This is a review of the Maxxis RC-1 tire and some comparisons with the Nitto NT-01 tire, as run on my 2000 Boxster S at Roebling, Sebring, and Road Atlanta, which are the three tracks at which I have run both tires. Sizes run were 225/45/17 front on a 17x7 wheel, and 255/40/17 back on a 17x8.5 wheel. My car setup is M030 sport suspension with Koni FSD dampers, with -2.5 camber in front with zero toe, and -1.9 camber in back with .08 degree of toe in per side. I seemed to have best results with hot tire pressures (after a cooldown lap) of 34-35 PSI. I do have a pyrometer but unfortunately I don't have much of a "crew" (they seem to be sleeping all the time) and I never was really ever able to get a good set of "hot" pyrometer data.
Initial impressions:
The Maxxis RC-1 has a very impressive amount of tread wrapping around the sidewall and has more of a "rounded" profile on the edges vs a more square edge (that often seems to wear away quickly) like the Hankook R-S3.
This lead me to theorize that it might be better on camber limited cars. At Road Atlanta and Sebring they wore very evenly with my setup above, only at Roebling do I experience the excessive outer wear on the outside edges of the left tires. Roebling is hard on tires because it is all sweepers and those left tires take a beating. I have chunked a set of Hankook R-S3 at Roebling before I got GT3 LCA in the front (and another set of R-S3 at Carolina Motorsports park back when I was only running -2 in the front) but I have really thrashed this set of Maxxis RC-1 with no chunking. Maybe because the tread depth starts at 6/32" and/or maybe because it is an R-compound?
Sizes:
The Maxxis RC-1 (when unmounted) seemed to be a touch narrower than the Nitto NT-01. Since 225/45/17 is fairly pinched on a 7" wheel and 255/40/17 is a little pinched on an 8.5" wheel, I felt that this may be to my benefit. I have seen in several places that running a narrower tire on the maximum supported wheel size is faster than a larger tire pinched on that same size, for example a 225/45/17 mounted on an 8.5" wheel would be faster than that same tire mounted on a 7" wheel, and maybe faster than a bigger pinched tire on the 8.5" wheel. I have no first had experience to back that up, but these RC-1 did fit very well on the stock wheels and did not look as pinched as the NT-01. The RC-1 also has a very stiff sidewall which may contribute to the fit and also how it felt when driving on these wheels. I am happy with these tires on the stock 17" Boxster sizes and don't see a need to go up at this time (which is handy since wheel sizes are limited in 17"s). I have been toying with the idea of running my front 225/45/17 tires on an 8.5" wheel to see if that does improve grip up front and help reduce some understeer, but so far I haven't been able to test that out.
This photo is an unmounted Maxxis RC-1 next to an unmounted Nitto NT-01, this is a comparison of 255/40/17. Unfortunately I don't have a comparison with tires mounted, or a measurement. It looks quite extreme in this photo but it is only a few mm, the biggest difference seems to be the sidewall of the NT-01 sticking up.
Balance and handling:
With my setup and these tire, the car does trend toward understeer. I do like a little bit of understeer, but this understeer was limiting me especially during mid corner and corner exit of long sweepers, and also somewhat during tighter corners as well. This was especially apparent at Roebling Road Raceway, which is all sweepers. The only time I got oversteer was if I trail braked too deep into a corner (I do a lot of trail braking) and didn't get on the gas, and also if I had to lift for any reason during the mid-corner phase. With just a little more grip up front, I think it would have been perfect. Right now it is pretty good:
- Corner entry - I have plenty of front grip especially when trail braking
- Mid corner - limited by understeer, I think I could go faster if I could even this out.
- Corner exit - understeer, but that is expected since I am at full throttle usually and all the weight is on the back
Feedback:
I feel that the RC-1 gives a good amount of feedback, depending on the track surface they can squeal or give a low rumble when you are getting to and past the limit. On tracks like Roebling with long sweepers, I was able to hear the tires singing, and I could also feel the car moving under me, but in a good way, and it helped me to build confidence to push the car harder.
(wow that front tire looks downright skinny from this angle...)
Wear:
These tire wore pretty evenly throughout their life right up until the end when I corded both left hand tires at Roebling, with the front left being corded worse than the back left. When they corded, that set of RC-1 had around 2400 street miles and 1006 track miles with 424 laps over 49 sessions and 10 track days, including 3 days at Sebring, 1 day at Road Atlanta, and 6 days at Roebling, 3 of which were open track days with around 75+ laps each day. This last trip to Roebling was an open track day followed the next day by 4 20 minute PCA sessions. If I had swapped the wheels over to the other side before that PCA day, I could have probably gotten another PCA weekend or two out of them, and if I had been able to flip them on the rim I bet I could have gotten several more. Maybe I was sliding the car more, or else getting faster and putting more load on the outer edges of the tires, but with the two corded tires, there was still some usable rubber left on the rest of the tire (and the other two tires are still good and I am keeping them as spares). The inner edges looked brand new. Although I did rotate the wheels side to side between events in order to even out the wear, I should have dismounted and flipped the tires after maybe the 7th track day and I bet I could have gotten another 7 days out of them. I may try that on my next set, depending on how they wear based on some upcoming setup changes I am contemplating.
This is after my first few track days on the tire:
Here are the tires after they were corded:
You can see there is some life left in the rest of the tire.
Street driving:
Although these tires are DOT legal they are not intended for street driving. However, I did drive them to/from all of my events (mostly highway driving) and they did fine. I did drive through some rainy spots, but luckily no major standing water. I would be fine driving these in the rain but would slow down majorly if water were to pool up on the roads. These tires have much less road noise when street driving than the Nitto NT-01, the few times I drove the NT-01 on the street I thought something was wrong due to all the noise…
Lap times:
I set new personal bests at every track that I took these tires to, but some of that can be attributed to my experience level going up, especially at tracks like Road Atlanta and Sebring where it is often a year between visits. I feel like I am an intermediate to advanced HPDE level driver, and while I am not fully maximizing the tires, I feel like I do an OK job, especially in the slower corners. Where I leave a lot on the table is in the faster corners. For my home track, Roebling, I rode with a pro driver/coach in Feb 2017 and he drove a string of mid 1:24 laps in my Boxster. I do not believe he was driving at 10/10 since it was my car, but he wasn't poking around either. At that time, my best was a 1:29.something and I reduced it to a mid 1:28 that day. (He was driving on Nittos, and I actually got my 1:28 on Hankook R-S3 that I switched back to because I corded the back left tire later that day). Since then, I have worked my way down into the low 1:27's on the RC-1, typically following this pattern: On a new track day, I would run strings of laps equal to my previous best, and then maybe get 1-2 flyers a half second faster. Next time, my strings of laps would be equal to my previous flyer, and I might get 1-2 a half second faster.
My best laps with the RC-1:
Roebling - 1:27.402
Sebring - 2:43.698
Road Atlanta - 1:52.17
These are my personal bests except at Roebling this most recent visits I got a 1:26.874 on the Nitto NT-01.
I still am leaving so much on the table at Sebring and Road Atlanta, but I am getting there
I just don't get to those tracks very often. At Roebling I am still leaving a lot on the table, just less than I leave at the others
You can see these lap times and videos here:
https://www.tracklaps.net/driverlaps.php?GID=37
Comparison with Nitto NT-01
Since I corded that set of Maxxis RC-1, I went back to my older set of Nitto NT-01 that got on sale last year. These tires had 6 sessions at Road Atlanta (set new best and shaved off like 7 seconds from my previous visit 18 months before, 1:53.something I think), 4 easy sessions at The FIRM in FL, and 4 session at Roebling (loaned them to a friend who had a tire issue that weekend). This was before I got the RC-1. At my most recent event which was my first event since cording the RC-1's, I used these tires for a weekend at Roebling with Florida Crown PCA. This weekend was unusual in that attendance was very light and they combined run groups and we got lots of extra track time, I ran 9 sessions ranging from 20-40 minutes. I got soooo much track time it was crazy, it was like an open track day at PCA prices. Compared to my previous trip to Roebling where I ran many strings of 1:27's on the RC-1, I only got a few laps in the 1:27's, but I did get one golden set of 3 laps with two high 1:26's and a 1:27.1 (previous bests were 1:27.4). However I felt like I had to work harder to get them (but this may be because I had been on the RC-1 for so long and the NT-01 felt different) The Nitto NT-01 seems to like to slide more that the RC-1, and you really have to slide it to get those faster times. Also (and this surprised me) the NT-01 seemed the be "looser" and I was getting oversteer in places I didn't get it with the RC-1, like on the entry to turn 1 at Roebling and more times in turn 5. At the end of the day, it was the back left tire that took all the beating, and the front left tire looked great with no unusual edge wear. [
edit: When I took my wheels off to inspect them, it turns out I corded my front left this time after all so scratch that] It was still biased toward understeer, but not as much as with the RC-1. To compare, with the RC-1 it was both left tires that corded but with the front being worse. I had heard of folks having to change their setup based on a different tires but this was the first time I had felt it for myself. To keep driving on the RC-1 I am going to have to do some setup changes on my car to get more grip up front and reduce the edge wear on the left tires at Roebling, but if I were to stay with the NT-01 I would only need to solve the wear problem on the back left edge, maybe either with more neg camber or maybe by reducing body roll? After this last weekend of use, the NT-01 are now down past the tread grooves (6.3/32" when new, by 3/32" the tread grooves are gone) which means I am past the halfway point, and if I don't solve that left rear tire wear, they will be done soon, much sooner that the Maxxis. I don't have a good photo of the outer tire edge wear as it didn't show up very well in the photo, but here is a photo of the overall tread.
Cost
The cost for the NT-01 and the RC-1 is about the same.
- Maxxis RC-1 - I bought my set of RC-1 last year when they were running a 20% off special, and they always have free shipping at MAXXIS - Victra RC-1 There is also a discount on the member benefits section of the SCCA website for 10% off. They are about to renew it for 2018 from what I understand.
- Nitto NT-01 - Discount Tire Direct seems to be the place to get them, I bought mine from eBay with their $100 off $400 special and split it into 2 orders so I could get $200 off, and I had to add a trailer tire to one of the orders to get it above $400. DTD and the local stores always have specials that are about equal to this special.
Verdict:
I like the Maxxis RC-1 better and I have bought another set of the Maxxis RC-1 and will run them when my current NT-01 are worn out. I think they are just as fast as the NT-01 and I think they last longer, at least for me, and I like the way the car feels with them.
Future car setup ideas:- Sway bars - to keep running fast at Roebling and not wear out the left outer edges, I am going to install a set of the Tarett GT-3 bars, to see if I can tame some of the body roll and hopefully keep more of the contact patch on the road on the left tires and spread some of the work out. If I was only running at tracks that weren't all sweepers, like Road Atlanta, Sebring, The FIRM, and CMP, I think my current setup would still be fine.
- Camber - I could probably get up to -3 in the front with my current hardware but I am maxed out at -1.9 in the back. Aftermarket eccentric monoballs or bushing would probably get me an extra -.35 or so, but I am on Meyle LCA and their inner bushing is 1mm larger than OEM so replacement bushing won't work. A 2nd set of GT3 LCA would solve that, but that is halfway to the cost of a set of PSS9. I am going to try the bars and see how that works out.
- Lowering springs? I really like the way the car feels right now and don't want to make a drastic change. ROW springs would only get me -10mm lower in the back at best and I don't know how much extra neg camber that would give me. Eibach pro springs are an approved combo with the Konis, maybe I will source a used set of those and see how it does.
- Maybe I just will be more diligent about rotating my tires and flipping them on the rim. I feel like I am pretty close, it won't be a drastic change that gets me the rest of the way there.
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