#13
Scooby Regular
iTrader: (15)
Join Date: Jul 2001
Location: Portsmouth
Posts: 8,606
Likes: 0
Received 0 Likes
on
0 Posts
Nail it with 1st banging the rev limiter for two second then into second. Too early it will bog, too late and you are losing time
Bob Rawle I believe is in 2nd by the time he passes the tree
18 August 2006, 11:15 PM
#15
Subaru Tuning Specialist
Join Date: Jun 2002
Location: 7.74 @179 mph 1/4 mile - road legal
Posts: 6,654
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by Rannoch
With this approach I consistently got 1.6-1.7s 60ft times, irrespective of spec , tyre and suspension set up; from standard right up to huge power and massive turbo.
Rannoch
Rannoch
18 August 2006, 11:34 PM
#16
Originally Posted by Rannoch
I am interested in the number "clutch slip" techniques here - feeding it in until the boost comes up.
Personally I think that will do far more damage to your clutch in terms of wear, heat and possibly glazing it (which I managed to do on my Sti V!).
I suggest the Shaun technique. Maybe not side step but certainly lift sharply as you foot pushed the accelerator to the floor. You need to start with between 5,500 and 6,000 rpm. This way you are more likely to break tyre traction which is far better for your car.
Nail it with 1st banging the rev limiter for two second then into second. Too early it will bog, too late and you are losing time.
With this approach I consistently got 1.6-1.7s 60ft times, irrespective of spec , tyre and suspension set up; from standard right up to huge power and massive turbo.
Rannoch
Personally I think that will do far more damage to your clutch in terms of wear, heat and possibly glazing it (which I managed to do on my Sti V!).
I suggest the Shaun technique. Maybe not side step but certainly lift sharply as you foot pushed the accelerator to the floor. You need to start with between 5,500 and 6,000 rpm. This way you are more likely to break tyre traction which is far better for your car.
Nail it with 1st banging the rev limiter for two second then into second. Too early it will bog, too late and you are losing time.
With this approach I consistently got 1.6-1.7s 60ft times, irrespective of spec , tyre and suspension set up; from standard right up to huge power and massive turbo.
Rannoch
19 August 2006, 04:30 PM
#17
Scooby Regular
Join Date: Apr 2006
Location: Still loving the Subaru but now in an Evo 8 MR FQ320
Posts: 569
Likes: 0
Received 0 Likes
on
0 Posts
5 - 6000 rpm . Dump the clutch . Straight on with the power . You get a big clunk from the back end as the 4wd engages . Front end lifts and you take off like a rocket. Into second gear almost instantly lol. Good technique but be prepared to brake stuff.
James
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
James
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
19 August 2006, 04:53 PM
#18
Scooby Regular
Thread Starter
Originally Posted by jamesbWRXRA
Front end lifts
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
out the window is prob about right lol
09 September 2006, 05:30 PM
#19
Scooby Regular
Join Date: Dec 2002
Location: devon
Posts: 2,944
Likes: 0
Received 0 Likes
on
0 Posts
thread hijack
what tyre pressure do folks recomend ?
i have done a 12.666 @ 109.28 but do 'bog' down alot on the launch
thinking if i add pressure to say 34 all round it may help, or is it a case of adding till i get slight wheel spin to avoid bogging ?
any thoughts ?
what tyre pressure do folks recomend ?
i have done a 12.666 @ 109.28 but do 'bog' down alot on the launch
thinking if i add pressure to say 34 all round it may help, or is it a case of adding till i get slight wheel spin to avoid bogging ?
any thoughts ?
09 September 2006, 07:15 PM
#20
Scooby Regular
Thread Starter
Originally Posted by scoobyDAZZA
thread hijack
what tyre pressure do folks recomend ?
i have done a 12.666 @ 109.28 but do 'bog' down alot on the launch
thinking if i add pressure to say 34 all round it may help, or is it a case of adding till i get slight wheel spin to avoid bogging ?
any thoughts ?
what tyre pressure do folks recomend ?
i have done a 12.666 @ 109.28 but do 'bog' down alot on the launch
thinking if i add pressure to say 34 all round it may help, or is it a case of adding till i get slight wheel spin to avoid bogging ?
any thoughts ?
10 September 2006, 01:20 AM
#21
Scooby Regular
Join Date: Dec 2002
Location: devon
Posts: 2,944
Likes: 0
Received 0 Likes
on
0 Posts
cheers bud
i do a few track days and always drop the pressures to 24-26
but can't help thinking it would aid the quarter mile by slightly inflating them to 34-36
i do a few track days and always drop the pressures to 24-26
but can't help thinking it would aid the quarter mile by slightly inflating them to 34-36
10 September 2006, 11:02 AM
#22
Scooby Regular
iTrader: (3)
Join Date: Aug 2000
Location: 1600cc's of twin scroll fun :)
Posts: 25,565
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by jamesbWRXRA
5 - 6000 rpm . Dump the clutch . Straight on with the power . You get a big clunk from the back end as the 4wd engages . Front end lifts and you take off like a rocket. Into second gear almost instantly lol. Good technique but be prepared to brake stuff.
James
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
James
Everyone itends to be a bit a gentle on the clutch but as soon as you get to the line the adrenaline kicks in and all sympathy for the clutch goes out the window.
than bringing the clutch up.Being the most unsympathetic you can to your car will lead to big bills and it isnt necessarily the best way to get the best performance out of her.
Tony
10 September 2006, 04:21 PM
#23
Scooby Regular
Join Date: Apr 2006
Location: Still loving the Subaru but now in an Evo 8 MR FQ320
Posts: 569
Likes: 0
Received 0 Likes
on
0 Posts
Each to their own Tony , But it seems to work in my experience. Next time i'm at the pod hopefully it will be a bit quieter and my car won't overheat so i can try a few more techniques
James
James
10 September 2006, 05:03 PM
#24
Scooby Regular
Join Date: Dec 2002
Location: devon
Posts: 2,944
Likes: 0
Received 0 Likes
on
0 Posts
does seem more trial and error , , i tried side stepping but then just bogged down, even at 6500 rpm . . tried more revs and still bogged.
so now i'm letting out and no bogging but am getting burn . . maybe i should let it out somewhere in between the 2 . . .
gonna have plenty of practice in october, got 3 weekends at long marston airfield
so now i'm letting out and no bogging but am getting burn . . maybe i should let it out somewhere in between the 2 . . .
gonna have plenty of practice in october, got 3 weekends at long marston airfield
11 September 2006, 08:18 PM
#25
You should not bog down daz,on the grid i pull 5600rpm dump the clutch and nail it.wheelspin for a split second then rockets of into the sunset.
now where is that video.
now where is that video.
15 September 2006, 08:17 AM
#28
Scooby Regular
iTrader: (8)
Join Date: Jul 2005
Location: Now with added 2.1 jun/cosworth power
Posts: 998
Likes: 0
Received 0 Likes
on
0 Posts
When i launch i like to deep stage so the car has got a little bit of momentum before i side step the clutch, i wait for my opponent to stage up first i then creep forwad lighting my firt set of oranges, i then hold the car at around 6000rpm an when the second set of oranges light, brace myself lol an on green side step the clutch second comes up all most instanlty so i full throtle change, by doing this iv acheived a 0-60 time of 3.33 secs my pb, and an overall 1/4 time of 12.8 at the pod.
15 September 2006, 05:02 PM
#29
Scooby Regular
Join Date: Dec 2002
Location: devon
Posts: 2,944
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by PAS
Dazz.
unless there is 2 scoobydazzas then you have been in my car on track at combe,in its standard state.
you know what is in the car now
poxy lol
unless there is 2 scoobydazzas then you have been in my car on track at combe,in its standard state.
you know what is in the car now
poxy lol
ello geezer . . . , , had me eyes shut as well as for what is in the car now !!!!!!
load of foam and burning smell innit
15 September 2006, 05:53 PM
#30
Well after a well known tunning company buggered it up it was lol.
Donated engine was not up to the job either,but i am gona sort a engine built for me from ZEN over the winter.
just need to sort a spec.
This paddle clutch is a bugger to use at slow speed but with the PPG box it launches well.
Donated engine was not up to the job either,but i am gona sort a engine built for me from ZEN over the winter.
just need to sort a spec.
This paddle clutch is a bugger to use at slow speed but with the PPG box it launches well.