The Problem With P: Power To The People

(featured image credit: David Yowe)

We are halfway done in the TUDOR Championship, and after several action packed races in P, here are the winning cars so far: DP-DP-DP-P2-DP-DP. See a pattern? So far the DPs have the upper hand over the P2 cars when winning time is on the line, at times P2s seem to be no match for them despite the times being similar, or even if P2s are faster. So far, it seems like Corvette DP and the OAK-Morgan Nissan has been consistently on the sharp end of the field, though ESM has the moral victories with a win in Laguna Seca and a near-as-damn-hell win in Sebring. The Morgan has been the “truest” thorn on the DP side, with consistent pace and presence (thanks to the relentless Gustavo Yacaman and Alex Brundle), while ESM’s form has been up and down.

In the DP side, there has been a power struggle between 3 teams: Action Express, Wayne Taylor Racing, and the suddenly slipping Chip Ganassi Racing with Felix Sabates; though a fourth interloper has just joined the party and is riding on a wave of momentum after winning the 3rd jewel in the Patron NAEC: Spirit of Daytona Racing. Watching the dynamics of the racing, it is very interesting how the protagonists in P wield their magic: The DP-Evo, with near 600 hp on tap, was a monster on the straight line and in acceleration. The LMP2, though short on power, relies on aerodynamics, lighter weight, and chassis sophistication for higher cornering speeds and overall momentum. In a natural terrain road course, especially in qualifying when traffic is non-existent, LMP2 cars would surely blitz around the circuit by as much as half a second, as Johannes van Overbeek and Alex Brundle proved. However, an open track is not the same as a full field, and with the inevitable full course cautions happening in a race, a P2 car with a 100-150hp deficiency would get swamped by angry and very loud Daytona Prototypes on restarts, much to the annoyance of their drivers. If a race goes all green and a P2 is ahead they can run away with it, which happened exactly in the sole blip in the DP win column in Laguna Seca. You can’t deny the close racing, and the data don’t lie: fellow NASportscar colleague Ben Wedge nailed it in his latest analysis of Watkins Glen. However, I reckon it could be closer. And people are asking: why are the P2 cars so gutless?


credit: Matt Kistler

credit: Matt Kistler

When LMP2 was introduced in 2006, it was the successor to the fast-but-fragile LMP675 class. The ACO’s master plan wanted factory teams and major manufacturers to go to LMP1, while LMP2 will be the domain of the privateer and customer teams. However, the LMP2 class still remained a featherweight compared to the bruising power of the LMP1 cars: P1 was at 900kg, LMP2 at 775kg. In the engine front, LMP2 and LMP1 allowed for bespoke racing engines and production based ones, and both have different engine package rules. In the case of P2, a 3.4 liter V8 was the maximum size and cylinder limit for a normally aspirated engine, while a 2.0 liter V6 is the biggest a turbo engine could go. A production based engine has a limit of 4.4 liters, but no one dared to try it for P2. During these days, a P2 engine would be in the range of over 500 hp: The Acura/HPD V8 found in the ARX series had as much as 550+hp in its various trims, according to Mulsanne’s Corner. The Porsche RS Spyder claimed of only having 503hp, but I reckon it could me more. Interesting provenances with the 2 engines as well; the HPD was derived from their successful Indycar engine program, while the Porsche’s was simply a whole new engine developed solely for the RS Spyder. Despite the lack of overall power and torque, the RS Spyder in Penske Racing’s hands humbled the factory Audi team in the ALMS in 2007, and was a constant thorn on the 4 Rings’ side until VAG decided to pull the plug at the end of 2008. Sadly, it became the momentum killer for the ALMS which continued until the formation of the TUDOR Championship.

In 2011, the ACO decided to overhaul the LMP2 specifications, particularly on the engine and cost part of the equation. Before 2011, LMP2 was seen as a lower-cost alternative to LMP1, but the advent of advanced LMP2 chassis like the Porsche RS Spyder and the Acura ARX series the cost and complexity to buy and run these cars went sky-high, far too high than the privateers the ACO wanted to cater. In came the cost capped parts and systems. The car also became heavier, also packing the same weight as P1 cars. And the move to an all-production based engine formula with engine power locked in at around 450hp. Normally aspirated engines are set at a maximum of 5.0 liters displacement, while turbocharged engines are pegged at 3.2 liters. The ACO has been frustratingly flip-flopping on diesel engines for LMP2, so it’s hard to get a bead on them. The most popular engines are the Nissan VK45DE, a well-developed, well-rounded, flat plane cranked engine with its origins from Super GT. Judd developed the BMW S63 engine-based HK V8, rumored to have the highest power output but the lowest torque figure. Honda Performance Engineering has the 2.8 liter twin turbo V6 known as the HR28TT, mainly found in Honda’s Accord. There are other engines as well, one seeing the light of day was the Roush-Yates developed Ford Ecoboost engine which ended up in Project Libra’s hands. Then it grew a bit more and was turned to a DP engine. The rumored Pilbeam coming from Africa will be using a Toyota 4.3 liter V8, and if you saw the article from Racecar Engineering, the Wolf LMP2 car rendering has Hyundai plastered over the rear wing!

In the Black Sheep Series, (aka Grand-Am), Bob Snodgrass, Jim France, Roger Edmonson et al. were trying to make prototype racing more affordable yet provide on-track action by the bucketload. They nailed the aerodynamics to a certain level, and shared parts were utilized, for starters. At the engine front, Grand-Am mandated that production based engines are used, with a shared, spec ECU from Bosch (post 2007). Forced induction was not allowed back then, all engines normally aspirated. Engine builders like Dinan Engineering, Roush-Yates, ECR, Lozano Bros. Porting and TRD all agreed that a massive, American-style V8 is the way to go for a DP engine, though Porsche still offered their flat-6 engine. Grand-Am had a nightmare balancing the Porsche flat-6 over the V8s that dominated the series. But along the way, the engines grew in stature and in power: DPs started close to 500 hp (the Porsche engine used by the Brumos Fabcar was rated at 475 for example), but has grown throughout its generations for BoP purposes. By the time of Gen 3, DP engines were rated at 550+ hp. DPs have shown slow but steady growth in the specifications and speed in the 10 years of Grand-Am, gaining over 10 seconds in Daytona since their debut in 2003.


credit: David Yowe

credit: David Yowe

When the decision to integrate P2s and DPs and the Deltawing into one Prototype class by IMSA was announced in 2013, it was met with apprehension and skepticism. These three types of cars are optimized on racing against the same type: LMP VS LMP; DP VS DP. Now the equilibrium has been turned on its head, and cars not used to racing against each other find themselves with new playmates. DPs have always been the slower formula due to its heavily cost-capped and controlled nature, but the consensus was to make them much faster. Some DP teams balked at the cost and backed out (GAINSCO, Team Sahlen’s, 8Star), some downsized (Starworks, Shank). The update package made the DP a more awesome machine and it still retained its raceability. Aside from the aero package, DP engine rules were also changed: Still retaining the production engine rule; DP engine sizes grew to a maximum of 5.5 liters for normally aspirated engines, the introduction of turbo engines, pegged at 3.5 liters, and surprisingly, turbodiesel engines at 2.5 liters max displacement. DPs also grew some more in power: 600 hp is the target limit.

For LMP2, IMSA thought they had to do some changes to make sure the P2 cars don’t run away from the DPs. If you would check the lap times in ALMS and Black Sheep Series competition, P2 cars have at least a 2-3 second advantage in circuits where both raced- and that was on rock hard Michelin LMPC tires! But then, on paper data is one thing, actual track experience is another. The DPs power advantage seemingly trumped everything the P2s had. IMSA retained all of the ACO specifications to the LMP2 cars, except two things: Use Continental slicks, and added a larger restrictor, around 5% bigger, to add even MORE power to the P2 cars. Post Watkins Glen, poor Scot Elkins was harangued by fans on Twitter (aka the same old people who want IMSA to fail because NASCAR) that the P2s are getting swamped on restarts and its IMSA’s fault, and IMSA is favoring DPs. Then Elkins dropped a bomb: At the start of the season, DPs were rated at 600hp. Now, they are at 570, which is close to 2013 power levels at Grand-Am. The P2 cars, ACO mandated at 450hp, are now pegged at 495, thanks to the 5% restrictor break by IMSA. Right now though the tires are clearly on the DPs side, as Tony Rizzuti told me on Twitter that the Gold and Black tires are the exact holdovers of the DP-I and DP-D tires respectively used in Grand-Am DP competition. But when it comes to the overall specification of the LMP2 cars in the TUDOR Championship, IMSA is doing whatever it can to make things more equal: the lap times have proven that, but it’s the way these cars find their speed that’s different. But why are the LMP2 cars not putting the filthy, prehistoric, and old DPs in their place, according to the purists? Well, you can point the finger to the ACO on that. 2011 LMP2 rules created by the ACO and the FIA was designed to be more accessible to privateer teams and gentlemen drivers. The older LMP2 specifications in the right track, with the right team, and the right conditions (*cough*Penske Porsche*cough*) are more than a match for an LMP1 car. Indeed, Penske was almost a full-blown Porsche factory prototype team akin to their work in Can-Am! Acura splashed a lot of money on their LMP2 programs as well with Highcroft, Andretti Green, De Ferran, and Fernandez! Mazda’s presence was with Dyson and with the defunct B-K operation, but it was nowhere close to what Porsche and Acura did. LMP2 was nearly going the way of LMP1, and the ACO sure thwarted that scheme. By making things more accessible and sustainable for teams, the ACO decided that certain performance level should be achieved. They attempted to do that with LMP1 with a target time around Circuit de la Sarthe, but the factories said “Screw the rules I have money” and proceeded to blast the ACO’s target time to smithereens. Do you know who complied? The privateers, who have little to no resources to develop their cars. Taking a page from The Black Sheep Series’ playbook, the ACO set up stricter homologation procedures and rules for car development and price caps, and most importantly, did a hard limit on engine power. Production based racing engines also work differently than a full blown bespoke racing engine, hence the sheer dominance of the Nissan VK45DE LMP2 engine over everyone. It’s just simply a well-developed, well balanced engine that came from the street to the track with some modifications for racing, not to mention it was developed in one of the most competitive series known to man-Super GT. IMSA is shackled to the ACO LMP2 homologation.

So what can IMSA do? Well they did the right thing in increasing power, but going even more can fall afoul of the ACO homologation, as well as a higher chance of grenading engines. I asked Jeff Braun about tinkering with the ECU of the P2 cars, but he said that it’s already a done deal: the ECUs are tuned for max power and the HPD guys know how to use it best. Strangling the DPs is probably the cheapest method, but with the DPs going much faster than they have been capable of I don’t think that’s smart. If P wants to position itself as THE premier class of the TUDOR Championship, they had better kept the DPs in its full engine power trim and balance the P2s to match it. The DP teams have spent a lot of money to be faster, I think the P2 teams can spend extra on power to make things more even. Aero is fine, LMP is already an aero-dependent formula. What I would like to see is this: IMSA should mandate its own engine rules for LMP2 cars. I want IMSA to grow a backbone and say to the ACO that your specification is weak on power and we will fix that.  Have HPD, NISMO, Judd, Dinan and future tuners comply. Have these engine manufacturers make an “IMSA-spec” engine for P2 cars which they can swap for an ACO-type engine for ACO series use. That way, an ACO-spec LMP2 engine won’t risk grenading itself in pursuit of power, while giving the P2 teams the flexibility to race IMSA and possibly ACO events. European teams looking in can purchase these engines if they want to do the Patron NAEC (or the Haywood Cup if you’re Sportscar Unleashed) or better yet, join the party in America. Let’s face it, WE are drawn to power. The DPs have done their share of the heavy lifting for the TUDOR Championship. Let the P2s get the power it deserves.

  • Louis

    Or make the DP’s use last years engine package which already had more torque and power than a P2 …

  • Jackson P

    Louis ^ No, the P2s are in need of new regs anyway, they’re not fast enough on the straights currently. I remember last year, the LMP2s at Le Mans were getting passed by GTs on the straights….

  • DoG

    Well the DPs are already at 2013 power levels…

  • Jackson P

    I’m not believing the 550 claim for last year’s cars TBH….But I don’t/didn’t follow Grand Am so they might have been up that high.

  • DoG

    Early season estimates that the Chevy V8 in Grand-Am was around 530hp (5.0 liter, 2013). Of course, Grand-Am was balancing it with other engines. Dinan’s BMW V8s has arguably the most power, but with less torque. Ford’s V8 is really rev-happy and is best on fast circuits.

    I started following Grand-Am during the Gen3 era, but thankfully a LOT of guys were there to show me the ropes.

  • Jackson P

    So they’re still 45 up from last year. And it’d be pretty pointless to take them down any more because that would make the new engine regs redundant anyway. So yeah I agree with your new-P2 point 🙂

  • DoG

    If Scott Atherton really means that IMSA will have links to the ACO and still has its own autonomy and identity, he should find the most decisive way to even the racing dynamics in P. Sure, they’re equal in lap times- but the racing dynamics could use a bit more evening out. They’re mighty close though!

  • Bit of inside info. The reduction on power in the Chevy DP’s is no way at 570hp. Maybe the Ford after their win in long beach and Sebring got brought down there, deff not chevy’s. The LMP2 there is no way we are running at 590hp. According to Zytech, our engine builders, we are maybe getting 15-20 hp more with the 5% bigger restrictor. putting us at 415ish. (barely indy lights power) There is a small issue with nissan powerplant and is that it was built and design to run with the small restrictor, any more and It just wont make any more power. To make power we would need to run more RPM but the Engine cant take it. We are stuck with what we got here power wise. HPD we believe is making more power than us because they just manage boost psi. They come off the corners a lot quicker than us but we catch up at the end of the straights because our onroak/morgan has less downforce and drag.

    The tires is a big problem, Conti tires are designed to work very well with the heavy DP’s. We cant make the tires work well in low to mid speed corners, therefor, we have a power disadvantage on the slow stuff, giving us crappy mid corner speeds, and even crappier exits due to lack of power.

    The fix is easy and I dont know how they have not applied it. Remember 2012 24 hrs of daytona that the Gen 2 body had less drag than the gen 3 and was way quicker on the straights? What did they do? they threw a good ole block in the back to slow down top speed by 3-5 mph (at daytona, any other track would be 2-3mph). This is the only thing we need to get everything working fair again I believe. This or a handford device. Easy, cheap and fair.

    thats my humble opinion.

  • DoG

    I am humbled. Thank you.

  • mkistler

    @Gustavo 1) Thank you for reading 2) Thank you for that info, all great stuff and it’s always awesome to read some insider views

  • DoG

    And another thing Gus: I asked Elkins about tweaking the rear spoiler found on DPs for drag, but he said that adding aero could cause an imbalance so they’re focusing on tweaking the power.

    The aero-block and the Handford device could work.

  • Anonymous

    Dp’s have as much front downforce as they can add. Giving them more rear downforce would make it an understeering pig. Blocker or hanford device does not affect downforce balance. Just adds pure spanking drag.

  • DoG

    I’m not so much a fan of aero treatments, because these cars should go FAST and be loud. I would prefer engine tweaks, but if IMSA could use these aero devices and make for better racing I can’t complain.

  • Jackson P

    Gustavo, your LMP2s were at 450 horsepower last year. So even with your 15-20 horsepower boost, the cars still make 470 horsepower.

  • my bad got confused a bit. Its got half a fiat 500 more power than an indy lights car 😉