Autocross Feedback
 

Below are a few videos from today's auto-X. Just looking to improve seems as I hit a plateau. I really need to make it to an Evolution Driving School.

Some of the habits I know I need to break are looking ahead more, getting a better line and making the best use of available course.

Vehicle Background
370Z CS
Sport Package
Bridgestone RE11 275F 305R both at 38psi
Eibach FSB stiffest setting
Stillen Catback
K&N Drop in filters

**I have a set of Koni Yellows I didn't install yet, didn't have time from when they arrived to today's event**



Thanks!

RUN 1: 50.430 seconds (Usually take it a little easy on the first runs...tried to fix this but runs start after 51 seconds.)


RUN 2: 49.326


RUN3: 49.301


RUN4 Fastest run at 49.107

I can tell without actually seeing you that you tend to saw at the wheel. You don't seem to steer enough on initial turn-in...then compensate after you get late on the turn by yanking the wheel. You are also a little late on the throttle. The evo school puts on one its best schools out there. Junior has a bevy of volunteers to instruct that event!

38psi rear seems high to me, although I run 285's. Try starting at 34psi next event and see how far you're rolling them over in comparison. Keep dropping until it plants hard.

I will say it was nice to see where the right front corners of our cars are! Nice videos.

You're right about the turn in. Not sure why I do that.

I used to run 35 psi, noticed roll over until the 37-38 psi range. It's time to invest in a good psi gauge :)

Thanks!

Another handy tool is a tire pryometer. Check, and data log your tire temps (outside, middle, inside) that will tell you if your running to much pressure or not enough, and even give you clues about what your camber is doing etc. Something to think about is start running nitrogen as well.
Longacre Racing - Online Catalog: Electronic Wheel Scales, Gauges, Pyrometers, Chassis Setup and More!

38-39 has been an ideal hot temp for my re-11s.

You are coasting into the the first long left turn. Stay on the gas longer, brake harder.

Good clean consistency though between runs 2-4

Not claiming to be an expert here but a few things I noticed:

1. Get your braking done earlier and get back to the gas quicker.

2. If you have to give up all your momentum for a hairpin/tight turn, just go tight to the inside. shorter distance = less time spent in the hairpin.

3. Look into trail braking. It made a huge difference once I started to do it. I'm still not that good at it but can tell the difference between when I get it right vs get it wrong.

4. Lastly, get ride alongs with the fast guys at the events (assuming it's allowed). It's amazing how much you can learn from them. It might even be worth it to offer one of them a co-drive for one event just to see how they handle your car. Local guy did that early this year and then proceeded to drop 1-2 sec off his times going forward.

As far as tire pressures go I ran 38 up front and 34 in the rear with the factory Nismo tires fwiw.

What 03350z says however a few more questions and tips. More important than a few psi in tires ...what are your alignment settings? I know you can't do much with front camber but toe out is critical. Secondly put camera where we can see your head and hands. I don't care what's in front of you. Lines are less important than you knowing where you're going next. We will help you far more by watching what you do behind the wheel.

In general with 370 Z you want to use brakes to set car into slower turns, use moderate throttle on exits. Look ahead. ...no really look ahead. I can see you hesitate. Not full throttle in couple places where car should be blazing. Don't be afraid to be aggressive. That's one of biggest mistakes some beginners make. Smooth is key but you can't forget to keep car on edge entire run.

It looked, and sounded like you were getting a bit of understeer is that right, and are you using the traction control?

Smooth is fast. Smooth braking, gas, and handling. Work on technic, and consistency, get that down, and speed/agressive driving will follow naturally.

For more on tire pressure. You won't be running the same tire pressure front and rear. It's important to check for increased pressure and adjust psi after each run, so you can keep the sweet spot when you find it, if your not doing that already.

For street tires, I run Nitto Invo's 265's front and 305's rear (I want to go wider in the front), and I will run 34 to 29psi front and 30 to 28 psi in the rear, and all depending on the course lay out, and how warm of day it is, but I always run more pressure in the front. I've heard a good place to start on the RE-11's is a 34psi front and 30psi rear.


Here are a couple links that have some good info. Autocross Course Driving Techniques
Autocross like a Pro
Longacre Racing Online -- Tech Article "More Than Pressure"

Here is one of my run from this year

VDC was off as well as SynchroRev. Not all the time but once in awhile if I auto-x with synchro-rev it will hold the gas on its own. The late Curtis Lee also experienced this in my Z when I first purchased it. Dealership looked at the car, couldn't replicate the issue so I have just lived with it since.

I do get understeer at times. I had less during this previous event. I'm .846 away from the first place Miata running A6s. My intent is to develop a faster driver instead of relying on mods.

Thanks!

Nasa-X Classes 2013 V.13.1
 

Attachment 76288
just in case anybody is interested.

SCCA rules are far from perfect, but NASA's flat out don't work for AX. Basically anything from BSP up would be in NXU....

I think a good plan of action is to work on those tire pressures, also might look at a faster tire like the Rival, and as Shamu suggested check and see what your alignment is doing. If your tires pressure doesn't solve your understeer issue try putting in a little bit more negative camber in the front.

Keep us up to date with what you end up doing, and how it feels at your next event.

Buying a bigger tire will take care of some of the plow. I have to be the only person that runs more pressure in the back than front

Damn it was PITA getting 275's up front on the Sport 19" wheels. I can't imagine my installers being thrilled about anything bigger.