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Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 11:33 am
by Enzio
Take out the bonnet spacers.
Proper air guides and ducting to your coolers will help a lot.

If you have your alignment settings - post them up, would be interesting to see. Have you tried increasing the length of the traction rods?

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 11:40 am
by Booster
well its as accurate as i can be with the string system in my garage. havnt yet been on a proper didgital wheel allignment machine.
Im running

Rear
1mm toe in on the rear and 0.5 deg negetive camber on rear.

Front is -4 deg neg camber
Caster 7 Deg
Toe - 1mm toe out

I have a feeling the the rear spring rate is maybe to stiff. But it could also be the cheap crappy tires im using. So im cautious as to not change too much now untill i can get consistancy with a good tyre.

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 11:49 am
by Enzio
I'm going to over-simplify here, but:

You are running very little rear camber (good for grip) but since your car is lowered a lot you will have a lot of camber gain and bump steer at the rear on compression due to the stock traction arm length.

My suggestion - increase the traction rod length by 5mm. Then redo the camber and toe as you had it before (1mm toe in, -0.5 deg camber) and test.
Then I would try it with a 10mm increase after that and see how it feels.

Even on cheap tyres, you should be able te feel a difference.

2nd Q: do you need rear end grip while the suspension is effectively settled (ie while in a drift) or while the suspension is in motion (while initiating of coming off of a drift)?

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 12:41 pm
by BigKriss
:!:

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 1:01 pm
by Booster
Enzio wrote:I'm going to over-simplify here, but:

You are running very little rear camber (good for grip) but since your car is lowered a lot you will have a lot of camber gain and bump steer at the rear on compression due to the stock traction arm length.

My suggestion - increase the traction rod length by 5mm. Then redo the camber and toe as you had it before (1mm toe in, -0.5 deg camber) and test.
Then I would try it with a 10mm increase after that and see how it feels.

Even on cheap tyres, you should be able te feel a difference.

2nd Q: do you need rear end grip while the suspension is effectively settled (ie while in a drift) or while the suspension is in motion (while initiating of coming off of a drift)?
cool its worth a shot ill give it a bash thanks. [smilie=200sx_200sx.gif]
Where i feel like i need more grip is after the switch back.
Especially when i initiate and have alot of angle. after the switch back, thats where i feel i need more.
Went out in a few other cars and its just a feel that im looking for.

Ill give the traction rod leanth a bash

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 1:35 pm
by Booster
Booster wrote:
Enzio wrote:I'm going to over-simplify here, but:

You are running very little rear camber (good for grip) but since your car is lowered a lot you will have a lot of camber gain and bump steer at the rear on compression due to the stock traction arm length.

My suggestion - increase the traction rod length by 5mm. Then redo the camber and toe as you had it before (1mm toe in, -0.5 deg camber) and test.
Then I would try it with a 10mm increase after that and see how it feels.

Even on cheap tyres, you should be able te feel a difference.

2nd Q: do you need rear end grip while the suspension is effectively settled (ie while in a drift) or while the suspension is in motion (while initiating of coming off of a drift)?
cool its worth a shot ill give it a bash thanks. [smilie=200sx_200sx.gif]
Where i feel like i need more grip is after the switch back.
Especially when i initiate and have alot of angle. after the switch back, thats where i feel i need more.
Went out in a few other cars and its just a feel that im looking for.

Ill give the traction rod leanth a bash
So let me ask a question at the risk, of sounding like a total doos. And stating the obvious.
The traction rod, what kind of handling changes can i expect. by shortening or lengthening it respectivly?

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Tue Apr 16, 2013 2:29 pm
by Enzio
Regarding the geometry:
If you lengthen it, you will decrease the toe and camber gain under compression. Thus less change in tyre angle in relation to the body. Shortening the traction rod while do the opposite.
This should help with stability and grip while drifting since you will keep the tyre contact patch fairly square on the road surface.

For grip driving you might want to keep the camber gain, so you have to weigh up the pro's and con's of any changes.

Consider this: when you lowered the car you had to lengthen the camber and toe arms to get the correct static alignment again. Thus all of the arms were lengthened except the traction arm - you will see it is pointing at quite a steep upwards angle. This means that effectively becomes shorter at a faster rate than the other arms when the suspension is compressed - effectively pulling the spindle towards it.

Another thing to check: whenever you make changes to the alignment - always look for binding by disconnecting the anti-roll bar and the shock and moving the spindle through the expected range of motion by hand. You can also use this technique as a guide to see how much bumpsteer and camber gain you have through the suspensions' range of motion. You can use 2 pens stuck to the hub and some cardboard to get an idea of the change in camber and toe.

Regarding the suspension:
Sounds like you have traction issues while shifting the weight from left to right if I understand your explanation correctly? Perhaps consider decreasing the damper bound/rebound setting on your coilovers a bit (I also have HSD's, it is a shame they are fairly basic and you cannot set bound/rebound damping seperately)

Just remember to ONLY make one change at a time!! So, set the traction rods 5mm longer and fix the geometry, then test it for a while at the track. ONLY THEN try to decrease the damping and check how much of a difference it makes.
Next time before practice, lengthen the traction rod another 5mm if the results were positive, etc, etc. It could be a good idea to get a book or something to document the changes and what settings you used - trust me, you WILL forget what worked and what did not.

PS: Asking a valid question does not make you doos. Also note, I am not an oracle - thus you are more than welcome to question my explanations :wink:

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Wed Apr 17, 2013 2:28 pm
by nirvash
im really liking this thread [smilie=200sx_200sx.gif]

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Wed Apr 17, 2013 10:08 pm
by SonOfAnarchy ZA
sad to see it limping off the track but hopefully a quick fix

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 11:38 am
by Booster
yeah just as i was starting to have a blast.
its sorted already,
The power steering pump keeps poping high pressure teflon steel braided hoses. So now im the moor in and i chucked in a steel pipe this morning.
pop that you bastard!

Starter motor.......mmm bolts loose

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 11:43 am
by Booster
Enzio wrote:Regarding the geometry:
If you lengthen it, you will decrease the toe and camber gain under compression. Thus less change in tyre angle in relation to the body. Shortening the traction rod while do the opposite.
This should help with stability and grip while drifting since you will keep the tyre contact patch fairly square on the road surface.

For grip driving you might want to keep the camber gain, so you have to weigh up the pro's and con's of any changes.

Consider this: when you lowered the car you had to lengthen the camber and toe arms to get the correct static alignment again. Thus all of the arms were lengthened except the traction arm - you will see it is pointing at quite a steep upwards angle. This means that effectively becomes shorter at a faster rate than the other arms when the suspension is compressed - effectively pulling the spindle towards it.

Another thing to check: whenever you make changes to the alignment - always look for binding by disconnecting the anti-roll bar and the shock and moving the spindle through the expected range of motion by hand. You can also use this technique as a guide to see how much bumpsteer and camber gain you have through the suspensions' range of motion. You can use 2 pens stuck to the hub and some cardboard to get an idea of the change in camber and toe.

Regarding the suspension:
Sounds like you have traction issues while shifting the weight from left to right if I understand your explanation correctly? Perhaps consider decreasing the damper bound/rebound setting on your coilovers a bit (I also have HSD's, it is a shame they are fairly basic and you cannot set bound/rebound damping seperately)

Just remember to ONLY make one change at a time!! So, set the traction rods 5mm longer and fix the geometry, then test it for a while at the track. ONLY THEN try to decrease the damping and check how much of a difference it makes.
Next time before practice, lengthen the traction rod another 5mm if the results were positive, etc, etc. It could be a good idea to get a book or something to document the changes and what settings you used - trust me, you WILL forget what worked and what did not.

PS: Asking a valid question does not make you doos. Also note, I am not an oracle - thus you are more than welcome to question my explanations :wink:
well that explain it clearly for me. Thanks bud!
I can tell you. That previously i was more inclined to spin out on a left hand turn when my right rear was under load.
So after reading what you said, before the track yesterday i measured the left and right traction rods. and yes. The right rear was 18mm shorter than the left.
So i made them both the same. and for sure last night was the most stable the car has felt for me. Im still new to this drifting, but at the end i was able to complete a few full runs with out spinning.
Im putting this down to just sorting the traction rods.... quite impressive

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 11:45 am
by SonOfAnarchy ZA
nice Dude. you were making real good progress last night on the track

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 12:02 pm
by Enzio
Nice! Glad it helped.

Well, for reference then the stock traction rod length for an S14 should be 210mm centre to centre AFAIK.

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 12:15 pm
by Booster
Enzio wrote:Nice! Glad it helped.

Well, for reference then the stock traction rod length for an S14 should be 210mm centre to centre AFAIK.
im curently on 225mm each side.

Re: Devil Pig Drift / Track car S14 Ls1v8

Posted: Thu Apr 18, 2013 12:17 pm
by Booster
SonOfAnarchy ZA wrote:nice Dude. you were making real good progress last night on the track
[smilie=200sx_200sx.gif]

didnt freaking sleep!!!!