The A-Street Thread
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The A-Street Thread
My goal with this thread is to discuss A-street builds. Feel free to share setups, advise, weights, tests, etc with the end goal being a more competitive group of CR's running against the mighty Corvettes.
A bit about myself. I am Todd Roberts and co drive Jason Kupka's 2008 s2000 CR. I have been driving the car since the beginning of the 2014 season. I began autocrossing in 2006 but have only been competing nationally for the past 4 years. My local group is the Texas Spokes Sports car club. While not an SCCA club, we follow that rule structure. The club is home to some serious national autocross talent. National Champions Andy Hollis, Eric Strelneiks, Drew Vanderploeg, and Brian Burdette are some of the names seen at local events. We have plenty of strong nationals trophy winners as well such as Vivek Goel, John Hale, and Ricky Crow just to name a few.
A bit about the car:
2014 Nationals
4th place in A Street
Configuration for nationals:
Delete conversion (a/c and radio removed)
Custom muffler delete
TR motorsport F3 wheels
Gendron bar: Bearing mounts, 1.25" solid bar 4th stiffest setting
80K mile stock shocks
Hawk pads (HPS fronts, HP+ rears)
Hankook RS3 V2 225 45 17 fronts 255 40 17 rears
Day 1 at nats
I was surprised to see how much pace the car had in it. I didn't know what to expect going in as we hadn't run against any AS corvettes locally. Comparing SoloStorm data with Ryan Otis (2nd in AS in a 2003 z06) we were achieving higher corner speeds and sustaining ~.2 higher lateral g-force in the CR and, big shock here, losing ground in acceleration zones...
Here is my second run on the West course. I had picked up .5 seconds on my 3rd run but overcooked the final slalom cone and decided to DNF rather than spin.
http://youtu.be/jEuuP8jUwbg
Day 2
Weather was very challenging. Rain was threatening as our heat started but it never really came down. The rain was intermittent which allowed some groups of cars a relativity dry course on runs 1 & 2. I didn't get a decent course condition until run 3 and the surface had not fully dried. I believe that this was a bigger hindrance to the momentum cars. The slickest areas of the course were the corners which had been rubbered in from 3 days of competition. The data showed that, again not shockingly, the CR makes its time on the Z06 in the corners and the rain removed that advantage. I would really like to know how I would have done on the East course with clear weather but that's racing.
http://youtu.be/vlXXoz9pidc
2015 Preparations
For 2015 we decided to do some dyno testing of cat back exhaust options. The muffler delete that I fabricated for the car was very light (~ 16 lbs utilizing the OE midpipe and a custom straight pipe from the axle back) but I couldn't help but wonder if we were leaving some torque/Hp on the table. We secured 2 additional systems for the test that represented, in our eyes, drastically different designs. The 2 cat back systems we tested alongside the straight pipe were: The T1R 70 mm Titanium system and the HKS 75 mm single exit stainless system. We felt that pipe diameter variables were critical to this sort of dyno testing and we decided that we would select the system that made the highest torque. All testing was completed during a 3 hour window with minimal temperature/humidity change. We made 2 passes with each system and the plots below detail the gains/losses compared to the custom exhaust.
The results
Custom VS HKS (red and blue traces) (28.8 lbs with all hardware included)
Custom VS T1R (red and blue traces) (14 lbs)
After discussing these results with Drew Vanderploeg he informed us that he had completed a similar test several years ago while prepping his car for b stock. His testing had found that the modified factory exhaust made the most power when utilizing the factory tune. He did not test the T1R on his dyno test. If I was daily driving an S2000 I would have a hard time recommending the T1R despite its slight advantage on the dyno. It is much louder than the HKS and the custom modified OE exhaust. In cabin drone increased significantly as well. Jason's CR is not daily driven and the slight bump in power compounded with it being 2 lbs lighter was just enough for us to decide on the T1R. (Matt Leach selling it to us used with a significant discount helped that decision as well)
Thanks for reading. I will keep the info coming as we begin tire testing the new crop of 200 TW tires. We have a set of 71r's that we intend on testing against the RS3 v2 on a surface that is very similar to Lincoln in its grip level. We won't be able to test the tires ability to work on OPR but should be able to provide reliable information on the pace of these tires after the sunbelt national tour.
A bit about myself. I am Todd Roberts and co drive Jason Kupka's 2008 s2000 CR. I have been driving the car since the beginning of the 2014 season. I began autocrossing in 2006 but have only been competing nationally for the past 4 years. My local group is the Texas Spokes Sports car club. While not an SCCA club, we follow that rule structure. The club is home to some serious national autocross talent. National Champions Andy Hollis, Eric Strelneiks, Drew Vanderploeg, and Brian Burdette are some of the names seen at local events. We have plenty of strong nationals trophy winners as well such as Vivek Goel, John Hale, and Ricky Crow just to name a few.
A bit about the car:
2014 Nationals
4th place in A Street
Configuration for nationals:
Delete conversion (a/c and radio removed)
Custom muffler delete
TR motorsport F3 wheels
Gendron bar: Bearing mounts, 1.25" solid bar 4th stiffest setting
80K mile stock shocks
Hawk pads (HPS fronts, HP+ rears)
Hankook RS3 V2 225 45 17 fronts 255 40 17 rears
Day 1 at nats
I was surprised to see how much pace the car had in it. I didn't know what to expect going in as we hadn't run against any AS corvettes locally. Comparing SoloStorm data with Ryan Otis (2nd in AS in a 2003 z06) we were achieving higher corner speeds and sustaining ~.2 higher lateral g-force in the CR and, big shock here, losing ground in acceleration zones...
Here is my second run on the West course. I had picked up .5 seconds on my 3rd run but overcooked the final slalom cone and decided to DNF rather than spin.
http://youtu.be/jEuuP8jUwbg
Day 2
Weather was very challenging. Rain was threatening as our heat started but it never really came down. The rain was intermittent which allowed some groups of cars a relativity dry course on runs 1 & 2. I didn't get a decent course condition until run 3 and the surface had not fully dried. I believe that this was a bigger hindrance to the momentum cars. The slickest areas of the course were the corners which had been rubbered in from 3 days of competition. The data showed that, again not shockingly, the CR makes its time on the Z06 in the corners and the rain removed that advantage. I would really like to know how I would have done on the East course with clear weather but that's racing.
http://youtu.be/vlXXoz9pidc
2015 Preparations
For 2015 we decided to do some dyno testing of cat back exhaust options. The muffler delete that I fabricated for the car was very light (~ 16 lbs utilizing the OE midpipe and a custom straight pipe from the axle back) but I couldn't help but wonder if we were leaving some torque/Hp on the table. We secured 2 additional systems for the test that represented, in our eyes, drastically different designs. The 2 cat back systems we tested alongside the straight pipe were: The T1R 70 mm Titanium system and the HKS 75 mm single exit stainless system. We felt that pipe diameter variables were critical to this sort of dyno testing and we decided that we would select the system that made the highest torque. All testing was completed during a 3 hour window with minimal temperature/humidity change. We made 2 passes with each system and the plots below detail the gains/losses compared to the custom exhaust.
The results
Custom VS HKS (red and blue traces) (28.8 lbs with all hardware included)
Custom VS T1R (red and blue traces) (14 lbs)
After discussing these results with Drew Vanderploeg he informed us that he had completed a similar test several years ago while prepping his car for b stock. His testing had found that the modified factory exhaust made the most power when utilizing the factory tune. He did not test the T1R on his dyno test. If I was daily driving an S2000 I would have a hard time recommending the T1R despite its slight advantage on the dyno. It is much louder than the HKS and the custom modified OE exhaust. In cabin drone increased significantly as well. Jason's CR is not daily driven and the slight bump in power compounded with it being 2 lbs lighter was just enough for us to decide on the T1R. (Matt Leach selling it to us used with a significant discount helped that decision as well)
Thanks for reading. I will keep the info coming as we begin tire testing the new crop of 200 TW tires. We have a set of 71r's that we intend on testing against the RS3 v2 on a surface that is very similar to Lincoln in its grip level. We won't be able to test the tires ability to work on OPR but should be able to provide reliable information on the pace of these tires after the sunbelt national tour.
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From: Austin, TX
Slurpscribed!
(got my eye on the competition)
Seriously though, this is great of you to share all this info. I'm really looking forward to seeing more people bring out CRs in A-street. Your data comparison with Ryan Otis is really informative.
(got my eye on the competition)
Seriously though, this is great of you to share all this info. I'm really looking forward to seeing more people bring out CRs in A-street. Your data comparison with Ryan Otis is really informative.
Joined: Oct 2011
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10th at 2014 Solo Nationals in A Street
2008 S2000 CR (non-delete)
HKS Hi-Power 75mm exhaust
TR motorsport F3 wheels
SFR/Gendron Monster bar 4/6
MCS Non-remote DA shocks
Dunlop Direzza ZIIs 235/40-17 front and 255/40-17 rear (day 1)
Dunlop Direzza ZIIs 235/45-17 front and 245/45-17 rear (day 2)
Camber 1.9*/-2.5*
Toe 0 / 1/8" (in)
~2810 at 2013 Solo Nationals in BS trim (same setup other than the steel bodied Koni 8242s and 275/40-17 Hoosiers)
Drove reasonably well on day 1, but it seemed like we had problems keeping the tires from greasing up mid run towards the end of the heat. As the first driver on day 2, I had to stand on an decent second run for the condition. The course was all wet on my third and couldn't improve.
- Tim
2008 S2000 CR (non-delete)
HKS Hi-Power 75mm exhaust
TR motorsport F3 wheels
SFR/Gendron Monster bar 4/6
MCS Non-remote DA shocks
Dunlop Direzza ZIIs 235/40-17 front and 255/40-17 rear (day 1)
Dunlop Direzza ZIIs 235/45-17 front and 245/45-17 rear (day 2)
Camber 1.9*/-2.5*
Toe 0 / 1/8" (in)
~2810 at 2013 Solo Nationals in BS trim (same setup other than the steel bodied Koni 8242s and 275/40-17 Hoosiers)
Drove reasonably well on day 1, but it seemed like we had problems keeping the tires from greasing up mid run towards the end of the heat. As the first driver on day 2, I had to stand on an decent second run for the condition. The course was all wet on my third and couldn't improve.
- Tim
Joined: Oct 2011
Posts: 124
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2015 plans:
Buy some tires, play with rear shock settings and alignment a bit, get a less droney exhaust, and figure out how to drive. I'm close to just getting a set of 255 ZII Star Specs, but am keeping an eye on the new stuff.
Thanks for those dynos, Todd. I'm on the lookout for a stock exhaust now.
Buy some tires, play with rear shock settings and alignment a bit, get a less droney exhaust, and figure out how to drive. I'm close to just getting a set of 255 ZII Star Specs, but am keeping an eye on the new stuff.
Thanks for those dynos, Todd. I'm on the lookout for a stock exhaust now.
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Mike-
Jason has always felt that the car is a bit "pushy" and I like the balance as is. Perhaps we should check the rear camber settings with a temperature probe to see if we should pull some out. I should probably check the state of the front lower control arm bushings as well. It would be nice to get a bit more up front based on how the hankooks have worn.
Jason has always felt that the car is a bit "pushy" and I like the balance as is. Perhaps we should check the rear camber settings with a temperature probe to see if we should pull some out. I should probably check the state of the front lower control arm bushings as well. It would be nice to get a bit more up front based on how the hankooks have worn.
Joined: Oct 2011
Posts: 124
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Mike,
This is not the best picture, but the outside rear tire looks happy at that setting.
That said, I think there's some speed to be gained as I'm not quite happy with the balance. I'm hoping to iron most of it out whenever all this snow melts.
This is not the best picture, but the outside rear tire looks happy at that setting.
That said, I think there's some speed to be gained as I'm not quite happy with the balance. I'm hoping to iron most of it out whenever all this snow melts.