No limit: ANDRA’s plans to improve Doorslammer & Pro Mod safety

ANDRA won't impose a speed limit for Doorslammers and Pro Mods


Update: Following the IHRA’s announcement of a 260mph speed limit for sedans, rival sanctioning body ANDRA have today revealed their own response to the issue.

Rather than imposing a speed limit, the short-term plan is to increase the maximum-allowable wing size and spill plate area, so that racers can voluntarily increase these. This will be followed later by rules that mandate miniumum wing and spill plate sizes. The IHRA is also looking into similar plans (see below).

The full release is here:

“In light of recent announcements within the Australian drag racing industry, ANDRA would like to advise that it currently has no intention to impose performance limits on Top Doorslammer and similar type vehicles.

“As a result of the increase in more serious incidents, ANDRA is currently conducting a preliminary review on vehicle aerodynamics on a range of classes with input from a qualified aerodynamics expert.

“In the short term we are looking to increase the maximum allowable wing size and spill plate areas across most classes, to permit racers to increase these if they desire.

“In the medium to longer term we will look to mandate minimum requirements for all vehicles based upon performance.

“ANDRA will continue to monitor the safety and performance of these vehicles. If such a time arises that it is determined that changes to any safety requirements, vehicle specifications or aerodynamic requirements are required, ANDRA will work in cooperation with the appropriate racer groups as we have been with Matt Abel, President of the Top Doorslammer Association, and other industry authorities to develop and implement any changes deemed necessary.”

What is the deck on a Pro Mod or Doorslammer?

A deck is the horizontal rear spoiler on the back of a drag racing sedan.

What is a spill plate on a Pro Mod?

The spill plates are the sides of the deck or rear spoiler on a Doorslammer or similar drag racing sedan

What is a wicker bill?

A wicker bill is the vertical end cap (sometimes removable) that sits on the end of the deck that provides more downforce, but also causes drag. Also known as a Gurney flap

How do Pro Mod racers decide what size rear spoiler to run?

Let’s turn to US drag racing legend Tim McAmis to explain:

“The size of the wicker bill and spill plates will be determined by how fast you want to go, how much power you’re making and the state and prep of the track. To run the car loose, you’ve gotta have a smooth track with a lot of bite on the finish line. It’s not uncommon to have two or three different wicker bills to go out with each car. The the customer can tune that to the get the optimal performance out of it.”

For more info, check out Tim’s video:

The story to here, 29 June:

In the wake of a series of serious crashes in the Pro Slammer ranks (including the death of Sam Fenech in January), the IHRA has announced a new speed limit for sedans of 260mph (418km/h).

Sportsman racers are familiar with speed or ET restrictions depending on their car’s tech or class to keep performance in line with the safety levels of the cars concerned.

However, in professional categories like Top Fuel, sanctioning bodies around the world have been preferred to impose mechanical restrictions in the hope of slowing the racers down, such as the use of rev limiters or mandatory final drive ratios. Reducing racing distance (such Top Fuel’s 1000ft distance) has been the other lever pulled by sanctioning bodies to reduce terminal speeds.

While many Australian Doorslammer racers have 250+mph runs to their credit, only a handful have so far eclipsed the 260mph mark, including John Zappia, Emilio Spinozzi, Kelvin Lyle and Daniel Gregorini. The fastest pass from the season just completed was 257mph by Zappia.

IHRA Pro Mod is run on a fixed index of 5.85 seconds over the quarter-mile, to add parity to a class that has some potentially very fast cars – as Paul Mouhayet showed when he ran 266mph over the quarter in 2016. Or consider Greg Tsakiridis’s Mustang, which has run 274mph in the US.

For IHRA CEO Maurice Allen, the decision is all about safety and sustainability.

“We have some very light, very fast cars with not a lot of downforce,” he said.

“In the US, Pro Mod cars are built for the outlaw world and run over the eighth-mile, but in Australia we have the same cars going unrestricted over the quarter.

“There are some very serious concerns around safety and insurance in our sport at the moment that I think everyone recognises. This rule is designed to address those concerns while we work on some longer-term solutions.

“We’re working on potential guidelines around chassis design and aerodynamics that we can bring in to slow these cars down.

“In the meantime, the reality is that there are only a handful of racers that this will affect right now, so the speed limit is a good solution that means we aren’t asking racers to make a lot of changes to their cars going into a new season.

“Parachute failures are another issue. The data shows that ’chute failures have contributed to an increase in crashes over the last 12 months.”

Heres the full bulletin from the IHRA website:

“In relation to a series of events over the last 12 months that have occurred on Australian drag strips with vehicles running in the Pro Slammer and IHRA Australia Pro Mod Categories.

“A review has been undertaken at a series of the past events in relation to the performance, driver behaviour, aerodynamics, parachute failures and accidents caused by mechanical failures, there is no doubt that through the advent of mandated rules under IHRA Australia that electrimotion, dual net systems, sand traps, attention to track prep have all aided in lifting the safety standards for these categories, with the recent increase in performances base on state of the art technology these particular vehicles are pushing boundaries far greater than what we see internationally. As a result, IHRA Australia will be implementing the following recommendations as follows:

  • All sedan-type vehicles to be restricted to 260mph (418kph)  

“IHRA Australia feels strongly that these guidelines must be implemented immediately until we can implement more specific updates to certain areas of these vehicles, i.e. aerodynamics, downforce, and other updates. IHRA Australia will also be implementing a driver standards policy along with the above-mentioned.

“Please note: A racer will receive an initial warning and will be logged appropriately, and any further breaches of these performance guidelines will see them excluded from the event.”