Putnam Park data analysis (M3/NSX/SRT-4/300ZX/Trans-Am/Corsica)

[Hornswoggler]

Earlier this season a handful of us from the Central IL area attended an HPDE (High Performance Driving Event) at Putnam Park, which is a road course about 30 miles SW of Indianapolis. The event was put on by NASA OH/IN. It was a great time. Weather was very hot for October, exceeding 90 degrees both days.

Being resourceful in our quest to conquer the track (none of the group had driven Putnam before), I brought along two Traqmate Completes, which are GPS-enabled data acquisition devices. There is all sorts of stuff to learn from the data acquisition, as the Traqmate can provide lap times, segment times, theoretical best lap, acceleration data (forward g's), deceleration (braking) g's, mph at any given point, and the ability to zoom in on different driving lines. All this can be handy to compare what techniques work the best or can be used for comparing different vehicles. Our goal for the weekend was to use it as a learning tool and with some analysis inbetween sessions, we were able to identify some potential opportunities for improvement.

With so much data captured, it was impossible to look at everything from the track side, and this report hopes to perform a deeper analysis, which can be useful for next trips to Putnam or possibly apply these techniques to similar corners at

other tracks.

Introducing the cars and drivers:

Jeff (racin17) - Quad Foursica
spyonu2007 - 1995 Trans Am
Tony (maglito) - 300ZX
TJ - NSX
Joe (jstbrd) - SRT-4
Collin (Hornswoggler) - e36 M3

Quite a variety of cars here, and drivers of different experiences/background. I am going to start this analysis with an intro for each driver/car and go over what I see from their data capture and make suggestions. Sometimes it is difficult to distinguish between vehicle traits and driver technique, so some input from the drivers is important in explaining some of what we will see in the data. Any of the drivers feel free to add your own story to how the car was behaving or any other issues with that session.

For those who want to play along at home and offer some insights/contributions, you can download the Traqview software HERE and use the program to analyze our data files:

(I am looking for a place to host the 2MB zip file, PM me your e-mail addy and I can send. if anybody can host, lemme know!)

On to the data...

Lap time results:

1:25.075 Collin (Hornswoggler) - M3
1:27.866 Joe (jstbrd) - SRT-4
1:27.878 TJ - NSX
1:28.789 Tony (maglito) - 300ZX
1:31.557 spyonu2007 - 1995 Trans Am
1:37.818 Jeff (racin17) - Quad Foursica

Order changes a bit for TBL...

Theoretical Best Lap:

1:24.244 Collin (Hornswoggler) - M3
1:26.481 TJ - NSX
1:27.282 Joe (jstbrd) - SRT-4
1:28.503 Tony (maglito) - 300ZX
1:29.876 spyonu2007 - 1995 Trans Am
1:37.053 Jeff (racin17) - Quad Foursica

Individual Analysis:

Jeff

Our first analysis subject is Jeff. This was Jeff's first track event and he comes into this with an autocross background. The Corsica has been his project car, and he definately had the market on exclusivity and sleeper factor here. Very unusual site to see a 20-year-old Corsica chasing down sports cars at a track day! I could tell a few people in his run group really didn't want to be passed by the Foursica, but they were either beaten into submission or felt so much pressure they spun off the road! Definately a site to see.



Name: Jeff
AKA: racin17
Car: Corsica (aka Quad Foursica)
Mods: Built Quad 4 engine swap, over 180 whp, Lowered springs, Rear sway bar
Tires: High performance street tires
Best lap: 1:37.818
TBL: 1:37.053

The first thing that pops out looking at Jeff's data is his deceleration g-forces. Max braking was 0.69 g's and sustained was about 0.50 g's. This could have been either technique (not threshold braking), braking system not able to deliver any more, or possibly the limits of the tires. I doubt it was tires, although if the car was not pointed straight while braking, you will never realize max deceleration.

Lateral grip was around 0.95 g's at peak, or about 0.80 g's sustained. Max acceleration had a peak of 0.23 g's.

Driving Notes:
Could have given more acceleration through turn 3. Average lateral grip used in this corner was around .67 g's, which is lower than the tires capable .80 g's.

There is more speed to be found by accelerating up to and through turn 6. Exit of turn 5 should be full throttle (no lifting), and turn 6 should be full throttle (entry, apex, and exit) for the Corsica. The tires should have some more grip available, which means you can take this a bit faster next time. The only concern is having enough time left to apply brakes and slow down sufficiently for Turn 7. With better brakes, or straightening the wheel and applying threshold braking, you can better exploit the gas pedal.

After seeing your in-car footage, you should always keep your hands at the 9-and-3 position on the steering wheel. No shuffle steering was necessary at Putnam. By keeping your hands in a consistent position, you always know where the wheels are pointing. 10-and-2 is OK as well (as long as you are consistent with hand positioning).

Chassis notes:
To make a car fast around the road course, it takes one of two things (or combination of both). You either need lots of
power, or the ability to maintain momentum by carrying high corner speeds. If you can build the car to be stronger in
both, great, but considering the engine has been pretty well tweaked already, I would focus on the momentum part. This
might be a combination of adding wider and/or stickier tires, suspension upgrades (shocks/springs/bushings), and making improvements to the braking system. Raising the limits of lateral grip and stopping power can make some huge gains in laptimes. There is always the chance the car/tires have more performance in them that just needs exploited.

Recommendations:
Further testing to determine maximum capabilities of the braking system
Consider improve the braking capabilities of the car
For maximum deceleration, try braking in a straight line. This could potentially shorten your braking distances
Add lateral grip
More speed through the kinks (Turns 3 and 6)
Keep both hands on steering wheel at all times (except shift, point-by) and at the 9-3 or 10-2 position. No shuffle steering.

[Hornswoggler]

Spyonu2007

Second analysis is spyonu2007 and his 1995 TransAm. This was Spy's first "official" performance driving event, although I would not be surprised if he had previously discovered his car's limits in a secluded parking lot. Like most cars here, the TA is a project car but with a strong focus on acceleration. The LT1 has been fairly built, and the power is estimated to be 100 horsepower over stock. Spy put on an impressive display of power while passing many cars on the front straight-away. With stock suspension, stock brakes, and all-season tires, the TA sounded like a handful in the corners but that did not put a dent into Spy's enthusiasm or willingness to extract max potential! This weekend was definately a HUGE hit from the go-fast crack pipe! I'm sure spy learned a lot this weekend and I have no doubts he will be back for more next year (maybe even in the EVO?).



Name: real name withheld
AKA: Spyonu2007
Car: 1995 TransAm
Mods: +100 or so horsepower
Tires: All-seasons
Best lap: 1:31.557
TBL: 1:29.876

Acceleration is very strong in this car, and lateral grip was good, but the braking (either hardware, technique, or both) jumps out as an opportunity for improvement. At the end of the front straight, Spy was the first to start braking. This is a combination of a. carrying a LOT of speed down the straight, b. possible lack of confidence in the braking system effectiveness, and c. the car was over-slowed for turn 1.

Turn 1 is the largest area of underutilized grip. I'm going to compare this vs Tony and his 300ZX as these two cars have similar traits (high HP, some challenge with under/oversteer) and took most corners at the same speed, except Tony was about 10 mph faster through turn 1. Taking this turn about 8-10 mph faster next time will result in better exploiting the tires capabilities, and would gain atleast 0.5 seconds per lap.

In the following picture, Tony is green and Spy is red:



Turn 3 looked very nice, great application of throttle through there. The other kink, turn 6, also looked really good.

Looking closer at the driving line, you should be making smooth lines and wide geometric arcs (think bigger radius). This allows you to "average" out the lateral load over a longer distance... which effectively raises the velocity you can take the turn. In other words, no sharp steering inputs or "pinching it" at exit. Always look far ahead to where you want the car to go. Be sure and use ALL the road for corner entrance, and track-out using all the road as well (you paid for the whole road, might as well get your monies worth!). As the old adage goes: he who points the car straightest, goes the fastest. I could see times where you got it right, but some stray data where you may not have been in your rhythm. The important part is being able to recognize when you got the driving line "just right", and in the chance your line was off, being able to identify and explain what might have gone wrong. Hopefully your in-car instructor was able to reinforce some of this.

Here is an example picture of Turn 5. Red line is Spy (multiple laps), green and blue are Collin in the M3 (from two different sessions):



Turns 9 and 10, it looked like a real handful from the variations in speed, throttle application, and inconsistencies in grip. Without being in the car, it is hard to make a diagnosis but you might have been over-driving in those turns. I would try dialing it back just a bit next time so you can keep it smooth, consistent, and in control. Once you can keep it consistently stable and smooth, then would be the perfect time to very gradually introduce more and more speed (all while staying smooth).

For a first event, I think you did great. Do not take this report as being critical, but see this as an opportunity to be even faster next visit. That is why we do this: to learn and improve.

Recommendations:
Higher temp brake pads; Hawk HP+ at minimum, Hawk Blue being more hardcore (track only, swap back to street pad after event)
Make wider, smoother driving lines
Practice smoothness and consistency, then speed
Carry more speed (about 8-10 mph faster) into turn 1

Tony

Next up is Tony in his Nissan 300ZX twin turbo. Tony has been doing track events since 2004, although he took a few years off while performing an engine rebuild. His previous tracks include Road America, Hallett, Gateway International Raceway, Motorsport Ranch, and now Putnam Park. Tony's attendance was a bit of a stretch since he was also booked for a wedding this same weekend... but somehow he worked his magic and made it happen, was glad he did! Like most of the cars out there, Tony's 300ZX is a project car in progress. Now that the engine is done, and the brakes are working great, I think the next area of focus will be revisiting the suspension setup. With over 500 wheel horsepower on tap, this is a lot of car to exploit.



Name: Tony
AKA: maglito
Car: 1991 Nissan 300ZX
Mods: Lots of power, Brembo brakes, shocks/springs/etc.
Tires: Dunlop Super Sport Race 255/35/18 (F) 285/30/18 (R)
Best Lap: 1:28.789
TBL: 1:28.503

At 135 mph, by far, Tony had the highest mph at end of the front straightaway. Spy was next closest with 119 mph... quite a difference!

Driving Notes:
Braking zones could start a little later as your brakes seemed very effective. There were times you were overslowing the car and you caught it so you reduced braking pressure. By postponing your braking zone by a little bit, it will maximize your acceleration time and result in less coasting. Exiting turn 1, I think you missed the opportunity to accelerate up until braking zone for turn 2.

adding to the driving notes on braking, I find it helpful to use trackside references for when I start my braking zone. If I find it was too early, I push it deeper next time. Once I go in too hot, I start a little sooner.

It also looks like you might have been lifting before the apex of turn 3. I would try to keep atleast some forward acceleration through the kinks as it keeps weight on the rear tires. Would the car misbehave if you took turn 3 any faster? I think your tires had more capacity here.

In most corners, your car seems capable of sustaining about 1g of lateral grip, but through turn 6, you only use about .70 g's. You could have carried about 10 mph more in this turn. Braking for turn 7 seemed really "soft" compared to the other braking zones. Your line through turn 7 seems to run out of track on exit, not allowing you to apply much throttle. I am usually a fan of geometric driving lines (momentum line) but the tight nature of turn 7 makes it well suited for a late apex. Try apexing T7 later next time and see if you are able to apply more power on exit.

Chassis notes:
When talking to Tony about the car and how it is handling out there, he mentioned experiencing both understeer and oversteer. Sounded like he could use a lot more grip. I would expect corner speeds to be a lot higher considering he was running a competition tire (Dunlop Super Sport Race) and fairly wide (255 front, 285 rear). Without driving the car in a high performance setting, it is hard to make a diagnosis but some ideas to consider: stiffer springs/shocks (coil-overs?), check cornerweights, alignment, condition of bushings, research if HICAS is more harm than good (could be a weight savings atleast), weight reduction, tire pressures, meaure tire temps, and if possible, replicate setup from SPL.

I suspect Tony was experiencing some mid-corner and corner exit oversteer. I say this because the changes in lateral g's seem much more drastic than expected "noise". This was most noticeable at exit of turns 4 and 7.




Recommendations:
1. Less coasting
2. More accel through corners
3. Later apex for turn 7
4. Exploit your braking hardware by compressing the braking zones (use reference points for brake markers)

[Hornswoggler]

TJ

On to the third fastest of this group, and best laptimes among the rookies, is TJ and his Acura NSX. Very cool looking car and looked great out there on track. TJ has previous auto-x experience, and I think this was his first HPDE.



Name: TJ
AKA: not on intarweb
Car: Acura NSX
Mods: Exhaust, adjustable suspension
Tires: Hankook Z211
Best Lap: 1:27.878
TBL: 1:26.481

With a little more seat time and less traffic, I have no doubts TJ will soon be in the runnings for a #1 or #2 position. For a first event, very impressive laptimes! TJ had a very nice friction circle for trail braking. Compared to Joe and Collin, turn 9 was very strong for TJ.

Driving Notes:
Looking for the single corner that lost the most time was turn 8 (Dead Bear). There is a loss of about .5 seconds here. Peak lateral grip looked good, but it looked like the turn-in was late and too easy at start, and acceleration coming out of dead bear didn't seem as strong as it could be for the 55-70 mph range. Up to 80 mph, I think you could still be in second gear? If so, that would be a huge equalizer and time improvement.

I think TJ could have carried about 8 mph more through turn 4 (target = 67 mph) and can take turn 7 about 5 mph faster (target = 42 mph).

When the NSX is accelerating out of turn 2 (60-80 mph) it seems to be at a disadvantage compared to Joe and Collin. I assume you are taking this in 3rd gear instead of 2nd? downshifting would be worth about .150 seconds between turns 2 and 3.

Compared to the front runners, TJ was braking much earlier. I do not know what brake pads TJ is running, or how close to threshold he was applying the brakes, but this jumps out as an opportunity to gain quite a bit of time (braking later and harder). Just comparing the braking zone for turn 1, Collin gains about 0.150 seconds by braking later. Similar gains can be made in the braking zone for turn 7. Braking technique is usually the last thing to perfect, after consistent corner exit speeds and consistent apex speeds. Having consistent corner speeds is important so the brake references are not a moving target.

Between these suggestions, should be able to shave atleast a full second off TBL.

Recommendations:
Earlier, more aggressive turn-in for dead bear (turn 8)
2nd gear for turns 2 and 8
More speed in turns 4 and 7 (use all of the road at entry for turn 7)
Improve deceleration forces (either hardware or technique)

Joe

Second fastest of the weekend is Joe and his SRT-4. Joe is Mopar to the core and really works this car for all it's worth. This is his second season of HPDE's and he has some previous autocross experience. As we move up to the faster and more experienced drivers, their opportunities for improvement become much smaller and more difficult to identify. Let's see what we can find...



Name: Joe
AKA: jstbrd
Car: Dodge Neon (SRT-4)
Mods: Suspension upgrades, Carbotech brake pads
Tires: street tires
Best Lap: 1:27.866
TBL: 1:27.282

We have quite a bit of data captured from Joe, showing solid improvement with every session. I will be focusing on his last recorded session of the weekend, which was the 3rd HPDE3 session on Sunday.

Driving Notes:

I see three turns where Joe loses the most time relative to the other faster drivers. Turns 3, 6, and 10 seem to present their own challenge. It may be the car, the tires, or the driver... hard to say without interviewing the driver and understanding what is going on during these corners. Turns 3 and 6 are both kinks, and 10 is the most important turn on the track (leading to the fastest straight away).

There may be an opportunity in turn 5 to use more of the apex curbing, allowing a higher apex speed. Comparing to club racer data, they are more likely to use more T5 apex curbing.

Looking at the friction circle for turn 6, I believe there is some more lateral grip that could be exploited. Possible reasons could include not having enough braking to slow it down in time for T7, the vehicle not stable while pushing through T6, or Joe not driving it hard enough.

Joe was slower in turn 10 than TJ and Collin. This could be a limitation of FWD? The sore spot (~.7 g's) seemed to be between corner entry and apex, where everything past the apex had good grip (~.9 g's). I would be interested to see if an earlier turn-in would help average out the lateral loads.

Chassis Notes:

Maximum braking was 0.97 g's, with max lateral grip around 1.22 g's. These are pretty good numbers considering the street tires. Next season would be a good time to upgrade to r-comp's, as Joe has the talents and experience to exploit stickier tires.

I am going to guess the car is understeering at corner entry, and unable to put the power down as effectively as RWD when exiting the corners.

Recommendations:
Upgrade to R-comp tires
Reduce understeer
Upgrade to more aggressive brake pad or BBK
Try different approach to turn 10


Collin

Last subject of this analysis is myself. Being my own analysis, it is a relief that I can be as brutal as I want. This is my 5th season doing HPDE's and I usually try to get the most out of the car in its current state before throwing more parts at it. I have been able to learn a lot from my traqmate over the last 1.5 years. This was my first time driving Putnam and I know I left some time on the table. Hopefully we can identify some improvement opportunities for next season.



Name: Collin
AKA: Hornswoggler
Car: 1997 BMW M3 (e36)
Mods: Coil-overs, cams, Stoptech brakes, etc.
Tires: Toyo RA-1 235/40-17
Best Lap: 1:25.075
TBL: 1:24.244

Driving Notes:

Starting from the start/finish line and going around the course clockwise, the first thing that jumps out is the amount of acceleration time lost while shifting to 5th gear. It requires much more effort than the 3-4 shift, but I should still be able to reduce it a bit.

Looking at the "average" lateral grip used in turn 1 compared to other corners, I can probably use more trailbraking and go another 4 mph at apex (from 73 to 77 mph). This would be worth .2 seconds by starting my braking zone later (not having to slow as much, and using more trailbraking), .25 seconds from higher cornering speeds, and another .2 seconds from higher corner exit speed (leading into turn 2 braking zone). Total opportunity in T1 = 0.65 seconds.

Turn 2 I was driving like a late apex corner, probably because the exit is a little blind. If I can start my turn-in a little earlier and make more of a geometric arc of it (more gradual turn-in), I should be able to raise my minimum corner speed by 4 mph (60 to 64 mph) to gain about .2 seconds.

Turn 4 is probably my biggest area of underutilized lateral grip. I should be able to take this turn about 8 mph faster. Starting with an earlier turn-in could help average out the lateral demands over a longer distance. There could be .4 seconds here.

Between these improvements and more consistency, I should be able to drop 1.25 seconds off my theoretical best lap, giving me the target laptime of 1:22.xx for next year.

Chassis notes:

I might want to try some wider tires next season (255/40-17) in hopes of more grip. I gave these a shot earlier in the year but did not have the time to make it work as I would need to raise the car a good bit, add spacers front and rear, and of course get it corner-weighted and aligned again.

Recommendations:
Increase shifting speed to 5th gear
More trail braking into Turn 1 can delay braking zone
Increase Turn 1 min speed by 4 mph (from 73 to 77 mph)
Momentum line through T2, higher min speed (from 60 to 64 mph)
Higher corner entry speed into T4 (from 66 to 70 mph)

Hope you all enjoyed the analysis. Post up if any questions/comments.

[Hornswoggler]

BTW, what is this crock about a 10,000 character per post limit???

[Warpedcow]

Originally Posted by Hornswoggler

The first thing that pops out looking at Jeff's data is his deceleration g-forces. Max braking was 0.69 g's and sustained was about 0.50 g's. This could have been either technique (not threshold braking), braking system not able to deliver any more, or possibly the limits of the tires. I doubt it was tires, although if the car was not pointed straight while braking, you will never realize max deceleration.

Only .5-.7G under braking? I'm glad he didn't rear end anyone! I was seeing .7-.8G under braking during a HEAVY DOWNPOUR. Time for a brake upgrade for the Foursica.

[thebionicman]

Nice lap times. I turned a 1:22.8 back in May at the NASA event. I like the 255/40s on the coupe. My problem now is the I run the NT01s with the new rules that bumps me up to TTB.

[Hornswoggler]

Originally Posted by thebionicman

Nice lap times. I turned a 1:22.8 back in May at the NASA event. I like the 255/40s on the coupe. My problem now is the I run the NT01s with the new rules that bumps me up to TTB.

Thats too bad Erik... I was going to be gunning for you in TTC next year! Was already comparing our laptimes, lol.

[kbrew8991]

Originally Posted by thebionicman

Nice lap times. I turned a 1:22.8 back in May at the NASA event. I like the 255/40s on the coupe. My problem now is the I run the NT01s with the new rules that bumps me up to TTB.

back to RA1s for joo

[Hornswoggler]

Data files can be downloaded HERE

[thebionicman]

Originally Posted by Hornswoggler

Thats too bad Erik... I was going to be gunning for you in TTC next year! Was already comparing our laptimes, lol.

Originally Posted by kbrew8991

back to RA1s for joo

Yup getting a set of shaved RA1s to stay in TTC. I don't know if I will make the Gateway date, but I plan on Putnam. My brother lives in Indy and it is definately worth the drive.

If you want the list of mods for my car to help with the comparisons just let me know.