Breaking Point


Inside an 8-second street Duster

By Scott Longman Photos by Paul Stenquist

High 8-second pass for this street-legal Duster is just one stop on this car’s journey to the twilight zone of acceleration, speed and the grocery store. (Photo: Bob Koegel

The technical term for it is “filial imprinting.”  It’s that deal where a bunch of baby birds, like say, whooping cranes, look out of the nest for the first time, and instead of seeing their mother, what they see is the cable guy.  In an instant, he’s burned into their frontal lobes, and that’s that:  they spend the rest of their lives following him around.  They never go do whooping crane stuff, but they get to be pretty good with power supplies, co-ax and housewives. Although it mostly happens with birds, there are documented instances among higher primates.  Which is how we explain Shawn Tripp.   His mother had had him up to her shoulder, and he’d been facing the hospital window, toward the driveway out front, when he opened his eyes.  The first image the baby’s retinas ever conveyed to his visual cortex was a red A-body parked there and, well, that was that.  And the whole phenomenon got way worse through a process known as secondary association, when his father bought a ’70 Dart Swinger and then spent plenty of time driving the boy around in it at high speed.  That meant that his imprinting on A-bodies expanded to include going really fast in A-bodies.  ‘Course, lots of brilliant guys like Shawn have inexplicable affinities.  They do things like join the bomb squad, run with the bulls at Pamplona, or take up with redheaded women.  But once you do any of that, well, you aren’t in control anymore.  The best you can do is hope to manage it.  And that’s just what Shawn did.

Red rocket can hold its own on show filed grass as well as the launch pad.

By the age of 15, he’d scavenged the funds to buy his first car – a ’73 Dart — and a few years later, he convinced his father to sell him the ’70.  Then a while later he bought another one.  And then one more.  And then a couple more after that.  And then something like maybe three more.  Well, it was five more.  And then something like another, well, eight of them.   Nineteen in total.  Many of them ended up as parts cars, but a lot of ‘em became projects.  One thing he noticed was that every time he did a project car he got divorced.   A new strategy he’s been running for a while now is not to get remarried.     

Anyway, the reason he bought the ‘73 you see here is that it was just like one he already had.  His friends spotted it at the local dragstrip, where it had blown the motor on a Friday night.  By Sunday, it was in Shawn’s driveway.   Now, you can reinforce your basement beams and put a ’74 Dart Sport in your living room, and a ’72 Swinger actually looks pretty good in the kitchen if you don’t mind about the sink.  An old slant-six will fit just where the TV used to be, and you can wallpaper the master bedroom in spare rolls of Mod Top, but sooner or later, you’re going to run out of room.  Then what?  Well, if you can’t buy any more A-bodies, then the secondary association takes over, and you simply make them go faster.  Way faster.

So, Bucky, what would you do if this Duster pulled up alongside your Hemi whatever at a stoplight? Run and hide or offer the guy Grey Poupon?  Weld supplied the rollers while Wilwood handles the braking duties.

As part of the A-body imprinting, Shawn’s a confirmed smallblock guy.  Won’t even consider anything else.  So, the Duster got a 340.  But the secondary association demands stunning levels of power, so he promptly turned it into big-block displacement with 416 cubes.  That was charming and delightful for about 2 minutes, before he determined it just wasn’t enough.   He went with nitrous, and instead of a nice, conservative one-quarter-of-the-engine’s-horsepower addition, he threw on a 250-horse plate system.  The only thing Shawn loves more than A-bodies is breaking them.  That’s because if he’s breaking them, he’s making more power – and going faster – than before, keeping the imprinting happy.  So of course he was delighted when the new nitrous system immediately cracked the heads. 

R3 NASCAR smallblock cranks 1200 HP at the wheels (1800 at the flywheel) with 16 psi boost. Mill is built with W8 heads, Ross slugs, Callies crank, Carillo rods and Jesel valvtrain motivated by a Comp Cams bumpstick. Intake relies on a Performance 1000 cfm carb. A bulletproof setup? Shawn is gonna find out.

As long as he was replacing heads, he did it in style with a set from Indy.   And since those are beefy units, he figured he couldn’t destroy them unless he also upgraded the juice to a 350 horse unit.  Good thing he did, too, or else he wouldn’t have broken anything at the 2005 Frigid Nationals in Rochester, New York.  There, Shawn was gunning it out for his club’s fastest street car title, running against a guy who could pull 9.60s, so he knew he had to beat that.  Someplace about halftrack, the Duster shot out the head gaskets at .30-06 velocities.   Following Editor Gromer’s legendary command, “Never Lift,” Shawn stayed in it and managed to pull a gasketless 9.37, winning the title despite an oil-obliterated windshield.

All important boost and fuel gauges monitor the Procharger. Shawn will add a third “blowup” gauge that indicates when parts self-destruct in case his hearing isn’t so good.

Right here in the story is where we would drop the plate system back to 250 hp and go attempt to convince the publisher that “Mopars in Hawai” is exactly what needs coverage next.   Of course, not Shawn.  Instead, he O-rings the heads.  But then figuring there was no chance he’d be able to take out the O-rings without help, he added a SECOND massive nitrous fogger system worth an additional 500 hp.  Problem was, it wouldn’t fire off.  He could use the original 350 system, or he could use the secondary 500 system, but once one was armed and fired, that was it.   He drove around that way for a while before one day it dawned on him:  he was using the starter stud as the power source for both systems.  He didn’t have enough voltage to throw both relays at once.  He immediately changed the power supply, and went to the strip.  As he hit the second system, the front wheels lifted off the track and stayed that way for 200 feet of explosive acceleration.   He was ecstatic – not because of the run, but because the nitrous then catastrophically watermelloned the block.

A 7.50-certified cage keeps the car—and Shawn—together in case of a mishap. So Shawn can squeeze another full second out of his ride before he gets kicked out of the track. ‘Course it won’t make any difference on the street. Setup is race function with street neatness. Wonder what the presets are on the radio.

So  just as Shawn was contemplating his next motor, karma sent Kent Ridder his way.  Kent has a lengthy racing pedigree, and more importantly, he has a warehouse like that one at the end of Raiders of the Lost Ark, packed to the skylights with smallblocks.   Of course, the imprinting’s secondary association took one look at that and started turning handsprings.  Shawn ended up with an R3 NASCAR Craftsman Truck block, with W8 heads; the R3 uses six bolts per cylinder instead of the stock four.  The block started out at 358 c.i.d., but a Callies stroker crank knocks it out to 385.  Carillo rods, Ross 9:1 pistons, Jessel valvetrain, and a Comp Cams roller bumpstick fill up the empty places.   Shawn became momentarily disheartened when he realized how hard it was going to be to break all that strong stuff, but then he had the idea of putting on an F2 Procharger, with an air-to-water intercooler.  That took care of that.  

To keep the impending breakage from also including him, Shawn made serious chassis mods.  The Duster was already tubbed when he got it, so that much was taken care of but he figured he’d add a Magnum Force front end.  Well, that got completely out of hand, and pretty soon it became a full funny car cage certified to rune 7.50s.   And while it was apart, he has his bud Josh Cobb shoot it in Probe Red.   Differential duties are by Dana, running Strange axles, a 4.10 and a spool.  It goes to ground through Weld wheels wrapped in MT ET Streets.  To further enhance his likelihood of survival, he’s got a chute system.

Smallblock is backed by a Tansmission Specialties 2-speed ‘Glide and spooled 4.10 Dana. Wing, ‘chute and wheelie bars give Shawn the edge in the stoplight wars.

So with the car put back together, he hit the track.  Carbureted blower cars are notoriously difficult to tune and this one was no exception.   At first, he couldn’t get it sorted out, and the car just wasn’t running.  Then a guy named Hal Saracola showed up.  Hal tunes jet engines for a living, and has developed a Dali-Lama-like total omniscience for matters of combustion.  Among the diagnoses that Hal came up with was that the carb simply wasn’t capable of flowing enough.  They added in a wet nitrous plate system without the nitrous, changed the air bleeds, and chanted a few mantras.  Results:  spot on.  Hal is now on our speed-dial

The way they knew it was spot-on is that Shawn promptly broke it.  On the first tuned run, the wheelie bars smashed up with such violence that they dented the subframe.   The fix for that one was better wheelie bars.  In final tune, the motor runs 19 pounds of boost on 116 octane, producing a chassis-dyno’d 1,228 horsepower at the Mickey Thompsons.   Shawn actually does drive the car on the street, but with a milder tune.  With full tune at the dragstrip, the Duster’s run a stunning 8.71, this past Fourth of July.  Shawn was ecstatic, not because of the ET, but because he blew up two pistons in the process – that wasn’t the fault of the tune, but because the fuel pump blew a fuse.  Of course, from the standpoint of the imprinting, it just means another chance to go even faster! 

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