Track guys,

I have been tracking my car for over a year. I have probably 6-8 hours of track experience so I am a novice at best. I am not a great driver but I am getting the hang of it. My setup helps...

Q #1 - I have camber and toe adjusters in front and back. I plan on making a 'mark' on them so I can drive to the track, pull out the jack, change them and simply change back for the drive home. Where should I set the fronts and rears? -2.5 front? What about rears and toe?

Q #2 - Read my sig on tire stagger. I should be feeling understeer right? If so, what exactly should I be feeling, what are the mechanics or better yet physics of understeer? Edit: Didn't put tire stagger in sig it's 245/275 19's

Q #3 - I am buying a LSD for this season. Which one should I get for track and daily and why?

Q #4 - What will be the inherent differences in the handling of my car at the track due to the LSD? Meaning, is it a big enough difference that I should take it slow and "re-learn" the car?

Sorry for all the questions but I am sure someone will enjoy sharing their track experience with a new guy. Thank you!!

 

We are all "right there with you". The universe of knowledge and experience comes to us only through effort and reading, seat time and learning. As long as we are all suitably humble and realistic about how little we really know, we stand a chance of living long enough to learn more.

1. Camber setting. I run 2.5 neg to 3.5 neg in the front. It depends on the track. Start with 2.5 neg and see how it feels to you before going more than that. Try 1.5 to 2.0 in the back, negative. Leave the toe stock for now.

2. Stagger. You will have understeer with that stagger. What that means to you for "feel" is that the car will "PUSH"....the front tires will be the first to lose their grip, and while you have the wheels, for example, turned to the left, the car will continue to go straight. Since you are in a turn this is not a good thing, especially if your first reaction is to take your eyes off of where you want to be headed...someplace to the left....and refocus straight ahead. When you do that, you have a tendency to fixate on the obstacle you may hit. When you are looking in a particular direction, you tend to wind up there!
Another natural reaction is to dial in more turn. ???????What is the point of that???????? The tire has already given up so putting in more turn is futile..there is no grip. To regain control you do a couple of things. First, let off the gas. GENTLY. This will put a little more downforce on the front, enabling grip sooner. Second, ease a touch of steer back to the corner, and then as you have grip, back into the turn direction you want to go. If you have to use brake, remember that the rears will be working but the fronts, at least at first, will not. They have already given up all their grip in the effort to turn, and since 70%+ of your braking is front......you get the picture? Understeer slows you way down, but it matches the natural reaction of most drivers who start to slide...they lift throttle and freeze....and given enough room on the road, it works to slow the car and regain some grip. So virtually all of your cars come from the factory dialed in that way very deliberately.

The other condition is of course "oversteer", and the feeling here is being "loose". The rear tires loose grip first and the back end starts to come around. In a left turn, that would mean that the front continues to turn on the track alignment of the front wheels, but the rear starts to slide out from under you to the right. In that situation you absolutely must NOT LIFT, for by shifting weight to the front in a throttle lift, you remove even more downforce to the rear and worsen the situation. Here you have a counter intuitive, and very quick, response required. Stay in the throttle and very quickly, as some say using "Jackie Chan hands", put a counter steering input in the direction of the curve. (This is not dissimilar to hearing somebody say, when the opponent throws a left hook.....lean into it!). But it works because the front, which is responsive with grip, momentarily takes away the excess of the inertial force sideways that is tearing the rear grip away, and you regain traction, and then reinput your left turn. Ah, but there is one thing else that happens. The side slide or "rotation of the rear end" (we are not talking about pole dancing, though it is almost as good!) yaws the car around towards the apex of the turn, pointing the car in the direction you want to go. This can allow you, when you have the ability to direct the slide and recover it at will (we are only talking a matter of a few degrees here, not some crazy Dukes of Hazzard slide that looks cool but is slow as hell) to power through a turn faster. This is where a lot of talk about "oversteer" being "good" and "understeer" being "bad" comes from. Of course, for the street......keep the understeer. And for the track...keep the understeer until you have learned how to deal with recovery of oversteer, or I should say, excess oversteer. When you get this down with some experience and practice you will be able quite literally to "steer with your feet". Go ride with an experienced instructor and have him show you so you can feel it when done right and then recognize what is going on. After awhile it becomes instinctive. But it is not at first and there is not time to ruminate on what is going on when it happens. Having left the track more than once backwards myself doing this, pick the turns you want to practice it on as the safest ones to make a mistake. No trees, ditches, walls or worse yet blind spot for the next car coming along behind you.

3. If you want smooth, get the Quaife. It will not in my opinion hold up to hard track use on a FI car, but it is seamless for the street and a very fine unit. If you want "grab" get the mechanical locker, like Nismo or Cusco or KAAZ. Middle setting of the three. It is a little bit of a "bad boy" around town in parking lots and slow 90 degree turns, but it makes a heck of a difference on the track. You can learn to handle it in town (coast around that tight turn with the clutch depressed) so it does not jerk and pop pop pop such that peoples are dropping their grocery sacks and reflexively shoving children between parked cars, while grandmothers give you the finger.

4. If you have the LSD, it gives you more the more you hammer it. The whole point is to grab under power. Don't baby it, hammer it to see what it will do. Otherwise you won't see the difference at all. That is what to "re learn"

Great questions. Have fun. This is "all good" stuff.

 

Great explanation of oversteer and understeer. At the beginning of my experience, I was with an instructor of course. He kept telling me that when I get it down, I can use my power to steer. I knew what he meant to some degree, but you made it more clear.

Thanks for the input on the camber and toe. I will set it that way and see how it does.

As for the LSD. I have heard great things about the Cusco at 60% with Motul. I will probably go with that one.

One more, my high boost can put me around 560whp or so on a fairly warm day. Should I keep it around 520whp for the track? Isn't there a point on track where you can have too much power? I have read that anyway.

Eagle1, thanks man. I really appreciate you taking the time.

BTW, I am really having a blast. I usually master things pretty quickly. This will take years no doubt and still may never "master" the art. Thanks again.

 

My suggestion is you invest a small amount of money on a powerful track tool - A tire pyrometer (you can get a great one for less than $100). This will tell you how to get the most grip out of your car.
If you are planning on changing your alignment all the time then at least buy a bubble camber guage. And if you plan on changing the rear camber you will need to get a toe guage, as when you change the rear camber you effect the toe on the Z. My suggestion is that you find a middle ground for the rear (around -1.5 camber) so you don't have to change that.
What ever you do make sure you only make one change at a time.
If you want to know to know more about set ups and what effect it will have than I suggest buying a book (Carroll Smith is one of the best).

As for a LSD - any of them will take some getting use to. And from everyone I have talked to that races - most people go with a clutch type (Nismo, Kaaz, ...) since it is cheaper. Yet, a gear type (quaife)- once you set up the car properly and get use to will give you longer life and can take just about any torque you send its way. I would suggest first reading, playing with the set up at track (taking tire temps) before you change the LSD.
I have mastered many other sports, yet what I love about this one is there is so much engineering involved in the car that can help the driver. The one thing I hate about this sport is how much of money pit it can become - fast!

As for hp, I took away hp on my Z and got faster (500whp to 440whp). Yet, I think I am now I could handle the hp since I now am a better driver and have tuned the car to get a lot more grip. So as far as having to much hp - it depends on how experienced you are and how much grip you can get out of the car.

 

MoodDude,

Thanks for the response bro. I bought a tire pyrometer last week. I have had a lot of issues with camber and inflation. I have not had one and it has been hard to figure out. Last time, I used another guy's meter and he helped me trying to dial it in so I figured I better get one.

The rear is at -1.5 right now. You are suggesting that I leave it there so I will do that. I have been told that I don't need to change the rear if I leave it at -1.5 before so you confirming that is good.

I must check out the Carroll Smith book. You really think I should wait on the LSD huh? Going out there without one won't hurt so I'll check it out for the first event. I haven't had one thus far and I have been doing pretty well because of my mods versus most everyone else in my class so it won't hurt not to have it.

Good feedback on the power. I felt like I needed to back off a little and get more control. I thought it was just me but this is a real 'feely' type sport. If I feel something, either literally or just gut, I should go with it. I am going to turn it down a bit and work on grip. It makes sense, I may be faster this way as a novice.

Thanks Dude...

 

Hi,

Saw that you are in Houston, which group do you go to events with? We (SPL) will be at Texas World Speedway on Jan 20 with the TWS Motorsports Club to test and tune my 300ZX before going out to a time attack event in California next month. Sfarrah will also be there in his 350Z. If you see us at the track, come by and say hi, we can help you take some tire temps and make recommendations on your suspension settings, especially since we are very familiar with the SPL front camber arms

 

I run with these guys http://www.thedriversedge.net/

I will have to check out TWS. I'll let you know!!!

I actually don't have the reg SPL arms. I have these.

 

Yup that's us, SPL PARTS.

I have been attending Driver's Edge events alot the last 2 years, but I don't think we've met, I have not seen a FI 350Z at the events. Do you know Chuck, Renee or Steve? Unfortunately with our schedule this year I don't know if we will have many opportunities to attend upcoming Driver's Edge events...

 

Good advice from MoodDude above.
Motul or Redline diff oil is fine. Think about adding MOC lubricant if you use a clutch type lsd, it really helps I have found.

As to having too much power. Hmmmm.

The issue with power is not having too much, as much as it is being able to hook it up effectively and to control it "at the edge". This is especially a problem with turbo power when you move into the realm of more than 500rwhp on our cars, and most others. And the reason is the oft spoke of "lag". Rather than go into a long dissertation, let's just simplify and note that with NA power, and even supercharger power, the response to the throttle is pretty much both instantaneous, and predictable with some measure of precision. With turbo power, which is dependent on having the turbos spooled up with your exhaust gasses, there are times when they are not going to deliver power in anything close to a linear fashion should their rpms (and we are talking 80,000+ rpms here) are below certain boost levels. To get the higher hp, you need to use larger turbos to flow more boost. But larger impellers require more exhaust gas, so they "lag" between application of throttle and build up of exhaust gas to turn the impellers. It also makes the power, when it comes, more of a kick in the pants. That is fun on the street...but on the track in the middle of a 100+mph turn a sudden surge in power can exceed the adhesion of the tires and whoops.....of into the weeds you go. At best you have a problem with then lifting throttle, counter steering and basically fighting for control when in a NA or SC car you would have had time to check the gauges. Some drivers refer to it as "tur-blow"!

So, the real key is smoothness. Really fast drivers don't look jerky or violent in their car action, and they are faster, way faster than the rest of us. If you can control the power, you can use it. If you cannot, it is wasted horsepower. It takes time to build up to it. Right now, around 500whp is about the most that a turbo application on our cars without significant lag can deliver.

Now, can you hook up 800hp? Absolutely. Can you do it today? Probably not. When you can............yikes look out.

 

+1 everything Eagle1 just said

Depending on the rpm and throttle position you're at, the consistency of throttle response and lag with turbos are not going to be consistent going through turns

Not only that but even on the same size turbo, the more boost you run, it still takes longer to reach 15 psi @ 4200 rpms than it does 8 psi @ 3500. Of course the goal is to always stay higher than either of those rpms anyway, but on really slow tight turns where you might have to drop into 1st gear normally but you decide to hang in 2nd instead - that might have an effect on how smooth you come out of the corner on your line.

With an exponentially increasing amount of torque as the boost goes up while you're linearly pushing the throttle down, you have less time to react to make corrections

 

To solve the turbo lag issue with my car, I did the following:

-Open the up the exhaust (I will open it up even more this winter to run some racing mufflers)
-Lighten up the flywheel
-Lighten up the harmonic balancer
-Lighten up the wheels
-Installed a boost controller and tuned the gain on a dyno so my torque would perfectly linear
-Turned down the boost to 9psi (I lost 60whp when I did this)

So now I don't feel any lag at all my car is so consitant than when I give other drivers rides in my car on track they are suprised when I tell them it is a TT.

 

yeah if you use turbos to give you just a little more power, that's going to be easier to control than having them be responsible for like 80% of the power the car makes while the engine itself makes 20%

another thing that can be done is get a stroked engine for more displacement

 

Mood,

That's some good stuff. Would not have thought of some of that.

Eagle1, I def hear you. No amount of whp is too much if you can control it. Its just like anything else. Extreme situations require extreme measures. Control, and fluidness, if you will, is the key for sure. I am just trying to learn some of the basics at this point. Rev-matching, and heel-toe is no problem. Its knowing what is going on with the tires, suspension, over-under steer, looking way ahead and using peripheral vision when seeing the line. Those are the things that make it difficult. Anyone can spend a bunch of money on a fast and track worthy car, but the talent and experience that it takes to put it all together is incredible.

Thanks.

 

True that. Nothing replaces displacement...

 

I think I may have met Chuck, almost sure of it, blue Z right? I had a lot of track time early 06 then fell into some ground/charging/electrical issues that cost me time behind the wheel. Everything is good now and this will be a good track year for me. When I get me schedule booked, I will drop you a line.

 

Great responses guys, I am very glad to see the ever growing number of track-go'ers in the Z & G community. '07 should be a great year indeed.....

 

WA2GOOD, I got your PM and responded. Thanks.