? for those with 949 big grip kit
 

Are you running the 14mm MSM rear bar on track? Sometimes it seems like it may be a little too stiff for me. When my rear end breaks loose it is rather sudden and I have spun or gone off a couple of times. I am a low level intermediate driver so it may be nothing more than a lack of skills. Don't get me wrong...I love this suspension, just looking to get the most out of my car with my abilities. I have 700/400 clubsports with the dual springs SA on a 2450# 2002 fully loaded car w/o me in it. I guess I could just install my 12mm and see, but wanted some feedback from the experts

Thanks!

Been running a 14mm rear bar since way before the BGK existed. It's definitely the right bar for track use, IMO.

There are so many variables to consider with your setup. Spring rates, bars, ride height, alignment, corner weights, aero, driving style...
I used to ask questions like this. Maybe I still do in private. Lol
But the only way to figure out what is going to work for you is to test things. Don't be afraid to try different things. I used to be afraid to make big changes in fear that it would be so far off that it could waste a session. However it's the only way to really learn what different changes will feel like.

Shaikh over at Fat Cat Motorsports has this Front Roll Couple calculate available (see the link bellow). It's a quick and simple way to see what changes springs, sway bar sizes, etc effect your FRC. He also has some good youtube videos.

FCM_MSDS_1_8NB.xls

14mm works great. I am running 700/450 xidas.

probably just need some practice with this stuff. catching the rear isn't always that easy depending on the situation. Lots of other factors as Eric mentioned.

Low-level intermediate? Spinning?

I'd recommend that you set the shocks to a middle position, run a consistent hot tire pressure and go get maximum seat time. I think that spending a bunch of time messing with the suspension before you really know how to rotate the car will be counterproductive. Once you're going fast enough that you're comfortable with throttle steering and trail braking, then you can start the suspension fine tuning.

In other words, work on the driver first.

I'm running the OEM non-MSM Miata rear bar on mine and would like more bar because it can be hard to unstick the rear sometimes. I suspect you will grow into the formula you have and start liking it more. It's a well-proven setup.

Ride height (too low) or shock settings are probably causing the abrupt oversteer with that setup. If it was just in general loose I'd be pointing more towards alignment being a problem, or having too much rake if the alignment was good.

I was running a middle setting (4) front and rear. I have more recently moved up to (5) front and rear and like that better. Seems to stick better. I use a pyrometer to set tire pressures. I think I do need more seat time. I've spent a lot of time and money over the last couple of years prepping the car. I can now afford to spend the extra money driving. When I first started (with this car) I had all season radials on it and discovered I could steer the car in some turns with the gas pedal. I am more afraid to do this now with stickier tires and higher speeds. I have never been good at deciding what my suspension needs. I raced Motocross and other offroad motorcycle racing for about 30 years and never was good at knowing how to set things up other than following what others did! That's why I followed Emilio's recipe.

I have the rake and the street and track alignment recommended on 949's site

My car is very similar, ~2530 lbs empty, 700/400 Big Grip kit. I've never had the rear feel overly loose as you are describing. When I was on Rivals or RS3's I ran the shocks at 8 front & rear. I have some aero now, a CoT wing planting the back and a front lip, but before aero the car was neutral and balanced. I've certainly spun it a couple of times, but it was always clear to me what I had just done to cause the spin. It's never had a sudden-breakaway type feeling like you are describing.

Can you describe the conditions under which you are feeling the car be loose? Knowing how you're loading the suspension with the car can help us figure out what to change.

I never said it was "overly" loose, just that when it does let go, it is the rear that goes. I thought a well balanced car would slide all four wheels at once. It has happened on a wet track when I thought the car had taken a set in a turn, it has happened in the dry, when exiting a corner that I late apexed for the next turn leading on to a straight. Sometimes I feel it letting loose and I catch it.

I think Hornetball is right I need to get more seat time

This is a myth.

No matter how well "balanced" a car is, at the absolute limit of grip either the front tires or rear tires will lose grip first. The more "balanced" a car feels, generally it means there is more ultimate grip but in the end, one end of the car will always break away first.

A car that is set up really well but at the absolute maximum tends to under steer is "safe" and "easy to drive". A car that is set up really well but at the absolute maximum tends to over steer is...fast.

That's taking a very basic few of things. Most cars exhibit differences in the "absolute maximum" behavior between turn-in, mid corner, and corner exit behaviors. You might have a car that overseers on turn-in, is well balanced through mid corner and under steers at corner exit.

Generally, sway bars have the largest affect on mid corner or "steady state" behavior. If you find that the car always seems to oversteer, if you're constantly fighting the back end of the car through the whole corner, then too much rear bar may be likely. If you find that it "snap" over steers on corner entry or exit then it's more likely that it could be shock settings, alignment, or tire pressure related.

OR, it could be that your still learning the car and aren't comfortable driving a "loose" fast setup. There's nothing wrong with that and most drivers usually don't like a loose car. If you truly feel the car is too loose and unpredictable all the time, then it might be worthwhile looking into setup changes that will tend to make the car under steer more.

Best of luck. Whatever you don't don't stuff the car into a wall driving a car you're not comfortable with because you set it up based on Internet "wisdom".

if you are oversteering during track out, then you may need more rear camber or stop pinching your turns after the apex. A lot of people tend to pinch track out. Also, late apex, before a straight on a slow corner...you maybe taking it too fast.

At intermediate levels (truly intermediate), you should be comfortable enough adjusting tire pressures and have a general/basic idea of what to do with compression/rebound. More importantly, know what your alignment is doing for you. You should experiment with these things lightly so you get a feel for their effect on the car.

Suspension setup will change drastically based on grip conditions, so keep that in mind if you have mixed conditions during your day/weekend.

It's not your rear sway bar. Sounds like it maybe bottoming out in the rear. Make sure you have enough clearance between the bump stops and the shock body. If not adjust ride height or trim the bump stops.

I find the rear bar affects turn in and mid corner the most. By track out it's less of an issue. I ran a 15mm rear bar before dropping down to a 14mm. Track out was pretty much the same with each.

We need videos so we can properly critique you :)

What is your exact pinch weld height with driver in the car?
Hot pressures?
How many clicks from full clockwise on the dampers?

Is the sudden over steer in response to bump or driver input? If driver input, lift throttle brake or steering?
Corner entry, mid turn or exit?
Only one direction or both left and right?

It's been awhile since I had it aligned, but I had the guy follow your street/track alignment.

I usually end up at 30 PSI hot with RS3s

In the wet I am on the softest setting. On a dry track I go clockwise 5 clicks from full soft front and rear

It is not from hitting a bump. Probably induced by me backing out of the throttle or too much steering input

Right turns, but my track is clockwise so there are more rights.

I'm not sure there is really an issue from reading the previous posts. This is not a regular occurrence. Actually it has only happened 3-4 times, but it shakes my confidence. I'm beginning to believe I am just making some small errors that lead to it letting go. My thought was it should go into a 4 wheel drift if set up properly, and I'd have more time to reel it in. I'm now realizing that may not be reality

consider playing with shock settings. its rare that I end up with a square setup.

I have a friend that has the same set up as I and I believe he is much stiffer in front than rear with his shock settings. Is that typical?

I am usually about 3-5 clicks stiffer (in the front). depends on tires, conditions, etc. though.

Need exact alignment, ride heights and in car video to diagnose.

949 alignment is quite aggressive on turn in. I would think if you don't have much seat time that this would be the best method of resolving the problem.

Also checking tyre pressures, tyre heat for Inner, Middle and Out.

This way you can start analysing your setup a bit more. Maybe too much camber, maybe too little camber etc...

BUT I agree with 14 mm bar being about right. I run a 16 and have had to compensate a bit as I was getting MAJOR oversteer in to corners..

A 14mm would be about perfect for my car too.

I think I still have the exact alignment spec. I'll look.

I'll measure ride height.

Does the video have to show me going off? I have only one and it's on a wet track so not sure how worthwhile that is. Plus need to put it on youtube so I can link it here and I'm not much of a computer guy. lol

We could tell you what you did wrong. In explicit excruciating detail :)

It would still be useful to see.

haha, pretty sure we have all gone off. I even have a video of me tapping a tirewall...
(turn to 22:22)
.


No one will make fun of you for it. :rofl:

I found my alignment:

Front camber -1.9
front caster 4.5
toe 0
pinch point 5"
wheel to fender 12 3/4"

rear camber -1.8
toe 0
pinch point 5 1/4"
wheel to fender 13"

You're running it pretty high considering your 700/400 spring rates.

Try running OEM rear toe and lower rear 1/8"

This from a couple of weeks ago. I got one good session in between the rain. The first 3:30 minutes are me getting ready, so you can skip that, just after 15:00 minutes I go off. Be gentle

Car looks fine. Looks like you were still on the brakes too late and hard (too much trail braking) and spun it. Your reaction wasn't severe enough. It's good to steer slowly into the turn but when you think it's letting go, your corrections should be violent. You could have caught the half spin if you had snapped full lock left the instant you felt it going around.

I notice your heel-toe's are hit and miss. Sometimes perfect, sometimes clunky, sometimes no heel-toe. It's important to be consistent with that to have your corner entries and trail braking overlapping smoothly. In teh turn you spun, you were not overlapping smoothly and hung onto the brakes too long.

Because you have some power, I'd suggest the OEM toe in on rear and lower rear 1/8". Car looks good otherwise.

Thanks!!

Seat time my friend. Lots and lots of seat time.

THIS

And what Emilio said. A little toe-in in the rear and lowering the rear end of the car should make it more to your liking.

Your biggest benefit would be to hire a coach.

I would put one day with a good coach up against 100 trackdays hacking around by yourself any day. Coaching, coaching, coaching. Even (and especially) pros have coaches.

yup

Seat time will give you the reflexes to drive the car how you want. A coach will get you to understand what exactly it is you want the car to do, and where, on that particular track.

Funny...I was thinking about doing this. There are a couple of veteran ex-professional race car drivers who offer coaching at my home track at a reasonable price!

Thanks to all!!

Was that your first off? No offense but it doesn't look like you've had that much track time to be worried about perfecting your setup. Not really pushing the limits in the corners. If your not throwing a tiny bit of counter in, your not finding the limits. A fast auto-x course is a good place to practice this and get your timing, car sliding butt-o-meter, etc. calibrated. And at less scary, less car or tire damaging speeds.

I see you're in IL. I ran at the GPS track times day @ Blackhawk Farms the other week. They had some truly amazing instructors available to ride along or drive your car and coach. I'd recommend that event to anyone. I learned a ton.

No offense taken! If I was afraid of a little constructive criticism I wouldn't have posted on MT! HAHA! It was not my first off. I've had about 3-4 others. I have more years than I care to mention off road racing motorcycles, but I'm a total newb at road racing cars(actually HPDE). I'm still nervous about the car sliding in turns, but I know some slip angle is the fast way around. In some turns I get a lot of tire squealing but not all of them. I have a long way to go, but not many years to get there HAHA. (62 years old)

As an aside...I am REALLY careful on a wet track since an off puts you in wet grass. For you southern California boys...wet grass is like greased lightning...once your in it, figure your going to hit the tire walls or the Armco or something!

Not to sidetrack the thread but the above is the reason why I don't drive my car anywhere but the street. It is my summer driver and I can't afford to lose it if I go off track and ball it up. I have heard though that some companies offer HPDE insurance. Has anyone heard of something like that? I was listening to a car related podcast and they were interviewing a guy who raced porsches and he said he paid a couple hundred dollars for insurance for the day (of HPDE). Now, a porsche is far more expensive than a Miata so I would think that the insurance price is a bit lower.

I know that if I had the option of paying $200 on top of the HPDE cost I would be much more comfortable driving the car hard.

Yes it is available. If you don't pay for the HPDE insurance you have to be able to afford to lose your car. That is a choice all of us have made one way or the other. There are still some people I meet at track days that think their insurance will cover them. They rarely do, if at all, anymore

Actually its state dependent. Some states require "Driver's Education" events to be covered by insurance (although the insurance provider may opt to drop you afterwards). The key though is that it can't be a timed event. Some of that has changed recently, so you will want to read about it (and not take my word).

Yes there are a lot of companies that provide HPDE insurance. They even offer discounts for multiple events if you buy at once. Its not too expensive either. Most of the ones I see ask you to declare a value and give you the price.

NC and TX used to have no exclusions for things like HPDEs.

NC closed that loophole 2 years ago by rewording the language to basically say "if you're anywhere near a race track or other facility where people go fast in circles, you can get bent". I don't know off-hand about TX.

Lockton Affinity

But I believe they have a $5000 deductible, so if you wad it up, you're out at least that much more.

Time for a new thread on HPDE insurance

Hi,

Where do most of you set your front bar? Soft or hard?

Set to hard currently, and car understeers quite a lot. I will try the soft setting, but thinking about 16mm adjustable rear bar.

Car specs:

Big Grip Kit
800/500 springs
basically full weight
4.5" front, 4.75" rear
Supermiata race alignment

Cheers.

Front full stiff but the swaybar must not bind (check first).. I had a binding bar and car was understeering. I did add washer to the bushings to have some movement and car came back to normal.

They are adjustable for a reason. Some setup, tire and track combinations mifht require either. There is no conceivable combination that will ever require a 16mm rear bar. If it does, there is something seriously wrong in your set up.
May I ask, were you using fresh tires? What size wheel. offset, tire size and compound?

What's your aero? Understeer all the time, or just at high or low speed?

+1 on running washers between the sway bar bracket and mounting point to avoid pinching the bar.

With those spring rates, I would not hesitate to experiment with a softer front setting.

Lots of variables . . . .

Just try it on the softest setting, and see how that changes things. I ran my previous car on the front swaybar soft setting for most of its life. 2740# with driver, 700/400, big grip, either toyo RR or Maxxis RC1 225 on 9's. This costs you nothing, and only about 30 minutes of your time.