Tune-Up Tips
'"Hey, that's my pal Nick Jennings on TV! Cool! So, it's a best two outta three. He better win or he'll never live it down!"
Have you seen the latest version of car-guy reality TV? It's Full Throttle on the History Channel, and it's remarkably devoid of WWII footage. Hosted by the Turbo Twins, Eric and Marc Kozeluh, the show pits two pairs of competitors head-to-head in similar vehicles. The contestants do upgrades to the cars and then shoot it out in a best two-out-of-three dragstrip face-off. The winners take the cars home and the losers walk.
Nick and Lauri Jennings wrangled their way onto the show when producers wanted male and female stunt-driving couples for an episode featuring pre-Bandit Firebirds sporting 350 Ponchos. When Lauri's male stunt partner failed to show, Lauri asked if her husband could substitute. She omitted the fact that Nick had grown up tweaking cars at his dad's Jennings Dyno Shop, a magnet for fast street machines in the '70s and '80s. Lauri also had a score to settle with her female competitor, who had beat Lauri out for the female stunt-driving duties in the movie The Italian Job. The stakes were far greater than just a couple of old Firebirds.
Skip to track day. Nick drove first and was promptly Tree'd by a girl. But ripping victory from the jaws of divorce court, he won with a come-from-behind victory, leaning heavily on the button. Both teams stepped up to a full 200hp shot of nitrous for the second round, but Lauri took the win and the Jennings drove home in a pair of Firebirds.
We watched the show and thought both cars were painfully slow, and apparently we weren't alone. The losing tan '75 Firebird was especially lame, since it barely ran 14.70s at 94 mph. We called Nick and Lauri to see if they'd take the '75 back to the track for a nitrous shot at redemption without changing any major components.
Act One
Both Firebirds had flaccid 7.6:1-compression two-barrel 350 Pontiac engines rated at a wheezy 170 hp for the yellow '74 and an even more lamentable 160 hp for the tan '75. The 10 hp difference is attributable to those awful first-year catalytic converters on the '75.
The TV duo had at least chosen good parts. Both cars sported Edelbrock 600-cfm Performer carburetors and Performer RPM dual-plane intakes. They also installed Nitrous Express plate kits capable of as much as 200hp shots. To light the fire, they added MSD distributors, 6AL boxes, and plug wires, plus Bosch plugs. Both cars had Flowmaster exhaust with X-pipes, mufflers, and turndowns.
Before leaving for Los Angeles County Raceway for the Car Craft sessions, Nick first checked fuel pressure under load, and found the stock mechanical pump capable of 6 psi-surely enough to handle the mild nitrous system. But when he yanked the fuel cap to add gas, he noticed a definite "whoosh" that told him there was vacuum in the tank and hence no vent. Nick traced this to capped-off carbon-canister lines, which eliminated the fuel-tank vent. We thought we might be on to something.
Next, Nick removed the MSD distributor and tossed the heavy mechanical-advance springs, replacing them with much lighter blue springs included with the MSD distributor. He also exchanged the stock MSD limiter bushing for the black one that delivers 20 degrees of mechanical advance at the crank. He then added 16 degrees of initial for 36 degrees of total advance. With only 7.6:1 compression, we needed all the timing we could get.
During the show, Nick tried to convince the twins to use shorter-reach spark plugs so the ground straps would not turn into cherry-red glow plugs. They declined, but we had no such reservations. Nick chose AC R43T plugs to help keep detonation at bay. Armed with those tweaks and two full Nitrous Express bottles, we headed for the track to see if the freebie Firebird would be any faster.