Maxxis RC-1 tire notes
 

Wanted to share some tire data for everyone else who runs the RC-1.

Over 200+ race miles on a set of these bad boys

Very nice. These are on Ohlins Road and Track kit? Are you using stock kit spring rates are custom rates and valving?

I may try your setup with a new set of RC's.

I like this thread.

Yes Ohlins R&T kit (USA version).

"Stock" 380lbs spring front and rear and "stock" valving.

Tried a few times to put on 500/550lb springs but the car become too stiff. Even with sticky tires like V710's or Michelin's, it seems the car (or driver) prefers a slightly softer set-up.

Next season i will change spring rates only because we've swapped our control arms and the rear could stand to be slightly stiffer. I'm thinking 400/425 range.

At some point in the future I'll post scale sheets with corner balancing numbers, just haven't digitized them yet.

Maxxis RC-1 tire notes
 

This is an awesome post! Much appreciate your response to my PM...

My Ohlins R&T are currently with Ohlins and were just about to get rebuilt with new springs...was going for 450f/500r but I will go for 380f/425r after reading this. Car is my daily and track/AX toy with Ohlins used Apr-Nov. Stock control arms and sways, Nitto NT01 235/40-17 on 17x9 RPF1. Just moved to HPD3 with NASA and practiced gas/steering rotation on LRP AX course a few times, in 2014, so still have a lot to learn. Would like the car to rotate a little easier without much throttle (with JRSC) and it looks like you found a good formula. Looking forward to trying this out, thanks!

Were the dampers revalved for the stiffer springs? I had mine revalved and am going to be running 650lbs front and 750 rear this year, most likely on 225 Maxxis RC-1's as well. I've driven around on the street with these rates a few times now (only had them installed a couple weeks ago) and I have to say that the ride really isn't all that bad. Its not much more uncomfortable than the default rates over anything but the biggest bumps.

We didn't have them revalved for the 500/550 springs

Springs are just one piece of the grand equation then I can't fully comprehend. With our set-up, the stiffer springs caused "flat slides with late hook-up". Meaning by the time the outside tires got traction they were over the curb and mowing the grass.

Best measure of all this mumbo-jumbo is driver comfort and lap times. Keep us posted after your first track day with 'em and let us know how it works. If you gain a few seconds, maybe it's worth a shot!

Take care

My pleasure.

Haven't raced LRP since they repaved it. Have a blast!

Ah, per Ohlins tech, you would have to revalve them when you go over 20-30% difference in spring rates

LRP is an interesting and technical track but I'm not a big fan of wearing left tires at three times the rate of right tires...6 out of 7 turns being right turns gets old for me quickly.

I'm having fun on their awesome half mile AX track (http://www.limerock.com/index.php?op...690&Itemid=286), very safe setup and a great way to learn car control at lower speeds with very little chance of damaging the car. Perfect for tires that heat cycled out and have some tread left...slide away ;)

Most recent scale #'s

1st is standard ohlins 380lbs springs front and rear.
2nd is 500lb front and 550 rear springs

wights are without driver

Maxxis RC-1 tire notes
 

I think that standard spring rates are 343lb front and rear. Ordered 380lb front and 425lb rear. Will see how they do at NJMP in April and May.

BTW, I thought that standard spring rates were very good as compromise for street and track, and they devoured curbing as if it wasn't there, but it took quite a bit of throttle (with JRSC) to rotate the car. Hope revalved 380lb front and 425lb rear helps, it should.

I just got my set of RC-1's today and happened to have a set of Hoosier R7's laying around to do some quick comparisons.

First off, width. From what I can tell, Hoosier's always run pretty wide and the R7 is no exception. My RC-1's are 225/45R17 and my R7's are 225/40R17. The R7's are about an inch wider than the RC-1's, despite the fact that they are both considered 225 width. Here's a pic comparing the widths:
http://i.imgur.com/OnO1bef.jpg
http://i.imgur.com/XP3Iyh0.jpg

The overall width of the R7 is just about 10 inches while the RC-1 is a little over 9. When you factor in that the RC-1 has a more rounded edge than the R7, the actual contact patch will be even narrower.

I also did a very scientific weight measurement (weigh myself, then weigh myself holding a tire) and found that the RC-1 is a little over 5 pounds heavier than the R7 (24.8lbs vs 19.2).

This NASA TT season is going to be interesting running the RC-1's. I'm betting that the points I got back from switching tires and spent on full exhaust and intake will overcome the time lost due to the lower grip of the RC-1's. I'll have to wait until my first event in March at VIR to find out how they compare.

Wow, that's a big difference in weight. I figure the width and height differences probably offset each other in terms of weight. Thanks for sharing.

To be fair, Hoosiers are unusually light; the RC1 is on the slightly lighter side within its category.

Option 1 Cup in Tw!!!! Thanks for sharing, Im just contemplating trying RC1 out instead of NT01, only problem is i like 215/45/17 which RC1 do hv ....

Good Luck next season!!

Thanks, we just did some testing the past 2 weeks and were the first N/A 86 to break the 2min mark (3.5km track) on old RC-1's.

With the increase in speed were starting to notice the grip levels in the heavy breaking zones more. I can't think of a better tire for the money, but they sure ain't no Michelin Slick when you gotta stop

Anytime you find yourself over here let us know. I think we may be able to find a ride for ya:)

Im indeed going back in March!! Would love to tour ur shop and hitch a ride!


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I'm back from my first track event with the Maxxis tires and thought I'd go ahead and post up some data comparing them to when I ran Hoosier R6's.

To be fair, this is not a straightforward tire comparison, as I made a number of other modifications that I'm sure helped out with the grip for the RC-1's.

Mods for Hoosier R6:
Essex AP Racing Sprint BBK
Ohlins Road and Track Coilovers
Hoosier R6 225/45R17
Delcious Stage 1 Pump Gas tune
ACT Prolite Clutch/Flywheel
Drive Shaft Shop CF Drive Shaft
Perrin Motor Mounts
Whiteline Diff Cradle
Whiteline Positive Shift Kit
K&N Drop In Filter
Crawford Performance Air/Oil Separator
Enkei RPF-1 17x8
-2.7 camber front
-1.8 camber rear

New Mods for Maxxis RC-1:
225/45R17 Maxxis RC-1
Custom valved Ohlins Road and Track (650lbs front, 750 rear)
Whiteline Rear Subframe lockout bushings
Cusco RS LSD
JDL EL Header, Over pipe, and high flow cat front pipe
GrimmSpeed Intake
Delicious Tuning Stage 2 tune
-3 camber front
-2 camber rear

Red Line: Maxxis RC-1 (relatively normal conditions)
Black Line: Hoosier R6's (perfect conditions cool air, warmed up track)
Blue Line: Hoosier R6's (relatively normal conditions)

Lap Times:
http://i.imgur.com/a57eT6l.png

G-Force:
http://i.imgur.com/FcbvXdi.png

So, just to be clear the black line was with absolutely perfect track conditions. Nearly everyone dropped 2 seconds that session, so I was hesitant to even include it in this comparison. The blue line was from an afternoon session that same day.

Here's my impression of the data and this weekend: With the extra mods that I had for the Maxxis tires I could pretty much match the grip levels I was getting from the Hoosiers last year. There are a few areas that were a bit lacking, namely turn 3 (turn 2 in the data) and turns 16-17 (turn 9 in the data). For turn 3, I had some better speed through that in other sessions (as you can see from the video I had a bit of a drift going through there on my fast lap), but I was consistenly 4-5 mph slower through there than with the Hoosiers. For turns 16-17 the car just didn't feel ready to turn in at the same speed with the Hoosiers and I was consistently 4-6 mph slower through there as well. I think I can pick up some of this time back with just some more experience with the tires and new setup and maybe tweaking a few settings.

For a more general feedback, the tires and suspension setup really felt great this weekend. While it has more to do with the suspension and diff setup than the tires, I had so much more confidence in the car when getting on the gas and was able to get on the gas much earlier, especially in the slow turns. The only criticisms I have for the tires was that they didn't seem to handle trail braking quite as well as the Hoosiers and the fronts would typically give up and result in some understeer under heavy trail braking conditions (turn 1, Oak tree). Through some fiddling with tire pressures (ended up with about 36psi hot all around) and adjusting rebound on the suspension I was able to minimize this, but it still wasn't as good as the Hoosiers. That being said, I will probably end up running the Maxxis RC-1's for most of the year thanks to their rather generous contingency plan for NASA's TT program. But when it comes time for the East Coast Nationals in September I'm probably going to be running on the Hoosier R7's (assuming the dyno reclass I'm going to submit works out the way I think it will).

Fastest Lap with Hoosier R6:
[ame="https://www.youtube.com/watch?v=B0dyiAhTbHM"]Fastest Lap @ VIR - 2:12.550 - YouTube[/ame]

Fastest Lap with Maxxis RC-1:
[ame="https://www.youtube.com/watch?v=Y5T6qtQAjaw"]Fastest Lap @ VIR - 2:14.503 - YouTube[/ame]

Good summary, Josh. My feeling last weekend at Road Atlanta on 225 RC1s was quite similar compared to my usual set of 235 Toyo RRs. Overall, the grip levels weren't too far off, but I found significant amounts of understeer with the front end washing out on me in 2 corners (T1 and T7 - both left turns). I'm confident the understeer can be dialed out with setup. I was having some brake issues, and decided not to push the car too much, so I didn't focus on collecting meaningful data.

I plan to reverse the testing process this weekend at Roebling Road. 225 RC1 (5hc) vs 245 RS3 (5k miles) vs 235 RR(15 hc). I know exactly where the RRs sit compared to R6. If the RC1 can be tweaked to match or outperform the Toyos given the points savings, then just like you it's a no brainer.

I know this is a tire thread but how are you guys adjusting rear camber without LCAs? Are you using bolts or just adjusting ride height?

You'll need a race alignment shop. They know the secrets, and more importantly, have the equipment to make it happen.

Quite frankly, getting this kind of work done will likely cost you more than just getting arms and a regular alignment. The only situation where you do something like this is when you have no options, or need to do it for classing purposes.

Yup. I would have gotten rear LCA's a long time ago if it didn't cost me 4 points in NASA's TT system. Managed to get -2 degrees in the rear just by lowering it, and not that much really. My car certainly isn't slammed or anything and I don't ever scrape.

Great chart!
very useful.

We will be using these on our Spec86 Cup car July 4th weekend at LRP. Will update with feedback after the race weekend.

-mike

You going to be running in TT as well that weekend? I'll be there for Saturday only, but I had a fun time competing against you and Rick at NJMP Lightning in April.

Yup. We will run it in TT and also our project BRZ in TTD as well. :)

Mike