951 on Toyo RA-1's
11-04-2003, 12:22 PM
#1
Rennlist Member
Thread Starter
951 on Toyo RA-1's
Archive's didn't reveal anything on this topic so hopefully someone here has some experience to share.
I'm mounting 245/45/16 RA-1's and getting an alignment on a 944 Turbo this weekend. They replace MPSC's.
What alignment specs are people running for track use?
What hot temps are people running at the track?
The car is in street trim and weighs 3150 with driver and half tank of fuel.
Thanks!
I'm mounting 245/45/16 RA-1's and getting an alignment on a 944 Turbo this weekend. They replace MPSC's.
What alignment specs are people running for track use?
What hot temps are people running at the track?
The car is in street trim and weighs 3150 with driver and half tank of fuel.
Thanks!
11-04-2003, 03:52 PM
#2
Three Wheelin'
Why are you switching from the Michelin...is it the cost?
I've gone from Kumho Ecsta V700's to MPSC's and loved the change.
But, I haven't tried the Toyo RA1...the price is definately nicer!
I use them on my 968, so they are almost identical to your 951 I would guess.
I've been using 2.5 camber up front and 1.5 in the rear.
Jason Judd
I've gone from Kumho Ecsta V700's to MPSC's and loved the change.
But, I haven't tried the Toyo RA1...the price is definately nicer!
I use them on my 968, so they are almost identical to your 951 I would guess.
I've been using 2.5 camber up front and 1.5 in the rear.
Jason Judd
11-04-2003, 04:35 PM
#3
Rennlist Member
Thread Starter
My experience with the MPSC's was not good but I attribute most of that to a bad alignment. I suspect (and hopefully confirm this weekend) that my alignment has changed significantly over the course of the year.
The result was poor wear on the MPSC's over the course of 6 track days and perhaps 2-4000 street miles. The insides wore first to the point that one of them corded at my last event and I generally got very poor grip and feedback out of them. Typically I slaughter and chunk the shoulders of tires with minimal wear on the inside. I'm running about 2.2 degrees of camber.
Can I ask what tire pressures you were running? I found 36psi hot to be good at Lime Rock but by my last event at Watkins Glen I was running 30psi hot in a vain effort to get more wear on the outsides. Like I said, I suspect the alignment has changed but I found it frustrating that I could never get the tire pressures dialed in.
So the move to Toyo's isn't necessarily an indictment of the MPSC's... but they are cheaper, appear to be more consistent lap to lap, and reportedly have great wear characteristics.
The result was poor wear on the MPSC's over the course of 6 track days and perhaps 2-4000 street miles. The insides wore first to the point that one of them corded at my last event and I generally got very poor grip and feedback out of them. Typically I slaughter and chunk the shoulders of tires with minimal wear on the inside. I'm running about 2.2 degrees of camber.
Can I ask what tire pressures you were running? I found 36psi hot to be good at Lime Rock but by my last event at Watkins Glen I was running 30psi hot in a vain effort to get more wear on the outsides. Like I said, I suspect the alignment has changed but I found it frustrating that I could never get the tire pressures dialed in.
So the move to Toyo's isn't necessarily an indictment of the MPSC's... but they are cheaper, appear to be more consistent lap to lap, and reportedly have great wear characteristics.
11-05-2003, 11:42 AM
#4
Drifting
Hugh,
I've run RA-1s on my 951S (stock suspension) at street alignment specs and had the same issues you had wearing the outside shoulder. I am not kind on my front tires (I tend to trail brake a lot).
I had the car set at a more aggressive alignment after installing new A-arms (-2.0 degrees and 0 toe) and they still wear more on the shoulder, just not as rapidly. I'd say your alignment of -2.2 would be a good starting point.
To reduce shoulder wear, I run the RA-1s at ~40-42psi hot on the front, starting at about 34 cold (slightly lower in the rear). I've tried lowering the pressure a few lbs but increase in grip is minimal and sidewall rollover increases quite a bit. Sorry, I don't have a pyrometer to check temps.
I managed to get ~20 track days out of my last set of fronts (most of those were before the alignment change).
I've run RA-1s on my 951S (stock suspension) at street alignment specs and had the same issues you had wearing the outside shoulder. I am not kind on my front tires (I tend to trail brake a lot).
I had the car set at a more aggressive alignment after installing new A-arms (-2.0 degrees and 0 toe) and they still wear more on the shoulder, just not as rapidly. I'd say your alignment of -2.2 would be a good starting point.
To reduce shoulder wear, I run the RA-1s at ~40-42psi hot on the front, starting at about 34 cold (slightly lower in the rear). I've tried lowering the pressure a few lbs but increase in grip is minimal and sidewall rollover increases quite a bit. Sorry, I don't have a pyrometer to check temps.
I managed to get ~20 track days out of my last set of fronts (most of those were before the alignment change).