Negative Camber vs Sway Bars: Which one?

I'm only about 25 HPDE days into this, but here's my experience.

There is nothing "fancy" I could have done to my car that would have decreased my lap times for about the first 15 days, or speeded up my learning. It took me that long just to learn how to maintain concentration for an entire session, turn in at the right spot and right speed, hit all my apexes, and track out to the right place consistently. It's a vision and feel thing.

I have been doing this in one light 140HP old BMW and one heavy new 400HP BMW. I learn everything faster in the light old car.

If you are driving a heavy-ish car on bigger tracks, somewhere in the first 15 days, it will be time to get heat-tolerant brake pads. There are pads out there like StopTechs that can take the heat of the track, don't eat your rotors, and don't cost an arm and a leg.

At about 20 days I evaluated the situation on car changes. I went with stickier tires, because that let me level up my learning on braking and cornering at higher speeds. This was on the advice of my instructors at the time; they wouldn't have wanted me on sticky tires before then. And in-car video, because I found I figured out a lot looking at video a couple days later.

I read Fred Puhn's excellent book on racing suspension, and studied it until it all made sense. But I didn't change anything in my car because I frankly wouldn't have been a good enough driver yet to tell whether it was helping or hurting

At about 25 days, I moved the rear spring perches on the old light car up one click to reduce neg camber and increase travel a bit.

So far, my best investment of time and money by far has been HPDE weekends with good in-car instruction. No question. I'm not sure how much autocross helps. The runs are so fast and it's all about transition from moment to moment, which isn't what I do on track. I'm sure it doesn't hurt, but plain-old wet skidpad seems to be a more transferrable car control clinic for the track.

wbjones wrote:

INITIALDC5 wrote: In reply to wbjones: im with you on the LSD...however im skeptical about the numbing of the rear suspension. For autocross (reffering to your STF remark) im sure that would be fine to get it to rotate, but for HPDE and track days only im thinking that would work again me and might even be catastrophic. I think ill just play with camber and seat time until I decide I need more. I would almost rather run a front wind splitter to increase front end grip than take any grip away from the rear...ive pretty much given up on autocross lol

ok … RealTime gave up on it because (so I've read) they couldn't fix the rear end

That was a lot of it. That and the TSX came out with more torque (k24) and a real suspension up front and fixed the rear. They were over 1500# rear springs trying to make the pig turn and it just didnt work. Unfortunately, the RSX suspension was one of Honda's largest mistakes.

Jamey_from_Legal wrote: I'm only about 25 HPDE days into this, but here's my experience. There is nothing "fancy" I could have done to my car that would have decreased my lap times for about the first 15 days, or speeded up my learning. It took me that long just to learn how to maintain concentration for an entire session, turn in at the right spot and right speed, hit all my apexes, and track out to the right place consistently. It's a vision and feel thing. I have been doing this in one light 140HP old BMW and one heavy new 400HP BMW. I learn everything faster in the light old car. If you are driving a heavy-ish car on bigger tracks, somewhere in the first 15 days, it will be time to get heat-tolerant brake pads. There are pads out there like StopTechs that can take the heat of the track, don't eat your rotors, and don't cost an arm and a leg. At about 20 days I evaluated the situation on car changes. I went with stickier tires, because that let me level up my learning on braking and cornering at higher speeds. This was on the advice of my instructors at the time; they wouldn't have wanted me on sticky tires before then. And in-car video, because I found I figured out a lot looking at video a couple days later. I read Fred Puhn's excellent book on racing suspension, and studied it until it all made sense. But I didn't change anything in my car because I frankly wouldn't have been a good enough driver yet to tell whether it was helping or hurting At about 25 days, I moved the rear spring perches on the old light car up one click to reduce neg camber and increase travel a bit. So far, my best investment of time and money by far has been HPDE weekends with good in-car instruction. No question. I'm not sure how much autocross helps. The runs are so fast and it's all about transition from moment to moment, which isn't what I do on track. I'm sure it doesn't hurt, but plain-old wet skidpad seems to be a more transferrable car control clinic for the track.

the biggest thing that I feel autocross helps with is, (well actually 2 things) it allows you to make mistakes at a lower speed that will be similar to what you can make on track … you can learn to correct the mistake with less chance of really screwing up your car …

the other thing that I see autocrossers able to do "better" than road racers is learn a new track more quickly … since they have to do that each event …

it does seem that autocrossers are able to transition to the track more easily than road racers can transition to autocross

wbjones wrote: it does seem that autocrossers are able to transition to the track more easily than road racers can transition to autocross

+1. autox is 20-30 fast turns and quick transistions in under a minute where road racing is the same 9-15 turns spread out over a couple minutes. I think learning to keep the car on the ragged edge to auto-x is what helps that transition to road racing because they've experienced that ragged edge 60-100 times in a single day session before with no real consequences.

People that dismiss auto-x so easily without ever trying it amuse me. It ain't easy that's for sure.

In reply to Bobzilla:

Well said.

Of course.... I said it so it must be true!

Autocross does indeed pay dividends, I know the reason I'm able to pass people in faster cars on the first lap of a race is I am way comfortable on cold tires......it's not just that I'm an ex motorcycle road racer and we tend to be "somewhat aggressive" in cars. As someone who as been instructing for the past 15 years there is one downside to autocross for a track day newbie. Many autocrossers are way to rough with the brakes becuase A. There are places on an autocross course where it just doesn't matter and B. as mentioned things happen so quickly that you can skate the front end and have it recover all in the span of 10ft and never be aware of it. Note that a lot of these drivers are also struggling to make the jump from say 3rd in class to winning but after the track day find the extra bit of speed.......it has nothing to do with the venue, they're driving at autocross was choppy as well BUT at a track day not having the opportunity worry about getting a good time, they get a chance to think about what they are doing.

Tom

In reply to Tom1200:

that is one area that autocrossers have to "fix" themselves as they move from the a-x to the track …and that is to smooth down their hand movements …

many times folk will come up to me after a run and say "darn, you sure do look smooth out there" and I laugh … because inside the car it's all shiny happy people and elbows …

the jerkiness of a-x really doesn't translate well to the track … and visa-versa … the track driver coming to a-x has to learn to speed there hands up A BUNCH

I find it easier to transition from AX to track than from track to AX on consecutive weekends. It takes me half to a full session to smooth out my inputs on track, but it takes me pretty much all of my runs tp figure out how to speed my hands up at AX. I have a theory about why friends who get into track stuff stop autocrossing and it involves adaptability.

I agree … it does seem that it's a bit easier to learn to slow you hands down, than it is to learn to speed them up …

crosses over to other sports also … Jack Nicklaus' Dad told him as a kid … swing hard .. it'll be easier to slow you down later, then it will to speed you up if you teach yourself to swing easy

and Casey Stengel used to tell his pitchers (this was before the abomination of the DH came into being) to swing hard … the pitcher just might hit your bat …LOL

Smoothness != input "slowness". It's smoothness at the contact patch, not the cockpit. Don't make the mistake of driving slower so you can smoothly blend inputs. If you feel like you are casually operating the controls on track you have room to push harder at a faster sample rate. They are small, quick test/correction cycles rather than big skidpad "catch" movements - but your hands should be busy.

I think your adaptability theory indicates that you could be going a lot faster on the race track using the same autocross skills you have already honed and at the same intensity - but a quicker pace.

It looks like I triggered a row of posts about the value of autocross here. I didn't mean to come off as dissing autocross, for which I apologize, seriously. It's a great discipline, filled with dedicated and talented drivers.

A concern I have been hearing around the pits with many track instruction programs is the way they advance drivers without serious wet skidpad experience or wet track experience. I know the wet skidpad time I got has saved me from probable spins, even on dry tracks. I don't have ABS in my '79, much less traction control. The only chances I get to lap people at my same point in the learning curve in that car is when it's raining and they can't put all that power down.

But for me, that's up to the sponsors of those programs to decide. I'm not the one making the decision to ride in the passenger seat with their students, and if they're fine with it, it's all good by me.

I did a day-long autocross school this spring with my daughter, and it was great. Develops vision, hand speed, dynamics and recovery, the whole lot. The instructors were really great drivers, and the ones my daughter and I got were super instructors as well.

The roll center of the strut suspension is very low. The angle of the control arm has more to do with what little camber curve there is. Odd thing, I you lower the car it lowers the roll center. the relationship with the roll center and center of gravity remains the same. With strut suspension, eliminating roll is most important. A very stiff rear anti-roll bar will help reduce roll and will also reduce under steer.

Giant Purple Snorklewacker wrote: Smoothness != input "slowness". It's smoothness at the contact patch, not the cockpit. Don't make the mistake of driving slower so you can smoothly blend inputs. If you feel like you are casually operating the controls on track you have room to push harder at a faster sample rate. They are small, quick test/correction cycles rather than big skidpad "catch" movements - but your hands should be busy. I think your adaptability theory indicates that you could be going a lot faster on the race track using the same autocross skills you have already honed and at the same intensity - but a quicker pace.

All of this is true, and is something I'll be working on next weekend.

We did go off on a bit of a tangent but it does apply in that worry less about wheel rates anti roll bars the exact brand of tire etc and just work on the fundamentals. Whether its autocross, rallycross road race or whatever you can have the most professional set up car and without fail some guy with a scruffy Miata will be going faster..............the Datsun has been a great instructor tool, when you pass someone in a 911 GT3 in the 100hp wonder they suddenly decide to focus on the nut behind the wheel. Its great that IntialDC5 is learning everything about the car he can (that's part of the fun) but seat time is what will beneficial. Of course he's overseas and needs to put that energy somewhere......so planning is good.

 Tom