Sierra Sierra Enterprises – Time Attack EVO 8

I mentioned previously that I was working with the crew at Sierra Sierra Enterprises (SSE) and their Time Attack EVO 8. SSE may be new to the time attack scene, but they have been racing and winning for years in Star Mazda and Formula Atlantic. They have taken a hiatus from open wheel racing at the moment, but decided to build a time attack EVO 8 in house from the ground up. Dennis, the owner of SSE, is a real car enthusiast and has just about one, two, or three of every cool car you can think of. However, it was the EVO that blew his mind several years ago (he has 3 other EVOs) and this EVO 8 is the one SSE will attempt to be the fastest in. After some engine troubles with other engine suppliers, SSE has teamed up with Cosworth to supply the engines, engine calibration (me), and turbos. I should also mention that the engine used in the SSE EVO 8 is comprised of an off the shelf Cosworth short block and off the shelf Cosworth CNC ported big valve cylinder head. As a special program for SSE, Cosworth assembled a long block and the ancillaries. This service is not available to the general public.

Cosworth 2.2L 4G63 power will handle horsepower duties. Cosworth spec’d out just about everthing on the engine except for the dry sump oiling. A new dry sump oil system is being thought out at the moment. Wiggins clamps at almost every air and fluid connection = serious. A C&R radiator handles cooling and the Garrett IC core lowers the charge temps. The Garrett stacked plate core is really good, but quite heavy so Cosworth will be supplying a core that is significantly lighter in weight. Currently the engine has a Garrett GT35R turbo and makes anywhere from 450whp (@14.5psi) to 5xxwhp depending on boost, but Cosworth has supplied something a little bigger and badder that will use a Full Race twin scroll exhaust manifold. When time permits, a new exhaust system will be fabricated to accomodate the big power turbo.

The EVO’s loom is motorsport grade with plenty of AS/MS connectors and made by Zen Tec in Lake Forest. Since Cosworth does not currently manufacture a 4G63 intake plenum, we used the next best thing: the HKS Kansai plenum (super nice).

This is the first and current rendition of the body/aero work. It may evolve over time. SSE worked closely with Kaminari to design and build carbon aero parts. Initial testing was done with Hankook C91s and Advan slicks.

The rear diffuser is functional and was fabricated in house. It’s nice to have Formula Atlantic engineers to consult with.

The fuel system is composed of a low mounted Fuel Safe cell, twin Bosch fuel pumps, and a -8 hard line feed to the front. That’s enough pump for over 1100bhp.

The wing stays are directly tied into the roll cage and machined from a solid aluminum plate. Also notice the linkage for the cockpit adjustable spline drive swaybar. This car is all business. Check out the championship winning Formula Atlantic cars in the background too. Notice that just about all of the sheet metal in this car is intact. It’s not the lightest car out there, but that’s nothing a sawzall and plasma cutter can’t fix.

That’s Mike installing the flat bottom belly pan. In the “tuner” world, I’ve seen some laughable attempts at flat bottom, but I’d have to say this is one of the few proper flat bottom cars in time attack in the US.

The 6 pot Brembo Monoblocks are d-d-d-dope. SSE took some racing shocks from their Formula Atlantic spares, re-valved them, and with some fabrication made them fit on the EVO. The shocks are from Dynamic Suspension with Eibach ERS springs. Thats a Peterson dry sump tank in front. Currently the suspension geometry is stock, but there are plans to revamp when the time comes. Testing and development will dictate that time.

Here we have a Pectel SQ6 ECU, Pectel Center Differential Controller, and Life Racing Power Distribution Unit (no relays!).  The SQ6 ECU is the basis of the Cosworth EC Pro ECU that I have been more or less working on non-stop. Admittedly the Pectel/Pi world takes a bit of getting used to, but once you understand the “system” you’ll find that it’s absolutely brilliant and super powerful. A Magden performance computer is currently used as a display dash. A Pi Sigma logging system and dash are going to be installed in the near future probably. The CDC and chassis track support is handled by Renu.

This is the only shot I have of the interior.

Well equipped would be an effective description for SSE.

Since the transports are made for open wheel race cars, the EVO has to be DUMPED to fit in the transporter. It BARELY fits when slammed.

This jet won the Reno Air Races last year. Going fast and winning is what SSE is all about. Their crew are all great guys with one goal in mind: winning.

The driver of the EVO also comes from Formula Atlantic, Jonathan Bomarito.  I asked him at a practice session, “So how is it coming from open wheel cars?” He said, “When you think about late braking, you better think twice!” Those open wheeled race cars must be fun to drive… Anyhow, look out for the SSE EVO at your local Redline Time Attack. Initial testing at Buttonwillow was pretty damn fast at low boost. Come and see for yourself this weekend at Willow Springs.

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