You can run UP TO a 9" front and 10" rear....I don't see anything illegal about his wheels. I wouldn't use an 8.5" front....especially not with the 275 spec tire.

 

from the Spec Z Rules

16 Wheel and Tires
16.1 Wheels
a) Any eighteen (18.00) inch diameter rim, with a maximum width of nine (9.00) inches front, and a
maximum width of ten (10.00) inches rear may be used.
b) No wheel permitted for competition use can weigh less than eighteen point five (18.50) pounds.
c) Wheels must be one piece. (i.e. No multi piece bolted, riveted, or welded wheels.)
d) Aftermarket wheel studs, lug nuts, and wheel spacers are permitted. If spacers are used they
shall be no greater than 13mm and equal per axle. Refer to Appendix A for recommended Nissan

 

Exactly,

Just like you can run a 9" square setup if you want.

 

Why wouldn't you use an 8.5? Just asking not being a 'dick.'

I ask because my autocross set up was 18x8.5 with a 295 front and 19x9.5 with 315 rear.

 

You're effectively narrowing your footprint...significantly. In the world of spec racing it will be a disadvantage. I can tell you in terms of autocross...my car was .6-.7s faster on 10.5" vs 9" wheel using a 285 A6. I ran back to back on the same course/day. Turn in is much crisper on the larger wheel.

In short, there is no reason not to maximize wheel size IMO. Particularly since you can't go below 18.5lb, and plenty of the larger wheels are in the same weight category.

 

Any clearifaction if you're allowed to use a oil pan spacer? Wanting to use a oil cooler(which can be used). But I didn't want to drill and tap my oil pan

 

No.

 

Thats where my misinformation was then...I'd just assume to run the max size allowed to take a full advantage of the spec tire. I apologize for false information!

 

Why not just use a sandwich plate?

 

Misihimoto makes a well priced universal oil cooler kit based on a sanwhich plate:

http://www.mishimoto.com/mishimoto-u...ooler-kit.html

 

Z1 has GREAT customizable kits as well.

 

Point of clarification, please, in section 6: http://www.nasaproracing.com/rules/s...rules_2012.pdf

03-04: 3100#
05-06: 3175#
07-08: 3300#

That means that at no point during the race can the car with driver weigh less than those amounts, correct? At SCCA last week, they weighed the car WITH the driver, I'm left to assume (gasp!) that NASA is the same way? Anyone?

Update: First "official" specZ race in NorCal is April 14-15, not March 11th weekend. I should have the car ready by then.

 

I actually spoke with NASANE director on Monday for clarification of this. Cars will be weighed as they come off the track WITH driver. So what ever your fuel load is at that point will play a part

Very good, thanks

 

Given that I would probably have some weight buffer. I still remember a friend losing nationals because he underestimated his tire weight due to wear.

 

Makes sense. I took a few car weights last weekend (full and ~1/4 tank (where I had some fuel starvation)), so I'm good there.

I have some buffer since it includes the driver. With the cats (so will drop about 20#), 10" wheels, 285 tires (so may lose a few more #s), and a passenger seat, I was at 3236# with me in the car with 6 gallons of gas left. I experienced a few touches of fuel starvation with that much gas, so that's my minimum weight to finish a race, giving me about 60# of buffer. I don't expect much change with the swap to 9/10 wheels compared to my four 10s, nor much changing from 285/30 to 275/35 (probably gain a few #s there, actually), but removing the cats and passenger seat (and brackets, etc.) should net me almost 40#, putting me closer to 3200# at the end of the race depending on how bloated I am that day. I was actually hoping I'd be able to add some rear ballast, since I'm 55% front heavy and 52% left heavy. A 40# weight in the right rear would have been useful. Hmm, where to find 50 more # to remove?!! Do we need headlights (and all the associated wiring)?

 

Not apples to apples in any way...but look at F1. Every car does an entire lap (unless they don't have enough fuel) as far off line as possible picking up all the marbles to make weight.

 

My setup weighs ~3250 when I come off track after a 45 min sprint race...

I use about 1/3 tank of gas in a race...depending on all kinds of factors...and I always start with a full tank...


I have 2004 Track DE...so I am fat by ~150 lbs based on the rules...oh well

 

What we did is a couple of years ago we bought some electronic scales and we have a friend who knows how to blance a car. It took all day last year before the runoffs to get the car to its optimum. We found out that our car will stutter when the gas tank get just above 1/4 tank so we calculated to fill the tank before every race and in all cases at the track we run we know what we will have at the end of the race. Road America uses the most gas as the top speeds there are longer time-wise. Its not a horrible penalty to fill the tanks as they weight is somewhat in the middle of the car and fairly low. So what we are doing is using the gas as a weight balance. Our car in SCCA trim with driver has to weight 3400 pounds so we aim for about 3416 to 3420 at the end of the race. We use to guess how many gallons we needed to end up legal but filling the tank works best for us. We do have lead weights in the car though. Our car is basically gutted except we have to keep the dash and gages. We also kept some of the center console for other uses.

 

Rules update coming soon

http://www.nasaforums.com/viewtopic....55008&start=10

 

YAY!!!!

Fingers crossed!