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Discussion Starter · #102 ·
Now while I'm done with the Yokohamas, I've still got a problem to solve with the Bridgestones. They're just not pulling the G-force in slaloms that I expect them to provide (by a large amount!). The problem has been evident for awhile in the data from Solostorm, but it was more important to address Pepper's shocks & balance.

Since the Yoks grip as well as they did in GS trim, but the 'stones are not, then I think I need to experiment more with tire pressures. My slalom style didn't change between Saturday & Sunday and the Yoks did not seem to need a different alignment from the Bridgestones, so that pretty much leaves tire pressures and they're easiest to play with. I think it is more likely they need to be lower than higher since they gain pressure on early runs and the results have been fairly consistent. My best opportunity for a full test will be the weekend before Memorial Day, just days before I leave for Lincoln & the spring Nats... hopefully I'll also be testing 17x9 vs. 18x9.
 

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Discussion Starter · #103 ·
Though I'm missing the apex here, probably on the first run, this picture demonstrates how little body roll Pepper has. Solostorm says about 0.8G at this angle as peak G came later in the turn. Tires are 255/40-17 Yokohama A052 on +48 17x8 Enkei RPF1 rims.

390785
 

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Discussion Starter · #104 ·
Turned up front compression 2 clicks (7 clicks in) and rear rebound 1/4 turn. Weather at this weekend's on-track autox at Oregon Raceway Park is going to be cool enough I'll stay on the MPS4S tires, so kind of a pointless tinkering with the shocks since the Fortune Auto 510s will go on soonish, but maybe I can squeeze one more outing in before that happens.
 

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Discussion Starter · #105 ·
Did not make one more event as it would have been another cold day and I've had enough of those this year. Undid that 1/4 turn of rear compression before removing Konis and am in the process of swapping to the Fortune Auto 510 setup... hit a snag in that the 2.5" helper spring couplers do not fit into the Swift springs, so everything is waiting on parts.

In the mean time, cogitating about tires vs. ambient temperature, I've come to the conclusion that my rear tire pressures are the best means of adapting. Final car balance will be on the tight side in warm weather when using my "normal" pressures, but I already know adding 2-6 psi in the rear will make it loose. Just have to build up a table of how much pressure for what sort of temperatures. GS trim was not as sensitive to ambient temperature as the STH trim is.

Analyzing SoloStorm data, being slow in slaloms appears to be more about my driving than about the setup. Apparently I'm still getting used to the STH setup and falling back into safe mode, particularly as I get fatigued. The other takeaway from SoloStorm data is that trying to be more deliberate with the brakes slows me down; honing my instinct will be better than being deliberate. This is not to say setup changes will be ignored, rather that right now there are more gains to be had from my driving, even just from mental attitude, than from tuning the setup.
 

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In the mean time, cogitating about tires vs. ambient temperature, I've come to the conclusion that my rear tire pressures are the best means of adapting. Final car balance will be on the tight side in warm weather when using my "normal" pressures, but I already know adding 2-6 psi in the rear will make it loose. Just have to build up a table of how much pressure for what sort of temperatures. GS trim was not as sensitive to ambient temperature as the STH trim is.
psi in the front, and in the rear, give or take the 2-6??
 

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Discussion Starter · #107 ·
psi in the front, and in the rear, give or take the 2-6??
Different tires like different pressures. For the RE-71R, it might look like this:
  • Fronts always 33.5-34 psi and bled back down after each run.
  • Rears are 31 psi below 50F, 32 psi at 50-55F, 32 psi at 55-60F, 33 psi at 60-65F, 34 psi at 65-70F, and 35 psi above 70F.
  • On rough surfaces, move up one temperature range and on slick surfaces, drop one. For ProSolos, because there's no time to bleed pressure between runs, you might start out a temperature range lower than normal.
The pressures are chosen for throttle lift and mid-corner conditions because the last thing I want is to waste time countersteering to catch snap spins or use extra distance by throttling out of a snapspin. Some countersteering is inevitable; just don't want to be grabbing handfuls of wheel. Technically, one would use tread temperature, but with autocross's short tire exposure (3-4 runs), air temperature is a good proxy predictor of how much grip there is for the rear tires.
 

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Discussion Starter · #109 · (Edited)
do you have a link/post\site with the regulations(what you can/can't do to the car) for your class??
Sports Car Club of America (scca.com)
Section 14, pages 85-96 for Street Touring Hatchback (STH). 14.10.C requires the AGS to be kept ("Removal of vehicle components to facilitate installation is not allowed."), which is the single item that riles FoST owners, and the only off-the-shelf intercooler that lets you keep the AGS is the expensive Vortech unit.

If someone has installed an intercooler that required removing the AGS, then their best class is Section 16 Street Modified FWD (SMF) on pages 119-124. Some might argue for D Street Prepared (DSP), but nationally it's faster than SMF even though it has fewer allowances.

The cheat sheet for allowances:
Street Touring® Category
  • Anti-roll (sway) bars, BOTH front AND rear ..............................89
  • Battery – relocate behind seats................................................. 92
  • Brake kits....................................................................................88
  • Brake ducts.................................................................................89
  • Bushings, suspension/steering .................................................90
  • Camber kits/bolts .......................................................................91
  • Cold air intake, up to throttle body or turbo inlet ................... 93
  • Engine accessory pulleys (EXCEPT supercharger) ....................94
  • Engine radiator and fan(s).........................................................95
  • Engine and transmission mounts .............................................95
  • Exhaust headers and high-flow “cats” ......................................93
  • Limited slip differential, 1 only (none allowed in STS)............95
  • PCM/ECU reprogrammed, OR fuel pressure regulator changed .....................................................................................................94
  • Pedal covers and “dress-up” items ............................................86
  • Seat(s), front...............................................................................86
  • Shift linkage kit...........................................................................94
  • Steering wheel.............................................................................86
  • Strut bars, tie bars (2-point only)..............................................87
  • Sub-frame connectors (bolt-on) e.g., Mustang, Camaro .........87
  • Suspension springs (including “coil-overs”) ............................89
  • Tire width determined by class ................................................ 88
  • Valve timing controllers.............................................................94
  • Wheel width determined by class, any diameter .................... 88
 

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Discussion Starter · #112 ·

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Did you take your rear seats out?
Street Touring and STH in particular is a class that takes fun turbo cars and allows people to install common/street legal-ish bolt on mods, while retaining somewhat of a factory appearance and driveability, like OEM+ ish. Not a Honda guys version of "street car" where it is gutted out, and the only thing that remains stock-ish is the body/chassis (I've seen some strange interpretations of what some folks classify as a "stock" car, or a "slightly" modded car in my years of autox lol)
 
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Street Touring and STH in particular is a class that takes fun turbo cars and allows people to install common/street legal-ish bolt on mods, while retaining somewhat of a factory appearance and driveability, like OEM+ ish. Not a Honda guys version of "street car" where it is gutted out, and the only thing that remains stock-ish is the body/chassis (I've seen some strange interpretations of what some folks classify as a "stock" car, or a "slightly" modded car in my years of autox lol)
There are some events, only a few hours away, I should be able to attend. They allow you to register last minute, which is great because i work most Sat.

< honda guy(prelude guy) my autox practice car, getting close to owning for 20 years... every last piece of interior still in there! wanted to show @gemery my Bridgestone Potenza Grid 225/60r16 97v purchased from TR about 5 yrs ago, installed last year.
391457
 

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Discussion Starter · #115 ·
Limits to Lowering & Tire Clearance for STH

I'll write more on this later after I've had time to digest what's happened this week. The quick & dirty version follows:
  1. With slotted strut mounting holes and the Fortune Auto camber plate, -3 deg of camber was achieved. The top nut of the strut was lathed down to slide under the lip of the center hole and, as @freakin_elrod noted, the adjuster knob is removed. In theory, a thicker camber plate could be used to drop the adjuster below the center hole lip and get more negative camber, but there are complications (see 2) and it's going to be a custom plate (hello Vorshlag?).
  2. For my desired ride height (1" drop) and race wheels (+38 18x9 rims with 265/35-18 tires), the Fortune Auto front springs need to be 6" long. 7" springs were what shipped. The tire sidewall rubs at the ride height adjuster nuts. The 7" springs will work if you limit lowering to a 1/2" drop of ride height or, as I have temporarily done, with 3/4" drop plus a pair of 5mm wheel spacers. Thicker wheel spacers with the +38 rims will only push the tire into the outer fender at this ride height unless more negative camber is available. I'm ordering 6" springs, but this won't be installed until next month, after I return from the Lincoln Championship Tours. The transport wheels (+40 18x9 rims with 245/40-18 tires) have plenty of clearance at 1" drop. These measurements are with Bridgestone RE-71R tires; tire specs for the Falken RT660 suggest they will be very close without wheel spacers even with 6" springs since there will be 2-2.5mm less clearance.
  3. I'll need to check the +45 17x9 rims with 255/40-17 tires for clearance. A quick check of specifications suggest they'll need the 5mm wheel spacers.
  4. An annoyance: I could swear I specified 65mm diameter springs from Fortune Auto, but they shipped 60mm. Discovered this when my helper springs from the Ground Control setup didn't fit, so I had to get some 60mm helper springs. Yes, if you're lowering the FoST with most coilovers, you always need helper springs.
 

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What spring rate do you need for the front? I have a couple of 6 inch Eibach race springs sitting in the garage, I think I have 500 and 600 lbs ones.
 

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Discussion Starter · #117 ·
What spring rate do you need for the front? I have a couple of 6 inch Eibach race springs sitting in the garage, I think I have 500 and 600 lbs ones.
Thanks for the offer, but it's more a matter of lack of time to install now. I'm using 10k springs and have some 6" 525 & 600 lb here now. Don't even know if you can seat 2.5"/65mm springs on the 60mm collars.

Am thinking, with the Eibach front swaybar I'll be wanting 15k or 16k rear springs instead of the 14k that are on there now, but will evaluate after this weekend while I get used to the new setup. Until I get a chance to settle down again, I will just swap rear swaybars if Pepper is too tight. Expect to do some tire testing (17" vs 18" and re-evaluate rear tire pressures) next weekend if the weather doesn't sour. And then it's off to 4 days of competition in Lincoln!
 

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Thanks for the offer, but it's more a matter of lack of time to install now. I'm using 10k springs and have some 6" 525 & 600 lb here now. Don't even know if you can seat 2.5"/65mm springs on the 60mm collars.

Am thinking, with the Eibach front swaybar I'll be wanting 15k or 16k rear springs instead of the 14k that are on there now, but will evaluate after this weekend while I get used to the new setup. Until I get a chance to settle down again, I will just swap rear swaybars if Pepper is too tight. Expect to do some tire testing (17" vs 18" and re-evaluate rear tire pressures) next weekend if the weather doesn't sour. And then it's off to 4 days of competition in Lincoln!
The 2.5 inch springs will work on the 60mm perches. I ran the eibach springs with no issues before so you should be able to throw your 525s on there if you really wanted to.
 
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Discussion Starter · #119 ·
Weekend Impressions

What a difference having adequate negative camber in the front makes! First run on Saturday unexpectedly gave me oversteer in a 6-cone slalom as I sped up. Unexpectedly because my spreadsheet suggested I'd be wanting less push, but the spreadsheet doesn't account for camber. Got it tamed with a combination of dropping rear tire pressure 1 psi and experience.

The Fortune Auto 510 shocks & struts are fantastic. Ride quality is much nicer on the highway than the Ground Control & Konis.

Using the 5mm wheel spacers in front in combination with the Titan 7 rims didn't work because there was not enough thread engagement for the lugnuts. Close examination without the wheel spacers suggested there was a sliver of daylight that would keep the tires from being shredded, so I bolted them up as-is, without wheel spacers, and they passed a little test drive around the autox site in Packwood, WA. Drove the mile into the town-proper for dinner, but smelt burning rubber as I reached 45 mph, so pulled off the highway to doublecheck. There was no smell... hmm... drove the remaining few blocks to dinner and then back to the site. Still no more burnt rubber smell. Pulled a wheel off and it looked okay. Chalked the inside and outside sidewalls and they passed another highway test drive. So... my conclusion is the burning rubber smell must have been another vehicle, like the log truck a 1/4 mile ahead.
 

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Discussion Starter · #120 ·
More Impressions

Driving Pepper is not a surgical, not a precise process. Very much a hang onto a wild ride sort of experience and make the most of what she gives you. This was also true back in G Street trim, but even more so now.

Slalom G-forces are back where they should be.

The e-diff is doing some work now, making the front brakes hot, yet without wheelspin being evident. Brakes are not as hot as they'd get without the Quaiffe, so I`m not ready to give up on the Eibach front swaybar since wheelspin is not an issue.
 
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