What’s really behind Team Penske’s ‘illegal’ parts

Pole qualifying for the Indy 500 took a dramatic turn as the Team Penske cars of Josef Newgarden and Will Power were pulled out of line due to unapproved parts at the rear of the car. The resulting action for the infraction sent both cars to the back of the field. All focus has been on the modifications to the rear attenuators on the No. 2 and 12 cars, but there is much more to this story. Not because the modifications are new, or just for the 500. They have actually existed for over a year and made appearances at multiple types of tracks. 

What is a rear attenuator?

In order to understand what transpired at Team Penske, we need to start with the function of the rear attenuator on an IndyCar. This rectangular piece sits at the back of the car and is attached to the gearbox where it serves two basic roles. Its primary role is to absorb impact in a crash and reduce the g-forces felt by the driver. It also serves as the mount for the rain light assembly.

The current base version of the rear attenuator was revealed by IndyCar in February of 2023 and was the biggest upgrade to the part since 2016 as Dallara was able to improve their Finite Element Analysis (FEA) tools and design a longer part that could reduce impact to the driver as noted by Tino Belli, director of aerodynamic development for INDYCAR at the time.

“The whole concept is to try and bring the peak G’s down, make them even lower and even spread the crush over a longer distance. This attenuator is longer than the one we have now. Dallara’s FEA – Final Element Analysis – of crushing structures has got much better over the years, so they were able to model it much better virtually before we took it to an impact test.”

The earliest batch of those rear attenuators that was released to start the 2023 season looked different than what we see today at Indianapolis as the smoothed panels in question for the Team Penske penalties did not exist yet. 

Dallara IndyCar bulletin concerning the required modification for the rear attenuator for the Indy cars, 2023.

Photo by: Dallara

The attenuators went through a number of updates during the 2023 and 2024 seasons with the first mandatory update coming in May of 2023 that required teams to return attenuators to Dallara in order to strengthen them internally after issues in races early on in the season.

Dallara updated bulletin for IndyCar regarding mandated Indy 500 rear attenuator modification, 2023

Photo by: Dallara

Another bulletin was released just a couple of weeks later and instructed teams to remove the new attenuator and revert to the 2022 version at the direction of IndyCar for the 2023 Indy 500. Teams were instructed to modify these older attenuators in order to fit mounting parts from the newer version.

Another bulletin from Dallara issued in 2024 on mandatory modifications needed for the rear attenuator

Photo by: Dallara

The new version of the attenuator saw its biggest change at the start of the 2024 season as a mandatory update required panels to be bonded internally and externally in order to make the attenuator stronger based on FEA analysis. The bonded panels on the outside that are in question in the current Team Penske penalties make their first appearance here as attenuators are sent back to Dallara in order to have those panels added.

Prior to this update the attenuators were one smooth piece, but now these carbon panels are glued to the outside in order to improve strength of the overall piece. The illustration above shows what the attenuators looked like prior to the start of the 2024 season and also highlights the new external panels in the illustration in blue.

What happened at Team Penske

According to multiple sources that aren’t authorized to speak publicly, Team Penske started receiving these updated attenuators back from Dallara in early 2024 and members of leadership were not pleased with the aesthetics of the new glued-on panels as they showed a bright glue line that stood out and with a large raised edge. A member of the technical leadership is rumored to have instructed members of their team to “clean up” the edges on the pieces in order to make the bright glue stand out less so these technicians applied a dark compound to the edges and smoothed them out.

Once these attenuators were modified, they were cleaned up and coated with sealer – per the standard procedure for many carbon fiber parts at Penske – and placed into their parts rotation to be installed on the cars to start the 2024 season.

Scott McLaughlin with his P1 award for starting pole for the 108th running of the Indianapolis 500, 2024

Photo by: Penske Entertainment, Chris Jones

How long has Penske been using the modified attenuators?

Based on discussions with a variety of industry figures and Team Penske personnel, these modified attenuators have been in use for well over a year. We dug through the IndyCar photo archives and were able to find an easy example of a modified attenuator on the back of the pole winning car of Scott McLaughlin at the 2024 Indy 500 as seen below.

A close-up of Scott McLaughlin’s rear attenuator from the photo above taken after he earned pole for the 2024 Indy 500.

Photo by: Penske Entertainment, Chris Jones

We’ve slightly zoomed into the area in question and it is clearly visible that there is a smoothed area from the rear edge of the bonded panels to the main attenuator assembly. Additional digging shows that the modified attenuator appears at a variety of tracks on the Team Penske cars as we can see in the photos linked below which show a similarly modified attenuator on the back of the No. 2 of Josef Newgarden after a crash at Road America: https://x.com/FormulaIndy/status/1800210075279348002

Industry members have spotted the same modified pieces at a variety of tracks in 2024 including on the back of the Indy 500 winning car of Newgarden which now sits at the museum at Indianapolis Motor Speedway where multiple have gone over in order to document the piece that was installed on the back of it.

Where did IndyCar’s technical inspection fail?

The fact that Team Penske has been running modified attenuators since last season, but has only been penalized now, brings the IndyCar technical inspection process into question. How did these parts get missed by technical inspectors for so long if they were so blatantly illegal? IndyCar Technical Director Kevin “Rocket” Blanch spoke to media at Indianapolis Motor Speedway after the No. 2 and No. 12 cars were pulled out of line.

“Well there was a body fit violation on that rear attenuator so as quick as this process happens we ran them through tech, we got everybody in line and then right near the end or prior to qualifying they decided they would just pull out of line.”

Blanch did not elaborate on their discovery, but according to reports from the track, the No. 12 car was sent to pit lane after passing through technical inspection, but the No. 2 car was eventually stopped for the modified attenuator. At that point, the No. 12 car was rechecked and found to have a similarly modified part. Team Penske technicians decided to attempt to clean up the parts to bring them back to the original specification, but IndyCar technical inspectors did not approve of that work as it is outside of the allowed changes once you are past technical inspection and in line to qualify. Rule 8.5.6 states: “While the Car is in the Qualifications line, an Entrant’s representatives may make front / rear wing angle, endplate angle and Tire pressure adjustments only. The Car must be moved as the Qualifications line progresses. A Car must not leave the Qualifications line without the approval of INDYCAR.”

According to multiple sources in the IndyCar paddock, the only reason that the modifications were discovered at this specific event was due to reports from other competitors to the IndyCar technical department urging them to check the Team Penske cars. This shows a failure of the technical inspection process as the parts have gone through over a season’s worth of technical inspections without ever being discovered until it was pointed out by a competing team.

Did Team Penske gain an advantage from the modified parts?

Smoothing out bodywork on a race car will often lead to speed as it can allow air to flow in a smoother manner over the car and reduce drag so the first assumption is that a smoothed out attenuator could be a performance gain but discussions with industry experts prove otherwise. 

Discussions with engineers, body fit specialists, and drivers all led to the conclusion that there isn’t laminar flow across the sides of the rear attenuator which means that the airflow over the car isn’t close enough to the side of that attenuator for a rough step or smoothed out transition on those pieces to make a difference to the airflow coming off the back of the car. The fact that the modified attenuators were found on road courses as shown in the images above also appears to corroborate these theories since the modified parts were installed outside of ovals where drag isn’t a focus as much as we see it at places like the Indianapolis Motor Speedway.

Was Team Penske penalized too harshly?

The cars of Josef Newgarden and Will Power were initially pulled from the pole qualifying session and allowed to retain their position in the Fast 12, but after additional evaluation by IndyCar officials, they were sent to the back of the field and will now start 32nd and 33rd. Based on the IndyCar rule book these penalties were likely too harsh as rule 8.5.13.1.7 states that “The results of Day 1 Qualifications when thirty-four (34) or more Cars have entered the event shall determine: 8.5.13.1.7.1 Positions one (1) through twelve (12) have secured a starting position and will participate in the “Top 12” group on Day 2.”

Additionally rule 8.5.13.2.6.5 states that “Any Cars not able to begin or complete a required Qualifications attempt shall be ranked at the rear of the “Top 12” group in order of Day 1’s Qualifications times.”

Based on the rules above, the No. 2 and No. 12 cars had secured their way into the Top 12 as soon as the scoring sheet from the first day of qualifications was signed, so the strongest penalty they should have received was to be scored 11th and 12th based on the wording of the rule book. IndyCar officials used their discretion in order to go above and beyond what is explicitly written in the rule book, likely due to the nature of the prominence of the race and the point at which these items were discovered.

Did Team Penske violate the rules?

IndyCar technical inspection may have failed to discover the modified parts for months and likely penalized the two Team Penske entries a bit too harshly. Looking closely at the wording in the rule book, the parts were indeed not up to the listed specifications. 

Rule 14.7.8.16.1 has a very explicit list of parts that can be modified an states that “The following parts may be blended to reduce uneven surfaces and gaps. Hard edges may be tapered or blended. These parts must remain separate parts and there must be a distinct joint line defining each part from its mounting surface or part(s). They must detach from their mating part(s) with the removal of the Tridairs or bolts. All intended shapes and radii must remain as designed. No tongue-and-groove, dovetail, or other types of body fitting will be permitted. Extra fasteners are permitted.”

The listing of that rule has sixteen lines worth of parts that are allowed to be modified and the rear attenuator is not on that list, which means that Team Penske violated this rule when they smoothed the transition on the rear attenuator.

The best case scenario for enforcing this rule would have been for IndyCar officials to catch the changes when they first appeared on track last season and penalize them with a monetary or points fine at that time similar to what we see for Prema’s recent penalty for modifying a spec part. Since this modified part was missed for so long and only discovered at IMS this week, IndyCar technical officials also had the option to tell Team Penske to swap the parts for conforming ones during any of the earlier technical inspections during the week. Unfortunately it appears that the parts were not discovered until competing teams raised alarms with IndyCar technical inspectors so the situation reached a bad scenario that was made even worse by Team Penske technicians attempting to return the parts to original spec.

Why did McLaughlin’s car not get penalized?

The No. 3 car of Scott McLaughlin was the only car that escaped penalties this week and that is due to the fact that it had an unmodified rear attenuator as confirmed by IndyCar after they seized the parts from his original Indy 500 car which was involved in a crash. According to internal sources at Team Penske that are not authorized to speak publicly, the No. 3 car had an attenuator from the latest batch that had come from Dallara and no modifications were made to it as technical leadership was pleased with the fitment of the externally attached panels and did not see unsightly glue on the edges so technicians made no changes to those parts.

The No. 2 and No. 12 cars were using attenuators that were from an earlier batch and had been cleaned up and resealed and then put back into service after use in previous races. Attenuators don’t typically get removed from services unless there is crash damage to the car that may compromise them so it is not surprising to see them cleaned up and reused multiple times.

Once the modified attenuators were identified and banned, Team Penske pulled additional attenuators from the latest batch that they received from Dallara and installed them on the No. 2 and No. 12 cars.

Other penalties

Many have called for additional penalties such as removing the cars from the race or removing past wins that may have involved those parts, and my belief is that those calls go way too far — much like moving the entries to 32nd and 33rd went too far since the results have been signed off. Especially because the cars used in those races are not longer available to be checked.

What IndyCar should do in the future…

It’s unfortunate that one of the biggest stories of the week is focused on a part that was likely modified for aesthetic purposes but Team Penske violated an explicit rule from the IndyCar rule book and even though they may not see a performance advantage from it, they still made changes to a single-source part. Team Penske representatives should have presented the parts to IndyCar officials if they wished to modify them and gotten approval before doing so.

IndyCar technical inspectors also bear some responsibility in this whole scandal because they missed these modifications for over a year and only penalized Team Penske after competing teams raised alarms during the biggest race of the year. Technical inspection procedures should be evaluated for the future and they should consider introducing digital imaging of bodywork as seen in other major series like IMSA and NASCAR which can quickly catch any body part that might be out of spec. IndyCar should also consider implementing a parts repair portal similar to what NASCAR has done in order to streamline approvals for any repairs or modification to single source parts.