Any engine rule change affects hundreds of engines needed during a full season of racing.

NASCAR is serious about reducing horsepower as well as adjusting the aerodynamics in the Cup cars to improve racing from a fan’s point of view. That means creating conditions that encourage side-by-side racing and increasing opportunities for passing.

Engine builders from EarnhardtChildress and RoushYates participated in a panel discussion at last year’s AETC conference. From left, Danny Lawrence, Robert Yates and Doug Yates.

Following the Pure Michigan 400 at Michigan International Speedway, where qualifying speeds were over 206 mph, NASCAR officials held a day-long test session with 10 teams to evaluate six different configurations — all with the eventual goal to tighten up the racing. The different setups altered downforce, changed rear gearing, increased tire grip and, of course, lowered horsepower.

“Our main goal is to harvest data today to help refine the 2015 package,” says Gene Stefanyshyn, NASCAR vice president of innovation and racing development. “We are listening to our fans, they have said they like a lot of passing, side-by-side racing and lead changes. That is what we are aiming to accomplish with these tests.”

More than 160 laps were turned at Michigan by each team. Data will be taken back to the Research and Development Center in Concord, North Carolina to be analyzed and modeled as NASCAR finalizes its 2015 rules package for the NASCAR Sprint Cup Series.

Teams participate in engine and aerodynamic tests at Michigan International Speedway. NASCAR photo-Robert Reiners/Getty Images

Options for reducing horsepower

But crews in the engine shops were watching closely as NASCAR tested three power levels by utilizing different sized spacers that restrict air flow into the intake manifold. Published reports said power levels of 850, 800 and 750 horsepower for the tests were achieved with the use of restrictor plates — but officials have indicated other methods are available to actually detune the engines for next year’s racing. One solution often discussed is reducing the size of the throttle bores in the EFI throttle body.

One solution discussed is a tapered spacer between the throttle body and intake manifold. These are already used in Nationwide and Camping World engines.

One option that doesn’t share favor with engine builders is decreasing the 358ci displacement. Last year at the Advanced Engineering Technology Conference held just before PRI, engine builders Doug and Robert Yates of RoushYates Racing Engines and Danny Lawrence of ECR Engines were part of a panel discussion and group Q&A. EngineLabs asked the trio about their reactions to downsizing rumors and how they would handle any rule changes. Following is a transcript of those answers:

Danny Lawrence: Back in the day when we knew the names of every one of our engines, it would have been easy to do. It would just about be devastating to us if NASCAR came in and said, ‘hey, we’re going to run 300 cubic inches.’ Believe it or not, we’re trying to make the racing better. We are making so much power, it’s hard for the guys to drive the cars at the speeds they’re at.

The eventual goal of the 2015 rules package is more passing and side-by-side racing. NASCAR photo-Jeff Curry/Getty Images

Adapting to rules

Lawrence cont: Whenever NASCAR makes a rule, we try to react to have the best engines we possibly can. [at an earlier 2013 test] they ran tapered spacers to try and slow down the cars. Took out 100 to 125 horsepower, and all the drivers were screaming. In my book, there’s only a handful of really good drivers out there. And what they’re trying to do is equalize everything, and it’s not going to happen.

Still, we are making a lot of power and we are going to do anything we can. If they come out with a tapered spacer, I’m sure we’ll pick up.

Decreasing the diameter of the throttle bores in the EFI throttle is one possible change discussed to reduce horsepower in NASCAR engines.

Believe it not, we, ECR and RoushYates, we actually work with NASCAR to help them figure it out, so they don’t just come in and say, ‘hey, we’re gonna do this or that.’ At our shop we’ve already messed around with smaller throttle bodies, just so we have some input.

When NASCAR decided they were going to do the fuel injection, we had multiple meetings to help them figure it out, because it was a direct reflection on us. It always works this way. They told us, the owners, it’s gonna cost about $500,000 to do this deal. I can tell you on our side, it really cost us about $1.5 million per car for the first year. The throttle bodies that Holley makes, we run the same ones over and over. They’re $2,500, but by the time we get through working on them they’re $4,000 for one throttle body.

Everyone has an opinion

Lawrence cont: That’s just the nature of the beast we live in. Whenever they say, ‘okay, we’re gonna take a little power away or we’re gonna try to do this,’ if we don’t work with them, and if in the racing nobody ever passes anybody, then we don’t have a job.

Gene Stefanyshyn, NASCAR vice president of innovation and racing development. NASCAR photo-Robert Reiners/Getty Images

Everybody has a philosophy. If we just do this, the racing will be way better. We have done everything that you can absolutely think of, and NASCAR has too, except for turning the cars around and making them run backwards. And if we thought that would work, we would do that too.

Back in the day at Darlington when the tires were smoking and you’d have a bad pit stop and get two laps down, you could make ‘em up. That doesn’t happen anymore. If we could figure out how to make it that way, to where if your car’s really good you could make laps up, I’m sure Doug and Robert and I would sure be for it.

Even though bore centers have increased with the latest generation of engines, the displacement remains at 358ci.

It’s really a hard question to answer, how are we going to do it. I don’t know how, but taking all the engines and all the inventory that we have, I don’t believe our company or these other companies can stand scrapping every thing we got. So we’re trying to help NASCAR figure out how to do it without breaking all these teams.

Robert Yates: What I would do, but i’m not doing it, so everybody relax. The valve spring would be out of here. I’d put in a pneumatic valve and they’d probably make 700 horsepower.

Doug Yates: In the 20 years I’ve been involved in this with same cubic inches, 358 cubic inches. When I started we didn’t have the compression ratio rule, we were making 650 horsepower. Today we’re making over 900 horsepower. So there’s a lot of smart guys working on this thing. I don’t know what they’re going to do, but racing is about advantages, and that’s why everybody is here, to learn something and go try to win some races.

Jeff Gordon won the Michigan race after qualifying at over 206 mph. GM photo.