Setup For Track: Adj Sway Bars And Shocks

[JCMarshall_Law]

Hey all,

I'm hoping someone can give me a few pointers, I have a R33 GTST with bilstien struts at the rear (stock springs), damping adjustable Nizmo shocks up front (stock springs), whiteline adjustable swaybars front and rear and polyurethane bushes all round.

I've never really done any development, I just installed the bars and set everything to be maximum stiffness. Now I'm wondering how I should go about optimising the setup for (at) an upcomming track day.

The things I have to adjust are the sway bars and the damping adjustable front shocks.

Should I keep everything stiff as possible, go out on the track, soften the front if it understeers or soften the rear if it oversteers. Is that the right way around? Is that the right way to go about things? Should I start the bars soft and get harder depending on over / understeer?

When should I start playing with the damping rates on the shocks?

As a side note: does anybody know which way to turn the little adjuster on top of the strust to make damping harder / softer, i.e. is position 5 the softest, or is position 1 the softest? (there is five positions on the little adjuster). The struts came with the car and I cant find a manual or anything.

Any help or discussion whould be greatly appreciated.

[Sydneykid]

Hey all,

I'm hoping someone can give me a few pointers, I have a R33 GTST with bilstien struts at the rear (stock springs), damping adjustable Nizmo shocks up front (stock springs), whiteline adjustable swaybars front and rear and polyurethane bushes all round.

I've never really done any development, I just installed the bars and set everything to be maximum stiffness. Now I'm wondering how I should go about optimising the setup for (at) an upcomming track day.

The things I have to adjust are the sway bars and the damping adjustable front shocks.

Should I keep everything stiff as possible, go out on the track, soften the front if it understeers or soften the rear if it oversteers. Is that the right way around? Is that the right way to go about things? Should I start the bars soft and get harder depending on over / understeer?

When should I start playing with the damping rates on the shocks?

As a side note: does anybody know which way to turn the little adjuster on top of the strust to make damping harder / softer, i.e. is position 5 the softest, or is position 1 the softest? (there is five positions on the little adjuster). The struts came with the car and I cant find a manual or anything.

Any help or discussion whould be greatly appreciated.

<{POST_SNAPBACK}>

Usually on shocks clockwise is harder, anticlockwise is softer.

This is what I do when I am training a driver to understand what each adjustment does on the race car, drive fast but not flat out (9/10th's if you like);

1. Set everything on full soft, do 2 laps. Think about what that feels like, write it down

2. Set everything on full hard, do 2 laps. Think about what that feels like, write it down

3. Set the front on full hard and the rear on full soft, do 2 laps. Think about what that feels like, write it down

4. Set the rear on full hard and the front on full soft, do 2 laps. Think about what that feels like, write it down

Now you have some idea of what everything does and how it feels. Start adjusting to suite your own preferences. Every car is different, different tyres like different settings, every day is different (sometimes a little, sometimes a lot) and each driver has their own preferences to suiite their driving style. There is no right or wrong, whatever suites you will generally give the fastest lap time.

The object is to try everything, know what it does so that YOU can choose the best one on the day.

cheers

[JCMarshall_Law]

Thanks heaps for the reply Sydneykid, I was hoping you'd reply.

Sounds like a good plan, I've only got 6 or so sets of 5-6 laps at the track day so I might have to comprimise a bit (I want a bit of time just to play around out there)

I might try:

1) hard front shocks, hard front bars, soft rear bars

2) soft front shocks, hard front bars, soft rear bars

3) soft front shocks, soft front bars, hard rear bars

That should give a bit better idea where I'm going, then I can make smaller setup adjustments after that.

Just wondering if there is a general rule:

- stiffining the rear bar promotes oversteer

- stiffining the front bar promotes understeer.

Is that correct or is it the other way around, or is there no general rule?.

I see what your saying with the testing at all the setup extreems so I can find out for myself what does what, but I'm asking just because of the limited track time I have. If I have that rule right in my mind I may be able to speed things up a little.

[Mr.R33]

Thanks heaps for the reply Sydneykid, I was hoping you'd reply.

Sounds like a good plan, I've only got 6 or so sets of 5-6 laps at the track day so I might have to comprimise a bit (I want a bit of time just to play around out there)

I might try:

1) hard front shocks, hard front bars, soft rear bars

2) soft front shocks, hard front bars, soft rear bars

3) soft front shocks, soft front bars, hard rear bars

That should give a bit better idea where I'm going, then I can make smaller setup adjustments after that.

Just wondering if there is a general rule:

- stiffining the rear bar promotes oversteer

- stiffining the front bar promotes understeer.

Is that correct or is it the other way around, or is there no general rule?.

I see what your saying with the testing at all the setup extreems so I can find out for myself what does what, but I'm asking just because of the limited track time I have. If I have that rule right in my mind I may be able to speed things up a little.

<{POST_SNAPBACK}>

Not sure if it helps, but I have the Nismo adjustable front shocks as well and 1 is the hardest and 5 is the softest. it doesn't feel like much difference if you just push down on the guard but you really notice it when you go on a long drive.

I am booked in for the track day on the 30th as well, so It will be interesting how your adjustable bars go, that might have to be my next aquisition.

[JCMarshall_Law]

Not sure if it helps, but I have the Nismo adjustable front shocks as well and 1 is the hardest and 5 is the softest. it doesn't feel like much difference if you just push down on the guard but you really notice it when you go on a long drive.

I am booked in for the track day on the 30th as well, so It will be interesting how your adjustable bars go, that might have to be my next aquisition.

<{POST_SNAPBACK}>

I've played around a bit on the street with the shock settings, but it is pretty hard to tell in the trafic. The car seems to corner better with soft front shocks and stiff bars but it seems to feel better with everything hard as it goes, like I said hard to tell on the street (driving sensibly and at the speed limit). I'll have more of a play at the track day.

I guess you know I'll be at the QLD raceway track day on the 30th so I'll have a talk to you about the shock settings then.

Anyone else have any input? Can anyone else answer the question in my last post?

[Sydneykid]

Thanks heaps for the reply Sydneykid, I was hoping you'd reply.

Sounds like a good plan, I've only got 6 or so sets of 5-6 laps at the track day so I might have to comprimise a bit (I want a bit of time just to play around out there)

I might try:

1) hard front shocks, hard front bars, soft rear bars

2) soft front shocks, hard front bars, soft rear bars

3) soft front shocks, soft front bars, hard rear bars

That should give a bit better idea where I'm going, then I can make smaller setup adjustments after that.

Just wondering if there is a general rule:

- stiffining the rear bar promotes oversteer

- stiffining the front bar promotes understeer.

Is that correct or is it the other way around, or is there no general rule?.

I see what your saying with the testing at all the setup extreems so I can find out for myself what does what, but I'm asking just because of the limited track time I have. If I have that rule right in my mind I may be able to speed things up a little.

<{POST_SNAPBACK}>

Holly cow, 6 sets of 5-6 laps, what a luxury. We get 1 X 15 minute session to practise, do the set up and qualify. You need a couple of mates and within 2-3 sessions you should have it sussed. Start with a plan, write it down and make sure your mates know what they have to do.

First session, select first set up, do 2 laps. make change, do 2 more laps.

Second session, make change, do 2 laps, make change, do 2 more laps.

Third session, make change, do 2 laps, then select the best setting you think will suite you, the track and the day.

Fourth session, fine tune that setting from the third session.

More front anti roll usually means less oversteer

More rear anti roll usualy means less understeer

Stiffer front shocks usually means more understeer

Stiffer rear shocks usually means more oversteer

Not the word "usually".

cheers

Edited August 23, 2005 by Sydneykid

[JCMarshall_Law]

Holly cow, 6 sets of 5-6 laps, what a luxury.  We get 1 X 15 minute session to practise, do the set up and qualify.  You need a couple of mates and within 2-3 sessions you should have it sussed.  Start with a plan, write it down and make sure your mates know what they have to do.

First session, select first set up, do 2 laps. make change, do 2 more laps.

Second session, make change, do 2 laps, make change, do 2 more laps.

Third session, make change, do 2 laps, then select the best setting you think will suite you, the track and the day.

Fourth session, fine tune that setting from the third session.

More front anti roll usually means less oversteer

More rear anti roll usualy means less understeer

Stiffer front shocks usually means more understeer

Stiffer rear shocks usually means more oversteer

Not the word "usually".

cheers 

<{POST_SNAPBACK}>

Thanks again sydneykid, I know 6 x 5-6 laps seems like a lot to you

But what I was saying when I said "limited track time", was the 6 x 5-6 laps might as well be 6 x 1 lap sets as it is not really possible to do two laps, come in, change the sway bar setting and go back out for two more laps before the session is over and all the cars are back in the pits. It is a private track day and the sessions run continuously with about 5 groups, so your group ends up with about 6 sets.

So I really only get 6 sets at different settings on the car no matter how many laps I do in a set. Still heaps compared to what your used to?

Thanks for your replies, I have a much better plan on how I'm going to go about things. cheers

Anyone else had experience setting up a car in this situation? With this gear?

Edited August 23, 2005 by JCMarshall_Law

[Sydneykid]

Thanks again sydneykid, I know 6 x 5-6 laps seems like a lot to you 

But what I was saying when I said "limited track time", was the 6 x 5-6 laps might as well be 6 x 1 lap sets as it is not really possible to do two laps, come in, change the sway bar setting and go back out for two more laps before the session is over and all the cars are back in the pits. It is a private track day and the sessions run continuously with about 5 groups, so your group ends up with about 6 sets.

So I really only get 6 sets at different settings on the car no matter how many laps I do in a set. Still heaps compared to what your used to?

Thanks for your replies, I have a much better plan on how I'm going to go about things.  cheers 

Anyone else had experience setting up a car in this situation? With this gear?

<{POST_SNAPBACK}>

You would be amazed what you can do in ~60 seconds (the time it takes to do 1 lap) with 2 guys (you stay in the car), 2 trolley jacks and the necessary tools all laid out ready to go. You don't need to take off the wheels to change stabiliser bar settings. Organise your schedule so that you only change one end of the car during the sessions and both ends of the car between sessions.

Have a talk to the organisers, tell them what you want to do. They are usually flexible with moving between sessions. Changing shock settings only takes about 10 seconds, at least you can do that during the session on your own.

cheers

[JCMarshall_Law]

Had the track day today in the pooring rain so I gave up with any serious playing with the suspension anyway - just had fun sliding around.

Bit of a bummer, I was hoping to post some decent times.

Bit hard to compare in the wet but I those adjustable sway bars made the car a nicer too drive - Under / oversteer seemed a bit more balanced - set shocks to hardest, front swar bars 2nd hardest of 4 settings, set rear hardest of 2 settings (ingnoring intermediate settings - links in different positions in either arm). Oversteered under braking (bit of a problem with compression braking), could be made understeer around corners, generally felt a bit more predictable.

No prob, I had fun anyway which was my main aim.

So I'll have a bit of time to add the last few bits to my suspension setup before the next track day:

1) Hicas lock bar

2) Pineapples (HD sub frame bushes) in the rear

3) Decent tyres!!!

4) Allignment

5) HD (stiffer) springs?

Whould it be worth getting stiffer springs for my setup? (stock height with aftermarket shocks, swaybars, etc)

[JCMarshall_Law]

Damm R33 GTST's what do you have to do to get them to handle ?!?!?

[JCMarshall_Law]

Besides change the driver

[Sydneykid]

Damm R33 GTST's what do you have to do to get them to handle ?!?!?

<{POST_SNAPBACK}>

They are no more diffficult than any other high powered rear wheel drive car to get the handling right on. You will find the HICAS removal and rear subframe bushes make a difference, but getting the camber and caster spot on is a big step in the right direction.

In the wet I would have softened up the shocks, not had them on full hard. The rear bar on full soft and then adjust the front bar to balance the handling. The hard shocks and rear bar are why you had the oversteer. Lucky you didn't have the stiffer springs in for the wet, they would have made it worse.

cheers

[GTRgeoff]

Damm R33 GTST's what do you have to do to get them to handle ?!?!?

Everything SK says. I outpace wrx's (not STi's need semi's to take em on) on semi's at phillip island using standard road rubber.

Standard shocks with lowered RSR springs (not yet run but fitted HDS HR coilovers but the standard springrate is too high), whiteline adjustable anti roll bars and pineapples set for traction. Still too low for best traction and camber needs adjustment. I can't wait to see just how fast it can go. As for best laptimes, my consistency is usually within 3 tenths of my average over the whole day so the bugger just can't go any faster.

[JCMarshall_Law]

They are no more diffficult than any other high powered rear wheel drive car to get the handling right on.  You will find the HICAS removal and rear subframe bushes make a difference, but getting the camber and caster spot on is a big step in the right direction.

In the wet I would have softened up the shocks, not had them on full hard.  The rear bar on full soft and then adjust the front bar to balance the handling.  The hard shocks and rear bar are why you had the oversteer.  Lucky you didn't have the stiffer springs in for the wet, they would have made it worse.

cheers 

<{POST_SNAPBACK}>

Yeah, I think I should have hardened up the front sway bar and softened the shocks a bit but like I said, I did not really bother playing with the setup (just left as I had it - except shocks) because of the rain. I did set the front shocks harder because it was oversteering. But I was figuring the oversteer was more to do with my driving style, I was getting compression lock up into corners that brought on the oversteer - I'll have to work on matching rpm and wheel speed.

Incedently I found a great setup for drift!

GTRgeoff, that HICAS lock bar I'm planning on fitting is one of yours - how they going?

All things equal, the R32 seem to handle better (get around a race track faster) than the r33 - is that a fair comment.

[GTRgeoff]

Starting fabrication today. Sorry for the delay.

One of the most innocuous elements that people overlook is a proper pedal setup. I took off 3 seconds alone at PI and Sandown with proper heel toe technique for smoother downshifts and smoother later braking.

[Sydneykid]

Yeah, I think I should have hardened up the front sway bar and softened the shocks a bit but like I said, I did not really bother playing with the setup (just left as I had it - except shocks) because of the rain. I did set the front shocks harder because it was oversteering. But I was figuring the oversteer was more to do with my driving style, I was getting compression lock up into corners that brought on the oversteer - I'll have to work on matching rpm and wheel speed.

Incedently I found a great setup for drift!

GTRgeoff, that HICAS lock bar I'm planning on fitting is one of yours - how they going?

All things equal, the R32 seem to handle better (get around a race track faster) than the r33 - is that a fair comment.

<{POST_SNAPBACK}>

The R32GTST has a weight advantage, but the R33 has bigger brakes and engine. It's a trade off. The real killer is when the R32 has a bit more weight off and gets the bigger brakes and engine, then the R33's struggle.

That said, Ian is still leading the NSW Supersprint Championship in an R33GTST. So it ain't all that bad.

cheers

[JCMarshall_Law]

Starting fabrication today. Sorry for the delay.

One of the most innocuous elements that people overlook is a proper pedal setup. I took off 3 seconds alone at PI and Sandown with proper heel toe technique for smoother downshifts and smoother later braking.

<{POST_SNAPBACK}>

Very true - I'm under no delusions that my lap times could not be improved by learning to drive a car properly on a race track. Unfortunatly I don't have anyone to teach me what I'm doing wrong or what I should do differently - I'm basically learning by trial and error (spending time in the kitty litter).

I never really understood the significance of heel-toe throtle control under braking untill after the track day yesterday - I thought to myself - what was happening when i cornered (requiring a downshift): jump on brakes, car squirms around, try to just stay off the ABS, begin turn in and pull clutch out --> instant oversteer --> leaving my speed on the tarmac in the form of black skid marks. So I'm going to have to work on my turn in and down shifts. Seems simple to those who know.

Any tips on learing how to drive - books to read, courses to do, practice exercises?

Sydneykid: Good to know a R33GTST is current NSW Supersprint champ - gives me more hope.

Edited August 31, 2005 by JCMarshall_Law

[Snowman]

Its really hard to propperly practise heel - toe on the streets as its hard to get "track-like" conditions. I've found the best places are round-a-bouts where you can see the traffic coming clearly and if you have a quiet industrial area with DRIVES (you know streets that form like a big U shape) there you can practise during quite times (eg Sundays) higher rmp down-shifts without the fear of traffic coming from the direction of your turn.

One other thing to enqure about is what brake pads you are using. Personally I found that having a much higher friction front brake will help stop the rear of skylines coming around in big braking corners.

eg - run something like Ferodo DS3000 front pads and RB74 rear pads.

That wont help compression lock-ups but will help keep the rear of the car stable heading into corners.

[jlnewton]

Conditions out there yesterday were terrible, so very slippery. The wet conditions certainly kept everyone on there toes. September 10 is the next Saturday arvo Sprint, you thinking of going out to that?

[GTRgeoff]

Wet is the absolute best time to practice going smoother and faster. No point going 100% so work on the lines and throttle/brake control.