Hey y'all. Here's the latest installment of the track tested mods I've done on my G35 coupe.

Went to my test track, Toronto Motorsport Park, and baselined the G with the stock calipers and rotors and Hawk HPS front and HP+ rear pads (couldn't find a more aggressive front pad because of the different caliper and pad shape Nissan went to on the RevUp G35's starting in '05). Best lap time was a 1:26.1, which is a respectable time for a 3500 lbs car on street tires (Goodyear Eagle F1 Asymmetric, 265/35-18's all around). We also took caliper and rotors temps using an infrared pyrometer so that we could compare heat control of the OE system vs the AP Racing BBK we'd be installing the same day.

With the baselining complete, we threw the car up on jackstands and ripped off the OE brakes and installed the AP's. Here's some comparo shots.

OE 12.6'' Front Brakes:


OE 12.1'' Rear Brakes:


AP Racing 14.25'' Front brakes:


AP Racing 13'' Rear brakes:


I opted for 6-piston front and 4-piston rear AP Racing brakes since we wanted the largest possible heat sink to absorb all the energy a car this heavy throws at them. The front and rear AP kits came complete with Mintex Xtreme Motorsports brake pads, DOT-compliant stainless steel brake lines, and all the brackets and fasteners required to make install painless. Took 3 of us about an hour to do the job, but we're all experienced mechanics. The two-piece AP Racing aluminum calipers that come standard in these kits have more rigidity than most monoblock designs and feature a hard anodized finish as well as dust seals and anti-rattle clips. The rotors are slotted (to increase pad bite and prevent pad glazing) and cross-drilled (to reduce weight), but the real magic happens inside where the curved vanes shed internal heat much better than the OE vented front discs and solid rear discs.

Once the install was complete we bled the brakes, pouring some fresh Castrol SRF brake fluid thru the system.



Then I hit the track to bed in the pads and rotors carefully, following the procedure outlined in AP's instructions.

Once the pads and rotors fully cooled (or close to it), I hit the track for the official retest for lap times and rotor & caliper temps.




Here's what the before/after temps looked like:

Temps After 2 / 4 Hot Laps OE Brakes AP Racing BBK’s
Front Left Rotor 734F / Over 1000F 500F / 572F
Front Left Caliper 334F / 500F 228F / 293F
Front Right Rotor 716F / Over 1000F 536F / 536F
Front Right Caliper 338F / 505F 239F / 284F
Rear Left Rotor 639F / Over 1000F 329F / 471F
Rear Left Caliper 333F / 482F 221F / 277F
Rear Right Rotor 597F / Over 1000F 347F / 412F
Rear Right Caliper 313F / 493F 214F / 271F

The 50% drop in rotor and caliper temps meant I could now lap for as long as I wanted, whereas with the OE brakes I could only lap for 2-3 laps before the brakes would start to fade badly. Better yet, the shorter braking distances provided by the AP brakes and Mintex pads delivered a big improvement in lap time, dropping down to a best of 1:23.7, almost 2.5 seconds faster than the OE setup.

If you take a close look at the G2X data, you'll see that I was able to brake later and get off the brakes earlier with the AP setup, as seen from the shape of the MPH curves (red line is AP and blue line is OE) on the graph, and you can also see that the AP's were providing higher braking g-forces or negative acceleration (orange line is AP and green line is OE). In fact, peak deceleration figures improved from 0.99g’s with the OE brake setup to an astounding 1.33g’s with the AP Racing brakes. That is a massive improvement.



All in all, a very satisfying upgrade given that I'm now able to do long lapping sessions whenever I want, and braking performance is now a real strength of the car when it was it's biggest weakness before. Plus the brakes look pretty gangster on the car and I look pretty gangster in it




If you don't have a laptop and WiFi but want to read this story on the toilet, go pick up a copy of the Nov issue of Modified Mag

Oh, btw, I have a bunch of good video from the track that I'll put together sometime soon, but for now here's a little external video I captured from the nose of the G using a GoPro Motorsports Hero camera. These cameras are dirt cheap at about $180 and can be mounted safely in all kinds of creative places (LOL), but the sound quality is spotty. Anyway, enjoy:

 

Nice work! You have the weights of the front/rear rotors?

 

Temperature differences are incredible and Props to you for doing a detailed review on a product yet again.

 

Awesome review!

Good to see a magazine quality write-up... oh wait you ARE a writer

 

Dave. I think you should clarify the brake fluid and age for both sets of brakes. I know the AP racing would have brand new fluid but how old was the fluid for the oem brake stuff? Thanks.

 

I had planned to weigh the parts, but overlooked it in the scramble to get ready to go to the track. Doh. But if I had to guess, I'd say any weight gain is minimal since two-piece rotors are always lighter than one-piece OE rotors and the cross-drilling helps a fair bit too. The calipers are also surprisingly light for their size. Holding the OE one in one hand the AP caliper in the other hand, there wasn't a perceptible weight difference. Hardly scientific, I know, but it's all we had at the time to compare. Anyway, I will weigh the stock rotors and pads and see if AP can send me weigh info, so that we can add this to the thread.

I know that adding unsprung weight is always referenced as a negative when it comes to discussing BBK's, but for me, the only thing that really matters is how the car performs on the street and at the track. The numbers don't lie - the car is way way quicker around the race track now, so whatever negative performance impact there may be from additional unsprung mass (if there is any), the improvement in braking performance has more than overcome that.

 

The OE calipers rotors had about 12,000 miles on them and were in excellent working condition. The Hawk pads, which are a real improvement over the OE pads on the street and for a few laps on the track, were basically new. Had maybe 1 previous track testing session on them and some street use for about 5k miles or so. Brake fluid was fresh Castrol SRF before and after the test. Prior to the test I had just bled in a full liter of SRF. As you may know, SRF has the highest wet and dry boiling point on the market, so there's no question based on the temp data we collected that the brake fade we were getting in 2-3 laps was from the OE rotors, calipers and Hawk street pads being overwhelmed by heat and being asked to perform outside their designed operating temperatures. With the AP's, because the heat dissipation and control was so much better, the pad and rotor performance was right in their temp sweet spot and therefore able to perform to the max of their ability.

Just so we're clear, the HPS/HP+ pads used are certainly not a reflection of how well you can expect a track-oriented pad from Hawk to stand up on your car. If something like the DTC-60's or HT-10's were available for the caliper/pad shape on my '06 Coupe, there's no question brake fade would have been delayed and stopping distances shortened since these compounds can survive at much higher temps than the HPS/HP+ combo and have a much higher coefficient of friction. But since nobody makes a track pad for the caliper/pad shape for my car, the BBK was really the only way to go for improved braking performance, which the car desperately needs for track testing and time attack use.

I really like the Mintex Motorsports pads that came with the AP kit from Brake Pros, since they work really well on the street but still take a lickin' and keep on tickin' on the race track, but there's certainly no reason why I couldn't go to a different brand pad if I want/need a more aggressive friction material in the future. Most of the major pad manufacturers will have a full range of products for AP calipers as well as calipers from other major brake system makers.

 

I do admit you do look gangsta in your G. And that is 1 gangsta review.

 

Haha...believe me, I'm the least gangsta person on the planet, but maybe the hairiest (on the body...not so much on the head).