Porterfield R4-1 on 2016 ND Review (Long)

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Porterfield R4-1 on 2016 ND Review (Long)

Post by DonaldR912 »

TL;dr: Install these with confidence, expect to clean wheels more often

Background: I am by no means an experienced racer but I have several track days under my belt in a Mini Cooper Convertible (non-S) kitted with Intake / Catback exhaust mods and Kumho V710 slicks but stock suspension, brakes and fluid.
I've driven the Mini at Palm Beach International Raceway (PBIR) previously so this is an comparison of the R4-1 pad performance on the Miata ND (*on stock summer tires*) vs. OEM Pad performance on the Mini at the same track under similar (dry/hot) conditions.

Since this was my 1st track event in my Miata, I signed up for Novice group and was happy to find that of the 50 or so cars participating altogether, the Miata was by far the most popular car with about 15 total in various stages of modification. Mine was the only ND and garnered a fair amount of attention.

Track: PBIR is a 2mile track with 10 turns and the main straight is ~6/10mile long.
Track Map Here if you're interested: http://racepbir.com/tracks/road-course

For the Miata, most of the corners are 3rd gear and aside from main straight, you touch 4th briefly in 3 spots, short straights before corners 1, 4, and 6. Hard braking with H/T downshifts required at same places. Each corner was marked with apex cone and had the normal series of cones marking the braking zones for reference though I'm not sure what the spacing was between them.
Each Run group was on track for 3 x 20min sessions w/ approx. 45min between sessions. When I ran this format in the Mini on OEM pads/fluid, the 1st session went well with hints of fade in last lap of 1st session, definite fade midway thru 2nd session requiring me to pit after 15 min, and only 2 laps at pace in 3rd session before I pitted due to lack of confidence in braking system. Upon inspection, fluid seemed ok (not boiling) but pads had glazed rotors and were smoking hot. :evil:

Performance: 1st lap from pit lane I drove moderately to allow tires / brakes to come up to temp, all laps following were taken with progressively more pace as I explored the limits of the stock suspension (sport), tires and upgraded brakes.
I experienced ZERO fade in all 3 sessions!

I found the R4-1's to give excellent initial bite (no jerkiness) and good linear feel through pedal travel to ABS threshold. Once I found that point, I was able to (i think) get the most out of the stopping power of the pads. The pads were consistent in that every lap, the applied power matched the applied input. As the brakes heated up (my lap times were in the 1:45-1:50 range), their behavior did not change. When I got off them, there was no release lag.

In the 1st session, I reached ~100mph and was on the brakes at the 4cone brake marker with much room to spare.
By the final session, I was consistently passing 115mph (best lap when I nailed corner leading onto back straight: 122mph ) and was was able to push my brake point to just before the 2cone marker, H/T into 3rd and take the "carousel" on the racing line. If only I was able to put together a consistent lap, I think I could have been down to the low 1:40's and with more practice I have expectations of breaking the 1:40 point regularly. At some point (soon, I hope), I'll put in a FSB & Koni's and that should have a major effect on handling and lap times.

  • Initial bite: Excellent and smooth
    Consistency: Best Feature, no difference (to my amateur butt) between 1st hard lap and last w/in session
    Release: Good, not lag or drag
    Durability: These pads lasted the entire event with no fade. Time will tell how long a $350 set (F&R) will last with mixed usage and 1-2 Auto-x + 1 Track event/month
    Noise: ZERO on track, minimal on street
    Dust: Significant. If that's the only price to pay, I'll work on my wheel cleaning technique.
You can view one lap from my final session here: https://youtu.be/lcmyZM5Hut4

Recommendation: Install these (coupled with Dot 4 fluid) and enjoy great street performance coupled with excellent Track performance.
If it matters to you, there will be some minor squeal at very low speed and you WILL have to clean your wheels more often to keep them clean or install Charcoal/Black wheels and it will be much less noticeable.

Next step will be a fast Autocross course on an airfield runway with Gulf Coast Autocross club in Fort Myers on Sept. 10/11. This will present an entirely different challenge for the Porterfields and I'll update this thread after the event.
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Re: Porterfield R4-1 on 2016 ND Review (Long)

Post by Brian »

Great review, thanks for sharing!
Brian Goodwin
Good-Win Racing
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