2-Days in a row at PIR....instead of "because I got high" it's "because I must drive"....
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From: Snowwhitepillowformybigfathead
2-Days in a row at PIR....instead of "because I got high" it's "because I must drive"....
I ran the Proformance Lapping day at PIR on Thursday, and the Porsche day on Friday.
Thursday was my first day on 225/45's and I was expecting more grip to equal more speed. The few laps that my Intercomp timer caught showed me in the 1:34's but I have no idea if those were good laps. There was alot of wind too. The tires are mounted on 7 inch rims, and while I'm quite sure that grip is increased, the tires seemed to be slower responding to transitions. Makes sense. I'm going to have to decide what's most important when it's time to buy tires again - I'll probably go with grip.
As usual Proformance ran two groups only with 30 minute sessions. Most everybody is pretty friendly, but I treated one of them very poorly. There was a guy in a white Subaru RS that was gathering a stack of cars behind him. He would carefully let only one pass him per straight. When he came up to me in the paddock after that session real bumbly friendly like, I didn't take up the subject that was on my mind, and merely responded to his questions with near hostile terseness. I felt bad later - not much for him, but that I came off as a *****. I should have been straight and told him what was what. He cleaned up his act later, so somebody must have talked to him.
I did something new this day. After talking to a few of the other drivers in the group who weren't getting PIR, I told them that when I'd come past them, that I'd slow and give them a couple of laps to follow me before ramping my speed back up. It went over pretty well.
All in all, Thursday was just another good day. Friday was very different, with lower lows and higher highs.
Porsche club always starts their days at noon. I always forget, forget to verify the time, don't trust my memory. So I got there at 8. I ran off and did some stuff, but at 10 I was back and getting ready. Those two hours took forever to go by. There was a demonstration going of Enduro Karts. I like wheeled vehicles generally, but I just don't see the attraction there. Watching those guys heads bouncing up and down gave me a headache. I suppose if you get to smell Bean Oil it's worth some discomfort - man I love that smell.
You may remember me mentioning a major clanking at the rear of the car as I pounded the curbing in T7. I was laying off the worst part of 7 because of that, but I now had the sound on both of the other Left hand turns (the chicane and 3) regardless of whether I hit the curbing or not. Furthermore there was a disruption of the chassis occuring at the same time - it felt like the outside rear was tucking under or something. I came in early from two sessions trying to figure out what was going on. I looked at and checked every part of the rear suspension and found nothing. In desperation I called Scott Zellner and asked him if they had had any component failure modes that resembled this. He told me nothing in particular, told me to look at everything Front and Rear - and that it was easy to be fooled into thinking something actually happening at the front was happening at the back.
The next session was about to start, so my friend Chris got in to listen more objectively. His impression was that it was the front. His saying this broke my fixation, and I decided that yes, the disruption felt like an abrupt lateral shift in the front end. I dropped the front dampers so that the front end would droop enough to get at the camber adjusters - viola: the right front camber adjustment bolts were loose. The disruption was the camber and toe changing as the load slammed the ball joint carrier outboard. Roughed it back and tightened it up.
Next session I took Chris out with me again (Chris is my AS friend with the shock dyno). The sound in the back was still there (and we both agree it's in the back now), but the disruption was gone. So we ran the full session ***** out. He was laughing at how fast my "stupid car" could get thru 7-8-9. I was laughing too - my day was back on. Key lesson - two problems at one time can be tricky to solve. It's very interesting how easily prejudiced my analysis of the problem was - I was being a simple minded doofus. When I eliminated the likely problems at the rear, the problem had to be elsewhere - but it took me too long to make that jump. I'll have to think smarter next time. In the greater scheme of things, what looked to be the end of a staggering string of mechanically reliable events is none such - my ITR remains unbowed, and it's driver justly impressed. I must point out that there appears to be something to RTR and King's contention that these cars don't like being dragged over curbs much. Scott says that the rear trailing arms can deform and crack, and on and on.... My new policy is to stay off the steep ones - not that I intentionally hit them, it was just happening all too often - it seems to me that when you know that they are seriously bad you're far less likely to accidentally hit them.
Chris did me the big favor of taking tire temps and lap times during the last session. Tire temps are tough at PIR because there's a long straight before the pit exit road. When you're really serious about temps, you rent the track and take them just past T5. Note that PIR is a clockwise track. Anyway here's what we got:
Pressure before going out:
LF 37 RF 37.5
LR 38 RR 38.5
Halfway (15 minutes)
LF 166 173 207 RF 205 164 148
LR 134 136 146 RR 124 124 117
End (25 minutes)
LF 144 159 188 RF 177 163 132
LR 129 132 137 RR 135 130 121
Hot Pressure:
LF 44 RF 44
LR 42.5 RR 42
This is with 3.5 negative front camber, 1.5 negative rear camber, 1/16 toe out front, and 1/16 toe in rear.
Most of my friends say they look for 10 to 15 degrees higher on the inside of the fronts - so they think a little less front camber is in order. I'm going to follow up on that with my tire guy and Scott Zellner - I wouldn't say no to some more front grip. A little playing with pressure too - but it's not too far off.
Best lap time of the day was 1:32.750 - two laps in a row. That's about 7/10's better than my previous best. It compares to Pierre's fast race and qualifying laps of 1:32.2 and 1:30.327. Getting closer, but it's getting harder.
One of the key things I was working on was bringing my turn in points back - turning in earlier and with more finesse. That proved to be of great assistance in prolonging the usefulness of the front tires, and made it easier to bring the rear end around. I have brainwashed myself somewhat about the late turn in - late apex. As my speed has gone up I've been fighting the car too much. I CAN turn in earlier and still hit my marks. This succesful experimentation was prompted by my friend Chris sitting in the passenger seat and making suggestions (only half of which I could hear). I (and you too) need as much coaching as we can get. It's a tough job to keep thinking about finding something new - another qualified person in the car can see things you might miss, and that can train you to do a better job for yourself when you don't have a coach.
Scott, who still has to find that noise at the back of the car...
Thursday was my first day on 225/45's and I was expecting more grip to equal more speed. The few laps that my Intercomp timer caught showed me in the 1:34's but I have no idea if those were good laps. There was alot of wind too. The tires are mounted on 7 inch rims, and while I'm quite sure that grip is increased, the tires seemed to be slower responding to transitions. Makes sense. I'm going to have to decide what's most important when it's time to buy tires again - I'll probably go with grip.
As usual Proformance ran two groups only with 30 minute sessions. Most everybody is pretty friendly, but I treated one of them very poorly. There was a guy in a white Subaru RS that was gathering a stack of cars behind him. He would carefully let only one pass him per straight. When he came up to me in the paddock after that session real bumbly friendly like, I didn't take up the subject that was on my mind, and merely responded to his questions with near hostile terseness. I felt bad later - not much for him, but that I came off as a *****. I should have been straight and told him what was what. He cleaned up his act later, so somebody must have talked to him.
I did something new this day. After talking to a few of the other drivers in the group who weren't getting PIR, I told them that when I'd come past them, that I'd slow and give them a couple of laps to follow me before ramping my speed back up. It went over pretty well.
All in all, Thursday was just another good day. Friday was very different, with lower lows and higher highs.
Porsche club always starts their days at noon. I always forget, forget to verify the time, don't trust my memory. So I got there at 8. I ran off and did some stuff, but at 10 I was back and getting ready. Those two hours took forever to go by. There was a demonstration going of Enduro Karts. I like wheeled vehicles generally, but I just don't see the attraction there. Watching those guys heads bouncing up and down gave me a headache. I suppose if you get to smell Bean Oil it's worth some discomfort - man I love that smell.
You may remember me mentioning a major clanking at the rear of the car as I pounded the curbing in T7. I was laying off the worst part of 7 because of that, but I now had the sound on both of the other Left hand turns (the chicane and 3) regardless of whether I hit the curbing or not. Furthermore there was a disruption of the chassis occuring at the same time - it felt like the outside rear was tucking under or something. I came in early from two sessions trying to figure out what was going on. I looked at and checked every part of the rear suspension and found nothing. In desperation I called Scott Zellner and asked him if they had had any component failure modes that resembled this. He told me nothing in particular, told me to look at everything Front and Rear - and that it was easy to be fooled into thinking something actually happening at the front was happening at the back.
The next session was about to start, so my friend Chris got in to listen more objectively. His impression was that it was the front. His saying this broke my fixation, and I decided that yes, the disruption felt like an abrupt lateral shift in the front end. I dropped the front dampers so that the front end would droop enough to get at the camber adjusters - viola: the right front camber adjustment bolts were loose. The disruption was the camber and toe changing as the load slammed the ball joint carrier outboard. Roughed it back and tightened it up.
Next session I took Chris out with me again (Chris is my AS friend with the shock dyno). The sound in the back was still there (and we both agree it's in the back now), but the disruption was gone. So we ran the full session ***** out. He was laughing at how fast my "stupid car" could get thru 7-8-9. I was laughing too - my day was back on. Key lesson - two problems at one time can be tricky to solve. It's very interesting how easily prejudiced my analysis of the problem was - I was being a simple minded doofus. When I eliminated the likely problems at the rear, the problem had to be elsewhere - but it took me too long to make that jump. I'll have to think smarter next time. In the greater scheme of things, what looked to be the end of a staggering string of mechanically reliable events is none such - my ITR remains unbowed, and it's driver justly impressed. I must point out that there appears to be something to RTR and King's contention that these cars don't like being dragged over curbs much. Scott says that the rear trailing arms can deform and crack, and on and on.... My new policy is to stay off the steep ones - not that I intentionally hit them, it was just happening all too often - it seems to me that when you know that they are seriously bad you're far less likely to accidentally hit them.
Chris did me the big favor of taking tire temps and lap times during the last session. Tire temps are tough at PIR because there's a long straight before the pit exit road. When you're really serious about temps, you rent the track and take them just past T5. Note that PIR is a clockwise track. Anyway here's what we got:
Pressure before going out:
LF 37 RF 37.5
LR 38 RR 38.5
Halfway (15 minutes)
LF 166 173 207 RF 205 164 148
LR 134 136 146 RR 124 124 117
End (25 minutes)
LF 144 159 188 RF 177 163 132
LR 129 132 137 RR 135 130 121
Hot Pressure:
LF 44 RF 44
LR 42.5 RR 42
This is with 3.5 negative front camber, 1.5 negative rear camber, 1/16 toe out front, and 1/16 toe in rear.
Most of my friends say they look for 10 to 15 degrees higher on the inside of the fronts - so they think a little less front camber is in order. I'm going to follow up on that with my tire guy and Scott Zellner - I wouldn't say no to some more front grip. A little playing with pressure too - but it's not too far off.
Best lap time of the day was 1:32.750 - two laps in a row. That's about 7/10's better than my previous best. It compares to Pierre's fast race and qualifying laps of 1:32.2 and 1:30.327. Getting closer, but it's getting harder.
One of the key things I was working on was bringing my turn in points back - turning in earlier and with more finesse. That proved to be of great assistance in prolonging the usefulness of the front tires, and made it easier to bring the rear end around. I have brainwashed myself somewhat about the late turn in - late apex. As my speed has gone up I've been fighting the car too much. I CAN turn in earlier and still hit my marks. This succesful experimentation was prompted by my friend Chris sitting in the passenger seat and making suggestions (only half of which I could hear). I (and you too) need as much coaching as we can get. It's a tough job to keep thinking about finding something new - another qualified person in the car can see things you might miss, and that can train you to do a better job for yourself when you don't have a coach.
Scott, who still has to find that noise at the back of the car...
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From: Snowwhitepillowformybigfathead
Re: 2-Days in a row at PIR....instead of "because I got high" it's "because I must drive".... (RR98I
Just a few more things.
In most of my talks with Scott Zellner he stresses alot of the basic rules about car prep and tuning. One in particular is "change one thing at a time". Another is "you can't make any car work perfectly everywhere on the track thruout a whole session". I frequently ask him setup questions because of his direct experience with such similar cars and the feedback he probably gets from his many customers. I think he probably gets sick of taking calls he percieves as rooted in a belief in quick and easy answers to something he and everyone else must work very hard at on a continuing basis. All of which is to lay a context for saying: I don't believe that the one change at a time rule is one that must be slavishly followed.
Several issues back in Racecar Engineering Paul Van Valkenburg wrote that after a lifetime of believing that he has come to the conclusion that this is no longer valid. The current issue has the first in a series examining tuning art and apparently decoupling from the old philosophy. I've made this argument myself recently, framing it like this: performance is most appropriately modeled as a topography, with multiple local maxima and minima, and singular absolute maximum, with no continuously improving path from where you currently are to that singular absolute maximum unless you are very fortunately very near it to start. In general then the one thing at a time philosophy is suitable to finding the nearest of the local maxima. I think a higher level of competence and insight can be applied to making a jump toward the absolute maximum. In either case documentation of the path taken is essential - and to me represents the core of the "scientific method" - not the one thing at a time.
There are two ways to look at the efficiency of either approach. First, we are looking for improvement on what we have. One thing at a time is certainly valid and useful. In fact, it is probably the best approach for beginning and intermediate chassis tuners. It is probably not the best approach for landing in the middle of a complex problem and fighting your way out.
I don't consider myself an expert in this stuff, but I think I know enough to understand the validity of each approach.
Next, the running of mulitple day events. Two days in a row really wore me out, and I've got bruises on my collarbones from my harness. The OpenTrackChallenge with 7 days is really going to be a killer. I am still mulling it over. It is a ridiculous thing to consider, but it is such a formidable challenge how can I not think about it?
Last, went to Indy for the F1 race. Did it on a vendors hospitality. Had to share a room with one of the worlds great snorers for three nights. Earplugs, TV on loud all night, and he still robbed me of at least 18 hours of sleep. I actually nodded off during the early laps of the race. We were sitting in H near the top. Had a nice view from just behind the first turn. We were surrounded by Ferrari fans speaking Italian. They were enthusiastic for Schumacher, but notably silent for Barichello. They went crazy over Montoya's pass, and were audibly dissapointed that his great drive was ended by a mechanical. I think that I saw more Williams-BMW hats than any other brand identification all weekend though.
I was disgusted by one of the effects of traction control. You know how the motors pop when the drivers off the gas? Well, that's alot what they all sound like on the gas in the tight stuff in low gear when the traction control is working. They only sound sweet from 3rd(?) on up. And they all sound about the same at that - except for the Minardi's.
The BBQ Giant Turkey legs were outrageously delicious. The Colombian Montoya fans were fun to listen to singing. The old guy on the PA system interpreting F1 to American Indy types was amusing but honest and undoubtedly well intentioned. The Museum was ok - it was nice to see the GT40, the Mercedes GP Streamliner, and the Miller/Offy stuff. There was a cutaway of a carbon chassis that provided my first look at the entirety of a T-Bar - that was cool. I'll sound like a jerk for saying that the place didn't pull on my heartstrings, but it just didn't. SAP had a simulator that drew alot of attention. It had a large viewing screen that helped me decide not to get into line - the graphics were such that you really couldn't read the course. And for a guy that's never even played GT, it just seemed out of the question to try this thing.
Scott, who wasn't strip searched at the airport like one of his associates on the trip......
[Modified by RR98ITR, 11:17 PM 10/6/2001]
In most of my talks with Scott Zellner he stresses alot of the basic rules about car prep and tuning. One in particular is "change one thing at a time". Another is "you can't make any car work perfectly everywhere on the track thruout a whole session". I frequently ask him setup questions because of his direct experience with such similar cars and the feedback he probably gets from his many customers. I think he probably gets sick of taking calls he percieves as rooted in a belief in quick and easy answers to something he and everyone else must work very hard at on a continuing basis. All of which is to lay a context for saying: I don't believe that the one change at a time rule is one that must be slavishly followed.
Several issues back in Racecar Engineering Paul Van Valkenburg wrote that after a lifetime of believing that he has come to the conclusion that this is no longer valid. The current issue has the first in a series examining tuning art and apparently decoupling from the old philosophy. I've made this argument myself recently, framing it like this: performance is most appropriately modeled as a topography, with multiple local maxima and minima, and singular absolute maximum, with no continuously improving path from where you currently are to that singular absolute maximum unless you are very fortunately very near it to start. In general then the one thing at a time philosophy is suitable to finding the nearest of the local maxima. I think a higher level of competence and insight can be applied to making a jump toward the absolute maximum. In either case documentation of the path taken is essential - and to me represents the core of the "scientific method" - not the one thing at a time.
There are two ways to look at the efficiency of either approach. First, we are looking for improvement on what we have. One thing at a time is certainly valid and useful. In fact, it is probably the best approach for beginning and intermediate chassis tuners. It is probably not the best approach for landing in the middle of a complex problem and fighting your way out.
I don't consider myself an expert in this stuff, but I think I know enough to understand the validity of each approach.
Next, the running of mulitple day events. Two days in a row really wore me out, and I've got bruises on my collarbones from my harness. The OpenTrackChallenge with 7 days is really going to be a killer. I am still mulling it over. It is a ridiculous thing to consider, but it is such a formidable challenge how can I not think about it?
Last, went to Indy for the F1 race. Did it on a vendors hospitality. Had to share a room with one of the worlds great snorers for three nights. Earplugs, TV on loud all night, and he still robbed me of at least 18 hours of sleep. I actually nodded off during the early laps of the race. We were sitting in H near the top. Had a nice view from just behind the first turn. We were surrounded by Ferrari fans speaking Italian. They were enthusiastic for Schumacher, but notably silent for Barichello. They went crazy over Montoya's pass, and were audibly dissapointed that his great drive was ended by a mechanical. I think that I saw more Williams-BMW hats than any other brand identification all weekend though.
I was disgusted by one of the effects of traction control. You know how the motors pop when the drivers off the gas? Well, that's alot what they all sound like on the gas in the tight stuff in low gear when the traction control is working. They only sound sweet from 3rd(?) on up. And they all sound about the same at that - except for the Minardi's.
The BBQ Giant Turkey legs were outrageously delicious. The Colombian Montoya fans were fun to listen to singing. The old guy on the PA system interpreting F1 to American Indy types was amusing but honest and undoubtedly well intentioned. The Museum was ok - it was nice to see the GT40, the Mercedes GP Streamliner, and the Miller/Offy stuff. There was a cutaway of a carbon chassis that provided my first look at the entirety of a T-Bar - that was cool. I'll sound like a jerk for saying that the place didn't pull on my heartstrings, but it just didn't. SAP had a simulator that drew alot of attention. It had a large viewing screen that helped me decide not to get into line - the graphics were such that you really couldn't read the course. And for a guy that's never even played GT, it just seemed out of the question to try this thing.
Scott, who wasn't strip searched at the airport like one of his associates on the trip......
[Modified by RR98ITR, 11:17 PM 10/6/2001]
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From: I started it
Re: 2-Days in a row at PIR....instead of "because I got high" it's "because I must drive".... (RR98I
Those tire temps sure lead me to think 3.5deg. negative up front might be a bit much. For what it's worth, last year I ran Carolina Motorsports Park on some 205-50-15 Hoosiers. This was one of the few times I've taken tire temps (I know, bad Karl) and they were within 7 degrees of each other in the front. I had 2.0 and 2.2 degrees negative (left right, respectively). I think RoadRacer has decided that something near the low 2 degrees negative works best on his GS-R, and he runs the 225-45.
I've never figured out why the left has less than the right - it's the lowest corner of the car (an artifact of setting the crossweights). Methinks it's time to get some kind of camber adjusters...perfectly legal for Honda Challenge next year. But if I delve into SCCA racing in ITS, they're not legal. Doh. The current setup - that is, lowering it down into the weeds to get the camber right - seems, so far, to work well. But I'm convinced that the car bottoms out on curbs, which just can't be that good for things like shocks and alignment. At VIR earlier this year I pounded my (urethane) damper fork bushing into powder - and a few weeks ago lost that shock.
Getting this stuff right is hard.
I've never figured out why the left has less than the right - it's the lowest corner of the car (an artifact of setting the crossweights). Methinks it's time to get some kind of camber adjusters...perfectly legal for Honda Challenge next year. But if I delve into SCCA racing in ITS, they're not legal. Doh. The current setup - that is, lowering it down into the weeds to get the camber right - seems, so far, to work well. But I'm convinced that the car bottoms out on curbs, which just can't be that good for things like shocks and alignment. At VIR earlier this year I pounded my (urethane) damper fork bushing into powder - and a few weeks ago lost that shock.
Getting this stuff right is hard.
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Joined: Feb 2000
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From: Snowwhitepillowformybigfathead
Re: 2-Days in a row at PIR....instead of "because I got high" it's "because I must drive".... (RR98I
Karl,
Thanks for the response. This stuff is hard, but then again so is driving these things.
I should mention that the first temp reading was a 110% lap all the way to the exit road - meaning flat out thru 7 the 4th gear right hander, braking before 8, and a little bit of 8. The last lap was 90-95% with an easy run thru 7-8. That was worth an even difference across the tire run vs run. So alot of that inside heat may have to do with the long straight, since the lower loading on a slow lap should result in less loss of negative camber resulting in higher inside temps which weren't there. The other consideration is that when I cord a tire with this front setup it occcurs in the outer third of the tire, and when you look at the tire profile the outer shoulder is more rounded than the inner.
Scott Zellner suggests going from -3.5 to -3 for a start and then take more temps. My tire guy had similar feedback, but want's to see the outer front from Friday.
What is really needed, as I've joked about in the past, is a Data Aquisition package with sufficient analog inputs for 3,6, or 12 infrared temp sensors - 3 per tire taking realtime data. My friend Chris uses SPA stuff and says he can put such a setup together, but he hasn't taken it up and I haven't put forward any money. To some extent I think anything short of such a setup is highly compromised.
The other thing I've been thinking about is how max speed might be achieved with excessive negative camber. Example - I make up a ton of time in T7 which has a gently sloped curb (inside of the rumple strip). Such a curb tilts the outside wheel more positively - so you might get the most grip here with a camber setting that was suboptimal elsewhere on the track. You'd have to evaluate the net effect to select the best setting. So it's not just the pyrometer, the stopwatch always has the last word - unless there's a checkered flag involved.
The other mechanical observation from the last few days is that my KVR slotted EuroRotors (front) have in 6 days been worn past the depth of the slots by one set of Hawk Blues. I don't know if the EuroRotors are composed of a particularly sacrificial iron, but I do know that the Blues ARE getting up to temp. Radial cracks are still under one inch in length generally. I think they may last to the end of that set of pads.
I expected somebody to come after me on the one thing at a time thing - but no takers apparently. Since writing that I've read that latest article in Racecar Engineering. It's a teaser, and I'm real interested to see how their methodology proposes to isolate factors and discover weighting without making changes to ONE THING AT A TIME. If this article had appeared in Road & Track's April issue I'd suspect a joke. We'll see.
In my original post I probably focused too much on the numeric aspects of the days driving. Those personal best laps were about the most satisfying of my life to date. I was totally in the zone as I was hooking T7 - and conscious of loving it. I didn't realize how much I had cut back on my braking till Chris pointed it out, then I also noticed that I had to brake harder for T8 (a fast S2 barely brakes for 7, and a ground effects FA (Tom Phillips) doesn't brake at all). I didn't even feel any lateral G's - it felt more like vertical G's. It wasn't just hard working technical driving - it was emotional, and that was ok this time. After that day I've had very little trouble with thoughts of superior equipment. Sure I got trounced by a Z06 on race tires with a very competent driver, but I should be. Sure my friend Lee Stohr's new DSR looks like THE car to be driving and developing (I got to follow it for a few laps). But the ITR has such a magical combination of driver feel/ergo, giant killer tweenerness, bankable reliability, and useful practicality that combined with the fact that every drive shows me just how much better this silly car is than I thought the idea of discarding it is ridiculous. These things are keepers. I never thought I'd be taken prisoner by a Japanese Front Wheel Drive Car. Is this what it's like to be in a cult?
And I'm really getting tired of screwing around with Timers. I'm going to revise my sensor mountings to look out the open door windows. I think glare (I need a theory) was preventing my Intercomp setup from working reliably late in the day. The sun was low in the sky seperated from my beacon signal by about 30 degrees. I see everybody else runs theirs thru rear quarter glass - why me?
The big disappointment of the weekend was that I didn't run the BMW day at PIR on Sunday. It was an intermediate rain day - it would have been great - arghhhh. I could have run the afternoon if I'd prepared. There was a guy named Adam from Vancouver with a White ITR with the factory body kit painted a sort of maroon color - it looked pretty good. He had an AEM intake and a Tanabe Medallion muffler - it sounded pretty good. That setup, whatever Robbie Montinola was using at the EXPO, and the Mugen are the only three that have sounded good to me.
Scott, who thinks this season went by awfully fast.....
Thanks for the response. This stuff is hard, but then again so is driving these things.
I should mention that the first temp reading was a 110% lap all the way to the exit road - meaning flat out thru 7 the 4th gear right hander, braking before 8, and a little bit of 8. The last lap was 90-95% with an easy run thru 7-8. That was worth an even difference across the tire run vs run. So alot of that inside heat may have to do with the long straight, since the lower loading on a slow lap should result in less loss of negative camber resulting in higher inside temps which weren't there. The other consideration is that when I cord a tire with this front setup it occcurs in the outer third of the tire, and when you look at the tire profile the outer shoulder is more rounded than the inner.
Scott Zellner suggests going from -3.5 to -3 for a start and then take more temps. My tire guy had similar feedback, but want's to see the outer front from Friday.
What is really needed, as I've joked about in the past, is a Data Aquisition package with sufficient analog inputs for 3,6, or 12 infrared temp sensors - 3 per tire taking realtime data. My friend Chris uses SPA stuff and says he can put such a setup together, but he hasn't taken it up and I haven't put forward any money. To some extent I think anything short of such a setup is highly compromised.
The other thing I've been thinking about is how max speed might be achieved with excessive negative camber. Example - I make up a ton of time in T7 which has a gently sloped curb (inside of the rumple strip). Such a curb tilts the outside wheel more positively - so you might get the most grip here with a camber setting that was suboptimal elsewhere on the track. You'd have to evaluate the net effect to select the best setting. So it's not just the pyrometer, the stopwatch always has the last word - unless there's a checkered flag involved.
The other mechanical observation from the last few days is that my KVR slotted EuroRotors (front) have in 6 days been worn past the depth of the slots by one set of Hawk Blues. I don't know if the EuroRotors are composed of a particularly sacrificial iron, but I do know that the Blues ARE getting up to temp. Radial cracks are still under one inch in length generally. I think they may last to the end of that set of pads.
I expected somebody to come after me on the one thing at a time thing - but no takers apparently. Since writing that I've read that latest article in Racecar Engineering. It's a teaser, and I'm real interested to see how their methodology proposes to isolate factors and discover weighting without making changes to ONE THING AT A TIME. If this article had appeared in Road & Track's April issue I'd suspect a joke. We'll see.
In my original post I probably focused too much on the numeric aspects of the days driving. Those personal best laps were about the most satisfying of my life to date. I was totally in the zone as I was hooking T7 - and conscious of loving it. I didn't realize how much I had cut back on my braking till Chris pointed it out, then I also noticed that I had to brake harder for T8 (a fast S2 barely brakes for 7, and a ground effects FA (Tom Phillips) doesn't brake at all). I didn't even feel any lateral G's - it felt more like vertical G's. It wasn't just hard working technical driving - it was emotional, and that was ok this time. After that day I've had very little trouble with thoughts of superior equipment. Sure I got trounced by a Z06 on race tires with a very competent driver, but I should be. Sure my friend Lee Stohr's new DSR looks like THE car to be driving and developing (I got to follow it for a few laps). But the ITR has such a magical combination of driver feel/ergo, giant killer tweenerness, bankable reliability, and useful practicality that combined with the fact that every drive shows me just how much better this silly car is than I thought the idea of discarding it is ridiculous. These things are keepers. I never thought I'd be taken prisoner by a Japanese Front Wheel Drive Car. Is this what it's like to be in a cult?
And I'm really getting tired of screwing around with Timers. I'm going to revise my sensor mountings to look out the open door windows. I think glare (I need a theory) was preventing my Intercomp setup from working reliably late in the day. The sun was low in the sky seperated from my beacon signal by about 30 degrees. I see everybody else runs theirs thru rear quarter glass - why me?
The big disappointment of the weekend was that I didn't run the BMW day at PIR on Sunday. It was an intermediate rain day - it would have been great - arghhhh. I could have run the afternoon if I'd prepared. There was a guy named Adam from Vancouver with a White ITR with the factory body kit painted a sort of maroon color - it looked pretty good. He had an AEM intake and a Tanabe Medallion muffler - it sounded pretty good. That setup, whatever Robbie Montinola was using at the EXPO, and the Mugen are the only three that have sounded good to me.
Scott, who thinks this season went by awfully fast.....
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Joined: Nov 2000
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From: Charlotte
Re: 2-Days in a row at PIR....instead of "because I got high" it's "because I must drive".... (RR98I
But the ITR has such a magical combination of driver feel/ergo, giant killer tweenerness, bankable reliability, and useful practicality that combined with the fact that every drive shows me just how much better this silly car is than I thought the idea of discarding it is ridiculous. These things are keepers.
Thank you for your post.
William
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From: Pacific Northwest, USA
Re: 2-Days in a row at PIR....instead of "because I got high" it's "because I must drive".... (RR98I
~snip~......performance is most appropriately modeled as a topography, with multiple local maxima and minima, and singular absolute maximum, with no continuously improving path from where you currently are to that singular absolute maximum unless you are very fortunately very near it to start. In general then the one thing at a time philosophy is suitable to finding the nearest of the local maxima. I think a higher level of competence and insight can be applied to making a jump toward the absolute maximum. In either case documentation of the path taken is essential - and to me represents the core of the "scientific method" - not the one thing at a time. ~snip~
This is great stuff Scott.John, who can't help feeling insignificant......
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