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DPis Given Power Increase for CTMP

Three of four DPi manufacturers given power increase for CTMP…

Photo: Rick Dole/IMSA

DPi cars from three of the four manufacturers have been given power increases ahead of this weekend’s Mobil 1 Sportscar Grand Prix at Canadian Tire Motorsport Park.

IMSA released Wednesday the revised Balance of Performance table for the seventh round of the WeatherTech SportsCar Championship season, which sees changes to all three categories.

It comes following the first victory of the season by a LMP2 car, which remains the performance benchmark for the Prototype class.

The Cadillac DPi-V.R has been given a 0.3 mm larger air restrictor, while there have been increases in turbo boost for both the Mazda RT24-P and Nissan Onroak DPis.

The adjustments have been made at the mid-to-top range for both cars.

Fuel capacity increases, meanwhile, have been made to all three of the adjusted cars to compensate for the power boost.

Corvette, BMW Adjusted in GT Le Mans

BoP adjustments have been made for the first time since Long Beach in GT Le Mans, most notably with a power increase to the Corvette C7.R.

The Pratt & Miller-built car will now have a 0.9mm larger air restrictor, bringing it to the same 31.5mm (x2) size as the Porsche 911 RSR.

BMW’s M8 GTE, meanwhile, faces a slightly reduced turbo boost for CTMP, despite struggling for pace at Watkins Glen.

Both the Audi R8 LMS and Porsche 911 GT3 R will have larger air restrictors in GT Daytona, with the Porsche having been given a 3mm increase, with a 1mm larger opening for the Audi.

While IMSA is typically required to publish BoP changes at least seven days prior to the start of each event, allowances have been given for CTMP, which falls the week after Watkins Glen.

“IMSA Technical Committee performed it’s standard post event data analysis for both the IMSA WeatherTech SportsCar Championship and the IMSA Continental Tire SportsCar Challenge,” a statement from the series read.

“After careful consideration, and in advance of this week’s Mobil 1 SportsCar Grand Prix at Canadian Tire Motorsport Park, IMSA will issue an updated Balance of Performance Table as permitted by IMSA 2018 Sporting Regulation attachment 2.4.5.”

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. daedalus

    July 4, 2018 at 1:08 pm

    I think IMSA needs to take a page out of SROs copy book and have track specific BOP rather than balancing the cars based on the previous race. So one BOP for high speed circuits like the glen and CTMP (where the DPIs would get more power), and another for slow speed tracks or bumpy tracks like detroit and sebring (where the DPI would get less power).

  2. Steven

    July 4, 2018 at 1:43 pm

    IMSA can’t have those pesky LMP2’s running up front and winning races I see. Got to keep those manufacturers happy or else they may pull out.

    • Jack

      July 4, 2018 at 2:27 pm

      yeah, its not the acura was the only dpi that was remotely close to the oreca p2’s pace.

      • Steven

        July 4, 2018 at 3:39 pm

        Maybe it was because the Acura is a slightly modified Oreca chassis perhaps? Watkins Glen is a more traditional European-style circuit. Hence why the Oreca and Ligier finally had pace against the others.

        It’s not like the fastest car in the race was a LMP2 either, that belonged to Acura.

        • Mike S.

          July 5, 2018 at 3:08 pm

          Totally the case. The P2s always did better on traditional road courses. Streets, bumpy Sebring,and rovals not so much. That’s why IMSA needs to stay course and don’t change anything, oh wait. I think Core, JDC, and PR1 would fit better in ELMS they don’t have the budgets of Penske and Joest.

  3. Pay Driver

    July 4, 2018 at 2:40 pm

    Time for the P2s to get torched again. Was fun while it lasted.

    That #58 will finally get into contention this weekend.

    • Jack

      July 4, 2018 at 2:43 pm

      Yea, it’s not like the dpi’s have significantly better driver lineups or anything…

      • Andres

        July 4, 2018 at 7:29 pm

        Actually they have, you cannot compare someone like Montoya, Rast, Castroneves, Van der Zande, Nasr, or even Taylor to the likes of Simpson, Goikhberg or whatever way that surname is written correctly

        • Andy Flinn

          July 4, 2018 at 10:55 pm

          Andres, Jack was be facetious. He’s also right. Most the DPis have more experienced drivers.

          It’s one of the reasons DPis have won 14 of the 16 races.

  4. Davy

    July 4, 2018 at 3:07 pm

    Give the P2’s a power boost so the DPi’s aren’t so nerfed. In GTLM it’s ridiculous that the Vette had a smaller restrictor than the Porsche till now. Front engined cars should have a power advantage over the easy-mode middle engined “GT” cheaters. You can’t buy such a 911 and the Ford “GT” is basically a homologation special as well.

    • TF110

      July 4, 2018 at 4:18 pm

      They can’t. The p2’s spec is locked in place. They should just split the class into two so they don’t have to dumb down the dpi’s anymore. There’s enough of them to do so. With proper tires next year they will probably be faster too.

      • Davy

        July 4, 2018 at 4:51 pm

        No, splitting the class is the worst thing they can possibly do. Two weak prototype classes like the WEC is an awful solution. Give the incompetent ACO the middle finger and lift some of the restrictions on the P2s.

        • Andres

          July 4, 2018 at 7:34 pm

          In fact is the best idea to split the classes, in the LMP2 spec cars you can barely find a pro driver, so is better having those cars in an inferior class, and the other one is that IMSA can say “fuck you ACO/FIA” and unrestrict completely those DPIs and rebrand them into LMP1/DPI and those LMP2s can be in their own LMP2 category, cause they have enough cars to do so

          • Davy

            July 4, 2018 at 8:16 pm

            If they split them, nobody would care about the P2s and they’ll become another dead category… just like PC. It would be the exact same deal. It’s an Awful idea.

          • Andy Flinn

            July 4, 2018 at 11:17 pm

            I’m cool with creating a separate class, points and championship for LMP2 (if that’s what they want) – under one condition.

            If that happens, LMP2 teams need to accept that they may be racing for the class win and eleventh place overall (behind 10 DPis) and NOT overall victory.

            Otherwise, if what LMP2 teams REALLY want is their own class yet ALSO a shot at overall victory against the DPis (like the SOD Ligier win last year or the JDC Miller Oreca win last weekend), I don’t think the LMP2 teams can ever be satisfied.

            It was cool in the ALMS with LMP1 and LMP2 while it lasted. However, we all know it didn’t last very long.

        • Fernando

          July 4, 2018 at 7:58 pm

          Completely agree with you. That’s the way to go. IMSA must stop trying to align with the ACO

      • John

        July 4, 2018 at 6:05 pm

        Few, if any, are asking for the return of PC, even with newer cars.

        Giving those teams a chance to move up and compete for overall wins in a combined class was a noble idea, but hasn’t worked out well in practice.

        If IMSA had the balls to require and enforce customer DPis, that would result in a consistent, stronger class, and allow it to run without the P2 performance encumbrance as well.

        That might come at the cost of the P2 teams at Daytona and such, but which of those in their right minds would come back anyway, with very slim chances of winning even against strangled DPis as they now stand?

        Poor BMW. Teething troubles with its brand new toy, and getting no love from IMSA or the FIA. Better rev up that FE effort.

    • Steven

      July 4, 2018 at 5:14 pm

      LMP2 has been the fastest its ever been though. Even with the awful Continental tires.

      IMSA knew what they were getting themselves into when they created the DPi class to co-exist with LMP2.

      If IMSA puts their LMP2 teams out of regulations. All the teams that run LMP2’s might as well join ELMS or WEC as they would never be considered for Le Mans.

      • Andy Flinn

        July 4, 2018 at 6:45 pm

        Steven, the IMSA LMP2 teams interested in racing Ligiers and Dallaras (and Riley/Multimatics – if any) would join the ELMS.

        These chassis still haven’t​ won anything in WEC LMP2. In fact, these chassis can’t even make the WEC LMP2 podium without Oreca disqualifications (Le Mans).

        No, WEC LMP2 is still owned by Oreca.

        • Steven

          July 4, 2018 at 7:53 pm

          Well, the last full time teams that raced Ligiers (ESM and Morand) left WEC and that was in 2016. The teams that already ran the Oreca 05 stuck with the brand when the 07 came out.

          Dallara and Ligier have an uphill battle to climb as Oreca has a lot of resources to play with in order to build a fast car.

          United Autosport seems to be the best team that could actually challenge the WEC teams, But you also seem to forget that the WEC teams that use the Oreca’s are also well-established racing teams with top quality drivers.

          • Andy Flinn

            July 4, 2018 at 11:38 pm

            Steven, none of your explanation changes the fact that Oreca continues to dominate WEC LMP2.

            The multi-chassis and multi-engine optioned DPi’s dominance over LMP2s in IMSA is awful yet Oreca’s continued domination over everyone else in WEC LMP2 is acceptable?

            That sounds like a major double-standard.

            By the way, you mention WEC LMP2 drivers yet you seem to ignore that LMP2 is supposed to be a Pro-Am category. So should the “top quality” drivers (the United Autosports Ligier has former F1 drivers) make that much of a difference? After all, LMP2 drivers are not fighting DPi pros for race wins in the WEC.

        • Davy

          July 4, 2018 at 8:18 pm

          Why would American IMSA teams join ELMS?

          • Matt

            July 4, 2018 at 9:49 pm

            They’re not really American, they’re funded by European/South African businessmen.

    • fourloko

      July 5, 2018 at 8:26 am

      vette also weighs less than the porsche

    • gmfansaredelusional

      July 5, 2018 at 9:37 pm

      Why should the front engined cars have more power?

      Simply because they are front engined?

      The Corvette has a much larger engine than the Porsche and is lighter than the Porsche, so why do you think it’s unfair that they have an oh so slightly smaller restrictor until now?

  5. Higgi

    July 4, 2018 at 3:44 pm

    Same old bullshit,If corvette don’t win give them more power,if someone else wins decrease theirs,all the announcers brag about is how corvette has won over 100 races,anyone who knows anything about the wins knows that at least 75 of the races there were only two cars in their class,one corvette two corvette,so that number means nothing

    • Andy Flinn

      July 4, 2018 at 6:48 pm

      Higgi, anyone who actually WATCHED the races knows that isn’t true.

    • Andres

      July 4, 2018 at 7:39 pm

      Oh a Ford fanboy detected, fact is that this is nowhere near to be true, only in the final year of GT1 there was no competition for Corvette,then Corvette is now running the smallest restrictor it ever ran in IMSA since 2015, so maybe you can just shut up and stop with the nonsense or go to a psychatrist

      • Louis

        July 5, 2018 at 9:12 am

        Ooooo ford chevy argument been a while, but got my popcorn!

      • gmfansaredelusional

        July 5, 2018 at 9:32 pm

        And corvette is still running lighter than the 911 with its 4.0 versus the corvette 5.5 with same size restrictor and don’t try to say that’s not how BOP works. That has to be one of the dumbest things I ever read here.

        What’s your point?

        • NotALarryFan

          July 5, 2018 at 9:55 pm

          Larry has a new user name, but still doesn’t understand what restrictors do. Can’t wait,to hear about engine size of the Porsche every BOP article.

  6. Dan

    July 4, 2018 at 5:01 pm

    Well, I don’t have the data IMSA has, but simply from the spectator side of the fence it’s hard to understand the BMW GTE’s coming out of WG with a >reduced< turbo boost???

    The BMW’s were back of the pack in GTLM and struggled to pass GTD’s, some of which have been granted larger air restrictors.

    Seems logical the BMW GTE’s could be running in the top third of the GTD class at CTMP.

    • DEJ

      July 4, 2018 at 6:37 pm

      It really is very simple to figure this out .BMW docent have the monetary clout Corvette has. Corvette killed GT1 with their constant complaining .Ferrari left and so did Asto Martin.

      • Andy Flinn

        July 4, 2018 at 6:52 pm

        DEJ, since the IMSA merger, AM has been doing the most complaining and the least racing in GTLM.

        Give Team Corvette credit. They’ve never gathered up their marbles and left any series.

      • seeking truth, looking for ignorance.

        July 4, 2018 at 7:10 pm

        Jealousy is eating you alive, and making you sound and look ignorant.

      • bjones

        July 4, 2018 at 9:53 pm

        when was Ferrari in GT1? I know when the boys in England built them and then changed to Aston So?

        • Andy Flinn

          July 4, 2018 at 11:46 pm

          Bjones, Prodrive, Raffinelli and Larbre raced GT1 Ferraris before Prodrive switched to Aston-Martins.

          Higgi probably didn’t know that, either.

          • Jake

            July 5, 2018 at 2:00 pm

            I think he was referring to Ferrari themselves competing. Prodrive were entirely behind the 550 GT1’s (one of my favorite all time GT cars) Ferrari then built the 575 GT1’s in Maranello.

        • Andy Flinn

          July 5, 2018 at 12:00 am

          Bjones, Prodrive, Raffanelli/Olive Garden and even Larbre all raced GT1 Ferraris, before Prodrive switched to Aston-Martins.

          Higgi probably didn’t know that, either.

  7. Pete

    July 4, 2018 at 7:48 pm

    Amazing…I can actually tell that every single person whining in here didn’t watch the WGI race. The Acuras and P2s were nearly inseperable, everyone else was just a little off pace.

    I’d say the prototype BoP adjustments were basically exactly what was needed after WGI. Every car that was hurting received some help, no changes to the fastest cars (obviously including P2s that can’t have changes made).

    So often it seems like they speed up the slower cars AND slow down the fast cars and it just creates a polar switch. On the surface, at least, these changes look promising. CTMP should be a top-to-bottom dogfight, and hopefully if it is they’ll leave it alone heading to Road America and onward.

    Oh, and I don’t comment on GT BoP, because regardless of the amount of bitching, we almost perpetually get fantastic races in both classes, so who really cares?

  8. Ryan

    July 4, 2018 at 8:31 pm

    Full disclosure, Corvette fan here. I was at Watkins Glen and for the life of me I can’t understand why BMW received a boost reduction. They were in an entirely different class, but in a bad way.

    Also I was surprised initially that the Vettes stayed within shooting distance to the Porsches and Ford GTs, but the Ford evidently had issues (broken roll bar) and the winning car had some issues part way through the race that they evidently fixed before the end. It was cool to see some strategy (and luck) give them a chance to podium after watching a tremendously boring Le Mans a few weeks ago (kudos to you though Porsche!).

    • Jez

      July 4, 2018 at 9:49 pm

      It’s a mistake in the article, the BMWs actually have a boost increase.

      • Ryan

        July 4, 2018 at 11:10 pm

        Ah, that makes much more sense. Hope they can mix it up with the rest of the class on Sunday.

      • Mpower

        July 5, 2018 at 2:09 pm

        Not a mistake, they have a decrease in boost at every RPM point from 3500-7500 rpm. They did get an increase of 2L in fuel capacity, the Corvette also got 1L increase in fuel capacity. Looking at 20180704 CTMP Balance of Performance Tables Revision 1

        • JEZ

          July 5, 2018 at 4:16 pm

          Unless the IMSA Competitor Technical Bullitens are incorrect, BMW is being given more boost. First number is RPM, second number is boost ratio allowed at Watkins Glen, 3rd is Boost ratio allowed at CTMP. I don’t see anywhere that there is LESS boost.

          3500 2.18 2.2
          4000 2.18 2.2
          4500 2.17 2.205
          5000 2.03 2.075
          5250 1.95 1.997
          5000 1.87 1.919
          5750 1.8 1.852
          6000 1.73 1.784
          6500 1.67 1.724
          6750 1.54 1.599
          7000 1.3 1.458
          7500 1.12 1.19

          • Ryan

            July 5, 2018 at 10:19 pm

            Agree with you JEZ. Looking at the bulletin it is an increase in power for the BMW, which makes much more sense.

    • Andy Flinn

      July 5, 2018 at 12:08 am

      Ryan, just like at Daytona, CGR has a lot of experience winning at Watkins Glen. It goes back to NASCAR and Grand-Am DP.

      Experience also helps explain how Team Corvette managed to win GTLM at Sebring three years in a row (2015-2017).

      It’s not all luck and BoP.

      • Ryan

        July 5, 2018 at 10:17 pm

        Andy, just a difference of opinion, but I don’t think it has to do with experience at the track. Not that it hurts for the Ganassi guys, but Corvette won Daytona in 2015 and 2016 (not to mention several other years), so they have plenty of experience there. I’d argue that the Glen just flat out suits the Ford GTs better (just like Long Beach is generally a better track for the Vette). The Glen has those fast sweeping corners and long straight-aways that give it a hint of an LM feel. The Vettes did catch a couple of breaks in the one GT having a broken swaybar and having some good strategy/pit stops to keep them ahead of the Porsches in the latter part of the race.

        At the end of the day, on pure pace, a healthy Ford GT was quicker than a healthy Vette, same with the Porsches. Not by much, but they did have the edge at the Glen. This isn’t intended to be a complaint by any means as BoP is just a necessary evil this day and age. Now, if I were a BMW fan, that would have been a painful race to watch…

  9. Mike coter

    July 5, 2018 at 1:10 pm

    I got a very cool solution why not kill the Dpi name and call it Lmp1 nascar needs to let go Of the daytona prototype name, it like obsessing over the one ex boyfriend/girlfriend because keeping there yout memoreybofbthem will keep happy when in reality it doing damage, in other words move on nascar

    • David Chaste

      July 5, 2018 at 8:54 pm

      Why dont the aco kill the LMP1 for their top class and call it DP1.

      Same argument.

  10. CD

    July 7, 2018 at 10:32 am

    Cadillac, Mazda and Nissan can use a slight power boost. Acura has pace to compete. The DPI machines will be protected. They will be the quicker car overall. Aside from Mazda. LOL!

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