Does anyone have experience with both Toyo RA-1's and Michelin PSC's?
What are the differences between them? Grip, longevity etc.
Also, has anyone had a chance to try out the new Hoosier R3S05? Hoosier claims it lasts longer than the S04, but I'm curious if there's any real world difference.
Jeff
'98 Red/Black M3 Coupe
I started out with Cups and now slowly (and reluctantly) in a transition to RA-1s. Two reasons why:
1. Cups too expensive. Argh!
2. They don't come in 235/40/17s.
I am a Mich person so my views are biased, plus Cups were my first set of R-comps. The Cups are like PS2s but better. They are good right out of the box, unshaved and not heat-cycled. Cups' traction are very sensitive to tire temp, at least that was what I observed for my car and my setup. But once you get within the temp range, it's a blast.
My experience with RA-1 isn't exactly comprehensive but I did try it for a session. I will post reviews soon.
No experiences with Hoosier.
[SIZE="3"][SIZE=1][b] Technik Engineering ASA Stage 1.
Supercharged E46 M54B25.
2011 NASA TTC So Cal Champion!
My reason for leaning towards cups is the Toyo's don't come in 245-40-17 and the fact that Tire Rack sells them. I'm really interested to get some feedback on tire life versus the RA-1.
Jeff
'98 Red/Black M3 Coupe
I love RA1's, hate PSC. PSC don't grip that well and are down right dangerous when the temp. is below 50 degrees. Yes PSC last forever, thats about their only advantage. RA1's have great grip, last 8-10 DE's, grip doesn't fall off that much over their life. I should add, i don't like 255 RA1's, they feel sloppy and aren't hardly any faster than the 235. The 235 feels crisp and for me is faster.Originally Posted by 98 silber sedan
I raced on the R3S05's, but was my only time on hoosiers. Too expensive for DE use. But off amazing feedback, great grip, fastest r-comp tire. They do fall off, you notice it the second weekend you use them. For me I race on them for one event, then they become practice tires.
For DE use, RA1's without a doubt.
Last edited by SG_M3; 01-28-2006 at 03:10 AM.
Sean
PSC is VERY sensitive to pressures also. A lot of people run pressures too high.
I have the spec sheet for the PSC that the Michelin engineers gave me at Summit Point... who by the way were awesome.. they came to take temp measurements, etc after each of my sessions to make sure I had the right setup
Salsa-Originally Posted by SG_M3
The 255 RA-1 feels sloppy b/c your rim is too narrow for them (17x8.5 K-1). They don't like 8.5" rims. The walls are not stiff enough to stuff them onto that wheel. Put them on some 9" or 9.5" and you will regain that lovin' feeling that you lost.
I have them on my 17x8.5 DINAN Fikse FM-5 and they feel a little sloppy as well. I am going to change out the half shells and go 9.5" (just gotta get the $$ @ $325 each). I was gonna just sell them & buy CCW but I really love the wheels. Besides they are a little lighter than the CCW.
C U 2morrow.
JT
Last edited by Toon///Man; 01-28-2006 at 12:42 PM.
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Eric...can you post that PSC tire spec sheet, or is it the same as available at Tire Rack?
Naw.. it's quite different. It's more of a informational booklet. I wish I could scan it... it shows how to cut the tire with additional grooves for wet use, etc. Just briefly.. it says:Originally Posted by Byron Smith
Optimal starting pressures are 25-28 degrees COLD. Looking at my notes, I run mine around that... 28F and 25R with 1psi or 2 more/less on a tire or side depending on the track.
It has tread compound with a "sweet spot" in the range of 160-220 degrees.
The optimal "grip" is around 3.5/32" (new is 6/32").
It also has a "laymans guide" to tuning pressures and temperatures.
I run these on 17x9 SSR Comps. Ive tried 2554017 RA1s also and they dont feel as grippy to me. However, like others have mentioned, the PSC does NOT like to be cold. The RA1 is also much better than the PSC in the wet (unless you cut additional grooves in the tread as recommended by Michelin).
For those of you who run Toyos, where do you find them for a good price?
My S03s are almost gone, and I'm looking forward to stepping up to R compounds all around.
"Arguing on the Internet is like competing in the Special Olympics. Even if you win you're still retarded." -Unknown
Buy my car!
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Talk to Ron at AIM Tires at Infineon.
http://www.aimtire.com/
He does a great job shaving tires.
I get all my toyos from him for my Spec Miata.
So far I've found www.TheTireShoppe.com to be the cheapest for a set of 235/40R17 255/40R17 for $646. BMW Wheels is $8 more and Edge Racing $22 more than TTS.Originally Posted by bmattick
My experience with PSC's is that they are finicky with pressure and temperature, have inconsistent grip throught a session, and run out of grip before they wear out compared to RA-1's. Granted the inconsistent grip could be due not having the right pressure, but the grip certainly doesn't last for very many heat cycles compared to RA-1's. I switched out the two sets of PSC's I had before they were physically worn out due to loss of grip. I run RA-1's down to the nearly the cord.
Rich
http://www.meisterschaftmotor.com/products.htmlOriginally Posted by bmattick
$500 for RA-1s, shaved to 4/32" and single track heat cycled in race qualifying.
Can't blame the tire if you can't get them hot enough. Cups kick Toyos all day long. I show up with the cups on, torque wheels and have fun. Yes they are not as good out of the heat range. That is not the tires fault though. If you cannot get them between 180 to 220 you are simply not going fast enough or don't have enough spring to put heat into them. Also just like SG M3 said, run the narrower cups, or narrower toyos. We used to test with cups on both our M3's and I run them on my Z06 now.
Wow, great thread. Here is my dos centavos, with admittedly less experience with PSC's than RA1's:
I agree with SG M3 about the RA1 width issue, and also about the PSC temperature issue. Frankly, it is extremely difficult to get enough heat in PSC's if ambient temps are in the 50's or lower, especially if they have a number of heat cycles on them. PSC's are very prone to heat-cycling to death well before they run out of tread, and at that point, unless it is very hot out, they are horrible.
Whereas RA1's actually seem to improve as they get more & more worn down, and are at their best right before cording. They can suffer some slight heat cycling, but not nearly as badly as the PSC's.
what are some good COLD pressures to start with on 234/40/17 ra-1's (mounted on 17x9 integrals)??? And what are good HOT pressures to shoot for?
thanks,
Matt Williams -
Current - 01 LSB M3
Past - #21 GTS-3 -
95 Alpine White/Yellow M3 - Stock, except for the stuff that isn't
Just my $0.02, take it for what it is worth:Originally Posted by ///Mracer
It all depends on your suspension & the track you are on...but try like 29.5 cold FRONT, 27.5 cold REAR, then adjust using a tire pyrometer after coming in hot from a solid run.
In my experience, once you get them set then, they are good to go all day. VERY easy & unfussy tires to set & forget.
Yup... tire pyrometer (probe) is key. There are way too many variables between all our cars to have a optimal pressure recommendation.Originally Posted by maranelloman
Start w/ maranelloman's pressures... then after a session, come in and measure temps... Id prolly run your right rear ar VIR a pound or two less...
Eric, I think you have that a bit backwards. The right rear is the least used tire...you'll probably need slightly MORE cold air pressure in it. But, you should make that adjustment once the tires are hot. I generally run a little extra air in the tires in the first session of the day, get them up to temp, and then pull into the pits really quick to bleed down to and even out all of the hot pressues.Originally Posted by magnetic1
Bingo. That's what I experienced the first few times I used the Cups.Originally Posted by magnetic1
The other observation I made, having mixed two RA1s and Cups on my car, is that RA1s have a higher rate of heating up. No biggie really. Just start with a lower temp on the RA1s.
98 silber sedan, these being posted and said, I think if any go try a set of Cups and a set of Toyos yourself. Get some good temp/pressure data as well. You are the only one with can evaluate the tires.
[SIZE="3"][SIZE=1][b] Technik Engineering ASA Stage 1.
Supercharged E46 M54B25.
2011 NASA TTC So Cal Champion!
Agreed.Originally Posted by B.Watts
http://www.michelinman.com/assets/pd..._technical.pdfOriginally Posted by Byron Smith
Simon
Spec E30 #116
Whoop.. that's what I meant... it's early in the morningOriginally Posted by B.Watts
Originally Posted by magnetic1
Man, I better request another instructer at VIR
Craig Lippe1998 M3 Coupe IP #66
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