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      07-18-2008, 04:04 PM   #23
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Just finished getting the car ready for the weekend. Pulled the front camber pins, probably not worth more than 0.2 or 0.3 but I'll take every little bit I can get.
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      07-18-2008, 07:03 PM   #24
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Just finished getting the car ready for the weekend. Pulled the front camber pins, probably not worth more than 0.2 or 0.3 but I'll take every little bit I can get.
wheels offset?
tire type?
your car is non EDC ?

more details please.
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      07-19-2008, 09:28 PM   #25
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Anyone have any recommendations on a good auto-x helmet to buy? I am having the hardest time finding a local place to buy one. I just can't get myself to spend the money on one unless I try it on in person.
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      07-26-2008, 02:31 PM   #26
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my next helmet willbe a HJC. carbon fiber.
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      08-06-2008, 04:40 PM   #27
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my next helmet willbe a HJC. carbon fiber.
I got my very nice Arai full face Snell M rated one through ebay for less than a hundred. Graphics package, removable liners, pads, shield and it's ventilated too... orange wasn't a good seller I guess. It's just fine for SCCA SoloII and Time Trials events. If you have to try it on, and you don't need the snell track helmets & fire suit, surely there is a large motorcycle dealership you could go to. I just measured my head and picked a helmet figuring that for less than a hundred, I could always get another and donate the old one to the club. Most come with various fitting pads as well to help make it work.

I'll be doing my first autocross sunday. SCCA Solo II, class SS... so I'll be facing Elise's and Vettes running sticky tires and vetran drivers. Gonna get monkey stomped with the stock tires, but hopefully learn a thing or two about what the M3 can do. I'll play with tire pressures, and load them with nitrogen (a trick for less heat expansion)... My E90 will look like a whale paddocked around all the Elises. I'll probably start with 35/37 pressures and see where to go from there, and I'll try to leave the EDC on normal with everything else cranked up.
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      08-06-2008, 05:15 PM   #28
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I'll be doing my first autocross sunday. SCCA Solo II, class SS... so I'll be facing Elise's and Vettes running sticky tires and vetran drivers. Gonna get monkey stomped with the stock tires, but hopefully learn a thing or two about what the M3 can do. I'll play with tire pressures, and load them with nitrogen (a trick for less heat expansion)... My E90 will look like a whale paddocked around all the Elises. I'll probably start with 35/37 pressures and see where to go from there, and I'll try to leave the EDC on normal with everything else cranked up.
It really should be in AS. Having driven both the M3 and the elise at autocross no way it keeps up.

For tire pressure I have had good luck with 36-40 front (depending on temp and tire) and 34-36 rear. Resist the temptation to run more pressure in the rear than the front. The car actually works better the other way around.
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      08-06-2008, 06:53 PM   #29
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It really should be in AS. Having driven both the M3 and the elise at autocross no way it keeps up.

For tire pressure I have had good luck with 36-40 front (depending on temp and tire) and 34-36 rear. Resist the temptation to run more pressure in the rear than the front. The car actually works better the other way around.
Cool, thanks for the advice.

I agree that it is a better fit in AS, but that'd hurt the E46 M3 (weren't they originally SS too?). Personally I think they ought to create a tweener class somewhere in the middle for all the new V8 coupes and sedans and keep SS as the high end sports cars. At least the way it's setup now, I know I won't win, so maybe I'll be able to focus on technique and figuring out how to drive the limits of what I have instead of worrying about setup to shave those tenths out.
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      08-18-2008, 04:16 AM   #30
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I ran this weekend on the stock tires, stock alignment, no mods.

I spun my first run. The Sport-Plus or Sport setting for the e-gas are useless. There is no purpose for these things. Gas response is non-linear, at high RPM (as I was through a transition) makes the car dangerous. I slightly hit the gas on turn exit, and the car just lost the rear grip, like and on/off switch when I just needed 20% gas.

Hot tire pressures 36 psi front/rear. I did two runs at 40F/36R but the car felt better and faster on 36/36. This is consistent with my tire pressures on Michelin PS2 and my GT3.

Suspension in Sport mode has a predictable feeling. This car doesn't understeer as the E46 M3 (which awfully understeers). Very well balanced car, and very fast, it feels lighter than it's. I was really impressed with the M-diff, the finish was a fast right sweeper (60 mph), at full gas the car started to get away progressively, but not losing control.

My fastest time was 1.9 secs behind a two time A-Stock National Champion with his Vette on race tires.

I know from experience how much faster are the Michlin Pilot Sport Cups against the Michelin PS street tires, but for autocross you can get even faster tires (A6/V710).

I think that this car will go to Super Stock and not A-Stock. In A-Stock it would be very competitive. I can easily drop over 2 secs just by switching to 275/35R18 A6. This would already put me as the fastest stock car at the event, and a few tenths behind the BSP and CSP National Champions (they were at the event).

Then add car preparation (alignment, light wheels, muffler delete, a 6-speed manual no option car) and the car would be even faster.
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      08-18-2008, 10:46 AM   #31
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My fastest time was 1.9 secs behind a two time A-Stock National Champion with his Vette on race tires.
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AWESOME!!! about how many seconds was a lap? who/where did you run?
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      08-18-2008, 11:34 AM   #32
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AWESOME!!! about how many seconds was a lap? who/where did you run?
Laps were in the mid to low 30s. SCCA at California Speedway (Fontana).

A nice group of SCCA National Champions. There was a Nissan GT-R driven by an experienced autocrosser. The GT-R was fast, it makes too many funny noises though.
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      08-18-2008, 12:23 PM   #33
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how was the GTR time compared to yours?
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      08-18-2008, 12:56 PM   #34
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I think that this car will go to Super Stock and not A-Stock. In A-Stock it would be very competitive. I can easily drop over 2 secs just by switching to 275/35R18 A6. This would already put me as the fastest stock car at the event, and a few tenths behind the BSP and CSP National Champions (they were at the event).
The 275 won't work well on the stock front rim, though I know some will try it. Also hoosiers are about 2 seconds faster on a 60s course. If times were running aroud 30s, you would need to divide that delta by half.
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      08-18-2008, 05:01 PM   #35
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The 275 won't work well on the stock front rim, though I know some will try it. Also hoosiers are about 2 seconds faster on a 60s course. If times were running aroud 30s, you would need to divide that delta by half.
Actually there is a better option on 19", 265/35 and 285/30.

With the proper tire pressure the 275 work with the stock wheels. The rounded shoulder (running a too wide tire for the wheel) helps camber challenged cars. I ran 275 RA1/V700 on 8.5" wheels with better results (lap times) than stock 235 in a 911.

Hoosiers A6 are around 4 secs faster on a 60 secs course. The stock car doesn't have race tires, it has Michelin PS2.

At a 60 secs track, my GT3 was 1.5 secs faster on MPSC compared to MPS2. If you were right, a lot of people would be running MPSC for auto-x given just that 0.5 secs difference against Hoosier A6 (0.25 on a 30 secs course), and way longer life, plus the ability to drive them on the streets.

The E46 M3 CSL gained around 20 secs at the Nurburgring by switching to MPSC, the 2007 GT3 gained over 10 secs at the same track by going to a street friendly version of the MPSC.

I have run R6 and they have much higher grip levels than the MPSC, around 1 sec faster on the same 60 secs track (Pocono North). I also ran Michelin slicks (S6/S7) and A6 for auto-x/track, at auto-x the A6 is faster, at the track they are even for the first 2 laps, after that the A6 goes greasy. There are multiple comparisons between R6 and real slicks from SCCA/PCA/NASA Club Racing.

I personally run half the event on my street tires when I run A6 at local events, so I get longer life out of the A6, and I keep comparing lap times.
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      08-18-2008, 05:21 PM   #36
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Lets just say your data and my data disagree....

The reason people don't run a MPSC at autocross is because of temp issues. You cannot get the tire hot under normal autocross conditions.

Pinching a tire, running too wide for the rim, generally doesn't generate more grip. However, this varries from tire to tire and hoosiers generally handle this better than most, because in part they are designed to run on narrower rims. However, for everything there are limits and 265 on 8.5" is really close. You have to think about what happens to a tire when the sidewall deflect during cornering.

Hoosiers are not 4s faster than PS2s on a 60 second course. There will also be variations dependant on surface conditions.


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Actually there is a better option on 19", 265/35 and 285/30.

With the proper tire pressure the 275 work with the stock wheels. The rounded shoulder (running a too wide tire for the wheel) helps camber challenged cars. I ran 275 RA1/V700 on 8.5" wheels with better results (lap times) than stock 235 in a 911.

Hoosiers A6 are around 4 secs faster on a 60 secs course. The stock car doesn't have race tires, it has Michelin PS2.

At a 60 secs track, my GT3 was 1.5 secs faster on MPSC compared to MPS2. If you were right, a lot of people would be running MPSC for auto-x given just that 0.5 secs difference against Hoosier A6 (0.25 on a 30 secs course), and way longer life, plus the ability to drive them on the streets.

The E46 M3 CSL gained around 20 secs at the Nurburgring by switching to MPSC, the 2007 GT3 gained over 10 secs at the same track by going to a street friendly version of the MPSC.

I have run R6 and they have much higher grip levels than the MPSC, around 1 sec faster on the same 60 secs track (Pocono North). I also ran Michelin slicks (S6/S7) and A6 for auto-x/track, at auto-x the A6 is faster, at the track they are even for the first 2 laps, after that the A6 goes greasy. There are multiple comparisons between R6 and real slicks from SCCA/PCA/NASA Club Racing.

I personally run half the event on my street tires when I run A6 at local events, so I get longer life out of the A6, and I keep comparing lap times.
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      08-18-2008, 05:54 PM   #37
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Lets just say your data and my data disagree....

The reason people don't run a MPSC at autocross is because of temp issues. You cannot get the tire hot under normal autocross conditions.

Pinching a tire, running too wide for the rim, generally doesn't generate more grip. However, this varries from tire to tire and hoosiers generally handle this better than most, because in part they are designed to run on narrower rims. However, for everything there are limits and 265 on 8.5" is really close. You have to think about what happens to a tire when the sidewall deflect during cornering.

Hoosiers are not 4s faster than PS2s on a 60 second course. There will also be variations dependant on surface conditions.
I agree on the MPSC and temp issues only when running on cold weather. On summer conditions, they're good on the second lap, I ran MPSC for three years.

At National level, the top cars/drivers are running wide tires on narrow wheels in all the stock classes. The 275 A6 works well with a 8.5" wheel, National top level Soltices are running 285 with shorter sidewalls on 8.5". I trust the experience from the highest level autocrossers in the country. V710/A6 allow this due to stiff sidewalls, the same cannot or should not be done with standard street tires.

If you cannot drop 4 secs between wider A6 and stock PS2 at an autocross (using a 60 secs course as a baseline), you might be under driving the A6. This is not applicable in the rain, so it is definitely surface condition dependent.
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      08-18-2008, 06:27 PM   #38
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If you cannot drop 4 secs between wider A6 and stock PS2 at an autocross (using a 60 secs course as a baseline), you might be under driving the A6. This is not applicable in the rain, so it is definitely surface condition dependent.
The wider tires are probably worth 0.3 to 0.5 all else being equal.

You should try running both tires on the same car at the same event. Last time I did this the difference was a lot less than 4s. I have not tried A6s on the E92 M3 yet. I have tried race & street tires on the old E46 where the V700 (older Kuhmo) was about 1.9s faster than my street tires. On the elise I have measured the hoosiers as about 0.5s faster than the 048s (M). Now this is on one lot (fine grain concrete), test at a different lot and results will vary.

[edit] The last GRM tire test had:
Street Tires:
1. 42.984 Falken Azenis RT-615
2. 43.254 Falken Azenis RT-215
3. 43.287 Yokohama Advan Neova
4. 43.511 Hankook R-S2 Z212
5. 43.762 Kumho Ecsta MX
6. 43.855 BFGoodrich g-force T/A KD

Track Tires:
1. 41.008 Kumho Ecsta V710
2. 41.142 Hoosier A3S05
3. 41.217 Hankook Z214 C70
4. 42.428 Yokohama A032R S

The A6 is slightly faster than the A5, espically on camber challenged cars.
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      08-18-2008, 10:51 PM   #39
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i think you are both right - conditions vary . I have seen tests from 2 up to 4 seconds difference between street tires and R-comp tires on a 60 sec course.
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      08-18-2008, 11:49 PM   #40
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The wider tires are probably worth 0.3 to 0.5 all else being equal.

You should try running both tires on the same car at the same event. Last time I did this the difference was a lot less than 4s. I have not tried A6s on the E92 M3 yet. I have tried race & street tires on the old E46 where the V700 (older Kuhmo) was about 1.9s faster than my street tires. On the elise I have measured the hoosiers as about 0.5s faster than the 048s (M). Now this is on one lot (fine grain concrete), test at a different lot and results will vary.

[edit] The last GRM tire test had:
Street Tires:
1. 42.984 Falken Azenis RT-615
2. 43.254 Falken Azenis RT-215
3. 43.287 Yokohama Advan Neova
4. 43.511 Hankook R-S2 Z212
5. 43.762 Kumho Ecsta MX
6. 43.855 BFGoodrich g-force T/A KD

Track Tires:
1. 41.008 Kumho Ecsta V710
2. 41.142 Hoosier A3S05
3. 41.217 Hankook Z214 C70
4. 42.428 Yokohama A032R S

The A6 is slightly faster than the A5, espically on camber challenged cars.
This is good information, as the Grassroot MotorSports guys perform these kind of tests once in a while.

I have been running Hoosiers since the A3S03 up to the R6/A6. I also ran V700, V710, RA1, Dunlop/GY/Michelin/Yoko slicks, MPSC, MPS2.

Although all my tire tests have been done in different cars (Boxster S and 911 GT3), I use either the same track or the same autocross event to compare them.

The V710 was a quantum leap forward for high horsepower cars. I was running 273/35 and 335/30 A3S04 and A3S05, and I could not get that much better grip than the A3S03 at my local events. When I switched to 245/285 V710, I gained 0.7 secs over my wider A3S05 on the same course. I ran these narrower V710 and got very good results locally. Hoosiers were suffering from early cords back in the day, so I quit Hoosiers.

When the A6 showed up, I was expecting same problems as the A3S04 and A3S05 (the A3S03 was great). All of a sudden, guys running A6 were improving their times, so I gave the A6 a try.

I ran the V710 and the A6 at the same event, and I gained close to one second on a 45 secs average course. This was with 285/335 A6 vs. 285/315 V710 (the V710 sizes I ran later). My V710 were fresh when I tested this (-30 runs).

After that I just ran half the events on shaved Toyo RA-1 and the other half on A6, or a full event on RA-1, until recently. A6 brought my car close to a National Championship in a class where people run slicks (FP), my co-driver won a National Championship with this same car.

The street tires tested by GRM are the choices for the Street tire classes, plus another 3 or 4 new tires, but the PS2 was never an option to win the ST classes as it was not competitive. Let's assume that the PS2 is as fast as the BFG-GForce and Kumho MX (and it isn't), we are looking at a 3.8 secs difference between PS2/GForce/MX against V710, before even considering that the A6 is faster than the V710, or considering wider A6 tires, and we are already assuming that the PS2 can keep up with these two street tires.

My experience with the Lotus Elise has been short (students or friends drives), but the A048 are not even close to MPSC performance, let alone V710 and A6. You should see more than 0.5 secs difference between A048 and A6 with the Lotus, this is assuming you're driving at 10th/10th (limits of grip on the intended line).
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      08-19-2008, 12:03 AM   #41
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My experience with the Lotus Elise has been short (students or friends drives), but the A048 are not even close to MPSC performance, let alone V710 and A6. You should see more than 0.5 secs difference between A048 and A6 with the Lotus, this is assuming you're driving at 10th/10th (limits of grip on the intended line).
I love how members new to the forum immediatly question my driving if I don't agree with their posts.

The 048M work pretty well new, but they heat cycle out very quickly. For autocross they are better than the MPSC on light cars. They also work at lower temps. Again, autocross specific. On a track I would take the MPSC.

Basically I think you are over-estimating the A6. Its a great tire, but not a 4s tire. Also I think the PS2 is a bit better than you are giving it credit for.
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      08-19-2008, 12:00 PM   #42
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Let's assume that the PS2 is as fast as the BFG-GForce and Kumho MX (and it isn't), we are looking at a 3.8 secs difference between PS2/GForce/MX
I am suprized the Khumo beat the G-force.

what car were these all on. ?
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