The STX thread!
The car did OK on Sunday, bit not quite where it was at the end of the year. Of course the driver sucked big time after 3 months of inactivity too I'm pretty sure the issue is the ride height. The 245/34-17 R1Rs appear to be quite a bit shorter than the printed specs for the 255/35-18 R1R. It looks like about 1.5" in diameter standing side by side. When I pulled it into thd trailer the driver door would not clear to open due to the lower ride height, so I had to raise the car up 1/2" for this. I'm in the process of raising the ramp stands higher in the trailer and plan to drop the car back down to the correct height once this is done. The straight line acceleration on the shorter tire was pretty impressive. Not only the shorter gearing and weoght decrease, but the moment of inertia is significantly lower too. I could rely tell the difference coming out of slow turns and on the top end. The lateral grip seemed slightly less, but since the tires were new and not scrubbed yet I'm withholding judgement on this. The 255s were terrible the first time I took them out, but came in rather sharply after a dozen runs or so.
Last edited by TeamRX8; Mar 1, 2011 at 08:21 PM.
Thanks for the update Mark. I've been contemplating going back to Toyos as well. As you say, it's a good single-driver tire.
I was looking at the 255/35-18, but 245/35-17, wow. That would be quick. Did you have any rev-limiter issues?
I was looking at the 255/35-18, but 245/35-17, wow. That would be quick. Did you have any rev-limiter issues?
Thread Starter
Row faster, I hear banjos
iTrader: (5)
Joined: Jul 2003
Posts: 2,217
Likes: 2
From: Charlottesville, VA
The stack height is not relative. You are only measuring sidewall width on a stack of mounted tires, not the treadwidth being put to the ground. This is especially true on street tires with rim lip sidewall protectors. The 245 treadwidth is slightly less than the 255. The question is whether or not the advantages outweigh the disadvantages. This will reveal itself in time.
BTW, if it weren't for this particular size I would not be using 17". The mounted weight of these 245/35 R1R tires on 17 x 9 +55 SSR Comp C wheels is 38# each vs 40# each for the 255-18 of same. The real difference is MOI though, the lower weight is concentrated on a smaller diameter for the 17" combo.
.
BTW, if it weren't for this particular size I would not be using 17". The mounted weight of these 245/35 R1R tires on 17 x 9 +55 SSR Comp C wheels is 38# each vs 40# each for the 255-18 of same. The real difference is MOI though, the lower weight is concentrated on a smaller diameter for the 17" combo.
.
Last edited by TeamRX8; Mar 2, 2011 at 04:37 PM.
George, up until now I have been on the factory 9k limiter. Based on the Toyo specs (23.8" vs 25.1" OD), the 245 needs approx 500 rpm more to equal the 255 speed in 2nd gear, or 9.5k vs 9k. I may consider upping to the max 10k limit for special occasions 
if the justification is there, but worst case I still have a set of taller 255s to fall back on for higher speed, sweeper intense courses if a 3rd gear shift looks unpleasant. At a minimum I plan to use the shorter 245s for Pro Solo and lower speed/tight courses. Still too early to tell, only one event on new unscrubbed tires and some slight changes to the car from last year with it still not fully setup yet. I get to run every weekend day through March including the Houston Tour and Mineral Wells Pro Solo, so we'll see what develops. 
BTW, I'm still not sure why I was getting crap at Nationals for the OE intake box insulator tray being removed. It is clearly shown as a part of the air intake system on both the service and parts manuals.
.
if the justification is there, but worst case I still have a set of taller 255s to fall back on for higher speed, sweeper intense courses if a 3rd gear shift looks unpleasant. At a minimum I plan to use the shorter 245s for Pro Solo and lower speed/tight courses. Still too early to tell, only one event on new unscrubbed tires and some slight changes to the car from last year with it still not fully setup yet. I get to run every weekend day through March including the Houston Tour and Mineral Wells Pro Solo, so we'll see what develops. BTW, I'm still not sure why I was getting crap at Nationals for the OE intake box insulator tray being removed. It is clearly shown as a part of the air intake system on both the service and parts manuals.
.
Last edited by TeamRX8; Mar 2, 2011 at 04:41 PM.
^Thanks Mark, makes sense. I like the use of the smaller tires for Pro events - I agree there should not be gearing problems there.
I'm probably going to go the 255/18 route, since my 17" rims are heavy. I have a buddy with an STR MX-5 running the 245/17 Toyos, maybe he'll let me take a few runs with his tires mounted.
BTW, Hankook sells a 255/35-18 now...
<edit> Also, good to hear about the airbox tray. Need to remove mine.
I'm probably going to go the 255/18 route, since my 17" rims are heavy. I have a buddy with an STR MX-5 running the 245/17 Toyos, maybe he'll let me take a few runs with his tires mounted.
BTW, Hankook sells a 255/35-18 now...
<edit> Also, good to hear about the airbox tray. Need to remove mine.
Last edited by GeorgeH; Mar 2, 2011 at 05:03 PM.
Update on FCM Shocks
So, I got Shaikh’s lastest valving in my FCM Bilsteins. I’m trying a new setup, using stiffer spring rates but no sway bars, and Shaikh has given me valving to match. He’s also progressed through several valving iterations since I first received my shocks last year.
Initial impressions on the street are encouraging – his changes seem to have paid off. The car is super responsive but very supple. Shaikh has really nailed the high speed valving here – the car seems to be completely unfazed by high frequency inputs, but responds beautifully to any input. Tires feel totally keyed into the pavement.
But, proof is in the clock, and the first event is this weekend. Not sure if I have the balance right yet, but I’m optimistic.
These are still non-adjustables, by the way. LOL.
Initial impressions on the street are encouraging – his changes seem to have paid off. The car is super responsive but very supple. Shaikh has really nailed the high speed valving here – the car seems to be completely unfazed by high frequency inputs, but responds beautifully to any input. Tires feel totally keyed into the pavement.
But, proof is in the clock, and the first event is this weekend. Not sure if I have the balance right yet, but I’m optimistic.
These are still non-adjustables, by the way. LOL.
Thread Starter
Row faster, I hear banjos
iTrader: (5)
Joined: Jul 2003
Posts: 2,217
Likes: 2
From: Charlottesville, VA
Mark, you're positively incorrigible....
It makes beating me so much more fun though 
I was just joking with George. No bar setups have gotten mixed results. They work well for some, others not. I'm fairly ecstatic with my current setup (street tires no longer suck, lol) and see no need to go there, nor would I care to after chasing my tail for several months last year trying to get a no rear bar setup to work. Better him than me.
I was just joking with George. No bar setups have gotten mixed results. They work well for some, others not. I'm fairly ecstatic with my current setup (street tires no longer suck, lol) and see no need to go there, nor would I care to after chasing my tail for several months last year trying to get a no rear bar setup to work. Better him than me.
^No problem Mark. I know it's all good, friendly banter between two competitors who badly want to crush, er, humble one another. 
I'll be sure and keep the thread updated. And, the FCM shocks are great, with or without a swaybar. Even with the high spring rates on the front I am now running, they are remarkably composed and compliant.
And, if I can't get the no-sway bar approach to work, I still have the springs & bars I need laying around. I'm just glad I'm doing this now instead of in June/July like I was last year. That was not fun.
I'll be sure and keep the thread updated. And, the FCM shocks are great, with or without a swaybar. Even with the high spring rates on the front I am now running, they are remarkably composed and compliant.
And, if I can't get the no-sway bar approach to work, I still have the springs & bars I need laying around. I'm just glad I'm doing this now instead of in June/July like I was last year. That was not fun.
Registered
Joined: Sep 2009
Posts: 55
Likes: 1
It makes beating me so much more fun though
I was just joking with George. No bar setups have gotten mixed results. They work well for some, others not. I'm fairly ecstatic with my current setup (street tires no longer suck, lol) and see no need to go there, nor would I care to after chasing my tail for several months last year trying to get a no rear bar setup to work. Better him than me.
I was just joking with George. No bar setups have gotten mixed results. They work well for some, others not. I'm fairly ecstatic with my current setup (street tires no longer suck, lol) and see no need to go there, nor would I care to after chasing my tail for several months last year trying to get a no rear bar setup to work. Better him than me.