project:BDR 2006 Evo STU build thread
Evolving Member
Joined: Mar 2011
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From: Maryland
Why does that seem low? It all depends on your setup. If you're running -3 degrees of camber up front, you don't need nearly as much tire pressure to prevent rollover. If you're running -0.5 degrees of camber, then you might need something like 44psi in the tires. But in this case, his pressures are pretty much dead on.
Evolving Member
Joined: Apr 2003
Posts: 441
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From: Seattle
from our own personal experience with a similar setup... makes me wonder if we didn't test it enough... tire temps and rollover were spot on though, but at much higher pressures (front). you guys racing on ice? 
all our testing was on full tread Z1s, maybe that's the difference
all our testing was on full tread Z1s, maybe that's the difference
Spring rates and therefore body roll also play into rollover. You can have -3deg of static camber, but that is relative to a level car. The more you roll and compress the suspension, the more the camber will change from static. Fortunately compression generally adds camber on a mac strut suspension, but the body roll kills it.
Evolving Member
Joined: Mar 2011
Posts: 111
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From: Maryland
Out of curiosity, what pressures are you running right now? How much higher are your pressures? For reference, I run 36psi with -3.2 camber in my STi. Pretty similar to John's Evo in camber to front pressures on the Dunlops.
I run a fair amount of caster up front as well, but with that I run closer to 34.5psi and have no rollover, BTW that is with full tread Z1s on both concrete and mid-grip asphalt...
http://www.youtube.com/watch?v=JcyGVlnLiFQ
http://www.youtube.com/watch?v=JcyGVlnLiFQ
Thread Starter
Joined: Jul 2002
Posts: 1,733
Likes: 154
From: Why do they always call the Evo the Dark Side?
Sorry, busy week...
That's why I wear a closed face... *hides in shame*
Definitely - I am quite curious. At this point the car's setup is not going to radically change for the rest of the year (unless a leakdown test shows something and I magically get more power) so it should be remotely scientific now.
Anyway, I'll take that. Shane's is probably $5 for hitting cones in a wallom (per run, not per cone
) and we'll have to come up with a good one for you 
FWIW... these tires started at full tread with the previous owner. They're now at about 6/32". On my WRX I usually ran the Dunlops at 38/36, but that was with 8" wide wheels.
Fedex is not as grippy as it used to be as they re-sealed a large chunk of the lot, but even back when I had the WRX I was using similar pressures on both these and the AD08s I had. I haven't pyro'd the Evo yet, but rollover looked right.
East-side / west-side tire pressure battlestage!
Car looks good John, didn't get a chance to really watch it on course though since Shane was driving right after you. We need to do a car swap during fun runs one day and see how much of a difference there is between the cars. But if you lose to a BMW again, we may just have to start making you pay up $5 each time, kind of like the classic Simmons bets. 
Anyway, I'll take that. Shane's is probably $5 for hitting cones in a wallom (per run, not per cone
) and we'll have to come up with a good one for you Why does that seem low? It all depends on your setup. If you're running -3 degrees of camber up front, you don't need nearly as much tire pressure to prevent rollover. If you're running -0.5 degrees of camber, then you might need something like 44psi in the tires. But in this case, his pressures are pretty much dead on.
from our own personal experience with a similar setup... makes me wonder if we didn't test it enough... tire temps and rollover were spot on though, but at much higher pressures (front). you guys racing on ice?
all our testing was on full tread Z1s, maybe that's the difference
all our testing was on full tread Z1s, maybe that's the difference
Spring rates and therefore body roll also play into rollover. You can have -3deg of static camber, but that is relative to a level car. The more you roll and compress the suspension, the more the camber will change from static. Fortunately compression generally adds camber on a mac strut suspension, but the body roll kills it.
Fedex is not as grippy as it used to be as they re-sealed a large chunk of the lot, but even back when I had the WRX I was using similar pressures on both these and the AD08s I had. I haven't pyro'd the Evo yet, but rollover looked right.
East-side / west-side tire pressure battlestage!
Thread Starter
Joined: Jul 2002
Posts: 1,733
Likes: 154
From: Why do they always call the Evo the Dark Side?
Thread Starter
Joined: Jul 2002
Posts: 1,733
Likes: 154
From: Why do they always call the Evo the Dark Side?
Event #12 - Capital Driving Club @ Winchester, 6-25-2011
Setup (new stuff in bold):
Moton Clubsports
front: 2/7 compression, 3/7 rebound
rear: 6/6 (?) compression, 3/7 rebound
600/800 springs
-3 / -1, 0 toe
245-40-17 Dunlop Z1s on 17x9 SSR Type C RS, 15mm spacers in the front
36/36 psi
WORKS 24mm rear swaybar on full stiff
Conditions: high 80s and sunny, I think
Capital Driving Club is a local group who started as an offshoot of the local Triumph chapter, hosting autocrosses. They’ve gotten really organized really fast and are now hosting 20+ events a year (a lot of Saturday+Sunday events). They don’t use SCCA classing - they have developed their own handicap system:
http://www.capitaldrivingclub.com/faq.html
My STU car is 1.00 for street tires, 1.03 for being over 250 whp and .99 for weighing more than 3000 lbs = 1.0197. The indexes have been tweaked over the years, and last year was the first time that a street tired car had won the overall end of year championship. So everyone is pretty much in the mix.
This event was at James Woods High School... er, James Wood High School in Winchester. It’s bigger than the Frederick and Woodbridge lots, while being smaller than Waldorf. It’s more rectangular than square, with some small elevation changes.
The only real change for this event was the addition of the WORKS 24mm rear swaybar. They picked a common word as a company name so I feel the need to capitalize it for clarity The hardest part of the install, by far, was getting the stock rear bar out, without touching the control arms. I was doing this the night before the event (never a good idea) and I didn’t want to risk rounding some important bolt or whatever - the car is from a cold climate and those bolts are not super clean. Anyway, just by un-hanging the muffler and fighting for a while I was able to get the stock bar off. The WORKS bar went in much easier than the OEM bar came out.
Since Winchester is a comparatively small lot (to Fedex) I decided to put the rear bar on the stiffest setting. If the car was too loose on a small lot, it’d almost certainly be too loose on a faster lot - but if it felt pretty balanced on a small lot, it might be just right for Fedex. Just triangulation
The course doubled back on itself once and the visuals were a litle hard to follow. I lucked out being in 2nd heat - I got to ride along with my friend Slava so I saw the course a few times at speed before driving it myself. As I was courseworking I saw one of the NASIOC guys throw down a 46.9 in his STU STi so that was my target.
My first run, my friends Slava and Andy rode along (family car!). This took me off my game quite a bit... mentally I was definitely in goof-off mode rather than clean patient mode. I left it in 1st for the entire skidpad and as you might expect had a ton of wheelspin. I was just driving like a yokel. The car felt a little pushy, but there were also two extra people on it - hard to get feedback. I ended up with a 49.7, +3.
2nd run I decided to try not being a yokel, and actually shifting to 2nd. This was better, but I ended up hitting the inside finish cone... which hit the outside finish cone... which knocked over the reflector. I think the raw was a 47.1, but it was at least +3, maybe more.
My 3rd run I made a conscious effort not to screw up the first braking zone (which I had hit on my first two runs) but... did it anyway. I went on to somehow hit 4 more cones. None of them square mind you, all of them with the rear of the car. Doh. 47.5... +5.
Yikes... 11 cones in 3 runs? I think that’s a record for me. Not something I aim for.
OK, last run. Focus, stupid! I finally nailed that first hard braking zone and stayed VERY patient in the long skidpad. The patience helped - not surprisingly the car felt a lot better. The run was feeling great, until I hit a cone crossing over from the bottom to the top (again... with the rear of the car). I finished up the run strong though. 46.4... +1.
With the cone, I was 16th/66 in raw time and 13th in indexed points. Without the cone, I would have been 6th in raw time, fastest on street tires and fastest by index. Crap!
No pictures / video but here’s the index-winning run from Ryan’s STi:
http://www.youtube.com/watch?v=bX8lfekgQh4
My front right tires were very hot - the course was almost entirely left turns. But no drama otherwise. The car did as good as I could expect in the really really slow sweepers. The rear bar so far feels like a real improvement in the steady state stuff.I can’t wait to get the car to Fedex!
Setup (new stuff in bold):
Moton Clubsports
front: 2/7 compression, 3/7 rebound
rear: 6/6 (?) compression, 3/7 rebound
600/800 springs
-3 / -1, 0 toe
245-40-17 Dunlop Z1s on 17x9 SSR Type C RS, 15mm spacers in the front
36/36 psi
WORKS 24mm rear swaybar on full stiff
Conditions: high 80s and sunny, I think
Capital Driving Club is a local group who started as an offshoot of the local Triumph chapter, hosting autocrosses. They’ve gotten really organized really fast and are now hosting 20+ events a year (a lot of Saturday+Sunday events). They don’t use SCCA classing - they have developed their own handicap system:
http://www.capitaldrivingclub.com/faq.html
Index System
The indexed time is a measure of how well you did relative to the other drivers. It is similar to a golfer's handicap. The indexed time will be your elapsed time multiplied by the following factors:
Tire Multiplier1
Street Tires = 1.00
R-Compound Tires With Treadwear Rating 100 - 139 = 1.02
R-Compound Tires With Treadwear Rating < 100 = 1.035
Horsepower Multiplier2
100 HP or less = 0.99
101 to 150 HP = 1.00
151 to 200 HP = 1.01
201 to 250 HP = 1.02
251 to 350 HP = 1.03
Over 350 hp = 1.04
Vehicle Weight Multiplier3
Vehicle weight < 1500 lbs = 1.03
Vehicle weight 1500 to 2000 lbs = 1.02
Vehicle weight 2,001 to 2,500 lbs = 1.01
Vehicle weight 2,501 to 3,000 lbs = 1.00
Vehicle weight 3,001 to 3,500 lbs = 0.99
Vehicle weight > 3,500 lbs = 0.98
1DOT approved street tires will have a treadwear rating of 140 or greater
2As measured at the driven wheels
3Curb weight without driver or passenger(s) onboard
For example, you drive a brand new 2008 Honda S2000. You run Kumho Ecsta V710 tires with a treadwear rating of 30. The car is rated at 237hp (SAE net) according to the manufacturer but it has an aftermarket cold air intake system and an aftermarket free-flowing exhaust system which puts it at just over 200hp as measured at the rear wheels (this can easily be verified with a chassis dynomometer). It has a curb weight of 2864lbs. Your best auto-x run resulted in an elapsed time of 46.88 seconds. Therefore, your indexed time would be:
46.88 x 1.035 x 1.02 x 1.00 = 49.49 seconds
The indexed time is a measure of how well you did relative to the other drivers. It is similar to a golfer's handicap. The indexed time will be your elapsed time multiplied by the following factors:
Tire Multiplier1
Street Tires = 1.00
R-Compound Tires With Treadwear Rating 100 - 139 = 1.02
R-Compound Tires With Treadwear Rating < 100 = 1.035
Horsepower Multiplier2
100 HP or less = 0.99
101 to 150 HP = 1.00
151 to 200 HP = 1.01
201 to 250 HP = 1.02
251 to 350 HP = 1.03
Over 350 hp = 1.04
Vehicle Weight Multiplier3
Vehicle weight < 1500 lbs = 1.03
Vehicle weight 1500 to 2000 lbs = 1.02
Vehicle weight 2,001 to 2,500 lbs = 1.01
Vehicle weight 2,501 to 3,000 lbs = 1.00
Vehicle weight 3,001 to 3,500 lbs = 0.99
Vehicle weight > 3,500 lbs = 0.98
1DOT approved street tires will have a treadwear rating of 140 or greater
2As measured at the driven wheels
3Curb weight without driver or passenger(s) onboard
For example, you drive a brand new 2008 Honda S2000. You run Kumho Ecsta V710 tires with a treadwear rating of 30. The car is rated at 237hp (SAE net) according to the manufacturer but it has an aftermarket cold air intake system and an aftermarket free-flowing exhaust system which puts it at just over 200hp as measured at the rear wheels (this can easily be verified with a chassis dynomometer). It has a curb weight of 2864lbs. Your best auto-x run resulted in an elapsed time of 46.88 seconds. Therefore, your indexed time would be:
46.88 x 1.035 x 1.02 x 1.00 = 49.49 seconds
This event was at James Woods High School... er, James Wood High School in Winchester. It’s bigger than the Frederick and Woodbridge lots, while being smaller than Waldorf. It’s more rectangular than square, with some small elevation changes.
The only real change for this event was the addition of the WORKS 24mm rear swaybar. They picked a common word as a company name so I feel the need to capitalize it for clarity
The hardest part of the install, by far, was getting the stock rear bar out, without touching the control arms. I was doing this the night before the event (never a good idea) and I didn’t want to risk rounding some important bolt or whatever - the car is from a cold climate and those bolts are not super clean. Anyway, just by un-hanging the muffler and fighting for a while I was able to get the stock bar off. The WORKS bar went in much easier than the OEM bar came out.Since Winchester is a comparatively small lot (to Fedex) I decided to put the rear bar on the stiffest setting. If the car was too loose on a small lot, it’d almost certainly be too loose on a faster lot - but if it felt pretty balanced on a small lot, it might be just right for Fedex. Just triangulation
The course doubled back on itself once and the visuals were a litle hard to follow. I lucked out being in 2nd heat - I got to ride along with my friend Slava so I saw the course a few times at speed before driving it myself. As I was courseworking I saw one of the NASIOC guys throw down a 46.9 in his STU STi so that was my target.
My first run, my friends Slava and Andy rode along (family car!). This took me off my game quite a bit... mentally I was definitely in goof-off mode rather than clean patient mode. I left it in 1st for the entire skidpad and as you might expect had a ton of wheelspin. I was just driving like a yokel. The car felt a little pushy, but there were also two extra people on it - hard to get feedback. I ended up with a 49.7, +3.
2nd run I decided to try not being a yokel, and actually shifting to 2nd. This was better, but I ended up hitting the inside finish cone... which hit the outside finish cone... which knocked over the reflector. I think the raw was a 47.1, but it was at least +3, maybe more.
My 3rd run I made a conscious effort not to screw up the first braking zone (which I had hit on my first two runs) but... did it anyway. I went on to somehow hit 4 more cones. None of them square mind you, all of them with the rear of the car. Doh. 47.5... +5.
Yikes... 11 cones in 3 runs? I think that’s a record for me. Not something I aim for.
OK, last run. Focus, stupid! I finally nailed that first hard braking zone and stayed VERY patient in the long skidpad. The patience helped - not surprisingly the car felt a lot better. The run was feeling great, until I hit a cone crossing over from the bottom to the top (again... with the rear of the car). I finished up the run strong though. 46.4... +1.
With the cone, I was 16th/66 in raw time and 13th in indexed points. Without the cone, I would have been 6th in raw time, fastest on street tires and fastest by index. Crap!
No pictures / video but here’s the index-winning run from Ryan’s STi:
http://www.youtube.com/watch?v=bX8lfekgQh4
My front right tires were very hot - the course was almost entirely left turns. But no drama otherwise. The car did as good as I could expect in the really really slow sweepers. The rear bar so far feels like a real improvement in the steady state stuff.I can’t wait to get the car to Fedex!
Thread Starter
Joined: Jul 2002
Posts: 1,733
Likes: 154
From: Why do they always call the Evo the Dark Side?
Nope. I don't think I am ready. I was hoping to be much further along at this point.
I don't think the car needs much but until I am closer to the fast guys I am a lot less inclined to travel. Hopefully next year... it will be a Pro then, right?
I don't think the car needs much but until I am closer to the fast guys I am a lot less inclined to travel. Hopefully next year... it will be a Pro then, right?
Evolving Member
Joined: Mar 2011
Posts: 111
Likes: 0
From: Maryland
Good to hear that the car is continuing to come along well. Just be careful hitting all those cones, people might start comparing to that Josh character. Nothing worse than "pulling a Luster".
I'm looking forward to getting a chance to drive the Evo as well. We run afternoon for the 7/10 event, so if the weather is looking good then perhaps we can swap rides and do fun runs.
I'm looking forward to getting a chance to drive the Evo as well. We run afternoon for the 7/10 event, so if the weather is looking good then perhaps we can swap rides and do fun runs.