Unofficial HRP Autocross Discussion Thread
09-17-2004, 03:01 AM
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Unofficial HRP Autocross Discussion Thread
I thought this would make a nice place to talk about autocross related topics pertaining to events held at HRP, to include strategies, techniques, equipment, people, track layout, theories and advice/suggestions.
Event results will be posted in a seperate thread.
Event results will be posted in a seperate thread.
09-17-2004, 03:05 AM
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Great idea Jimmy!
So what's our plan for beating up on on Pat Olsen and Curtis Lee? Should we take a tire iron to them like Tara Lipinski, or just find a fair way to win?
So what's our plan for beating up on on Pat Olsen and Curtis Lee? Should we take a tire iron to them like Tara Lipinski, or just find a fair way to win?
09-17-2004, 03:33 AM
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I've taken a lot of time thinking about what it'd take to match Curtis Lee's level of times, however maybe I'm approaching this whole thing the wrong way. I know first hand about how much of a difference a driver can make when he/she's not driving well versus when you're in the zone. However no matter how good you are as a driver, you'll soon reach a point where the car will limit your times until you improve on the car more. I'm wondering if Curtis' car is more "car" than what we currently drive, in an overall perspective.
I'm guessing that I need to identify some of the key differences and see if I can match it with an appropriate equivalent S2000 feature.
1. Power (my fave subject). His car's estimated power/torque output is a bit of a mystery to me. A 280Z engine in a 240Z body makes for a super broad torque band. It seems to me that he drives the majority of the course in 2nd gear and he would seem to stretch 2nd gear a lot from lower to higher rpms. I'd suspect that his motor is modded to the extent of what's allowed in BSP class so the numbers should be known somewhere on the internet, for a car with ignition tuning, performance carbs, exhaust, valve adjustment, cams and exhaust on a 280Z motor. Then we'd be able to calculate the effective power to weight ratio based on a normal 240Z car with the interior intact (since stripping is illegal for street prepared class). He has to have some of the highest HP #'s for a NA car that's shy of a V8.
2. His gearing has to be stock to include his final drive gearset, save for an aftermarket clutch in order to be in BSP, so the speed limitations for each gear should be documented somewhere on the web and the absolute figures known. The time he saves by shifting less throughout the course may allow him to focus more on other things.
3. Suspension. The word is he's on Tokico Illumina gas shocks which I'm very familiar with. Very easy to tune, and works great. I can't believe there's none made for our cars, oh well. It's lighter than comparable Konis, and doesn't require the external oil res container to control damping. The feel of the Tokico's are very forgiving from my own experience.
4. Chassis reinforcement. His car appears to be very stiff and predictable in the turns. The benefits would be sharper steering, and better handling by controlling chassis flex-related alignment changes. In comparison, it behaves a lot differently from Dean's Kapu Racing Z.
5. Grip. Colin's favorite topic. His big 255's on Victoracers (not Hoosiers) definitely gives him an edge during corner exits and he still has enough power to break the tires free in a straight line. It's like he has enough power to overcome the grip potential, yet retains the ability to use the throttle to steer the car. I've witnessed in person the first case of severe understeer this past event, right at the crossover. He had the fronts turned in, but the car went straight. I know he went into the turn too hot, but I think his car is tuned a little biased towards understeer for more stability.
6. Alignment. His front to rear camber appears to be greater than mine by a lot. I've got comments about how aggressive my own car's rear stance is (at -2.2) but I think Curtis is running more in the back and the front. I think this is one of the keys to success. My guess is that his car is aligned so aggressively that it jeopardizes a little street driveability. The price for being the top driver and car.
7. Seats. His car has Recaros and I'm uncertain as to how they'll benefit our cars if we had bucket seats, in relation to our times. Sure, we'd move around less but will it improve our times?
8. Driving experience. Let's not leave out the most important factor here since Curtis' times are usually a little less than Jenn's times (who isn't too far behind dad), and mom Amy Lee is close to my times (or vice versa) meaning the Lee family is always in the top 15. Without more exposure to competitive driving, perhaps driving lessons and more seat time, it's going to be difficult to match Curtis' level of driving.
I'm guessing that I need to identify some of the key differences and see if I can match it with an appropriate equivalent S2000 feature.
1. Power (my fave subject). His car's estimated power/torque output is a bit of a mystery to me. A 280Z engine in a 240Z body makes for a super broad torque band. It seems to me that he drives the majority of the course in 2nd gear and he would seem to stretch 2nd gear a lot from lower to higher rpms. I'd suspect that his motor is modded to the extent of what's allowed in BSP class so the numbers should be known somewhere on the internet, for a car with ignition tuning, performance carbs, exhaust, valve adjustment, cams and exhaust on a 280Z motor. Then we'd be able to calculate the effective power to weight ratio based on a normal 240Z car with the interior intact (since stripping is illegal for street prepared class). He has to have some of the highest HP #'s for a NA car that's shy of a V8.
2. His gearing has to be stock to include his final drive gearset, save for an aftermarket clutch in order to be in BSP, so the speed limitations for each gear should be documented somewhere on the web and the absolute figures known. The time he saves by shifting less throughout the course may allow him to focus more on other things.
3. Suspension. The word is he's on Tokico Illumina gas shocks which I'm very familiar with. Very easy to tune, and works great. I can't believe there's none made for our cars, oh well. It's lighter than comparable Konis, and doesn't require the external oil res container to control damping. The feel of the Tokico's are very forgiving from my own experience.
4. Chassis reinforcement. His car appears to be very stiff and predictable in the turns. The benefits would be sharper steering, and better handling by controlling chassis flex-related alignment changes. In comparison, it behaves a lot differently from Dean's Kapu Racing Z.
5. Grip. Colin's favorite topic. His big 255's on Victoracers (not Hoosiers) definitely gives him an edge during corner exits and he still has enough power to break the tires free in a straight line. It's like he has enough power to overcome the grip potential, yet retains the ability to use the throttle to steer the car. I've witnessed in person the first case of severe understeer this past event, right at the crossover. He had the fronts turned in, but the car went straight. I know he went into the turn too hot, but I think his car is tuned a little biased towards understeer for more stability.
6. Alignment. His front to rear camber appears to be greater than mine by a lot. I've got comments about how aggressive my own car's rear stance is (at -2.2) but I think Curtis is running more in the back and the front. I think this is one of the keys to success. My guess is that his car is aligned so aggressively that it jeopardizes a little street driveability. The price for being the top driver and car.
7. Seats. His car has Recaros and I'm uncertain as to how they'll benefit our cars if we had bucket seats, in relation to our times. Sure, we'd move around less but will it improve our times?
8. Driving experience. Let's not leave out the most important factor here since Curtis' times are usually a little less than Jenn's times (who isn't too far behind dad), and mom Amy Lee is close to my times (or vice versa) meaning the Lee family is always in the top 15. Without more exposure to competitive driving, perhaps driving lessons and more seat time, it's going to be difficult to match Curtis' level of driving.
09-17-2004, 03:52 AM
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So, if we want to beat Curtis, either Colin needs to start using some of the Jedi Driving Force, or we need more equipment to match or best his car.
1. (power) I'm guessing that it's not possible for an ASP-tuned car at the limits of what's allowed to match Curtis' effective power to weight ratio, since I'm almost certain we're 500 pounds too heavy. In my car, that'd mean cams and a different header, perhaps even a completely different air intake system, especially if these improvements increase volumetric efficiency upwards of 10-15% of what Steve's and my car already does at peak power levels. I truly don't think that FI is the key (too much power at VTEC could be bad), so my theory is we need to do it with NA power. Perhaps weight reduction is in order, but how much weight can be shaved off without seriously altering the car?
2. The gearing situation goes hand in hand with #8 (driving exp). Not much to say about this except for that course layouts sometimes benefit 1 type of gearset over the other. Our courses are a bit too closely spaced so it may give a slight edge towards tighter geared cars... this is one of those hit and miss things. I think we have enough gearing to get the job done. If both Steve and my car is setup the same way (suspension and all) where the final drive is the only difference, then we can actively compare the section times between a car with 4.44's versus 4.10's to see which one was better.
3. I need to get beyond the OEM stuff as I'm starting to understand what Steve meant by "I need to wait for the car to finish dancing in the slaloms". Steve already has the RS suspension, perhaps with a little fine tuning, we could taylor the car for his style of driving or better yet, for the conditions found in HRP.
4. I don't see much flex in my car to the point where I feel I need more bracing. Steve claims that he could tell what the X-brace is doing versus without. I may want to give that a try, but I think it's more for driveability than something to improve on times.
5. We need larger wheels to fit bigger tires. The biggest we can fit on the lightest stuff, but it must be matched to the suspension to take full advantage of it. Steve's car is already there, but maybe use Hoosiers for more added lateral grip? I was thinking this myself since I don't have the $$$ to spend on suspension, new wheels/tires. Hoosiers seem to improve Avery's Miata times by 2 seconds over the Kuhmos in an underpowered car. 2 seconds is what I need to stay close to Steve and Colin's times... I'm getting left behind as it stands.
6. This is going to be hard but I wonder if Jason Saini's setup is the way to go, but I don't like the amount of toe-in in the rear (that's got to suck on the highway). Curtis' car seems to behave a little biased towards understeer in a few sections (it's tiny, but it's there if you observe closely), but it behaves like a very neutral car during the turn-in portion of a few sharp corners. Could this be the result of a little toe-out in the front, helping the turn-in?
Did I miss on anything?
1. (power) I'm guessing that it's not possible for an ASP-tuned car at the limits of what's allowed to match Curtis' effective power to weight ratio, since I'm almost certain we're 500 pounds too heavy. In my car, that'd mean cams and a different header, perhaps even a completely different air intake system, especially if these improvements increase volumetric efficiency upwards of 10-15% of what Steve's and my car already does at peak power levels. I truly don't think that FI is the key (too much power at VTEC could be bad), so my theory is we need to do it with NA power. Perhaps weight reduction is in order, but how much weight can be shaved off without seriously altering the car?
2. The gearing situation goes hand in hand with #8 (driving exp). Not much to say about this except for that course layouts sometimes benefit 1 type of gearset over the other. Our courses are a bit too closely spaced so it may give a slight edge towards tighter geared cars... this is one of those hit and miss things. I think we have enough gearing to get the job done. If both Steve and my car is setup the same way (suspension and all) where the final drive is the only difference, then we can actively compare the section times between a car with 4.44's versus 4.10's to see which one was better.
3. I need to get beyond the OEM stuff as I'm starting to understand what Steve meant by "I need to wait for the car to finish dancing in the slaloms". Steve already has the RS suspension, perhaps with a little fine tuning, we could taylor the car for his style of driving or better yet, for the conditions found in HRP.
4. I don't see much flex in my car to the point where I feel I need more bracing. Steve claims that he could tell what the X-brace is doing versus without. I may want to give that a try, but I think it's more for driveability than something to improve on times.
5. We need larger wheels to fit bigger tires. The biggest we can fit on the lightest stuff, but it must be matched to the suspension to take full advantage of it. Steve's car is already there, but maybe use Hoosiers for more added lateral grip? I was thinking this myself since I don't have the $$$ to spend on suspension, new wheels/tires. Hoosiers seem to improve Avery's Miata times by 2 seconds over the Kuhmos in an underpowered car. 2 seconds is what I need to stay close to Steve and Colin's times... I'm getting left behind as it stands.
6. This is going to be hard but I wonder if Jason Saini's setup is the way to go, but I don't like the amount of toe-in in the rear (that's got to suck on the highway). Curtis' car seems to behave a little biased towards understeer in a few sections (it's tiny, but it's there if you observe closely), but it behaves like a very neutral car during the turn-in portion of a few sharp corners. Could this be the result of a little toe-out in the front, helping the turn-in?
Did I miss on anything?
09-17-2004, 05:03 AM
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That sounds pretty much right. I like to focus especially on the 'shedding weight' theory. Colin taught me a valuable lesson by pointing out that losing weight isn't always good if you don't keep the balance of the car in mind.
Case in point: The auto-x before the last one, I didn't take time to put gas in the car and figured I could make it through the day without it. The car was extremely loose, and we concluded that the tires were dead (well, they were) but Colin also asked that I fill the gas almost to the top for the next event. I did so and even on the dead race tires, the following event was like night and day. The car was behaving neutrally, and was a lot more predictable (and fun!). The weight of all that extra gas really kept the rear planted.
I want to shed more weight, but not strip the interior yet.
For more grip, I would like to eventually upgrade to 17X9JJ on the rears so I could fit 265 or even 275/40's. I'm currently running 17X8.5JJ on 255's. The Volk CE28N's are probably the best bet because they're the lightest and most affordable.
Case in point: The auto-x before the last one, I didn't take time to put gas in the car and figured I could make it through the day without it. The car was extremely loose, and we concluded that the tires were dead (well, they were) but Colin also asked that I fill the gas almost to the top for the next event. I did so and even on the dead race tires, the following event was like night and day. The car was behaving neutrally, and was a lot more predictable (and fun!). The weight of all that extra gas really kept the rear planted.
I want to shed more weight, but not strip the interior yet.
For more grip, I would like to eventually upgrade to 17X9JJ on the rears so I could fit 265 or even 275/40's. I'm currently running 17X8.5JJ on 255's. The Volk CE28N's are probably the best bet because they're the lightest and most affordable.
09-17-2004, 06:13 AM
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WOW!! I thought AUTO-X was supposed to be fun.... This sounds like work, but a whole lot funner. I will definitely try and come out to the next auto-x when I get back, I just really hope I don't damage the car at all. A couple of cone marks won't stop me but a concrete wall mark will.
09-17-2004, 10:44 AM
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First learn crawl, then learn walk. When you're ready to run, take it easy and learn the car and let the car learn you.
You'll be okay Bruce, just don't spin where it's narrow... take if from an ace spinner.
You'll be okay Bruce, just don't spin where it's narrow... take if from an ace spinner.
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09-17-2004, 11:12 AM
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That's a good case in point Steve. You may be putting down more hp than Curtis but his car's weight (if I were to take a guess) should be mid 2000 pounds, so his p/w ratio is still higher, with the added bonus of a much broader torqueband.
Colin's weight lesson is a valueable one. Fuel weight is one of the easiest to shed as long as you don't upset the balance of the car. I'm very amazed that you don't have an upgraded front sway bar which has to account for a lot of the looseness issues you guys have. My car runs at 3 bars of fuel and it runs great... IMO, it's much faster than when the car has 5 or more bars, but I have the Comptech front bar which helps settle the rears. I believe an adjustable front sway bar can make all the difference in the world Steve... if I can make a suggestion, make this your next upgrade.
Your car has gear reduction so the added torque multiplication helps you break the rears free during acceleration even though you have more rubber than me, especially when you power out of corners (during the exits or while you're in the corner past the apex). This is one of the reasons why Colin is focused on increasing grip because it's easier to break the tires free on your car than mine. If you watch the videos with Colin "drifting" in the off-camber, Colin drifting 5 feet from the starting point, Colin drifting in the crossover, it's always common to see that the car's front is under control, but the back end swings around. He does a very good (quick) job at countersteering, but all that sliding is hurting the times. It can also be said about extra camber. It's a friend in the corner by allowing more tire to contact the road, but extra negative camber can hurt if you try and accelerate in a straight line since only the inside half of the rear tires are actually holding up the car, reducing the contact patch, and reducing grip potential. With HRP's uneven surface, it may get a little "bumpy" in a few areas and when you drive over these areas at high throttle (or more accurately, more forward "G's during full-power acceleration), that spells out trouble for grip. That's where AWD cars IMO have the upper hand, they can fly past the areas of lesser grip and keep more power to help accelerate the car.
Colin's weight lesson is a valueable one. Fuel weight is one of the easiest to shed as long as you don't upset the balance of the car. I'm very amazed that you don't have an upgraded front sway bar which has to account for a lot of the looseness issues you guys have. My car runs at 3 bars of fuel and it runs great... IMO, it's much faster than when the car has 5 or more bars, but I have the Comptech front bar which helps settle the rears. I believe an adjustable front sway bar can make all the difference in the world Steve... if I can make a suggestion, make this your next upgrade.
Your car has gear reduction so the added torque multiplication helps you break the rears free during acceleration even though you have more rubber than me, especially when you power out of corners (during the exits or while you're in the corner past the apex). This is one of the reasons why Colin is focused on increasing grip because it's easier to break the tires free on your car than mine. If you watch the videos with Colin "drifting" in the off-camber, Colin drifting 5 feet from the starting point, Colin drifting in the crossover, it's always common to see that the car's front is under control, but the back end swings around. He does a very good (quick) job at countersteering, but all that sliding is hurting the times. It can also be said about extra camber. It's a friend in the corner by allowing more tire to contact the road, but extra negative camber can hurt if you try and accelerate in a straight line since only the inside half of the rear tires are actually holding up the car, reducing the contact patch, and reducing grip potential. With HRP's uneven surface, it may get a little "bumpy" in a few areas and when you drive over these areas at high throttle (or more accurately, more forward "G's during full-power acceleration), that spells out trouble for grip. That's where AWD cars IMO have the upper hand, they can fly past the areas of lesser grip and keep more power to help accelerate the car.
