The RACER Mailbag, July 3

Welcome to the RACER Mailbag. Questions for any of RACER’s writers can be sent to We love hearing your comments and opinions, but letters that include a question are more likely to be published. Questions received after 3pm ET each Monday will appear the following week.

Q: Been following racing of all types for my whole life. Kind of miss the unknown possibilities of a blown engine during a race affecting the outcome with these almost bulletproof engines (unless it was someone I was rooting for).

I’m looking forward to attending another fun weekend with the IndyCar circus and other fans at Mid-Ohio, and wondering what (if any) type of problems do the new hybrid systems bring to the power trains? What can go wrong with them that could cause some type of engine failure?

Mike Nikishin, Burgettstown, PA

MARSHALL PRUETT: We’ll need to hold the first hybrid race to have a better idea on the issues that might arise. Thousands and thousands of testing miles have been completed, but we’ve never had a full race distance done with 27 cars, and with contact between cars and all the other normal things that happen and go wrong between the green and checkered flags that can shake and rattle the ERS.


We could have an ESS or MGU failure. An ESS problem wouldn’t necessarily be the end of the world, but a seized or broken MGU, since it connects to the motor’s crankshaft via the input shaft, could lead to may hem. Overheating of the ERS unit — ESS or MGU (or both) — could cause failures.

The MGU is the main area of sensitivity at the onset of hybridization. There’s nothing wrong with the thing, but IndyCar doesn’t want to push it too hard, which is why the power figures are being kept somewhat low. When IMSA went hybrid, there were expectations for all kinds of ERS problems, but it never developed into a serious issue. There were occasional hiccups, but nothing widespread.

Famous last words for me here, but IndyCar’s final-spec ERS has done a lot of running and the reliability has been quite good, so based on that reality, I’d expect Mid-Ohio to continue the trend. Said another way, it would come as a surprise if all of the reliability we’ve seen with the final-spec ERS goes out the window and leaves us with half or more of the field sitting parked and smoking on the side of the road on Sunday.

Q: I realize the charters are a foregone conclusion at this point in IndyCar, but I just don’t understand why the series has been so hellbent on adding them? I totally understand why the teams want them, but it doesn’t make much sense to me from a series standpoint — it’s not as if it is struggling to attract car owners and interested teams right now. Why go through all of this trouble, turn away potential interested parties, and reward charters to the incumbent teams? They don’t have charters now, and those same teams show up every week and there is a full grid. If this was 2007, I could see how charters would hold value for the series at a time when it was tough to get a full grid every week, but are they really worried that a bunch of teams are going to up and leave now without a charter system in place?

I would much rather the series embrace the opposite stance and lean into competition — embrace bumping! You could run road and street course qualifying with Round 1 split into three groups — the top two from each group automatically advance to the Fast 6. Bottom two or three from each group go into a Last Chance Qualifying like Indy for the final spots on the grid, which would be in place of the now-moot Fast 12 segment. It would certainly make qualifying even more exciting and would force teams to up their game if they want to continue to play — which can only be good for the product, considering it’s a professional series.

Matt, Nazareth, PA

MP: I’ve had the same struggles to find the overwhelming reasons to create charters, but we do know that team owners would like to have their entries protected, so guaranteeing starting positions in every race — except, thankfully, the Indy 500, which they backed away from after receiving a big backlash from fans — is something they will receive.

And attaching a free-market monetary value to their entries is another thing they won’t turn down, so that’s what they’ll get as well. It all fits with the spec-minded direction the series has been on for many years. Strip away as many areas that you can where failure could exist, like multiple tire suppliers and multiple chassis suppliers, so nobody is at risk of picking the wrong vendor, and that way, you’re all but guaranteed to be able to compete at the highest level.

It’s also protecting your ability to compete in all but one race while letting the newcomers be the only ones at risk of failing and potentially going out of business. That’s not the spirit of racing I fell in love with.

Minus the guaranteed starting positions, the charter works for me, but maybe I’m looking at it the wrong way.

Charters have obvious benefits for the teams, but perhaps at the cost of competition. Phillip Abbott/Motorsport Images

Q: As an engineer, I have no problem switching between U.S. and metric units to make comparisons. However, a lot of fans on social media are utterly befuddled by IndyCar’s insistence on using the longstanding U.S. units for power and torque for the ICE but metric for the ERS. To be honest, I think that is deliberate obfuscation to cloak just how impotent this ERS is in practice versus all that was promised.

Power is torque times rpm, plus any necessary conversion factors. 30 Newton meters of torque at 12000 rpm is equivalent to just under 51 hp, woefully short of what the originally stated goals were at the out-set.

The series will allow 105 kJ of energy deployment per lap at Iowa. That’s equivalent to 50 hp for 2.8 seconds, assuming that the driver is able to harvest and deploy that much with everything else going on during an 18 second lap — and a 100% efficient MGU, which we know is not possible.

A standard rechargeable lithium battery pack on a homeowner-level weed whacker is 30 watt-hour capacity. One Wh equals 3.6 kJ, thus that pack contains 108 kJ energy. Obviously, I don’t expect Hinch to be making that comparison on screen, even though it is realistic.

A gallon of E85 contains about 94,000 kJ of heat energy, and a turbo engine at full throttle can reach 40% efficiency in converting heat energy to kinetic energy at the driveshaft. 105 kJ is only about as much en-ergy as the ICE puts out the back end from burning 0.14 ounces of E85.

I’ve been a fan of the series since the turbine era, and I’m having a real hard time understanding the hype around this “development.” It’s a mass of complication with precious little benefit versus allowing a little more turbo boost, OEM marketing efforts be damned.

Steve Jarzombek

MP: I hear you, but there are a lot of constraints IndyCar gave itself by sticking with the same chassis since there was no space to build a stout high-voltage lithium-ion battery solution. Left with a small void to fill in the bellhousing, what Chevy and Honda came up with is, as I’ve said many times, a marvel of packaging. But due to the extreme limitation of space to fit an ESS and MGU, they weren’t able to make a monster ERS that delivers giant horsepower and torque.

The series says it could go as high as 150hp with the unit one day, so that would be great. But it’s starting at a modest 60hp and 33.2 lb-ft of torque to maintain the reliability it’s achieved with the MGUs.

First and foremost, this is a marketing exercise, not a deep technological exploration by IndyCar, Chevy, or Honda. It’s to give its current and hopefully more auto brands in the future the relevance they need to stay in or join the series. So far, from 2013-23 (and half of 2024), no manufacturers wanted to join IndyCar while it was non-hybrid.

The new ERS package might not produce the staggering performance we’d hoped — at least at the outset — but I’m but focused on what the move to hybridization could do to bring more car companies into the series.

On the units of measurement, I’ve conveyed the concern and need for the series to Americanize everything related to the ERS units. Newton-meters and kilojoules just don’t jive here, so let’s hope the advice was taken.

Q: Any chance the Milwaukee race will again be named after Rex Mays? And here’s a future scenario: Open engine competition either with ICE, hybrid, electric or hydrogen. May the best technology win!

Isaac W. Stephenson

MP: Doubtful. Also, every IndyCar fan under the age of 50 who just read this said, “Who’s Rex Mays?”

Q: Have you ever seen a 40-minute race run without a single green flag lap completed? The first Mustang Dark Horse race at Watkins Glen was. Yes, the Mustang hit the guard rail a ton, but with no real TV time constraints, the race should have been red-flagged for repairs! At least reset the clock for 15 minutes of green flag racing.

Now to the 6 Hours. A simple tow in, like the ERA LMP2 car on lap five, should not be a safety car. A WEC FCY would work fine there and save 15 minutes of green flag time. Does IMSA have any thoughts on that? To their credit, they did try three laps under green to allow the car to resume, but then threw the safety car. And I understand it was early in the race, but we come for green flag racing.

Next was the red flag for the rain. Never saw a wake that impressive from a GTP car going 10 mph! Yes, the red flag was required, but it certainly seemed like a long time was needed to get the race under green again. In addition, again with no TV, why wasn’t the time added back on, like at the Spa WEC race?

For the fans, from The Boot.

MP: IMSA isn’t WEC, so I wouldn’t expect IMSA to start making things up and running its races like WEC. At least for how most things work here, series are given a maximum window of time from their broadcaster, and yes, there are exceptions, but those are rare. NBC broadcast the race, and it ended on Peacock.

Then you have things like the 1000-plus people in the paddock with the teams, and those who fly in for the weekend for IMSA, and the volunteer course workers. who need to go about their lives, catch flights home, get back to their day jobs, take the kids to school Monday morning, and so on. I get that six uninterrupted hours of racing wasn’t produced due to crazy weather getting in the way, but I’m not sure the racers need to have their lives turned upside down, miss their flights, etc., just so the racing time lost to weather can be run.

Q: I’ve done a bit of research on racing damper development after having several people explain how important it currently is. I asked an IndyCar team member what kind of parameters they measure and got led down the path of inerters. Can you explain in non-engineering terms what they are trying to accomplish? My understanding is that they are attempting to separate suspension inputs induced by roll from the vertical squish and rebound from the tires. Is that correct and, more importantly, what does that mean in the cockpit? Are there yet more areas of interest beyond this and old-fashioned jounce and rebound?

Jack Smith

MP: You’ve summed up the areas of influence by inerters, which are cool little devices inside the dampers that look like a threaded screw with a threaded weight that spins up or down depending on the movement of the shaft. Independent of the vertical forces the suspensions experience while pounding up and down over curbs that are managed by the dampers and springs, you also have the warbling movements and oscillations of the tires on the rims, and that’s where inerters come into play as a device to try and manage and minimize the disruptions to the tires vibrating and deforming.

I think of inerters like noise-cancelling ear buds/headphones. They detect the frequencies of the noise and do their best to match and minimize them with opposing frequencies. Teams use inerters to try and produce the same neutralizing effect with the disruptive frequencies tires experience over rough roads and curbs, and if they can find and match the vibrational frequency, they’ll have a more consistent contact patch between the tire and road.

Q: I watch IndyCar on Peacock: practices, qualifying, and the races. I think it’s a bargain, and don’t see why others complain about network coverage when there’s a simple solution with Peacock. My only complaint is, it seems like it’s about 70 percent engine noise, and 30 percent announcer voices on the volume scale. Makes it very hard to understand the commentary. Is it me and my TV, or the same for everyone?

George, Seattle, WA

MP: It’s not just you. The audio mix on Peacock, which is different than the broadcast mix, is something that has received many complaints in recent years.

Q: Have you ever driven the original public road courses at Elkhart Lake and Watkins Glen? If so, what was your impression of them? I think that those racers back then had to be crazy!

David K., Coventry, CT

MP: Just in Watkins Glen, and yes, insanity was required. But that was the norm back in the day. Today, we still have it with most WRC events where hitting trees, boulders, or plummeting off the sides of mountains are part of the accepted risks.

Q: Since the contract between McLaren and Pourchaire apparently isn’t worth the paper it’s written on, what about Palou’s contract? Double standard?

Doug, Texas

MP: Meh. I’d be surprised if Theo isn’t being paid whatever amount McLaren said they’d pay him to finish the season. Palou not only agreed to drive for McLaren, but he signed a contract and is alleged by McLaren to have taken advance payment on his services. I don’t see the commonality between the two.

Aside from reality not quite going according to the script, the Pourchaire/Palou/McLaren scenarios have little in common. Jake Galstad/Motorsport Images

Q: IMSA uses a BoP process of weight and air restrictors. WEC’s BoP uses a torque sensor. I understand weight and air restrictions to try to equal the BoP, but how does the torque sensors work to provide BoP? I read that IMSA is looking at going to the torque sensor method.

Frank, Mooresville, NC

MP: IMSA has used torque sensors on its GTP hybrids since January of 2023; the WEC did its first race with the same torque sensors in March of 2023 with its LMDh (GTP) and Hypercar models.

The difference today is the WEC is also using torque sensors on its GT cars, which IMSA will be doing in the near future as well. The sensors give both series an accurate and immediate read on the power being put to the ground through the rear tires, which is helpful while making informed BoP decisions. Think of them like little onboard dynos. The sensors attach to the rear axles and the bearings inside the sensors clamp to/are spun by the axles.

On the GTP side, the torque sensors are also used to instruct the engine to stay at or below the 680hp power limit for the class. If there’s a big surge in engine power or energy recovery power, the torque sensors provide live input to the ECU and tell the engine to pull back however much is needed to always maintain the 680hp limit.

Q: The problem with the closing of the pits for a full course caution is that race control’s decisions to go full course seem to be arbitrary and inconsistent. Sometimes it is immediate, and sometimes they make sure everyone has been able to pit. This could be easily resolved. Unless the incident is affecting the pit entry or pit exit, the pits remain open. As soon as the race goes to full course caution, the drivers must maintain a predetermined speed or delta time until they catch up to the pace car. This will also eliminate the announcers going on and on about the “danger zone.”

Since this rule change would be fair to all drivers and is easy to implement, IndyCar will never go for it. Maybe you have already talked to the drivers about this, but are any drivers in favor of closing the pits for a full course caution? From the interviews I have seen they all seem to hate it, but maybe you have more insight.


MP: It seems to change every year or two. Process-wise, IndyCar holds its winter meeting with drivers, and as I’m told, the latest efforts to build a consensus had the series wanting to close the pits immediately, but a majority of the drivers said to keep it open. That could change again during the offseason, of course.

Q: Is there any connection between Andy Petree’s sudden and immediate retirement and RCR’s on-track performance this year?

David, Waxhaw, NC

KELLY CRANDALL: While I can’t say those two are directly connected, I think the timing is certainly interesting — it’s not common to see someone retire in the middle of the season. I will also point you to my conversation with Keith Rodden from last week — I felt some of his comments were pretty telling.

From Robin Miller’s Mailbag, July 1, 2015

Q: In your message to Mark Miles, you wondered if anyone was watching the Fontana race at home since only 3,000 attended. I watched it, but I had intended to record it. My wife and I were up on the scaffold painting our house when I left to record the race. I wasn’t expecting much from 23 cars on a big oval for 500 miles. I pressed record and heard Dave Despain’s golden voice give the command to start engines. I thought, that’s a good start. I’ll just watch the first 10 laps live until the field gets strung out, just like Dixie predicted, then I’ll go back painting.

A half an hour later my wife came in yelling at me for leaving her on the scaffold. She calmed down and for the next four hours we watched the greatest IndyCar race I had ever seen, not including Indy 500s. We wasted some expensive paint and brushes, but it was worth it because as much as I was spellbound, there was a little voice in my head that said, “When this race is over, IndyCar will make sure we’ll never see this racing again.” Will we see that kind of racing again? And you mentioned in your message to Miles that you thought Fontana was one of the top five races you’ve ever seen. What are your top five?

Gerry Courtney, San Francisco, CA

ROBIN MILLER: So, in other words, it wasn’t like watching paint dry? It was a can’t-look-away race that nobody saw (at least in person) and that was the real tragedy. I guess 1982 Indy 500, 1995 Michigan 500, 1960 Indy 500, 2000 Michigan 500 and 2014 and 2015 Indy 500s.

Story originally appeared on Racer