Maxxis RC-1 tire notes

[Doozer]

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

[Jetbill]

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.

[CSG Mike]

I like this thread.

[Doozer]

Originally Posted by Jetbill

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.

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.

[dp1]

Originally Posted by Doozer

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.

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!

[ja1217]

Originally Posted by Doozer

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.

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.

[Doozer]

Originally Posted by ja1217

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

[Doozer]

Originally Posted by dp1

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!

My pleasure.

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

[dp1]

Originally Posted by Doozer

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

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

[dp1]

Originally Posted by Doozer

My pleasure.

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

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

[Doozer]

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

[dp1]

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.

[ja1217]

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:



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.

[Pat]

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.