GTT Drag Time

[cat007]

You're right about the 2nd part. But not so much the first.

Haha, well I guess you're the one who's studied this stuff right?

I've not studied squat. But I've spoken to various people who've got more experience than you or I combined

[Malcolm]

and therefore decree yourself to be right? The only reason you put less shock on your drivetrain from riding the clutch on the handbrake is because your clutch gets hot and rooted, and can't grip as aggressively anymore.

[anthonym]

I found a picture of the fastest GTT in NZ, possibly the world, after it achieved its terminal velocity.


The figure in the background is a member of Project Jonah rushing to the scene .

[cat007]

and therefore decree yourself to be right? The only reason you put less shock on your drivetrain from riding the clutch on the handbrake is because your clutch gets hot and rooted, and can't grip as aggressively anymore.

Think of it this way - Put your hand on the floor, get someone gentle stand your hand eventually having their whole weight on you.

Then get them to do the same thing but starting with their foot 12 inches above your hand slamming down onto it.

Tell me which one hurts the most

[99gtt]

You are either going to run a flat 14 if you totally rape it or like a 14.3 if you take it easy, for the sake of .3 seconds is your drivelines death worth it?

unless you launch your car you will be doing high 15 low 16 sec passes if you load up on the hand break you wont make it home your clutch will burn

[Mr Revhead]

and therefore decree yourself to be right? The only reason you put less shock on your drivetrain from riding the clutch on the handbrake is because your clutch gets hot and rooted, and can't grip as aggressively anymore.

Think of it this way - Put your hand on the floor, get someone gentle stand your hand eventually having their whole weight on you.

Then get them to do the same thing but starting with their foot 12 inches above your hand slamming down onto it.

Tell me which one hurts the most

Are you sure you are not getting confused with cars with proper drag autos and trans brakes?

[iOnic]

http://www.youtube.com/watch?v=o0pi7xSKM6g

Loading it up against the brakes reduces the instant shock of all the torque suddenly being applied to the entire drivetrain when you've got big sticky slicks and the car leaves the line a lot cleaner. You need a big angry clutch to hold back the power. All the quick AWD drag cars do it

Worth doing on a big power AWD drag car. All you're going to achieve doing it on your factory Caldina is a blown clutch and not going anywhere in a rush.

[sergei]

I found a picture of the fastest GTT in NZ, possibly the world, after it achieved its terminal velocity.


The figure in the background is a member of Project Jonah rushing to the scene .

did it fell off the cliff? Doesn't look much damaged?

[Malcolm]

Think of it this way - Put your hand on the floor, get someone gentle stand your hand eventually having their whole weight on you.

Then get them to do the same thing but starting with their foot 12 inches above your hand slamming down onto it.

Tell me which one hurts the most

Hi, thanks for being patronising, I do actually understand the concept of impact loading - hell I can even start throwing some numbers at it because part of the mechanical engineering degree I did involved learning about the theory behind this magical idea of yours.

Unfortunately, the taking it to the extreme like your example is completely irrelevant to the situation. Applying a force instantly, rather than gradually, multiplies the stress seen in components by a factor of 2. Any further increase, as in your jumping on someone's hand example, is achieved due to any momentum in the object that's applying the force. Now, because in either case of preloading or not preloading your drivetrain, the only difference is the momentum of the components between the clutch and the wheels - you have to have a massive amount of backlash in your drivetrain to make any real difference (and just so we don't go there, you don't have much backlash in your drivetrain).

It could in fact be worse, because components that are designed to have some level of elasticity - i.e. the sprung hub in the factory clutch, will be preloaded and therefore will not be able to absorb as much shock as it would in a free state.

[Skin]

I used to do a few of the night speeds in my old st205, would just sit it at 6K then drop the cltuch!!! never encountered any problems.


the gearbox dying was completely unrelated too

If your going to drag it properly, do it properly. If your worried about screwing the clutch, replace it first. No point in doing it half arsed, then your mates will just give you shit about your 17 sec turbo 4wd toyota....

[cat007]

If your going to drag it properly, do it properly. If your worried about screwing the clutch, replace it first. No point in doing it half arsed, then your mates will just give you shit about your 17 sec turbo 4wd toyota....

Fu(k that. Just get out there and have fun man! It's a total blast!

[Skin]

If your going to drag it properly, do it properly. If your worried about screwing the clutch, replace it first. No point in doing it half arsed, then your mates will just give you shit about your 17 sec turbo 4wd toyota....

Fu(k that. Just get out there and have fun man! It's a total blast!

I think you may have missed my point a bit. What I mean is if you are going to run it down the drags, no point in nana'ing it off the line. Balls to the wall, or not at all!!!!

[Mr.Phreak]

Balls to the wall, or not at all!!!!

Pretty much, if you're not prepared to have your car trailered home, don't run.

[cat007]

Balls to the wall, or not at all!!!!

Pretty much, if you're not prepared to have your car trailered home, don't run.

OR - go down, don't thrash the crap out of your car, have a good time, drive home

[BZG Wagon]

As mentioned I'm going down to race a couple friends for a bit of fun - not to set any records or trailer my car home.

Other than the skyline the STi & my GTT won't be launched, and it's highly unlikely I'd beat the STi anyway. I'm just trying to figure how to do a relatively quick start without wrecking my car.

Re the handbrake loading; my thoughts were along the lines of putting the car under a little tiny of load (just where you can feel the clutch starting to engage) so when the lights go green and the handbrake goes down, the car has already started rolling.

Talking to someone with an ST205 GT4 running 17psi - a 5k launch gave a time of 14.2, a hard clutch-slipping launch gave a 14.6. Not a massive difference in the scheme of things.

The skyline driver also lost 3rd gear last time he was at the drags and posted 15.5sec - again I'd expect I'd do better than 17-18 seconds someone quoted. My standard BZ corolla did 16.0sec (prev. owner) and I'm sure even without a launch my GTT would beat that over 400m.

[sergei]

Talking to someone with an ST205 GT4 running 17psi - a 5k launch gave a time of 14.2, a hard clutch-slipping launch gave a 14.6. Not a massive difference in the scheme of things.

For one I would not take my ST205 to drags.
I took my ST165 to drags though. I gave it 5000rpm launch, the tyres were shit, my changes were shit but I managed to do ~13.5 on 1bar/CT20b/stock motor.
Launches are the most fun you can have at drags. If you take out launches what is the point going to drags? There always be someone who is faster/consistent than you.

Drags are pointless American invention, because Americans could not make cars that handled.. Take your car out on real track.

[cat007]

Drags are pointless American invention, because Americans could not make cars that handled.. Take your car out on real track.

Clearly you've never seen the brakes on a stock ST215 then lol

They're like milk bottle tops, with semi-soft butter for pads...

[sergei]

Drags are pointless American invention, because Americans could not make cars that handled.. Take your car out on real track.

Clearly you've never seen the brakes on a stock ST215 then lol

They're like milk bottle tops, with semi-soft butter for pads...

Yeah, I run 278mm rotors (I assume same as caldina) on my ST165 and they are marginal on the car that weighs ~30% less....
Although on Hampton Downs I never had problems with brakes on my ST205...

[cat007]

Drags are pointless American invention, because Americans could not make cars that handled.. Take your car out on real track.

Clearly you've never seen the brakes on a stock ST215 then lol

They're like milk bottle tops, with semi-soft butter for pads...

Yeah, I run 278mm rotors (I assume same as caldina) on my ST165 and they are marginal on the car that weighs ~30% less....
Although on Hampton Downs I never had problems with brakes on my ST205...

They aren't completely crap, but it takes VERY little for them to fade to black...

[sergei]

what pads do you run?