Hey everyone! This past weekend was Round #7 of the 2009 Redline Time Attack series and the third round for the Street RWD West season championship. The DoubleDownMotorsports.com Time Attack Nissan 370Z was out there competing in the Street RWD class. Here is our story from the weekend as well as our quick impressions of some new parts that we finally got to track test.
The Setting:
The event was held 45 min outside of Las Vegas at a track called Spring Mountain Motorsports Park. It was blazing hot with the asphalt reading 150 degrees...in the paddock so I figure 165+ on the actual track. The track itself was 3.1 miles long with 18 turns. Definitely the perfect track for lightweight cars that have high cornering speeds and definitely not a horsepower track. Our 370Z would surely have its hands full in both the temperature department and the wieght department. Especially with the abundance of lightweight S2000s and Lotus' (Loti?) we would be competing against.
The New Parts:
The last time attack this car was at was Round #2 of the Redline Time Attack series at Willow Springs back in May. Since then we have added a few things to the car.
Back at Round #2 the high temps and lack of front camber adjustment from the factory left our front tires screaming for mercy after about a half of a lap. To fix this, we put SPC Performance front camber arms on the car and adjusted the camber to -3 degrees on the two front wheels to take advantage of a full contact patch of tire in the turns. We also added some Hotchkis Performance sway bars to combat the body roll we were seeing and set the rear sway bar in the middle setting so we could adjust either direction if necessary.
In the wheel & tire department our lightweight 18" Forgestar F14 wheels showed up without another minute to spare. We went with 9.5" fronts and 10" rears. We are limited to running a maximum tire width of 285 in the Redline Time Attack street class, so thats exactly what we ran in the rear, with a 275 width tire up front to compliment. This is a big change in both weight and tire width as at Round #2 we were running 245/275 tires on 19" rims. We stuck with the same Nitto NT05 street tires we ran in Round #2.
In the power department we added the Berk Technology Cat-Back Exhaust, but since the production versions aren't ready we were running the prototype version with h-pipe instead of the x-pipe, which made a bit more power. We also switched from the Jim Wolf Technology Dual Pop-Charger intake setup to the Injen Technology Dual Cold Air intake setup to see if there was any major noticeable difference.
On the cooling end of things, we were unfortunately not able to upgrade our oil cooler setup from the Mishimoto universal kit, but we did get a Jim Wolf Technology oil pan spacer kit which added an extra quart of oil capacity to help distribute heat and keep temps lower.
The last performance change we have made to the car since our last track outing was a Carbonetic 1.5 way LSD to replace our wounded stock one.
The Good:
The car is defintately faster overall with the new parts than it was at Round #2. Mid corner and corner exit have improved greatly with the wider tires, sway bars, and being able to dial in proper camber settings on all four wheels. Acceleration also feels noticeably better with the lighter wheel/tire package, exhaust, and intakes. The Carbonetic LSD is incredible and really let me start putting down power early exiting the corners.
The other good news is that there were no major issues we didn't already know about or expect going into the event.
The Bad:
We will start with the worst hang up of my weekend, the Hawk HP+ brake pads. At Round #2 we started surpassing the limit of these brake pads operating temperature range. After that event we had ordered some Carbotech XP10/XP8 pads to replace the Hawk HP+ for track duty. Unfortunately a customer called a week prior to this event and needed those exact pads for a track day of his right away. Well the only ones I had in stock were the ones I had set aside for my car so I sold them. I immediately called Carbotech and placed an order but a communication error resulted in the pads not showing up in time. So I was stuck using the Hawk HP+ again but this time the problem was 10x worse. Higher corner exit speeds, wider front tires, and a track that is much harder on brakes than Willow Springs meant that it didn't take long at all to reach the pad's operating temperature limit. And unlike Willow Springs you use the brakes often at Spring Mountain so there are really not enough periods without using them for them to cool back down. So if the brakes were completely cool, like cool to the touch, then I could get one hard lap on them before they were useless and I had to let them cool down completely again. This left me with one good lap for each practice session, which is nowhere near enough and even though they worked fine for that one lap, my confidence in them was shot, which had an effect on my driving.
The second biggest problem would have been the good old oil temperature if I had gotten more than one lap at a time. Because of the brake pad issue and only being able to run one hard lap at a time, oil temperatures never got hot enough to get the car to start cutting power, but after one hard lap it was close, around 260 degrees. At that rate, there was no way I would be able to run a full 20 minute session (about 4 hot laps at that track + warm up/cool down). Now, although my oil temp problem is not fixed, the JWT oil pan spacer did indeed help the situation making the oil temps rise slower than before. The reality is, a bigger cooler core will be the only way to eliminate the problem entirely if I will be pushing the car at 100% in the summer in the desert.
The third biggest problem, is another problem we also already knew about but had gotten worse with the higher cornering speeds. Since the car could now sustain higher lateral g-forces due to the handling improvements, it amplified the fuel starvation issue. At round #2 we would start seeing fuel starvation issues starting at a little over half a tank and below. At this last event, the fuel starvation started occuring at anything below 3/4 tank so I had to keep the tank completely full to avoid the issue which is a lot of extra weight to be carying around when you are trying for your best lap time.
The fourth problem is a small and temporary one that is normal. I battled all weekend with an understeer issue that I am attributing to the front sway bar mostly. With switching from a 245 front tire with not enough negative camber to a 275 front tire and the proper negative camber you would think that oversteer if anything would be the prevalant issue. This was definitely not the case. The understeer was occuring on corner entry and mid corner and would go away as I rolled on the throttle for corner exit. The car rotated and exited the corners so beautifully that I concentrated on tweaking the front compression/rebound and tire pressure settings first. With the brake pad issue leaving me with one lap every session to test & tune, I didn't get much opportunity to play with it but by the second and final time attack session the understeer issue had gotten better, but still not anywhere near 100%. I personally think that the front sway is too stiff for my setup and tires, but since it is not adjustable I will have to play with the things that are adjustable to try and offset it. It was a problem that affected my overall results but a problem that will go away with more testing and tuning.
The Results:
The previous record for a Street Class car in time attack competition at this track was set back in 2005 at the very first Redline Time Attack event ever. The record was a 2:49.439 in the same month and I am sure the same hot conditions. I am not sure the details on the car or driver who set that record, but the rules back then for Street Class were WAY more open than they are now so I didn't really know what to expect out of myself or the 370Z since I haven't run a timed event at that track in that configuration since 2005 in my old 350Z before it was even turboed and it was probably my fourth track event ever. When the weekend was over my fastest time was a 2:42.213, a little over 7 seconds faster than the previous record! Now, don't get too excited because a lot of us shattered that record and I ended up with 4th place in Street RWD hahaha. That being said, given the fact that my 370Z is nowhere near the limits of the Street Class rules, or even the Stock Class rules, I am extremely happy with the outcome. I was almost exactly one second behind 3rd place and 2.3 seconds off of 2nd place which isn't a lot on a 3.1 mile track. In a perfect world with 100% confidence in my equipment and no handling issues, I really truly think I could have taken 2nd place. 1st place went to Manly Kao and his rule bending Lotus Elise which is incredibly fast, especially at a track like Spring Mountain with 18 turns.
I do also want to give a quick congratulations shout out to Paul and the guys at AE Performance who took 1st place in Stock RWD with their 370Z coming in with a lap time of 1:43.830!
Stay tuned for more photos and video from the DoubleDownMotorsports.com 370Z!
CLIFF NOTES:
- Car is faster than it was at Willow Springs in May
- Hotchkis Sways get our approval, although the front sway may be too stiff for street tires.
- Carbonetic LSD gets our approval
- Jim Wolf Technology Oil Pan Spacer gets our approval
- Injen Intake/Berk Cat-Back get our approval
- Hawk HP+ pads suck unless your car is completely stock
- The fuel pickup placement in this car is absolutely rediculous. Everyone will need a baffled fuel tank or fuel surge tank to track this car.
- Broke the track record from 2005 by over 7 seconds!
- Still only good enough for 4th place in Street RWD, but only one second off the podium.
- AE Performance won the Stock RWD class with their 370Z!