Chris Tynan’s Rat Attack ’55 Chev has a 30-year history of running at the pointy end of New Zealand drag racing fields. rat attack two is looking to follow that tradition

The original Rat Attack

Although this month’s cover car might indeed be Chris Tynan’s just-completed, brand new drag racing ’55 Chevrolet Bel Air, in reality this thing started its life way back in late 1983. Converted to a two-door by methods uglier than the fluffer in a Tijuana donkey show, and painted bright orange in a one-car garage, the high and mighty ‘Rat Attack One’ featured nothing more than narrowed rear frame rails, leaf springs and ladder bars. While the rest of the chassis was remarkably as Chevrolet had made it, its 427ci big block was just as pedestrian, an oval port motor with cast pistons, a tunnel ram and a big street cam. Almost everything else in it was stock ” even roller rockers were for rich folk, so to speak. It also ran a TH400 and nine-inch, and in that first half season it ran 12.2s, while dropping rust and dust on the track at every pass. With a Chrysler four-speed fitted it leaped into the mid-11s ” and leaped is the right word: the car would stand up and scoot when the clutch was dropped. Eventually one of the cast pistons cried enough and disintegrated, and Chris still has most of the pieces in a jam jar tucked away on a trophy shelf. Thankfully, those are only a few of the pieces of shrapnel metal he has kept, as a four acre warehouse would be required to house them all. Is there anybody who has raced, almost continually, for as long as this mug?

Old Axe, New Handle

A Liberty clutchless transmission was fitted, and despite being fun, driveline parts often gave issues in the early days. Eventually a wasted trip to Hastings with yet another broken axle on the first pass led to the decision to build a lighter ’55. A whole new chassis was welded up on the front lawn of the old man’s house, bits of ’55 Chev tin were cut out and discarded, and by the time it was finished the stunning new tube-framed blue machine weighed 227kg less than the old one. On its very first pass it broke an axle. Another fine theory into the toilet¦ An auto was fitted, breakages stopped, and the car started clicking off easy mid-nines but was as boring as bat shit. After an aluminium rod got out of the motor while going slow, Chris decided to rethink his whole racing strategy.

Wild Bunch racing looked like fun, and it was. The now red and white ’55 ran 8.40s as easy as falling off a log and never hurt anything. The fans loved the hunting idle and the way the car would lurch into stage, and Chris ripped off the Chi Town Hustler and started pulling off those crowd-pleasing, ridiculously long and oh-so-cool burnouts, including an infamous full-track skid and one that went around the Christmas tree. That resulted in a lecturing from an area steward. Ironically, Chris is now the guy in charge of them.

Another New Handle ” And A Sharpen

A desire to get the car into the seven-second bracket led Chris to purchase a four-speed Lenco and build yet another new chassis around it. And so began the most famous incarnation of this tri-five Chevy. So low it seemed stuck to the ground, the car could do all its predecessors’ tricks, and go incredibly fast as well. On its first full pass the car broke into the seven-second bracket with basically the same combination as used before. The motor consisted of a truck block (as found in Chevy trucks), Brodix heads and the same 8-71 supercharger, and the new chassis and engine tuning made the difference. Capable of 7.50s anywhere, this car beat absolutely everything from 1992 to ’94, only losing two races by wheelstanding for a third of the track, ripping off a strut on landing, and putting guardrail-shaped indents into the Chevy’s flanks.

New Head

By 1997, Rat Attack was running consistent high sixes with a 14-71 on a Rodeck giving a best of 6.74 seconds. A change to Pontiac heads and a 16-71 saw the combination turn sour for Chris. Despite the occasional promising half pass, the engine would not stay together. After much deliberation, and thanks to a kind offer from Tim Watkins, the Chev finally cut all family ties and swallowed a Hemi. With pretty much the same tune-up that the Rodeck rejected, the Hemi-powered Technical Welding/Scrap Palace-sponsored Chevy flew to a best of 6.49 last year, but it was becoming obvious that power was not what was holding the car back from its potential. It was almost 90kg overweight and still had remarkably stock dimensions, and everyone, from sponsors to friends and family, all agreed it was time to put the car out to pasture in Supercharged Outlaws or something. Scrap Palace was keen to substantially increase its involvement; after 30-odd years it was time for a new race car.

New Chainsaw

After building all the old car’s chassis, Chris thought it was time to step aside and let eldest son Robert (who fabricates “stuff” for Bretto, owner of Future Performance in Hamilton) stick this one together, which did cause the occasional argument. “The old man likes to go for it, function over form every time; as long as it works he’s happy,” Bob claims, “but it only takes half as long again to make it nice in the first place.”

It’s not the first tube-chassis car Robert has built, but it’s the first to be featured in NZV8, as most of his work has the wrong exhaust note. After much discussion the parameters were laid down: it had to be sleeker and lower with less frontal area and better aerodynamics, but it still had to look like a ’55 Chevy. In keeping with that thinking, headlights and tail lights would be repo ’55 stuff and, as on the old car, they’d be functional.

Building A Better Chainsaw

Chromoly was the material chosen, both for its weight saving and because the car has to be legal in Australia in case the opportunity to race there arises again. “Originally dad wanted to replicate the Rat Attack chassis, only lower and out of ’moly, but that was never going to work with what we wanted to change, so I started with a clean sheet of paper,” Robert says. “The first bars were bent in July, so time was always gonna be an issue; less than six months and it was mostly all done after work and on weekends, but we got her done.”

Double frame rails form the backbone, while other bars snake their way throughout the car, every tube performing multiple functions in the way only experienced chassis builders learn to achieve. With all that extra pipe and the much lower profile there is less room in the new car; it’s full with just a steering wheel, one seat, three pedals and a bunch of levers. There are two fire bottles in residence on the other side.

You can’t see that much of it but Robert also performed all the tin work. If you study a ’55 Chev from the front three-quarter view, you’ll notice that although they’re as aerodynamic as a brick outhouse, they do have a slight teardrop shape. On Rat Attack Two this tapering has been improved upon in various subtle ways. Bretto and Chris made moulds off the old car and then hacked them up so that Mike Shaw Fibreglass could pop out a more slippery shell.

The roof has been chopped but a little differently than the normal straight slice, the bumpers have been blended into the body, the boot lid eliminated as the wheel tubs inside and the wing on top render it useless. Anything that could slow down the airflow was tweaked as long as it didn’t alter the look of a ’55, and to make Rat Attack Two easy to work on the body can be removed in minutes. Bretto sprayed the shell in go-fast orange and black, then ‘the Hippie’ from Mahana Graphics did the lettering, while Warren ‘Moses’ Houston performed his magic with an airbrush to make all that plastic look metallic.

Weld Wheels were used all round, with the correct proportions at either end and appropriately-sized Hoosier rubber. There are Strange Engineering struts up front (“We used to make our own, but for what these cost, why would you?”) while out back the suspension is traditional four-link and coil-overs. Chris is pretty happy with already clocking Top Doorslammer’s quickest 60ft times in the old car, and hopes to drop them some more with less weight.

The diff is a Strange-equipped, fully floating 40-spline 9.5-inch-based unit, which Robert built with the emphasis on strong but light. The driveshaft is the same ’moly unit from out of the old Chev, as is the Lenco, still with four forward (and one backward) speeds, although the ratios have been slightly revised. A titanium bell housing is used to drop truckloads of weight. Inside it is the same Crower triple-disc clutch, and bolted to that is the 526ci Hemi that pushed the heavier version to sub-6.50s, albeit with a different injector hat and bigger zoomies.

It has a lot to live up to, this thing. Its predecessor is still one hell of a race car, and more than one person thinks it is sacrilegious to replace such a drag racing institution. But time, especially elapsed time, waits for no one. Evolution was necessary, and this new Scrap Palace car is quite possibly the trickest ’55 Chevrolet in drag racing anywhere. Robert, Chris and Bretto, and everyone else who has had a hand in its construction all have a hell of a lot to be proud of.

First Time Out

Just before this issue went to print, the car hit the track for the first time. The car’s first ‘half-track’ pass was a 6.70 at 170mph and the second pass was an impressive 6.45 at 213.33mph. Severe tyre shake saw the car scrape the wall and put it out of contention for the semi-finals. But a 6.45 with a new car on its first outing has shown the huge potential of the new machine to run at the top of the Doorslammer field. Bring on the next 30 years of racing.

Specs

1955 Chevrolet Bel Air

Engine: 526ci (8620cc) Hemi, TFX billet fuel block, Brooks B2 rods, Bryant crank, JE pistons, 11.3:1 compression ratio, Stage 5 fuel heads, titanium valves, Manley springs, Crane Cam, one-inch lifters, Littlefield 16-71 Supercharger, Quadstar injector, Waterman fuel pump, MSD Mag 44 magneto, Future Performance stainless zoomies

Driveline: Crower triple-plate 10-inch clutch, Trick titanium bellhousing, Lenco CS1 four-speed transmission, manual shifted, chromoly drive shaft, Strange Ultracase 9.5-inch diff head, 40-spline Strange axles, Future Performance sheet metal housing.

Suspension: Strange heavy-duty adjustable front struts, QA1 double adjustable rear coil-over shocks, Future Performance four-link

Brakes: Strange four-pot callipers, 280mm front discs, Wilwood four-pot 280mm disc rear, Strange master cylinder

Wheels: 15×4.5 and 16×16-inch Weld Alumastar rims, Hoosier front runner tyres and 34.5×17 Hoosier slicks

Exterior: Full fibreglass body, moulds made by Future Performance and copies made by Mike Shaw Fibreglass. Paint by Bretto ” Future Performance. Airbrush work by Warren Houston ” Custom Dept. Sign writing by Mahana Graphics/Hippie

Chassis: Tynan design, built completely by Robert Tynan ” Future Performance ” as are the wheelie bars, fuel and oil tanks

Interior: Not much! One race seat, RJS harness, Jegs switch panel, Auto Meter tacho, oil and boost gauges, 20lb DJ fire system, aluminium panels and steel floor by Chris and Bob

Performance: 6.45 @ 213mph

Driver

Chris Tynan

Chris Thanks: His wife Colleen for the years of living with an obsessive-compulsive drag racer who can’t help himself. His son Robert, who engineered the complete chassis, diff, zoomies and tanks. Robert’s partner Jenny and son Alex for putting up with his absence. My other three kids David, James and Jennifer for their help when they could have been doing other things. Major sponsor Scrap Palace for funding this project (and other drag racers), enabling us to step up to the opposition. Robert’s boss Bretto at Future Performance (the one-stop race shop) for preparing and painting the body, and for the use of his workshop during the build. The guys at Rocket Speed Equipment for gear use and encouragement. Eric Brooks for wiring, Mike Shaw Fibreglass for body, Matt and team at G&N Sheetmetals.

Sponsors: Scrap Palace, Future Performance. Brad Penn ” oil, Mahana Graphics ” signage, Warren Houston ” air brushing, Mike Reid for helping secure parts and looking after old faithful while I race the new one until I retire.