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IMSA Introduces New Balance of Performance Process

Inside IMSA’s new data-driven BoP process with Geoff Carter…

Photo: IMSA

Photo: IMSA

As new regulations debut in the GT Le Mans and GT Daytona classes this weekend at Daytona, so too does a new Balance of Performance process, with IMSA implementing additional data-based measures aimed at closing the performance gap.

IMSA has rolled out with a new proprietary scrutineering data logger system — mandatory on all GTLM and GTD cars — that measures various things such as RPM, throttle position and airbox pressure.

Along with a newly implemented in-session scrutineering checks, the sanctioning body now has a significant amount of new data to work from in determining BoP, according to WeatherTech SportsCar Championship Senior Series Manager Geoff Carter.

“We were able to take the timing and scoring data, the vehicle data and the car configuration at that time, melt all that together and we have a much more clearer picture of what the car’s actually doing,” Carter told Sportscar365.

“Instead of going from a one-dimensional analysis, we’ve almost got this three-dimensional method now by adding two other elements.”

Previously, IMSA had primarily utilized timing and scoring data to determine BoP, but an overhaul has been made by its technical team heading into the 2016 WeatherTech Championship season.

Carter said the new Bosch logger systems — which costs $18,000 per car to outfit — mirrors the FIA’s recently introduced system that is being used for the same purpose.

“What that allows for us is to collect the car data in a pure, standalone form, so the channels have not been altered or modified,” Carter said.

“Not only do we know how it goes from A to B. We know the vehicle dynamics data of what it was doing from A to B.”

The second at-track component is the introduction of “spot checks” during sessions, which sees cars ordered to IMSA’s scrutineering bay to verify a car’s configuration.

A similar procedure, which generally takes 3 to 4 minutes, has been utilized in the FIA World Endurance Championship, most notably at the Le Mans Test Day.

“We pulled the cars straight off the track, ran them through the tech process, pulled some critical elements, such as wing angles, weight and ride height and did an updated [data] dump at that time,” Carter said.

Manufacturers have praised IMSA’s added BoP data measures, particularly after a season that saw one of the largest gaps in performance among the GTLM class cars in recent years.

“The key to this whole thing is IMSA recognizing that they can do better… and they have,” Corvette Racing Program Manager Doug Fehan told Sportscar365.

“When you recognize where your soft spots are, that’s the first step in getting them fixed. We’ve got that recognition from them and their expressed willingness to improve.”

IMSA also took all GTLM and GTD class cars to the wind tunnel late last year to determine the aerodynamic characteristic of each model. Carter said that data was used to determine the initial 2016 BoP.

“We had a great Windshear wind tunnel test with all the manufacturers,” Fehan added. “It was a very, very, very productive test. It’s the starting point.

“Balance of Performance will never be perfect but we know it can be a lot better.”

Defending GTLM class champions Porsche have also been in favor of the more data-based system, despite the added costs to outfit the cars with the data logger units.

“Like I said last year, the sport can’t survive if BoP isn’t working,” Marco Ujhasi, Overall Project Leader for Porsche GT Works Motorsport told Sportscar365.

“If you look at the different car concepts here, from one extreme of the Ford to the other with the BMW, it’s not easy to balance this.

“Therefore, if you want to have these cars running in the same class and the same competition, you must look at the performance windows and the reference engine curves.

“If it’s really working, then I’m quite confident that it will go in the right direction and it would stop some day, hopefully.

“One thing’s clear, you need the BoP if you want to run such different cars. It’s essential for GT racing.”

Carter said some of their first findings were quite revealing, with IMSA’s data from the Roar Before the 24 showing that every single car, for a lack of a better word — sandbagged — during the three-day test.

“Ultimately, what we found across the board was an element of underperformance that was pervasive,” Carter said.

“We simply took the top-five fastest laps of every car and we were able to identify in every single one of those laps, in every single car — all 54 of them — an area of underperformance. In every single one of them.”

The data was presented to manufacturers during video conference calls, with whitewashed graphics in order to prevent the identification of the offenders.

Carter said: “What we did was put up the [slides with anonymous data] and said, ‘Guys, here’s what we saw and you’re all guilty of it.’

“We did it in a group setting, with everyone on the call, and allowed all of the manufacturers to comment on what they had just seen.

“In the end, we took an extra day to understand it and got some additional feedback and by Thursday mid-day, we published the [pre-Rolex 24] BoP.”

While currently being used in the two GT categories, Carter said they will implement the same data loggers on the Prototype class next year, when the new P2/DPi formula debuts.

The ultimate test will come this weekend, to see how close IMSA has come with its new data points. So far, Carter has been pleased by the response from the manufacturers.

“The manufacturers have been asking for structure in their own way and have been very responsive to the changes IMSA has made,” he said.

“We’re all very encouraged from IMSA’s side and from the manufacturers’ side that things are going in the right direction.”

John Dagys is the founder and Editor-in-Chief of Sportscar365 as well as the recently launched e-racing365 Web site for electric racing. Dagys spent eight years as a motorsports correspondent for Channel, and contributes to other publications worldwide. Contact John



  1. Mark

    January 28, 2016 at 9:02 am

    I think too much control will kill this sport.

    • Bakkster

      January 28, 2016 at 9:33 am

      We’ve already seen too little control kills it. Even Porsche says without it the sport won’t survive. In the old days the Ford GT would have signaled the end of GTE. They’d dominate this year, everyone else would pull out next year, then Ford would reach the end of their 2 years, have nobody to race against, and pull out as well.

      The important thing here is that now they have the data to make fully informed calls. That’s a very good thing.

    • NeilRR

      January 28, 2016 at 11:04 am

      I agree, IMSA will still manipulate the outcome. There are much simpler ways to regulate and one that can’t be altered by IMSA. They just admitted they whitewashed the data from each manufacturer so the others could not see what each team was doing. They then say everyone was sandbagging, it was practice not a race!!!! I’m not running my car flat out making hot laps! There’s a word for teams that would do that , STUPID! That word fits IMSA as well! As long as there is IMSA, this sport will flounder!

  2. Redcap

    January 28, 2016 at 9:39 am

    Very few normally asperated engines have been able to compete during a turbo era. Let’s hope this ” logger system” will help in that aspect. It will be interesting to see how this works over a season.

    • Bakkster

      January 28, 2016 at 9:54 am

      GT3 has done pretty well with it, the trick has been to limit the boost pressure by rev range. Instead of getting a global 1.5 bar, for instance, you might get 1.5 bar at 2000 RPM, 2.0 bar in the mid ranges, and no additional boost at redline.

  3. Tom

    January 28, 2016 at 9:42 am

    Bop – the ruination of the sport – I already attend less races because of it / maybe A boycott of sponcers should be in order… This pc of give everyone a trophy for showing up, will ruin real competent R&D.. Who loses in that scenario? All of us.
    Keep it up,

    • Maurice

      January 28, 2016 at 10:50 am

      You would have way less big time sportscar racing without BOP. Why do you repeat such ascinine nonsense about BOP ruining sportscar racing?

      • Jordan

        January 28, 2016 at 11:18 am

        Here is the point:

        If no one is allowed to build a better car than anyone else, it is all meaningless. It isn’t a sport. Sport involves improving yourself and team to try to be better than others. Mindless entertainment is more like what this is.

        This would be the equivalent of 12 people from this website playing the Golden State Warriors in the NBA. Golden State would probably win 300-20 or so as well as they should.

        Instead, the NBA says everyone is entitled to a close game and no one is allowed to be better than anyone else so they introduce a BOP system. Now they make Golden State play the game wearing 100 lb ankle weights to bring them down to our level. When this happens, it isn’t a sport anymore as there is no point to improving yourself.

        • Maurice

          January 28, 2016 at 11:51 am

          Oh, I get it. The wealthier teams should be allowed to buy championships. That’s what true sports and competition is all about????? The NBA has a BOP, it’s called the draft. The NFL has a BOP, it’s called the draft. There are also free agency restrictions. So, I guess you think the NFL and NBA would be better leagues if they abolished the draft and had full unfettered free agency year to year????? Again–ASCININE NONSENSE!

          • Jordan

            January 28, 2016 at 12:04 pm

            You can’t equate BOP in racing to professional sports league draft systems. Lets use the NBA again as an example. For simplification, we’ll just say that the worst team in the league gets the #1 pick and so on even though the NBA uses a lottery system.

            The NBA allows the weaker teams to draft players who will help improve their team, but here is the difference to BOP. Those players improve the weaker teams by their SKILL, TALENT, and HARD WORK. In other words, the league doesn’t give the team handouts or make the other teams weaker to bring everyone else down to their level.

            To continue, during the 2002-2003 NBA season, the Cleveland Cavaliers tied the Denver Nuggets with the worst NBA record at 17-65. They selected LeBron James in the draft. The next year, with the addition of LeBron James’ SKILL and TALENT, the team improved to 35-47. The team would eventually improve enough to reach the NBA finals.

            The NBA didn’t help them improve by making the Cav’s basket at their end of the court a foot wider or move their 3-point line closer nor did they artificially hurt other teams by making their opponents wear 10lb ankle weights to “slow them down” or shrink their baskets so they can’t “pull away” as much, which is exactly what BOP does.

            If you want the racing equivalent of a draft, then have a draft. If Ganassi finishes last in the Prototype standings, then he gets the #1 pick. If his main problem is lack of horsepower, then he can draft a smart engine builder out of Purdue. Then the next year, the car may be 2 seconds a lap faster due to the TALENT and SKILL of that engineer builder. If you don’t want to do privateers building their own cars, then just switch it to factories. If Honda finishes last in the standings, then they get the #1 pick.

          • Maurice

            January 28, 2016 at 3:20 pm

            We would already know who could build the best cars that lasted the longest–the 1 or 2 teams with the biggest racing budgets.

        • Maurice

          January 28, 2016 at 12:14 pm

          The hell you can’t. The purpose of the draft and free agency restrictions is balance of performance between teams in the league. They want competition, not an exhibition. You want to turn the NBA into a glorified Harlem Globetrotters exhibition league. All the best players on a few teams that dominate forever.

          • Jordan

            January 28, 2016 at 12:26 pm

            The purpose of the draft is to improve your team by TEAM CHEMISTRY, TALENT, and SKILL.

            BOP is the equivalent of the NBA saying that at 42-4 the Golden State Warriors are too good so they are forcing them to shoot into a smaller basket compared to everyone else in order to bring them down to everyone else’s level.

          • Kirk

            January 28, 2016 at 1:13 pm

            The best example of BoP in sports isn’t the draft, it’s the salary cap, which the NHL, NFL, and NBA all have – and MLB has the luxury tax. It keeps the richer teams from buying all the best players. If you watch the NFL/NHL/NBA and thrill at how close the games are and how much parity there is in the leagues, you’re cheering for BoP.

          • Jordan

            January 28, 2016 at 1:36 pm


            Rules themselves aren’t BOP. As long as everyone plays to the same rules.

            In the NBA, there is a salary cap of ~$65 million. Every team plays to this limit. Each team also has to shoot into the same size basket. Each team gets a 24 second shot clock. All the rules are same for everyone.

            To apply this to racing, restrictions themselves aren’t BOP as long as everyone plays to the same rules. What would be BOP is if someone built a car that was 10 seconds faster than everyone else, and the rule makers artificially slowed them down or artificially sped everyone else up.

          • KirkH

            January 28, 2016 at 1:50 pm

            Which is the way sports car racing was in the past, which led to instability and low car counts. If you liked the Can-Am, IMSA GTP, ALMS, etc. and you wonder why they’re no longer with us, it’s because there was no BoP. I’m not a fan of contrived racing either, but it’s a way to obtain stability in the starting grid. No one car wins all the races and forces everyone else to go home. I don’t think IMSA needs to change the BoP as often as they do, but the concept is pretty much a requirement these days if you want a stable racing series.

        • Maurice

          January 28, 2016 at 1:26 pm

          Without the draft, and free agency restrictions, the biggest budget would dominate the NFL and the NBA. Without BOP, the biggest racing budgets would dominate , and the fields would shrink until it became too expensive for the last two teams left, and what would be the point???

          • Jordan

            January 28, 2016 at 1:31 pm

            Who can build the best car and make it last.

            That would be the point.

          • KirkH

            January 28, 2016 at 4:42 pm

            And that only works if cars show up to race. I’m a purist as well, but seeing a series like the ALMS had near the end with only one or two top cars isn’t enjoyable either. I’m not a fan of the BoP, but I see it as a necessity. One can always hope for sports car racing nirvana with one set of rules and huge grids of cars, but anybody who’s followed the sport for any length of time knows it’s not sustainable. There will always be one dominant car/team that forces the other teams to either expend huge sums of money to race competitively, or else find a new series to race in.

  4. Woody

    January 28, 2016 at 10:22 am

    I’ll tell ya one thing, in IMSA the Ferrari based teams are made to run the smallest restrictor of all the GT teams …IMSA has made it clear they do not want foreign cars winning “their” race against their precious domestic Chevy Vette or the Ford GT40’s…but the WEC does do that to the US makers who enter their series… IMSA YOU SUCK!!…

    • Woody

      January 28, 2016 at 10:24 am

      DOES NOT do that to US made cars in the WEC^^^^

    • Maurice

      January 28, 2016 at 10:41 am

      Lol, so why exactly do foreign cars win their races and their championships???????????

    • Bakkster

      January 28, 2016 at 10:55 am


      The GTE 488 is running more boost than the Ford.

      The GTD 458 has a larger restrictor than every other NA GTD car except that old Audi (45.5mm on the Ferrari, just 38.0mm on the Viper).

      You must be looking at the fueling restrictor, which is smaller because the Ferrari has the smallest tank, since they’ve asked to run their car lean and fuel efficient.

    • NeilRR

      January 28, 2016 at 11:07 am

      Your nuts, Porsche GTLM, BMW , had much more power last year than the Corvettes! The facts don’t support your theory !

  5. Ma7mgte

    January 28, 2016 at 10:24 am

    @Tom – So, run what ya brung? That will just lead to a price war.

  6. scottypinthemix

    January 28, 2016 at 11:50 am

    Wow. I’m here for the LULZ

  7. Rick

    January 28, 2016 at 4:37 pm

    It’s one thing to have the data and another to fairly implement BoP based on the data. Can IMSA do that? I’m not tons sure.

  8. Wayne Ray

    January 29, 2016 at 8:09 am

    With all of this BOP BS, when the cars are 100% equal, all you will have is a parade not a race.

    Set standards that ALL cars must adhere to in order to race.
    Then stand back and let the best car win. Racing can improve the cars ONLY if the are allowed to innovate and improve.

    Winning would mean a lot more to the teams AND the fans, if the winner did so because the car was better than it’s competition, and not given an edge because of BOP BS.

    When I raced NHRA in the 60’s, it was basically “Run what you brung”! Once you were assigned a class and met the rules, the gloves were off!

    GTLM fans don’t want NASCAR type ‘racing’ with 30 or 40 cars all running together 3 wide and 10 deep, where one car fails and wipes out 10 others! That’s gambling, not racing!

    IMSA< set the rules for everyone, then stand back and enjoy the RACE!

  9. Criag

    January 29, 2016 at 11:13 pm

    It’s funny watching Jordan dissect someone down point by point while Maurice just has to make up stuff.

    Lack of BOP is not a competition and an exhibition like the Harlem Globetrotters? Really Maurice?

    That’s exactly what BOP is. It isn’t a competition. It is an exhibition of contrived closeness. The Harlem Globetrotter games are where you would find artificial gimmicks like being allowed to travel, no shot clocks, running out of bounds, etc and not in professional NBA games.

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