Scarlett: the Ultra4 italian way by ACE Racing

In this article we present you “Scarlett”, the new rig of Ace Racing. This is a real Ultra4 style 4x4 built using the most modern technical solutions and the best components on the market.

Photos and text by Paolo Baraldi

Acerni - Acerni Custom Engineering - ACE Raging 

ACE Racing Born in the Motor Valley of Parma, the life of Acerni could only be dedicated to engines and competitions. In particular, the love for 4x4 and the Jeep brand can be traced back to the post-war era when Tonino Acerni came into possession of a Willys Jeep left by the Americans in the surrounding countryside in Varano de Melegari. The passion and art were handed down by Tonino to his son Pier who naturally followed in his father’s footsteps. In addition to their excellent preparation, both have won important awards and victories in the most famous national and international competitions. Eventually a crown at King of the Valleys in the UK lead to the dream of racing in the United States at the prestigious King of the Hammers with a 4x4 made entirely in Italy “Black Jaws”. From this moment on, an indistructable combination has been created between Acerni Custom Engineering, once Acerni Offroad, and Ultra4. To keep up with the opponents and be competitive, a continuous technical update is necessary and even though Black Jaws was ahead of its time, it had reached the point of not being able to be further adapted to the new requirements of the race.

Pier Acerni, owner of Acerni Custom Engineering and racecar driver of ACE Racing
Pier Acerni, owner of Acerni Custom Engineering and racecar driver of ACE Racing


Thus the decision to focus on a new project to participate in the Ultra4 Europe 2018 championship was inevitable. In this article we present you “Scarlett”, the new rig of Ace Racing. This is a real Ultra4 style 4x4 built using the most modern technical solutions and the best components on the market. From the powerful and rare Mopar LMP V8 6.0L engine with 700 horsepower housed at the rear, to the next-generation Gigglepin high-performance winch through the shocks of the King Shocks. Everything has been designed and positioned to achieve optimal vehicle balance and maximum performance. We had the pleasure of being able to witness the first tests of Scarlett that took place at the Varano racetrack, where performance and reliability were evaluated, and then off-road driving simulating a race to get the necessary feedback for the final set up. In both situations, Scarlett showed her great potential, confirming the good work performed by Pier Acerni and his team. Among the qualities of this 4x4 that we liked most, leaving aside the thrilling sound of the V8 that only those who love these engines can understand, certainly the excellent drivability and the perfect balance are some of the secrets up her sleeves, coupled with an engine that has incredible progression and power that seems to take off like an air force fighter. The perfect 4-link geometry of the suspension and the King Shocks performance dampers used are the icing on the cake that allow the engine power to be unloaded to the ground, allow full control both in the straight ahead and in the mixed steering as in the insertion into curve. 

Hard to say what we did not like; at the moment we are satisfied with what we have seen even if, as for every racing car, the final test is the one on the competition field. If we really must find a "flaw", then we must take a few steps back to get to the design phase where we would have chosen an IFS system that allows better driveability on the fast. But this is only our preference and we understand very well the choice of the solid axle that in addition to being more strong and reliable also requires less maintenance. As soon as the test was over, we collected the impressions of Pier Acerni: "The vehicle behaves very well, I was worried that it would understeer when cornering especially with the 2WD, but in no case does this fault occur. The engine above 5000rpm becomes really scary, the car becomes lighter and floats on obstacles. No problem with the temperatures during all the tests both on the track and in off-road. Light, sensitive and precise steering even at high speeds (on the 170kmh track), excellent braking, limited roll to a minimum ". 

Mopar LPM V8 6.0L 

The 6.0-liter Mopar LMP V8 engine is truly a rare and extraordinary piece. It is a prototype built only in 16 units by Caldwell Development Inc. of John Caldwell, a well-known race driver and race engine manufacturer, based in Southern California. Chrysler were to develop this project dedicated to participating in the Le Mans 24 in the LMP category with a Dallara chassis, used many investments; pity they only ran once in 2001. When the project was closed, only 3 engines and numerous spare parts remained. Two of the LMP engines were sold to the same buyer, in separate transactions at the end of 2006 and early 2007, who was planning to rejoin the Dallara chassis to engines for racing in the classic car category. The third was an engine for development, a "mule" for testing that was given to a guy who wanted to install it on a Mopar road car. The project stopped due to lack of funds and the engine was sold again to get into the hands of Ryan Falconer Racing Engines. At this point, the story, at least that told by the Americans, becomes a bit smoky and it is not clear whether the gentlemen purchaser of the two engines, in 2006 and 2007, was actually the French Oreca team that ran the cars on behalf of Chrysler. The fact is, that Scarlett's engine was bought by Oreca. Whether it is one of the two mentioned before or one of those supplied to the team at the time of Chrysler's LMP adventure we do not know and we will never know. Perhaps it is better this way, with a veil of mystery that hovers around this unique and rare engine.

The 6.0-liter Mopar LMP V8 engine
The 6.0-liter Mopar LMP V8 engine

Scarlett Tech Specifications

- The chassis, model Podium Rear Engine, was created by the American Jimmy's 4x4 Chassis with 2" tubes in Chromoly 4130

- The engine, positioned at the rear, is a rare 6.0-liter Mopar LMP V8 with 700 horsepower at 7000rpm. The engine management is entrusted to an Efi Euro4 control unit.

- Carbon air filter is entirely designed and manufactured by Acerni Custom Engineering

- Burnt gas exhaust has been developed by Acerni Custom Engineering

- The radiator to cool the engine, in the rear, is a CBR with Spal fans

- The 3-speed automatic transmission is an ATI Performance Products TH400 specially updated by Jimmy's 4x4. It is combined with a CBR radiator

- The gearbox is from the 40-spline TrailWorthyFab Hero.

- The axles are Spidertrax Off-Road ProSeries in chromoly 4130 with Spidertrax 40 spline axle shafts with Yukon Superjoints. Rear spool and front D&G Atom Locker.

- Disc brakes are 355mm Wilwood with 6-piston Wildwood pliers

- Suspension geometry is made with a 4 link; at the rear with Trailing Arms and at the front with Leading Arms. In both cases with uniball QA1 and made in chromoly 4130

- The suspension consists of the combination of King Shocks 2.5" RS coilover and 3.0" RS 5 Tube Bypass for each wheel to which are added 2.0" bump stops

- The Full Hydro hydraulic steering system is of PSC Motorsports with Trophy Truck pump and CBR radiator

- The alloy wheels are of the 17X8.5 Raceline Monster beadlockers with BF Goodrich KM3 Baja Tire 40X13.50 R 17

- The 120-liter fuel tank made by ATL is positioned in front

- The winch is the new GigglepinWinches GP100 with a short drum

- The XPR 40" front led bar is from Vision X as well as the two Solstices positioned next to the winch

- OMP steering wheel

- The seats are PRP as well as safety belts

- All the carbon dashboard was made by Acerni Custom Engineering with AIM MXS Dashboard, Lowrance GPS, PCI intercom and Kenwood UHF radio.

Acerni Custom Engineering

Via Giovanni XXIII, 3

43040 Varano de' Melegari

Phone: +39.052553231 

Web: www.acerni.it

Pier Acerni (on the right) and his co-pilote Nicola Bondi
Pier Acerni (on the right) and his co-pilote Nicola Bondi