When NHRA’s Factory Experimental concept hit the drag racing community, it did so with rave reviews and great anticipation. However, a little over a month later, the iconic Factory Experimental designation no longer exists.

NHRA has given the extension of Factory Stock Showdown and possibly the new redesign of its Pro Stock division, a trendier designation.

Call it Factory X, the artist formerly known as Factory Experimental.

“It went through AFX, it went through Factory Experimental, but Factory X will be the official name of the class,” said Lonnie Grim, NHRA’s National Tech Director. “Factory X will be presented by Holley.

Make no bones about it. Factory X is the grandchild of the classic designation that manufacturers were allowed to play fast and loose with the regulations handed initially down in the Super Stock divisions.

“Factory X was the original name in development when we started this class. Then the whole AFX, which had, for the ones of us that have been around NHRA, and have bled some NHRA blood over the years, loved the history of the NHRA. The AFX, or Factory Experimental, through the fifties, sixties, and seventies, was a very lucrative term to NHRA because to NHRA and the fact that OEs were involved, privateers were involved.”

“The Factory Experimental [designation] meant that manufacturers didn’t have to build 50 cars. Manufacturers could just build one, as like the Hemi days or the ZL1 Camaro days. The Factory Experimental ended up really evolving into Funny Car with the altered wheelbases and that kind of stuff. And so along the path, we thought that the ones of us who live and breathe the history of NHRA; this is really the modern-day of Factory Experimental, so it made sense. So as this evolved, the name kind of fell into AFX.

“[We felt] maybe that would work, and because it was only one if you had another manufacturer that said, ‘Hey, we want to put this motor in this car, and that’s our Factory X, our factory experimental.”

“In the history of NHRA, that worked well. It seemed to have some heritage to it, but this thing continued to evolve; it was looked at again that for its direction is not altered wheelbase, it’s not going to become a Funny Car. So there were many kinds of holes you could throw into the AFX or the Factory Experimental. So that’s why it landed back on Factory X. Factory X appears to be modern; it’ll still have people call it experimental, it’ll still have other names, but its official name landed back at Factory X.

NHRA has released some clarifications to the Factory X ruleset, which Grim has clarified.

Grim understands the Factory X class will attract new participants, possibly from Pro Stock, Comp, Super Stock, Stock, and even Factory Stock Showdown, where SFI chassis specs limit the cars to 7.50-seconds or less.

“We know this from an internal Stock, Super Stock standpoint, but the general public may not be as aware of the Stock, Super Stock rules for the engine,” Grim said. “So a couple of places in cylinder heads, we clarified relocation of intake or exhaust port openings prohibited.

“It lets other ones looking at the class for potential, lets them know that you may be able to work on the runner a little bit. There’s still obviously a runner volume, CCs that is maximum numbers, same for the combustion chamber. The intake and exhaust runner both have a CC volume maximum. The combustion chamber has a CC maximum. And this way, we just make sure that nobody thinks that, ‘Well, I’m just going to move the port around.”

“The port openings have to remain in a stock location, which has been the case. That’s nothing new. It’s just to the general public that sometimes doesn’t understand the Stock, Super Stock idea of the engine assembly.

Grim confirmed that outside of SFI chassis spec, the rules virtually mirror those of Factory Stock Showdown.

Grim said another considerable measure of these announcements is the NHRA’s intent to maintain reasonable competition costs.

“That is 100% true,” Grim confirmed. “It’s also that this is not just Stock or Super Stock guys that are interested in Factory X. And so as that interest is developed in, let’s just say you have a Pro Stock team that’s interested in Factory X.

In Pro Stock, the engine platform is pretty unlimited as far as what you can do to the engine. There are very few rules. There’s some weight of rotating assemblies, piston, rod weights, that kind of stuff that is adhered to within Pro Stock.

Especially when we talk about the heads, intake manifolds, Pro Stock teams or Comp Eliminator teams and Super Stock have always been allowed very much an unlimited idea on what they wanted to do to those items. In this case, we just, again, closed the door. The primary goal of that is to contain costs.”

Here are a few areas that have received adjustments.

STARTER

“The starter has to remain in the stock location. There, again, to keep people from relocating the starter and going to a much smaller flywheel or starter ring. So this doesn’t necessarily mean that you have to run the stock-sized flywheel. You’ll just have to make your starter ring arrangement will have to be mandated. You’ll have to work around the starter being in the stock locations.”

THE OFFICIAL ECUs

“The Holley HP and the Holley Dominator will be the only accepted ECUs in the category. And you will not, repeat, will not be able to hook any external; we’ll call them chassis sensors, driveline sensors, shaft speed sensors, infrareds, etc. You will not be able to hook those to the ECU. You can use those items, but they will be utilized only in a standalone data recorder. So maybe RacePak, maybe other brands, but there’ll be certain functions, really any external functions other than engine parameters to not be hooked to or viewed by the ECU.”

“We did point out if you do have, obviously, in the ECU with the Holley HD and the dominator, you can say, ‘Hey, I don’t need to buy a standalone data recorder, because these things will data record, whatever parameters you hook to them.”

“As we stated earlier, there’s a minimum amount of parameters that there’s a lot that you’re not allowed to hook to the ECU in this case. We also clarified if you want a data recorder to look at other functions or other information throughout the chassis, throughout the car, your shock monitors, meaning your standalone shock monitors will tell you how quick and how far a shock may move, the drive shaft speeds, to be able to look at clutch and clutch input sensors.

“Those will all be taken care of by a standalone data recorder, whether it is RacePak or whoever. Any NHRA accepted data recorder is permitted. But most of the parameters of information you want to look at for your car, again, won’t be hooked to the ECU but is permitted to be hooked to a standalone data recorder.

“Somebody might ask down the road, a reader might ask, what is standalone? Well, that really means that there are no functions of fuel or spark control. That is also the system that looks at the other parameters of the car. So, because if you had a system, and this goes back to what is standalone, if you had a system that say, shocks, shock monitoring or wheelie bar pressure sensors, or ride height sensors, especially if they were hooked to the controlling factor of the engine parameters, obviously it can be construed as traction control.

“You can allow those parameters to also, we call it “write rules.” You can write rules in your ECU so that if this pressure sensor or this driveshaft speed sensor gets this margin, it will pull fuel or pull timing and control the tire or control the driveshaft. When we say it’s standalone, it means we don’t mind that you are receiving the information, but it’s received in a way that it is not tied to, or talking to, the ECU controller of the car. And so that’s what standalone is.”

NO POWER ADDER ALTERATIONS

“We did state that any modification to the factory supercharger, the intake manifold, or the factory intercooler is prohibited. And that would sound like wording that should have already been in Factory Showdown, and it was, but it only was about the supercharger. And it was just understood within the realm of Factory Showdown that you couldn’t modify the intake nor the inner cooler. But now we made that where it’s very public and transparent. No modification to the supercharger, the intake manifold, or the intercooler.”

INTER-COOLER TANK

“The intercooler tank, we have mandated it as an OEM style, and size intercooler tank permitted, and must be mounted forward to firewall. So really, the OEM intercooler tank, or even if it is an aftermarket tank, but it is of the same size and style as the OEM, it’ll be mounted out there. Primarily, the guys that are already working on a couple of cars have found that back in relatively stock location works well because then, if you do have a secondary engine, the hose hookup, everything will be very similar to what is found in the Factory Showdown car. The crankshaft height has been regulated at 13 inches. That 13-inch measurement, remember that this is a wet-sump engine, so the oil pans can’t get real short and snug to the block because, in most other categories with a much lower crankshaft heights, they have a dry-sump option. And this it’s a wet sump only. We don’t want the cost of developing a very shallow oil pan to be able to get the crankshaft heights down where you would like for them to be.

“This allows for a bolt-on stock pan without modification or a bolt-on accepted factory showdown pan. So it keeps the pan depths decent. The bottom of the pan must remain at a minimum of three-inch clearance. Only the headers or anything 12 inches behind the front spindle, only the headers, and any of the rest of the car can be at two inches behind the front spindle. So the normal clearance deal was three inches from the front of the car to 12 inches behind the spindle, and it excluded headers and oil pans. Then now, that three-inch includes oil pans.”

NO ZOOMIES

“No zoomies, no side exit headers. The exhaust rule does say exhaust must exit under the vehicle, side-exit exhaust prohibited.”

CLUTCHES

Clutches are 1.5 in the SFI spec. And in most of the rule sets throughout the rule book. It calls out from 1.1 to 1.4 clutches that you can run. But whenever you start looking at those clutches or a certain amount that don’t meet the spec, if it’s a supercharged application, it doesn’t meet the spec. When you put multiple discs in the clutch for its containment. And so 1.5 is the clutch required. The SFI spec is 1.5, and that particular clutch is built in relationship to as many as three discs and for supercharged applications, as this will be. An eight-inch is the minimum disc diameter.

“The reason that we pointed out disc diameter, as opposed to “Well, why don’t you say it’s an eight-inch clutch?”

“Well, it’s an eight-inch disc because, in a race clutch application, you could run one eight-inch and multiple seven-inches, or you could run eight to seven to six, two eights, and a six. You can kind of hybrid that clutch mentality, so this calls out the clutch disc minimum being eight inches. You can run as many as three discs in the clutch. We expect that most will run two eights. Some may end up at three eights, but I think the normal we’ll see is two eight-inch discs. Speaking of the clutch and eight-inch for the ones that are very savvy and experienced with clutches, especially coming from Pro Stock, they would say, “Well, that’s a little more clutch than we need.”

“That is correct. But when you have just as much clutch as you need or even a little bit of at the minimum, you definitely have to have a clutch guy on the crew. You are cutting that clutch every run; you’re pulling it out. You’re putting it on the bench. You may be even changing discs from run to run. In an eight-inch application, we feel like that once a team has been tested and may receive some clutch help in that testing, really for an event you can change the base and the counter and keep the clutch tuned up for the event, and really won’t service the clutch till they get back home. That potentially cuts out one to two crew people for the … It potentially cuts out one to two crew people for a team, that instead of having to have those on board, they can be much more at a level … that more of a consultant level. And you can go race for the weekend with an eight-inch clutch in the car and probably not touch it.

THE BELLHOUSING

“As far as right behind the clutch, we mandated a 6.3 is the approved bell housing. Some would go, “Man, a 6.1, it’s a lot lighter. It’s this; it’s that.” The deal is when we start talking about 10,000 RPM and multiple discs inside that can we still want to be safe. 6.3 is the can of choice; we feel like that there’ll be no can issues down the road. It will contain a catastrophic clutch explosion with no problem. A 6.3 can is what we call a “rotational” can as well, meaning that it not only attaches to the back of the engine block, but it has some lugs that also promote mounting on the perimeter of the engine, just through the mid-plate. And so that if you happen to have a crank issue that tears the engine away from the mid-plate, or you have a clutch explosion, the mid-plate and the clutch can are all still intact; they didn’t go anywhere. And so we call that a rotational can, meaning that it just has some other mounting outside of just the back of the engine block and actually mounts itself to the mid-plate. And so therefore, it’s more of an anti-rotation, so it adds what we call rotation quality,

THE SUSPENSION

In the suspension, even through our Phase One interview, we talked about how simple the suspension package is in Factory X. It had places where it pointed out no degressive springs, no degressive shocks. And in a lot of cases, people say, ‘Well, that means kind of everything.”

“Well, there’s a new word in the world of suspension called inerter, inertance, but it’s called inerter shock packages. And so what we did is we added those words to the suspension that says inerter shocks/struts prohibited.”

TIRES

“We had already said 33 10 5W 16 for the rear tire and a 26-inch tall front tire. You could put it on a 15 to 17-inch front wheel. We feel like that because the body dimensions are all stock. The wheel openings are stock. We’ll see most everybody mount a 26-inch front tire on a 17-inch tall wheel, but we don’t mandate the front wheel. We only mandate the rear wheel as being 16 by 16 double beadlock.

SEATS

“We looked over several seats present at the PRI to see what the seat choice was. There are a couple of FIA applications. There is SFI, which is widely known throughout the drag race industry. There is a 39.1 and a 39.2 seat in the ruleset now. So you can use a particular FIA containment seat, or, and they’re all levels of price point, but some are very affordable. There are 39.1 and 39.2 SFI seats that meet the exact requirements for this class. And most of the 39.1 and 39.2 stuff has been utilized in NASCAR, Indy car, road race, standard Saturday night dirt track stuff. And there are some very affordable price point seats there. Those companies have ramped up their interest into developing drag race seats, and they have them now, but there’s less of them, but those companies are, in leaving PRI are starting to ramp up some drag race seats in 39.1 and 39.2, and so those have been added.

“One and 39.2. And so, those have been added to the rules as well. We just cleaned up the wording on the dashboard. The dashboard must retain OEM exterior appearance, but the dashboard can be fiberglass or a composite. If a dashboard has a center console or a center area dropdown as wood, like the Mustang and the Challenger, the COPO, we’re not expecting that center dropdown area of the dash to be retained. So basically, the gauge area and what you and I would consider the glove box area of the dash and the dash pad, the top of the dash, that those areas are what we consider to be the dash of the car. So dash must retain OEM exterior appearance, excluding the center console dropdown portion.

THE OVERHANG FACTOR

“The front overhangs of the bodies, that’s been a point of conversation, that the front overhangs are … it’s imperative that all the cars must maintain the same overhang so that once we leave the starting line to get to the finish line, they all ran the same distance. That will be taken care of via a stripe taker. We’ve all called it other things, but we’ll call it the stripetaker. The overall overhang dimension would be measured from center of spindle. Again, the wheelbase is stocking these things where you have a one inch variance total to work with, but the overhangs will be measured from the centerline of the front spindle to the furthest portion of the nose, plus the stripe taker.

“In the next week or so, we’ll be naming what that measurement is. But all cars will have a small stripe taker. It will be bolt-on so that if ever down the road we add another manufacturer and the overall overhang needs to be adjusted based on what another body style is, then everybody has a bolt-on strap taker that can be adjusted if needed.

“What we expect to see is our shortest version of an OEM car now is approximately in the 30, 31, 32-inch range at the lower balance. Not the front bumper, but at the lower balance in the area taking the stripe at the top end of the racetrack. So we look at it as roughly the first twelve inches of the car in the nose. And so the stripe taker, the stripe taker will be six inches tall, maximum height. And its length will vary from body style to body style. But the longest stripe taker right now looks like four to five inches. And the shortest will be a couple of inches. There’s only about six inches difference between the shortest OEM Factory X and the longest OEM Factory X. So; the stripe takers won’t be something large, stuck out the front. They’ll be very minimal. You have to be looking for them to see them, but it will allow everybody to have the same overall overhang in the front of the car, and still, yet, the body dimensions will be factory.

THE COMPOSITE FACTOR

“There’s a multitude of composite companies that are showing interest in jumping into the composite side. There’s a lot of companies already built doors and deck lids. So those are pretty easy replacement, OEM stuff. Some of the builders are even looking at if you shell the steel door to where it just really contains just the door’s skin; we’re not for sure that there’s a lot of weight difference between it and a carbon door. Some people may just choose to shell the stock door, put a carbon fiber door panel in it, and call her good.”

“We have a couple of cars builders that we talked to while we were at PRIwilling to continue forward with steel front fender and a bolt-on carbon hood that still latches, still closes. And that at whatever point a composite front end becomes available, they may switch over. But, they’re going to build it as lightweight as possible and still use the factory components.”

“In the Mustang world, there currently are available carbon fiber bolt-on fenders. And so a couple of the Mustang guys say that’s the road I’m going to go down right now. Again, all I care about is that it’s factory dimensional. It’ll still have to be factory dimensional if it shows up as a one-piece FRP or composite front end.

“At the end of the day, they all got to weigh 2,650 pounds.

“There are still a few questions to answer as we move forward. But, we feel like the phase two update of the Factory X does start to send us down the road so builders can get started. I spent four hours with some great friends who own a nice body shop locally. I spent four hours with them, and I now have a whole packet of each of the accepted body styles, currently, with all the dimension values of what the door opening is supposed to be, measured six ways, of what the trunk opening is supposed to be, what the front windshield, what the roof is supposed to be.

“It’s the exact measurements they use to repair a crashed car. And they’re all OEM measurements. And so they printed me out a complete packet of those, which I don’t mind sharing with any builder that would reach out and needs to know what I got to work around. And, so here is the 100% factory dimension. And, throughout the car build, it’ll be a plus or minus maybe a quarter of an inch that you could miss that dimension.

“In many cases, when you buy an aftermarket door or use a stock door, the door is going to set your dimensional value for your door opening. We did spend a lot of time and got those measurements, and we can share those. As soon as we move into phase three, we will actually have a body sheet completed for all three currently accepted cars. And, it’ll have your widths, it’ll have your roofs.

“We soon to hope have that in what we call a body legend sheet. So that just one sheet we can share with a particular builder and he knows this is how wide the quarter panel’s got to be, this how wide the tail light panel’s got to be. And so that’ll make life really easy. So far, no ongoing problems with any builders, any questions that they’ve had. I still will always say that anytime we talk, we’d much rather you ask for permission than forgiveness.”

IF IT’S NOT IN THE RULEBOOK, NOT NECESSARILY LEGAL

“We want to be transparent. We don’t want guys doing this thing twice. Obviously, the builder’s trying to build it to the best of his ability to give the best product to the customer. At the end of the day, the customer’s the one paying for it. The more mistakes we can prevent in that whole program, the better it is for everybody. So helps us keep a builder from getting himself in a bad place. If he just built a car and XYZ was the number that the customer spent and he shows up the racetrack, it puts us all in a bad spot. So that’s where we’re quick to say, ask for permission and not forgiveness.”