The 4-Cylinder Porsche that Chases Front Runners

By: Kevin Sims

  Send To A Friend

The famed rear-engined Porsche 911 has won more races than any other car model in history. With such a track record it's no wonder why it is the Porsche of choice at SCCA, HSR and PCA Club Racing events. It has been commonly said by racers that if you want to race a Porsche, then the 911 is your ticket to the podium. However, there is a group of Porsche racers that believe this adage is not universal.

Ivan Arzola, owner of IMA Motorsports in Fairfax, VA, is a member of such a group of Porsche racers. His indigo blue 951 stands out in a crowd for its non-911 lineage and its intimidating ways. The car is regularly seen as a front-runner at east coast races and has accumulated a string of class victories in 2007. It commanded a win in the GT3S class at the Barber Motorsports Park's PCA Club Race in Alabama. In the HSR series, it claimed the C4 class victory honors at Road Atlanta against tough competition. In addition, the car holds the fastest lap record at the Summit Point 12 Hour race. With its massive power and astute handling, IMA Motorsport's 951 has proven itself as a Porsche racecar to reckon with. We are delighted to have a discussion with Ivan about his image breaking Porsche:

What was your inspiration for building this particular 951 racecar?

Ivan Arzola : IMA Motorsports wanted a car that we could race within Porsche Club Racing (PCA), SCCA and HSR. We wanted to remain faithful to running a Porsche, however wanted something unique. There are so many 911-based racecars competing at any given track. Considering the 951's neutral handling and relative low weight, we felt the 951 was an underappreciated platform that could be developed into a race winner. It was our thought to build a 951 with a strong attention to detail to show what the car was truly capable of doing.

How difficult is it to build a car to compete with the different rules imposed by the various racing sanctioning bodies?

It is not that challenging. Within SCCA we selected a class that is kind of a catchall. It's almost the same thing with HSR, which has a run group that allows a broad set of cars to be run.

I'm not looking to go into HSR and really race, however. It's a little difficult because of the variety of cars that are there. I'm running the car on Hoosier tires, so that limits the amount of speed and lap times you can get out of the car. For me the SCCA and HSR are just about having fun. PCA Racing events, however, are a different situation. When I go to a PCA race I want to be competitive. I enjoy having a 951 racecar at PCA events. As much as I love 911s, having one at a PCA event is hardly exclusive. Most people are surprised by the performance of my blue 951. At the Road Atlanta PCA race I qualified my car at pole position, which stunned people.

How was the frame altered in building your racecar?

We started with the car we had at the time, which was an '86 951. The basic tub is pretty much the same from year to year. We modified so much that in the end it wouldn't have mattered what we started with. We chopped off the front end from the shock tower forward. The structure was fabricated to install two radiators and an intercooler in between them. The chassis had been reinforced throughout by a roll-cage. We also strengthened the car's suspension points. We removed the car's floor and installed a thicker sheet of steel to protect the driver against anything coming through the floor during an accident. Safety is just as important as performance in building a racecar. We found that the added reinforcements increased the car's overall rigidity. Stripping out the car's interior in traditional racecar fashion, our blue 951 is almost a custom car.

In general, what was done to the engine to prepare it for racing?

We modified the engine quite a bit. As with the 911, we installed a dry sump lubrication system - to protect the engine during hard corning and to reduce running temperatures. We had Carrillo produce a set of custom rods that were much lighter and bullet proof. We decided to leave the crankshaft pretty much stock except for cross-drilling the oil journals for better delivery. The block was re-sleeved with custom steel units. JE Pistons produced a set of custom pistons for us with the stock 8.0 to 1 compression ratio. Due to HSR rule restrictions we retained the 951's stock 2.5 liter displacement. John Miller produced a custom intake manifold based on a barrel valve design with a custom plenum. The manifold's air/fuel flow is very unrestrictive and vastly improved. The headers were custom built to accommodate turbochargers on the passenger side of the car. We had a specially designed camshaft produced to work with the characteristics of our cylinder head. There was really nothing else done to it other than taking the time to properly measure clearances. We have tested the car in its current form on a Mustang dyno and produced from 450 to 500 horsepower, depending on boost levels.

SUBSCRIBE to read more of this article. Ivan goes in detail about the car's modifications. This is a Porsche Tuner must read.

Click SUBSCRIBE to view all the photographs. Plus read more about other tuner Porsches.

Subscribe to Autobahn Ambition! It's Free!