Max Anti Squat = Max Traction For Track?

[JCMarshall_Law]

I am getting subframe allignment bushes in my R33 GTST and I would like to set it up for max traction for circuit / track work (NOT drift).

I have been given conflicting info on what "max traction" translated to in suspension talk.

Is "max traction" for the circuit (not drift or drag) = max squat or max anti squat???

I was under the impression max squat was better for drag and max anti squat was better for corners??? Could someone please clear up this up for me.

I need this info so I can quiz my suspension shop so I know they are doing what I want them to do.

One other question: Is it worth getting just a castor kit on the front (ie. without the camber kit) or should I buy the camber kit as well.

These are the settings I was going for: (If I don't buy the camber kit)

Castor (front) = +7 degrees (with the kit)

Toe (front) = 0 (Std Adj)

Toe (rear) = -2mm (std Adj)

Subframe allignment = "max traction" for track (whatever that may be)

Camber - can someone confirm standard adjustment is 0 up front (ie I'm stuck with 0 degrees camber unless I buy the kit).

(based on a thread by SK and many hours trawling through this forum)

Other mods so far are: damping adjustable Nizmo front struts, Bilstien rear struts, standard springs, blade adj whiteling bars front and rear, HICAS lock kit, 17x8 AMG mags.

If you can answer any or all of these questions I'd appreciate your reply.

Cheers.

[djr81]

I am getting subframe allignment bushes in my R33 GTST and I would like to set it up for max traction for circuit / track work (NOT drift).

I have been given conflicting info on what "max traction" translated to in suspension talk.

Is "max traction" for the circuit (not drift or drag) = max squat or max anti squat???

I was under the impression max squat was better for drag and max anti squat was better for corners??? Could someone please clear up this up for me.

I need this info so I can quiz my suspension shop so I know they are doing what I want them to do.

One other question: Is it worth getting just a castor kit on the front (ie. without the camber kit) or should I buy the camber kit as well.

These are the settings I was going for: (If I don't buy the camber kit)

Castor (front) = +7 degrees (with the kit)

Toe (front) = 0 (Std Adj)

Toe (rear) = -2mm (std Adj)

Subframe allignment = "max traction" for track (whatever that may be)

Camber - can someone confirm standard adjustment is 0 up front (ie I'm stuck with 0 degrees camber unless I buy the kit).

(based on a thread by SK and many hours trawling through this forum)

Other mods so far are: damping adjustable Nizmo front struts, Bilstien rear struts, standard springs, blade adj whiteling bars front and rear, HICAS lock kit, 17x8 AMG mags.

If you can answer any or all of these questions I'd appreciate your reply.

Cheers.

<{POST_SNAPBACK}>

If it is traction you are after then you will be needing the rear to squat. Squat/anti squat & anti dive (for the front end) is not a first order issue when it comes to cornering. Best not to worry too much about it in relation to this issue. But (Always is one) if your setup is prone to power on understeer introducing more rear weight transfer (ie more squat) will exacerbate this problem. Fitting pineapples is neither hard to do yourself nor too expensive to get someone else to do it for you. May be best to put them in the neutral position first & then make a judgement call, rather than pre empt it at this stage (Just my humble opinion)

As for the camber/caster issue. I found that when doing a wheel alignment on my car (an R32GT-R) that introducing more caster via the caster rods reduced the amount of static camber the tyre had. So I would expect similar for your car.

Of the two (Caster/camber) the camber you are running is more important. Castor only has an impact (a beneficial one) when steering lock is applied, ie you get more -ve camber by running more +ve caster but only when you turn the wheel.

Most cars (I assume for R33's) have some degree of camber adjustment - so you should be able to get atleast some without bushes. Having said that & if you have to make a choice I would recommend some camber bushes in preference to the castor bushes. Both is better again.

Edited January 18, 2006 by djr81

[GTRgeoff]

Nice reply djr but a few points worth noting on the R33 GTSt.

Camber and castor are equally important for both a braking traction and a turn in response/mid corner traction perspective. The system must be viewed as a whole and not discreet elements, especially if you use the HICAS lock without Tomeis' little box of tricks as it can result in occasional hardening of the steering at really low speed but is almost indistiguishable with extra caster.

Most people worry about a lack of turn in response with the GTSt, and subsequent understeer so the caster adjustment gets the front turning quickly and increases camber through the steer angle increase. The front end becomes much more lively and responsive allowing for a more positive approach to a turn. Static camber does not do this but is more important for the straight line braking traction and tyre wear/life.

Any R33 lowered a bit is running too much camber and since they have no adjustment from factory for camber (or castor) you will need the bushes.

Finally, anti-squat is just that. It prevents squat so what dj says is absolutely right in that you need a little rear squat to weight transfer some load to the rears to get traction, even exiting a corner.

Good luck with this Patrick.

Geoff

[djr81]

Nice reply djr but a few points worth noting on the R33 GTSt.

Camber and castor are equally important for both a braking traction and a turn in response/mid corner traction perspective. The system must be viewed as a whole and not discreet elements, especially if you use the HICAS lock without Tomeis' little box of tricks as it can result in occasional hardening of the steering at really low speed but is almost indistiguishable with extra caster.

Most people worry about a lack of turn in response with the GTSt, and subsequent understeer so the caster adjustment gets the front turning quickly and increases camber through the steer angle increase. The front end becomes much more lively and responsive allowing for a more positive approach to a turn. Static camber does not do this but is more important for the straight line braking traction and tyre wear/life.

Any R33 lowered a bit is running too much camber and since they have no adjustment from factory for camber (or castor) you will need the bushes.

Finally, anti-squat is just that. It prevents squat so what dj says is absolutely right in that you need a little rear squat to weight transfer some load to the rears to get traction, even exiting a corner.

Good luck with this Patrick.

Geoff

<{POST_SNAPBACK}>

Fair point about it being viewed as a whole. I guess I was trying to break it into more discrete lumps to help explain things. From trying to set up my car I have found that the caster angle needs to be set up before the camber - because adjusting the caster changes the camber, but not the other way around. Thats with rods, not bushes, but we don't need to go there.

What I would happily kill for is a model of the front end of a Skyline that allows you to determine the total -ve camber over a range of conditions and settings.(ie the combined effects of caster, camber, body roll & everything else). Can't ever see this happenning, however.

From peddling my 32 I have found that it is not worth trading more +ve caster for less -ve camber - atleast on an R32 this tends to make the front end grip go away. However as the 32's run much less caster in the first place it isn't necessarily apples with apples.

I don't claim to understand the tyre wear issue for 33's either. For me I have found that unless you are bagging the rears the fronts will wear more quickly. On the track and on a road/race compromise set up mostly the wear is to the outside of the tread face (for both R compounds & road tyres). Because of this reason I am happy to run -ve camber to deal with front end grip and worry less about wear on the inner edge of the tyre. Also, if you have standard rotors/calipers it is difficult to consistently lock anything up on the track - making the degredation in straight line grip due to -ve camber less of an issue than it may be (more so for R compounds than roadies) Have a look at the data log screen dump of a nothing burger lap of Wanneroo. You can see that the lateral gees (green) is much more than than the longitudinal (red) gees. (Blue is the rpm which needs recalibrating). Point is the brakes cannot generate as many gees as the tyres can handle - so the compromise is then weighted towards making the thing corner. The fact that I need some bigger brakes is a whole other issue.

Just what I have found to try to illustrate a different compromise for a different car.

Edited January 18, 2006 by djr81

[JCMarshall_Law]

Cheers guys, thanks for the replies. Gotta love this forum.

So what I got out of your posts:

1) I agree, you have have to look at the system as a whole, but I have to ask questions about discreet elements - I just try to ask them in such a way so I can apply the answers to the whole system.

2) I should go for squat rather than anti squat to increase rear grip. I can hopefully dial out any increased understeer with the bars and adj front shocks.

3)

As for the camber/caster issue. I found that when doing a wheel alignment on my car (an R32GT-R) that introducing more caster via the caster rods reduced the amount of static camber the tyre had. So I would expect similar for your car.

Bummer, I'll have to talk further about this with my suspension shop. Makes just buying the castor bushes a no go.

I should have mentioned that it is just a cost issue, I ultimatly want the whole camber castor kit, I'm just trying to do things progressivly to go easy on the credit card. The castor kit is quite a bit cheaper than the camber kit.

4)

Most people worry about a lack of turn in response with the GTSt, and subsequent understeer so the caster adjustment gets the front turning quickly and increases camber through the steer angle increase. The front end becomes much more lively and responsive allowing for a more positive approach to a turn. Static camber does not do this but is more important for the straight line braking traction and tyre wear/life.

Exactly the reason I was hoping to just buy the castor kit first.

My car is not lowered so the camber should not be a "problem" with the current setup, although not ideal for track circuit work.

5)

caster angle needs to be set up before the camber - because adjusting the caster changes the camber, but not the other way around.

So I could go get the castor kit and find out that I end up with positive camber(bad thing) and I will have to get the camber kit anyway.

6)

I have found that it is not worth trading more +ve caster for less -ve camber - atleast on an R32

Ah ha, very important point.

7) I would not mind one of those dataloggers djr81.

Does anyone else have an opinion about the combination of camber and castor kits or the squat / anti squat issue.

Cheers.

Edited January 18, 2006 by JCMarshall_Law

[djr81]

A couple quick things:

Think of a corner as something you take in four parts

1. Brake.

2. Turn in.

3. Mid corner - 0% TPS or close

4. Corner exit.

The only part of the corner that the anti squat characteristic has an large impact is in the last bit, ie power down. It wont make any real difference in parts 2 or 3 & only marginally in part 1 (Anti dive takes care of part 1)

Data logger is just a 3D GTECH RR using an exported csv excel file. Highly recommend one for I think about $500.

It is probably worth the exercise of sitting your car in the drive way & then applying say a quarter of lock of steering. This will give you a bit of an idea as to how much (or how little) the caster affects the camber. The result may suprise you. Best bit is it costs nothing.

Edited January 18, 2006 by djr81

[GTRgeoff]

A quick search for some setup detail by Sydnekid will show

1. All Skylines have too little castor

2. All Skylines, when lowered to a useful competition height (not extreme) will have too much camber

So ultimately you will need both but caster is the most important first step for the 25t.

A datalogger and the geometry model would be nice. Maybe one day.....

[scathing]

I don't claim to understand the tyre wear issue for 33's either.  For me I have found that unless you are bagging the rears the fronts will wear more quickly.

Not unsurprising. Your fronts will do more work on the track.

When you brake, the fronts to the vast majority of the stopping. Steering loads are higher on the fronts, and that will happens when you turn-in under brakes as well as when you hit the throttle post apex. So they're under stress more of the time than the rears.

What's the weight distribution on Skylines like? Is it a little front heavy? That's going to exacerbate your wear rates too.

[scathing]

I would like to set it up for max traction for circuit / track work (NOT drift).

I have been given conflicting info on what "max traction" translated to in suspension talk.

Is "max traction" for the circuit (not drift or drag) = max squat or max anti squat???

<{POST_SNAPBACK}>

Neither, if you mean the best suspension setup to get you through a set of corners.

Your suspension setup will be a compromise and dependant on the circuit. On a track with single corners and long straights, you'd run more squat so you can put more power down out of the corners. This kind of setup encourages a more "slow in, fast out" approach.

On a circuit with more flowing corners and shorter straights, you'd run it a bit more neutral so you don't unload your front tyres when you pick up the throttle and cause understeer. Its more for "medium in, medium out".

It depends on how easily adjustable this stuff is. If you can't do it without having access to tools you can't easily get a hold of (like if you need a hoist or wheel stands), or you don't want to go through the effort of constantly adjusting it, you're going to need to compromise and find a setup that's "good enough" for all the tracks you're likely to drive on.

[JCMarshall_Law]

Cheers fellas,

I spoke to the workshop yesterday, they confirmed that I should go for the camber and castor kits at the same time. (Although buying both kits results in an extra $300 for them).

For now I have just got a set of pineapples going in for "max traction" (Fulcrum in Stafford, QLD).

I'll get the camber and castor kits for the next track day.

Just a couple of questions:

1) What is the standard front camber and castor on a r33 GTST?

2)

2. All Skylines, when lowered to a useful competition height (not extreme) will have too much camber

That is, too much negative camber?

3) Had anyone used Fulcrum's setting "max traction" for the pineapple kit? What are your opinions.

Cheers

[GTRgeoff]

http://www.whiteline.com.au/Project/skylineR33gts-t.htm

http://www.whiteline.com.au/docs/fact_shee...line_R33GTS.PDF

Will get you started.

Oh and that was neg as the 33 uses a short upper arm so as the car goes lower, the top of the tyre comes in.

I use the whiteline pineapples (subframe bush kit) @ $120 a set on both the GTSt track car and the GTR33. I have them set in max traction. The squat is not extreme but is sufficient to add that extra hookup that is needed. Both are mild cars with very fat 220rwkw in the GTSt, so a large average power and 260rwkw on the GTR, which still needs that bit extra.

Fitting is pretty easy if you can swing a spanner but constant changing would be a pain just to chase setup. Set to whitelines figures and leave. For more detail talk to SK as he can recommend for specific outcomes you desire.

[JCMarshall_Law]

Damm, a little bit more conflicting information.

By the looks of things on that whiteline sheet, they suggest the castor kit in the handling pack and the camber kit as an option?!?!?

[GTRgeoff]

And if you are not lowering aggressively, I would suggest it is the best course to take if you want to limit your budget.

[Sydneykid]

Sorry only just catching up with this thread, been busy doing the race team budget for this year….frightening…….

I have found that what works for GTR (4wd) does not always work for a GTST (2wd) and vive versa. So I will stick to GTST (2wd) for this post.

Rear subframe bushes (pineapples), the best setting I have found for circuit work is the “all round performance”. As per the Whiteline instructions;

The maximum traction (squat) position tends to give too much understeer on corner exit power application as it transfers weight off the front wheels. It is great for drags, but not dry track circuit work. If you have a guaranteed wet track then it is good for that as well, as it lessens the power on oversteer. Very high powered (400 rwkw plus) cars can benefit from this setting as they have lots of power oversteer and a bit of understeer is not a problem, just apply more right foot.

The minimum traction (anti squat) position is not something I would use on a GTST for circuit work, good for drift though. Lack of antisquat is not a problem as the stabiliser bar holds the rear of the car upright on corner exit as there is still diagonal weight transfer going on.

The “all round performance” setting is the easiest as you don’t have to drop the subframe down to insert bushes above it, they all go below the subframe. If you can change a flat tyre, you can do this. As the picture of the RHS front subframe bush on the Stagea shows, simply undo the 2 X bolts and 1 X nut holding the bracket, drop the bracket, slip the bush in and replace bracket, then do up the nut and bolts.

The LHS front bush is the same, the 2 X rear bushes are even easier as there is only 1 X nut holding each bracket.

I would always do the caster bushes first, Skylines cry out for more caster, they have around 5.0 to 5.5 degrees standard, which is simply not enough. I have seen a few with ~3 degrees as the bushes have been pounded by hitting bumps, pot holes and speed humps at speed. Around 7 or more is such an improvement. There is a compromise (you loose camber when you wind on caster) but on a GTST it is only a very tiny amount, not worth worrying about.

This is not really a full DIY job, the standard bushes need around 10 tonnes to press them out, sometimes more if the steel shell of the bush has started to rust itself to the radius rod. You can get a workshop to do it all, or simply remove the radius rods (each rod has 1 X bolt at the front and 2 X bolts at the rear) and take them along to have the bushes pressed out and the new ones pressed in. Only takes a few minutes once they are out of the car.

Hope that helps

cheers

[Scooby]

Sorry to commit a minor hijack, but while we're on it may I ask what works best for a 4wd?

[JCMarshall_Law]

Wow, thanks SK, that is a better reply than I ever expected, once again thanks for sharing you knowledge.

So if I go for the "all round performance" option the squat characteristics of the car will not actually be changed? I understand that the purpose of the pineapples in this case would be just to replace the crappy silicone bushes with stiffer polyurethane ones, resulting more controlled movement of the subframe? Have I got that right?

I think I'll still just go for the camber and castor kits at the same time so I dont have to pay for two wheel allignments.

Cheers,

[djr81]

Wow, thanks SK, that is a better reply than I ever expected, once again thanks for sharing you knowledge.

So if I go for the "all round performance" option the squat characteristics of the car will not actually be changed? I understand that the purpose of the pineapples in this case would be just to replace the crappy silicone bushes with stiffer polyurethane ones, resulting more controlled movement of the subframe? Have I got that right?

I think I'll still just go for the camber and castor kits at the same time so I dont have to pay for two wheel allignments.

Cheers,

<{POST_SNAPBACK}>

The pineapples are an addition to the silicone bushes. You don't actually replace the bushes, just fit the pineapples over the outside. I only know this because I had to ask the same question the other week. It is a pretty simple job.

[Bobjones]

SK sorry to point out...BUT you have your numbers arse about on the pictures...the large pineapple goes towards the front of the car, thus picture 1 should be labelled 1 & 2 and NOT 3 & 4

[GTRgeoff]

Running the standard diff (well my second one now) I needed the full traction setup to prevent the bugger from open wheeling to the left after 3 laps at somewhere like Sandown. Sure I should get a decent one way but with 5 cars and a dive hobby who can jsutify one of them.......

[Fastrotor]

The minimum traction (anti squat) position is not something I would use on a GTST for circuit work, good for drift though. Lack of antisquat is not a problem as the stabiliser bar holds the rear of the car upright on corner exit as there is still diagonal weight transfer going on.

Gary if your saying this here , how come on the R33 gtst group buy in the settings for the bushes you say "max anti squat" ?

Im getting the car aligned finally tomorrow (i bought the full kit). Hill climb is on sunday so i need to know if i should swap the bushes back to neutral... ?

Also while im going, with the adjustable bars .... what conditions warrant what changes ? ie if its tail happy, or understeering etc which bar to change to help condition ?

Thanks

Gary