Denny Hioureas is one of up to 30 NMRA Pure Street drivers who follow the circuit on a reg
Horse Sense: NMRA Pure Street engine builders have really pushed the technology of the venerable pushrod Ford 5.0 V-8. Even with factory hydraulic lifters, they've been able to use lightweight valvetrain components and modern camshaft designs to allow these little 310-inch motors to spin well past 8,000 rpm.
The world of heads-up Mustang drag racing is one of compromise, dedication, and sacrifice. The sanctioning-body rule makers control the combinations and-with the stroke of a pen-your hard work, testing, and research can go down the drain. This can be extremely tough on the lower classes, which by their nature are the most monitored and limited classes offered. Take the NMRA's wildly popular Pure Street class for example. It's limited (for pushrod combinations) to a small hydraulic-roller cam (0.500-inch lift max), 311 cubic inches, street-type cylinder heads and intake manifolds, and base weights (3,100 pounds) that deter gutting a car's interior, but racers in P/S have still run in the 10.30-10.50 range with regularity. You don't really appreciate those numbers unless you've tried to run mid-10s with your street car using a supercharger, a huge camshaft, and race-ported cylinder heads, only to come up a second short of your intended goal. Nope, P/S racers are truly a special breed-a group of Mustang racers who can make a 311-inch street Mustang get up and beg.
If you're running a power-limited class such as Pure Street, then you need to maximize wha
Maximizing what you have and what the rule makers allow you to get away with has always been a fascinating concept for Denny Hioureas of Orland Park, Illinois. A friend introduced Denny to P/S, and from then on he's worked steadily to improve his program. "My friend Bob Smith used to race Pure Street back when Tommy Payn was the man to beat. Bob passed away, and I bought the car from his wife. That's how I got my start. It wasn't the best car-not compared with what the cars are today-but it was a good, solid car that I had some history with.
"The Cobra [pictured here] was purchased in February 2001 from Total Performance [Clinton Township, Michigan] as a body-in-white. After a few weeks, we began to assemble a rolling chassis. Once the car could be rolled out of the garage, it went to the chassis shop for a 12-point 'cage and frame connectors. I picked up the car, and then it sat in the corner of my garage for over two years. During that time, I campaigned Bob's '91 hatchback, but I struggled to stay competitive in P/S. This class leaves no room for error-the hatch's chassis wasn't up to the part, and the drivetrain just wasn't as fast as the Big Dogs. I finally parked the '91 hatchback and took the cover off the body-in-white. We began by installing all new front-suspension components, the fuel system, interior, and glass. We tried hard to have the car ready for the '04 season, but that did not happen. My brothers, George and Sam, and I work together at our dad's repair shop where we all work six days a week. All our spare time and effort were put into this car after work and on the weekends. We finally got it done in time for the '05 NMRA Joliet event."
The brothers' thrash session focused on transferring everything from the '91 to the new car while updating and modernizing the suspension of the '01 Cobra to maximize what power can be made from a P/S engine combination. The car responded with a best of an 11.13-second e.t. at 122 mph with a 1.42-second short time-not a record setter, but a much better start than he had with the old car.
A 12-point mild steel 'cage surrounds the driver while in the heat of battle. A Pro-5.0 sh
Along the way, Denny picked up quite a few P/S tricks he was willing to share with our readers. One of the most interesting aspects of this car is it makes more than 400 hp with a stock computer processor without an additional tuning or piggyback computer system. Denny says P/S racers on a budget should install a computer processor from a '95 Mustang GT five-speed car. He says the rev limiter with this computer was set at 7,000 rpm versus 6,250 rpm for the more traditional EEC IV processor. That's a neat trick for any street 'Stang looking to pick up some valuable rpm without bumping the rev limiter.
Denny has also been fortunate to enjoy the engine-building talents of Ed Curtis and his Flow Tech Induction team. When speaking with Ed, you realize that, like most naturally aspirated classes in any form of heads-up racing, P/S is all about rpm. As a general rule, for every 500 rpm you can raise the operational range of an engine, you'll be rewarded with a tenth off your e.t.
"Denny's got what I would describe as an entry-level P/S combination," Ed told us. "That's not to say that he can't win with it, but it's not a $30,000 race engine like shops are selling these guys. We've got him set up to shift the car at 7,500 rpm. Once we get the clutch setup right and the chassis working-I like to see high 1.30s out of P/S car-then we can raise the rpm limit to more than 8,000 rpm. When Darrin [Hendricks] made his run in the "Twin" car [to an NMRA championship], he was leaving the line at 8,800 rpm! We can do that with my combination of parts-we don't bottom-out lifters; we don't use exotic, expensive stuff; there's just some oil-system tricks and lightweight valvetrain parts."
Denny has a few friends who join him at the races.
In case you're wondering, Ed's entry-level package is in the $16,000 range. So that gives you an idea of what kind of jack a P/S racer has in his car before he goes testing, blows up a few clutches, bends a few pushrods, and snaps a few other parts. Ed is also adamant about the importance of low-lift flow-rate numbers of P/S heads. At 0.500-inch lift (the max in the class, remember), Denny's Trick Flow Twisted Wedges flow 296-298 cfm and 200 cfm on the exhaust. (The variation is from intake runners.) Ed also sets up these guys with a camshaft that is in the 0.485-0.495-inch-lift range, or well under the maximum allowed so that his customers won't have a problem during a tech inspection. Remember, Pure Street is heavily policed, and Thom Bates, NMRA's technical director, just loves to yank these engines down to the crank-no kidding-to make sure everyone is playing by the rules.