I've been doing SCCA Autocross for a few years now and love it. I'm looking at going to a local Track Day at Watkin's Glen and everyone recommended that I get some high-temp track pads. The problem is that I have an '07 G35x that has the small 2-piston base calipers and there's no selection for track pads.

I'd like to upgrade my brakes to the larger OEM "sport" brakes that came in the '07 - '09 Sport packages on RWD cars (which my research tells me will work) but I'm wondering if it would be possible (or make sense to do at all) to just replace the front brakes and leave the base rear brakes... My reasoning is that typically brakes are balanced pretty heavily toward the front and that they would take most of the heat / beating anyways, and I may not even need the larger ones in the back. It would literally cut my costs in half if I could do that. Thoughts!?

It's a very popular step...most of your braking is up front anyway, go for it

Where do people get the parts commonly? I posted a WTB in the classifieds but other than $250 a piece new from the dealer, I'm not sure what reasonable options I have.

I just realized you probably meant AutoX to Track Days is popular, not base to Sport brakes lol but I guess the above question stands if upgrading half of the brakes is a viable option.

Are you talking about the Akebono brakes? Those came out starting in 09 on the sedan. The biasing will be off quite a bit w/ the huge calipers/ and larger rotors. Also not many wheels can accommodate the large Akebono front calipers without spacers and your stock spare won't work either. If you're talking about the previous sport brakes (07&08) disregard my reply

The Akebono's came out in 2009 with the G37 as the "Sport" option, but in the '07-'08 G35's, the "Sport" option was a large single-piston OE looking regular brake kit with 13" rotors all the way around. So what I'm looking at isn't a BBK

Will the larger / different front calipers mess up the biasing of the brakes though? That's one of my concerns regardless.

For the '07 - '08 sports front brake, do you need 18" rims to clear the rotor?

I have the sports brake and they are nice to have on the track. On hot days, I still got slight brake fade but I guess that's so much heat that the OEM brakes can handle.

I am wondering if you can upgrade to something better and stay with the same OEM wheel setup (or with the 13" sports brake rotor). I don't know if Wilwood has something small enough to clear OEM 17" or 18" sports rim without spacer and stay with OEM size rotors?

That's a valid question, I'm pretty sure 13" rotors will fit though. I feel like there's a lot of room between the stock 17's and my rotors. I'll have to measure to be sure. Good call! Mainly cost is the reason I'm looking at the stock Sport setup so unless a better aftermarket setup was available for a couple hundred bucks, I probably wouldn't be considering it right now.

What may be a decent option is finding someone w/ an 09-12 model G w/ oem "journey" brakes that has upgraded to the big Akebonos and wants to sell their smaller brake setup.
The rotors and calipers for those years are bigger than the 07-08s and do a nice job w/ braking and the part availability is extensive. You might find them pretty cheap too.

Sorry, but that's just not true. The standard brakes on the 09-12 sedans are identical to the standard brakes on the 07-08 sedans, so the 07-08 sedan Sport brakes are still larger than them. Only the G37 coupes (all years) have larger standard brakes, but even then they are only just equal (actually they are identical) to the 07-08 sedan Sport brakes.

Damn, I thought the base in 2009 got larger rotors, that's what I get for thinking
Thanks for the clarity VQ