1994 Ferrari 348 Challenge Twin Turbo

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Any Ferrari is cool, and yes we said any, even the 1980’s 400i sedan. As long as there is a prancing horse on the hood, these cars are destined to be cherished for generations to come. The Ferrari 348 series is no different and it spawned one of the most loved modern Ferrari’s in the 355 model. One issue that people tend to have with the 348 is that there was a lack of power from its V8. All that really means is that when you take a 348 Challenge model and bolt on some serious power upgrades you’ll end up with a super cool Ferrari.

Steve Maxwell and Stacey Slead were two men that fell in love with the original driving dynamics of the 348 and put in some serious effort to make this one of the most powerful 348s on the road today. The two became friends when Maxwell was selling his Ferrari 348 Ferrari 348 and Slead wanted to buy it after a one-night test drive. Soon after Slead became the owner and Maxwell turned into a mad mechanic handcrafting over 200 pieces for the Ferrari it has now become.

After a few new donor Ferraris, a near death experience, and plenty of late nights deciding how to put it all together this Ferrari now makes over 600hp and eats newer models for breakfast. A challenge model Ferrari is nothing to take lightly in the first place, but adding turbochargers and a host of other one-off performance pieces can turn your run-of-the-mill Ferrari into an entirely different animal.

Hit the jump for more details on this Ferrari 348 Twin Turbo.

Source: European Car

The Engine Build

1989 Ferrari 348 TB

Ferrari 348 TB

The car that Maxwell had sold to Slead was the beginning of the project and Maxwell began working on the engine immediately. Others had taken this Ferrari V8 and built turbo versions that worked well and produced a lot of power, so they decided to follow the same plans. The engine and mechanical workings of the vehicle were the most heavily modified pieces and the engine itself received low compression pistons, new valves, ported and polished cylinder heads, and machined guideplates to match the ports perfectly. Moving away from the engine block they decided to get a pair of mandrel-bent equal length headers and mate those to a stainless steel exhaust system to cut weight.

Turbocharged engines make much more heat than a normally aspirated unit and therefore cooling needed to be addressed. The team ordered two very large radiators and a liquid intercooler. One issue with modifying a Ferrari is that every inch of space is already being used. Therefore they had to fabricate aluminum ducts in the bumper to increase airflow as well as move the battery into the trunk compartment. Even without the new T3/T4 turbochargers powered up, the engine modifications and 8.75:1 compression ratio helped the engine make more power than ever before.

Putting It All Together

The biggest problem encountered by the two was with the body of the Ferrari. On a quick trip to a neighborhood Wal-Mart, the car was sideswiped by a handicapped driver in the parking lot. Luckily they found a car for sale in Michigan that was actually one of the factory racing models, a 348 Challenge. This car was ideal because it had no insulation, sound deadening, or weight added by a luxurious interior. The stronger chassis made possible by solid metal suspension joints and factory roll cage also made things that much better. The car did have imperfections, but Maxwell had everything set straight at GA Coachworks where the body and paint were redone.

It was finally time to put the original engine in the new car and begin to finish the project. Right as everything was beginning to fall into place a small miracle happened. The team learned of a Ferrari 355 which had crashed and was now being sold as parts. They had the idea of upgrading the running gear of their car and immediately bought the suspension pieces and gearbox from that car and began to plan how the new pieces would fit together. Basically every mount on the car needed to be changed and they machined new crossmembers, and machine arms for the gearbox. In order to keep cost down and reliability up, they used many Toyota pieces for things like the alternator and coil-on plug coils.

Interior modifications were mainly for function and not aesthetics. They were able to use a modified 355 shifter with a new center console. The computer system used was a DTA Fast system from England. This allowed for traction control, launch control, wet traction control, boost control, idle motor control, sequential injection, and drivers for each individual coil. Having every system run off one computer also helped to increase reliability and this particular unit interfaced with the Bosch sensors well.

1989 Ferrari 348 TB

Ferrari 348 TB

Road Test From Hell

After everything was completed, the duo took their new Ferrari out for a little test run. It was time to open her up on the freeway and the car began to steadily climb into the 150mph range. Slead quickly realized that as he let off the gas the car was still accelerating…160mph and counting. Clearly something was amiss and the car pulled strongly into 170mph territory. Nnot looking to smash their new project into the freeway divider, Maxwell hit the emergency stop button just as the car crested 180mph. After a quick change of underwear the team got the Ferrari up on the dyno to see what was going on. As the car began to hit high speeds, the engine literally lifted several inches off its mounts showing that it had broken all the brackets. When this occurred the throttle would jam wide open under the intercooler providing an answer for the theatrics from the earlier road test. The team has since rectified the problem and can now drive this beastly Ferrari complete with its 609hp and 486 lb-ft of torque without worry.

1989 Ferrari 348 TB

Ferrari 348 TB
  • Ferrari 348 Challenge body
  • One-off Custom Parts
  • Increased Performance
  • Not for the weekend mechanic
  • Reliability issues


Well,This seems to be the whole pieces are worth it. It is indeed amazing packaged capacity to a higher level performances. This type of Ferrari Turbo will surely you will be treasure for the rest of your driving experience.

hmm. But its a good thing that this car doesn’t look hideous just like the other vintage car! Well, I like the boosting power of this and I want to know if the engine that it was used is already rare?

I like the tuning sound of this car.. I just wonder is that’s real. It gives me a feeling that I’m actually driving in the F1 race!

Yeah, they definitely went to a lot of work in order to achieve the performance that they have put into the car. I just can’t imagine what they will be able to come up with next.

Wow! I like the tune of this car! This is definitely a hard challenge for the team creative since the original performance of the car is less powerful.

I wonder how much the whole project costs. The 1994 348 would alone cost more than a hundred grand. Add to that the parts needed for this particular setup, and all I can say is that this one isn’t going to be cheap.

I’m glad that they have made and the performance increases. I think this is the most challenging job for the Ferrari.

Well, that’s something that they might need to work on more there. Actually, that one is a common problem to a a lot of projects like this.

Well, as far as i know this car has an amazing performance and changing the engine from twin turbos kind of challenging but still the reliability would be questionable.

I agree that this one is definitely one heck of a work. Those two guys are certainly mechanical geniuses to be able to upgrade the 348 to such a level.

This one is definitely one heck of a project. Imagine that, they were able to squeeze in over 600 hp on that thing, and the exterior body work looks cool too.

Wow, this one would definitely be a must have, especially with all those add ons that they have included. It’s just bad that there are still some reliability issues that they need to iron out.

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