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I wanted to update this thread...a generous GT4 owner is bringing his car to our shop tomorrow for a test fit. I'll post what we find. If all goes as we hope, we may have our AP Racing Radi-CAL brake system available for purchase next week. Thanks!
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'09 Carrera 2S, '08 Boxster LE (orange), '91 Acura NSX, Tesla Model 3 Performance, Fiesta ST
Jeff Ritter
Mgr. High Performance Division, Essex Parts Services Essex Designed AP Racing Radi-CAL Competition Brake Kits & 2-piece J Hook Discs Ferodo Racing Brake Pads Spiegler Stainless Steel Brake Lines
704-824-6030 jeff.ritter@essexparts.com
Jeff, AP calipers look so much smaller.
Rotors looks smaller too - are they?
So how you achieve better braking?
Bigger contact area of pads?
Thicker rotors?
Other tricks?
For anyone considering the black brake calipers at $900, these are not only considerably lighter, but also serve the same purpose of not contrasting with the wheels so much.
Jeff, AP calipers look so much smaller.
Rotors looks smaller too - are they?
So how you achieve better braking?
Bigger contact area of pads?
Thicker rotors?
Other tricks?
Our calipers are smaller and lighter, but our front disc is actually larger. Our front disc is 394x34mm vs. the 380x34mm OEM unit. Our caliper isn't nearly as tall and it is more compact, so our complete system actually fits inside the envelope of the OEM iron system despite the larger discs. That means superior wheel fitment. Better braking is achieved through superior cooling, stiffness, and thermal efficiency. There's also a long list of convenience benefits.
I'd suggest reading our complete product page in the link below. It has detailed comparisons of our components vs. the OEM ones, including pics lining them up. It will give you a more complete picture of the technology drives the results: https://www.essexparts.com/ap-racing...orsche-981-gt4
I'd also suggest checking out the thread below in the 991 GT3 forum here on Rennlist. It traces the development of this product starting several years ago, and has lots of real-world owner feedback and track results: https://rennlist.com/forums/991-gt3-...t-finally.html
You can see in these pics how much shorter our caliper is, and it has internal fluid pathways. That means the AP Racing caliper has a more compact footprint, and it's much less prone to damage from track debris. The external crossover pipe can get dinged or clogged. There is no external pipe across the end of the AP caliper. That is particularly helpful when running large discs crammed tightly into the smallest wheels possible.
In this image you can see that the OEM caliper has a fixed bridge. That prevents you from changing the pads without completely removing the caliper. That's always a real treat when doing track prep! Our caliper just has two small hex bolts that slip out, and then the bridge pieces come out and you can slip the pads in.
Also, the OEM caliper is attached with a hard line (pic below), again making it harder to remove the caliper for a pad change. Our system replaces the hard line with a flexible line.
One of our goals is to avoid this...
We do so via this...
Our AP Racing J Hook discs are far more efficient than the OEM units. You can see the difference in how much air can enter the back of the discs...huge increase in cooling airflow:
You can see in this image that our disc is actually larger in diameter:
Here you can see how many more complete directional vanes our discs have:
He meant that if someone wanted a more stealth look and didn't want to spend $900 just for black caliper paint instead of the standard red paint, they could put that $900 towards our kit instead (while also saving weight).
Believe it or not, years ago someone actually asked me if red calipers weigh less than black. That's on my all time greatest customer questions list in my head.
We have confirmed that our components for the 981 GT4 are a perfect match for the 718 GT4. We now have our complete array of Ferodo Racing pads for the OEM calipers and our AP Racing calipers, AP Racing 2-piece Discs that mate with the OEM calipers, and our Complete AP Racing Radi-CAL Competition Brake Kits available the for the 718 GT4! Full Menu of options for the 718 GT4 are here:
Also, the OEM caliper is attached with a hard line (pic below), again making it harder to remove the caliper for a pad change. Our system replaces the hard line with a flexible line.
Congrats on your solution! Now the big question is whether there are any 18" wheels that will wrap around your calipers? I'm guessing not, as you only list 19" wheels (Forgeline GE1R, GS1R, and GA1R in 19x9 +52). I'd love to know if Titan or APEX had reasonably-priced options for us track rats.
Jeff, do you have a solution for this hard brake line behind the front caliper? Is it as simple as just adding a flex line to replace the hard segment, or should the new flexible brake line go all the way back to the brake line where it is attached to the unibody?
07-24-2020, 04:14 PM
