My Own Worst Enemy…
By Ted Pelech
October 21, 2009

Photo by Tom Turrill
Detroit, Michigan -- Memphis turned out to be the continuation of a series of unfortunate events for us. A few weeks earlier, we began making passes in order to update my competition license and prepare for the forthcoming NMCA World Finals in Memphis, TN. We slipped into the final Norwalk Raceway Park 'Open Test & Tune' of the season and immediately knocked the teeth off second gear in our 3-speed Bruno Transmission. Undeterred, we returned to the shop and got to work installing our exceptionally reliable Hutch's Transmission Service built 2-speed Powerglide. We headed to Milan Dragway a few days later hoping to pick up where we left off. This time, all of the parts held up but our traction did not. Of the five runs we made that evening, only one actually stuck, netting a very encouraging 7.27 second elapsed time at 186.6 mph. What made the pass so encouraging was that is was made using only the first stage of our three stage Applied Nitrous Technology dry injection system. It had been a trying few days but we now had hope. The next week would be spent doing routine maintenance on our race car and handling pre-race logistics in anticipation of our return to the NMCA's Super street class.

When we arrived at Memphis Motorsports Park, I was shocked at what I saw. The pits were already packed and the line at the gate was loaded with even more racers looking to get in on the action. If the economy is on life support, you wouldn't know judging by the participation at this event. We pulled into our pit spot and got to work preparing for a test run during Friday Open Time Trial session. Jeff Prock from Applied Nitrous Technology was with us this weekend so it was a relief to know that he'd have the answers to the questions our uncooperative car was generating. On top of that, the track prep looked outstanding! Enthusiasm was running high that our car would produce great numbers!

Photo by Jake Amatisto of FSC Magazine

I slowly pulled through the water box wetting the tires and executed a short burn out a moment later. Jeff & Tim lined me up in the ideal location on the starting line and when the starting lights flashed, tire smoke and the sound of the rev limiter filled the air. No traction. I mean none at all! This was particularly troubling considering how good the racing surface was.

We return the pits and begin downloading data from our Racepak Data Acquisition System and our MSD Ignition Controller. As that was happening, Jeff said he could see the car isn't compressing the rear suspension like it did in our earlier Mooresville testing. A moment later, the Racepak suspension graphs supported his observation. Furthermore, Jeff said he was standing next to the car and he noticed my hand come off the trans-brake button to launch the car but the car didn't move instantly as it's supposed to. Racepak's Roger Conley works a little of his magic with the graphing and points out exactly where in time the trans-brake button was released and the 0.25 second lag time until the nitrous turned on. This is no good. In order for our suspension set up to work properly, the nitrous needs to be on NOW. Could this lag be the source of our traction problem? The video kind of indicates that. It shows the suspension barely squatting, the tire doing full turn, and the nitrous turning on as the suspension is already unloading. Then everything disappears in tire smoke.

The suspicion now turns toward the processing speed of an electronic controller within our car. Maybe it's slow and can't get the nitrous solenoids open immediately? The decision is made to cut all wires related to nitrous and ignition retard operation going to and from this component. We'd simply insert a handful of stunt-relays as substitutes. Friday's first round of qualifying was drawing near and it didn't look like I was going to have the rework wrapped up in time of join the fun. Fortunately, or unfortunately maybe, drizzle would move in a short time later, cancelling qualifying activities for the night and allowing the needed time to finish my electrical butchery.

Saturday's first qualifying effort would have the nitrous come on instantly but the rear suspension still didn't work and there a giant, bright orange backfire out of the exhaust that shut the car off. Roger Conley again visits our pit but this time he brings a really cool 300 frame per second video clip of our car and says, "Your suspension is just plain bound up. Watch this." Roger shows us the only thing that compresses during the launch is the tire - which quickly un-compresses. Prock now wants to know what the hell we've done to the car that he had producing great 60' and 330' incrementals at our Mooresville test sessions. "Did you adjust anything?" Nope. "Have you taken the rear end housing out of the car since then?" Nope. Well, wait a minute. Um… Yeah... We pulled it out to fab new wheelie bar attachments. With barely a word, Tim & Jeff crawl under the car, take some measurements from this set up, and plugged the numbers into the 4-link software. We're appalled by what we see. The theoretical intersect of the 4-link is parked dead on our car's calculated 'neutral line'. When this happens, the 4-link doesn't know what to do when torque is applied, it just sort of hangs in this leverage-less dead spot.

Tim & Prock make the required suspension corrections for Q2. At the launch, the car hooked like an overly ambitious prostitute! The Racepak says we generated 2000psi load on the wheelie bars and compressed the rear shocks-a-plenty. Lots of bite! Too much bite! Our traction problem is clearly solved. But then the car backfires the exhaust again. And on top of that, the MSD Ignition graphs show the trans-brake circuit made contact for fractions of a second twice after the launch - which most likely explains the huge backfires out of the exhaust. What this showed is that something must be messed up in the relay circuitry I cobbled together for nitrous, timing, and trans-brake control. Now qualifying is over, we're completely lost, and decide we should just go home to get our act together.

Had we discovered the suspension problem first, we probably wouldn't have touched the electrical. Prock probably would've simply used alternative ignition tuning to band aid the nitrous lag and it probably would've worked just fine for the weekend. But that's all hindsight now.

Photo by Tom Turrill

So the question I'm most frequently being asked is, "How did it go 7.27 at Milan?" Answer: Dumb Luck! Four other passes at Milan were smoke...

Ted & Tim Pelech
Pelech Bros. Racing