dkmura

iTrader: (64)

Yesterday (11/23/02), I ventured to Pueblo Motorsports Park (PMI). PMI is a 2.2 mile, 12-turn road course set in the high desert. It's been a favorite of mine for years, with a combination of long straights leading to a fast, slightly banked right-hander. The rest of the course is a combination of scintillating elevation changes and linked right-left combinations with a hairpin in the middle. Pavement is not Mid-Ohio smooth, but the best feature is that it can be rented cheaply (the going rate is $60/car). Unfortunately, none of my SCCA friends or any of the local 350Z or S2K communities showed up, so I paid the track manager and went to pit road by myself.

Arriving at 1 p.m., I planned to initially bed in a set of Hawk HP Plus (purchased from Andy Lim of Cobalt Friction Technologies- thanks Andy!) for my track model's Brembos and run a set of five progressively faster laps. My redline 350Z eagerly headed out and flew down the combination dragstrip and front straight. I could immediately sense that the brakes did not feel right, with a soft petal, as I trailed the brakes into the first turn. I pitted and asked the track manager (who had a few tasks to complete) for a little help. It was great not having to pull the wheels to bleed the brakes, but that is another advantage to having the Brembo bleed screws near the open spokes of the Rays wheels.

After going out again, the brakes were fine and I proceeded to put in two sessions of five and seven laps. Each lap I tried narrowing the brake distances before turn-in and experimenting with the line to get the car a bit more balanced. As raceboy has commented in his posts, the 350Z has such resolute understeer that it was difficult to get the car to rotate properly. Once up to speed, almost every turn was marked by front slip angles getting progressively larger after initial turn-in. Backing out of the throttle allowed the line to tighten up, but in some of the faster four-wheel drifts, this unbalanced the car. Even dropping the throttle on a flat-in-third uphill right-hander failed to provoke the rear end out.

Since I hadn't driven competitively since a July SCCA event, I needed the initial laps to knock the rust off my driving. After this, I ran a 15-lap session in which I switched off the VDC after the first few laps to see what difference it made. This finally got the tail out in a big way, by booting it out of the tight, left-handed hairpin that is turn seven. The weight and power of the car swung the Z out and yet it managed to be a controlled power-slide, without tank-slapping the other direction. Driving without VDC was definitely fun on a dry track as squeezing the throttle of the VQ35 achieved the best exits off the turns. Best I saw at the end of the long front straight was 118 MPH, but I was fairly conservative in doing my laps (after all, it was my a** on the line if anything bad occurred).

After this I played around with the drag strip and trying to use the digital display to give me 0-60 times, but I seemed to be ham-handed and could never trip it properly. The wheel hop was pretty evident on any launch over 3K RPM, but this could also be due to the junk that was laid down on the start pad. After this, I let the car cool down a bit and took some tire pressures to verify what the digital tire read-out was telling me. Sure enough, on a clockwise road course the left side tires were gaining pressure more quickly and I was taxing the right front more than any other tire. The OEM Bridgestone 040s failed to impress me and I noticed some chunking in the middle of both front tires. Thinking they might be overinflated, I tried dropping two PSI on the fronts. But this failed to make much difference (except some sign of sidewall rollover) during the next session.

By now, the sun was beginning to set and it was proving difficult to see as I dove into some of the west-facing turns. I was about to pack it in, when it occurred to me that running the course counterclockwise was an option. PMI has never been sanctioned by SCCA for running 'backwards' and the reasons were plain to see. As I drove some moderate laps, I noticed several sections where inadequate run-off would make the course dangerous indeed. Still, I enjoyed the rhythm of this configuration and the 350Z seemed to enjoy the moderate pace and 115 MPH blasts down the front straight.

So what did I learn? The 350Z is indeed track worthy and my assessment is that there is a lot of potential (better tires, more front camber, stiffer rear roll rates and less body roll) in the development of the car. The VDC and built-in understeer will serve to keep many out of trouble. The built-in technology of my Z helped out on several occasions, when my aggressive instincts had me going (deep-deep-DEEP!) into the turns and the ABS (don't panic- keep steering and keep your foot firmly planted on that pulsating pedal) bailed me out of running out of road or some flat-spotted tires. Tonight it's snowing here in Colorado- hopefully there will be more opportunities to get more track time before the year ends...

John

iTrader: (17)

Good review!

CoachZ

Sometimes, I miss Colorado. It's 80 degrees for a high today in Fort Lauderdale, so taoday isn't one of those days

Great write-up! Must be a blast to have a track to yourself.
Josh

Chebosto

iTrader: (43)

hey that's pretty cool,

what did you think about the Hawk Track pads? where did you get them and for how much?

have you tried driving aggressively with the stock pads?


what are you thoughts on the dusting issue with the hawk pads?

hmm. what else can i ask you,

oh yea. were there any chicanes or saloms on the track and if so, how did the car feel from the quick transisiton from left/right w/ and w/o VDC?

thanks!

--cheston

ChinaClipper

iTrader: (2)

Thanks for sharing.

John

iTrader: (17)

Andie at Cobalt Friction sells them. I don't know their price though... Hawk HP+ pads are their AutoX pad, but will suffice for HPDEs... very grippy, but leave a TON of dust... Hawk's "track" pads are the Hawk Blues or Hawk Blacks, which will eat your rotors, especially when they're cold.

I'm not going to answer all your other questions since I don't want to hijack the thread, but I'd like to see the authors opinion so that I can compare mine to his...

dkmura

iTrader: (64)

To Cheston and Hedonist-

You're right, I bought some HP Plus pads from Andie Lim at Cobalt Friction Technologies. They were available on short notice and Andie gave me the 'My350Z.com' discount, so they were not too expensive. Let me know if you need his # or e-mail and I'll post it.

The HP Plus is just a step up from the stock pad and I didn't notice a lot of difference in braking efficiency. BUT they did hold up well, which is more than I can say for the OEM pads! When I swapped them out, the OEM was about a 1/3 worn with only 1700 break-in miles on them. Those service checks will be important just to make sure you don't score those pricey Brembo rotors! I've used the Hawk black compound on a tube-frame race car and thought they worked well. Recently, we switched to Performance Friction's '97' compound and found it had better bite and a higher co-efficient of friction (read: they stopped the car faster). All of these are full-race compounds, are tougher on rotors and are designed to work better at higher temperatures.

As for the dusting problems, I think the 350Z is simply a (relatively) heavy and powerful car- the HP Plus did have as much, if not more, dust than the OEM pads. Andie mentioned that he will be carrying Ferodo's new 3000 compound for the Brembos later and this may be something I'll try next summer for track events.

Finally, there are some linked right-left esses at PMI that tested my 350Z's responses. The car felt quite stable, both with and without VDC. Driving the line and using smooth inputs was more critical in this regard.

Hedonist- don't be shy- what are your thoughts on a good brake pad? Think of something that works well in freezing temperatures as well as being tortured in blazing heat. Also, they should be cheap, long-lasting and not put any of that pesky brake dust on our shiney wheels! LOL!