Thrust SSC - Mach 1 Club

ThrustSSC Mach 1 Club

All Revved Up...

All Revved Up
- and nowhere to go?

David Tremayne


It's got 5000 bhp and the aerodrag of a knitting needle, but Chet Herbert's streamliner with no name is in danger of having no track, either, on which to prove its ability to top 500mph.

We're all familiar with the supersonic cars lining up for a crack at Richard Noble's land speed record - Noble's own Thrust SSC, Craig Breedlove's Spirit of America and Mclaren Maverick - and with Rosco McGlashan's subsonic Avssie invader but the wheel - driven LSR is under every bit as much pressure from a number of American sources.

The big problem they all face, the automobiles even more so than the jets, is finding a suitable track. Chet Herbert's latest Bonneville car - which follows Al Teague's example in possessing no proper name - went to the salt in 1990,'92 '93 and '94 but has so far made fewer runs than an English cricket team due to a combination of mechanical ills and bad weather. When yovr paper specification suggests you have a car well capable of knocking over the existing record of 409.277 mph set in 1965 by Butch Summers and equalled by Teague's 409.986 in 1991 , that spells Frustration with a capital F.

Herbert himself hides it well. Wheelchair-bound since contracting polio as a teenager, this champion of the roller cam knows enough about the capriciousness of Mother Nature in general and the salt in particular. Back in the '50s his cars which bore the name Beast were legendary before he switched his attention to drag racing with partner Roy Steen. Where Herbert runs his thriving camshaft and hot rod accessory business in California's Orange County, Steen and his sons Josh and Clayton run their machine shop up in idaho Falls. Herbert drew the streamliner on his CAD system in 1989 having taught himself its rudiments, and the Steens then built the aluminium pencil. Long, low and narrow, it boasts a very competitive drag coefficient, and its 5000 bhp promises solid speed. As and when nature cooperates...

" I decided it would be nice to be back at Bonneville again," he says, "and I talked to Roy about being partners. We'd done a twin F85-engined car before, and he was keen..."

The Summers Brothers' gorgeous Goldenrod produced 608 bhp from each of its four supercharged Chrysler Hemis. It was 32 ft long, 48 in wide, and most of it was 28 in high. The wheelbase was 207 in, and the whole car weighed 8450 lb. The Herbert car is 36 ft long, 30 in wide and 30 high, and now sits on a 340 in wheelbase after 60 were added during transmission modifications. It weighs around 9000lb. Both use four-wheel drive.

The streamliner also employs four engines, also mounted in-line, but the 6.9-litre Rodac Chevrolets now conservatively provide 1250 bhp apiece on Hillborn fuel iniection and a diet that is 25 per cent nitro. Air scoops add around a pound of extra manifold pressure per hundred miles an hour, which at the vehicle's estimated maximum should generate some 200 bhp more per engine. The exhausts are stack pipes, like the 1962 BRM V8 and like most drag cars. It's one of Herbert's signatures. "I had the first drag race zoomies back in 1958, and now they all run them! They stabilise the cars because they help to hold them down on the road, and they work just fine on our car." The streamliner has about double Goldenrod's power. Consider that the latter was still in the third of its four gears the day the late Bob Summers set his record, and the newer car's potential is put into even greater perspective.

Initially two three-speed BJ transmissions were used, in conjunction with a third transmission which helps to minimise wheelspin and ties all four engines together so they run at the same speed. This one is located between the front and rear pairs of engines. The front two V8s are mounted back-to-front to counteract the vast torque, estimated at around 5000 lb ft in a car that's less than three feet wide, it has a serious influence on dynamics! The front engines, logically enough, drive the front wheels, the aft pair the rears.

Subsequently the BJs were modified to seven-speeds, "because we didn't need so much bottom-end torque and too much gear reduction was snapping driveshafts," explains Herbert. After their initial trail, the seven speeds were reduced to five, which has proved the best compromise. A pneumatic drag-race shift is used. The Steens made the differentials themselves, utilising tank gears!

Where Goldenrod had an uptilted nose and spats around the lower extremities of the wheels, the streamliner is squarer-bodied, dissuading air from flowing beneath its fuselage.

"It's '50s thinking to throw air under the car," Herbert declares. "There's air going under ours. It has the lip at the front so the air has to go over the top, and the flow is very stable from that lip backwards."

Surprisingly, however, the car hasn't been in a wind tunnel, because he believes: "The shape could basically be refined two or three per cent, but to get the basics like that there's not a hell of a lot you can do." There are many engineers who would disagree with that, but he continues: "It's as little and as smooth as it can be." There isn't a chassis frame as such, either. With those four Chevies and their associated equipment, there isn't a lot of room for one. Instead, three-quarter inch aluminium plate forms the sides of the car and the engines are bolted to this and with crossmembers help to form a basic monocoque structure. "The engines just barely slip down inside, and the whole thing is very stiff. Even though it's 36 ft long, you can lift one side of it at the front and it'll lift the opposite side at the back. That's how stiff it is. The car's so strong, if it did go over it'd probably lay down and iust slide."

Motorcycle land speed record legend Don Vesco was the first man to try it, back at Bonneville in the days when the vehicle sat on solid aluminium wheels and had no svspension. He didn't have to test out Herberi's latter suggestion. "We did half a mile down the course and it vibrated so much, the course was so rough, that he had to shut it off," recalls Herbert. A year later they installed some suspension and added tyres and planned to try again, with Dan Soran driving. Roy Steen designed a neat suspension system allowing three inches of travel, using doughnuts like lock washers which would compress under load. By adding or subtracting washers the team could stiffen or loosen the springing medium, which took up little of the preciovs space. The wheels were now 18 in tractor wheels. Unglamorous, but practical and strong. Herbert says: "They're the same as Al Teague's, and if they're good enough for him, they're good enough for us." Like everyone else who's ever met him, he likes Teague, (January 1992) 1992), rival or not. "What he's done, he's done the hard way."

Tyres were initially a problem. "In '90 we briefly tried some old-style Mickey Thompsons but they threw the rubber at high speed, and we also had trouble with the transmissions; they just weren't strong enough The three-speed units we had then gave us a big problem with a big rev drop-off between shifts which bogged the engines down. For '91 as well as the svspension and tyres we fitted the seven-speed transmissions," he adds. With the original drop-off problem the driver had to resort to slipping the clutch to get the car going fast enough for the gears to take over, with the inevitable supplementary problem of burnt-out clutch linings. Now heavy duty drag racing bronze clutches have been installed, which will put up with any slippage and which lock up from 100 mph on. The streamliner is geared to reach 200 in low qear, with subsequent changes in close steps to avoid the originaI problem. "We can still spin the tyres any time we want" says Herbert, "so Clayton has to be easy on the throttle."

The problem was that all the work ate into the summer, and they missed the salt time. In 1992 they made a couple of passes, now with 21 year-old Clayton at the wheel, but had further trouble with the tyres. In 1993 he only got one good run because of the weather, in 1994 only two for the same reason. They were sufficient to indicate a number of things, however. "We know that our new M&H tyres are good," enthuses Herbert. "They've been spin-tested to 700 mph and our problems there have been solved. Now we know that the car could run 500 if we got a good course and enough passes. Clayton hit over 400 in two and a half miles according to the tech, but he had to shut it off before the lights. We got a bearing problem in the engines, but we now hope that a new dry-sump system will have fixed that. We have 20 quarts of oil in each engine, but it just wasn't draining back enough.

"The good thing is that we know the car has very good traction and accelerates faster than anything else. It was 60 mph quicker than anything into the first mile in '94."

What's it like to drive? Clayton laughs. "It takes off pretty good. I pulled one and a half gees off the startline. . . As far as the driving characteristics are concerned, it drives fine. Unless you get yourself in trouble, you'll go straight. You just need to be relaxed and not jerk on the wheel." In 1992 he averaged 364 mph one-way through the mile, and that's been his best to date thanks to the conditions. "We didn't get a return, because we were still trying to get the bugs out of its one way."

The current problem is that life so far has proved anything but a case of have car, will travel. If they are to avoid the fate that befell Donald Campbell's Bluebird CN7 - whose eventual 403 mph record was way below its own 500 mph potential Herbert and the Steens must find the right track. Naturally, they're interested in the activities planned for 1995 at Lake Gairdner in South Australia, where the international Speed Challenge body is hoping the establish the salt used by the Dry Lake Racers of Australia (DRLA) as the new mecca for high speed seekers. But Clayton is also hopeful that Bonneville will yield up suitable salt in July.

I don't know what it's all from," says Clayton of the Utah course's surface problems. "'Cause you know, they mine that potash out from underneath the salt. They moved the race course further down the flats the last race this year, further from the access road and down around the end of the first dyke. And there was fairly good salt in the middle of the course. The beginning and the end were soft, but the centre stayed good and hard."

"We estimate that he hit 437 before the lights on his run in 1994," says Herbert "A lot of figures have been blagged arovnd, but he was reaching around 440." Steen is more circumspect. "That was just from the onboard data on our own computer system, what the rpm readings were versus where we were at on the course. That's nothing official." "It was the first time he'd been full throttle for so long," Herbert continues. "Then the oil pressure light came on because of the bearing problem, so he had to shut it down. We reckon that run would have been good for 450 otherwise."

Such figures are easy to bandy a round, and until it's in the record books it doesn't matter. But Teague's 1991 best-way run at 425 through the mile and a 132 foot pass at 432 are indications of what the future can hold for the wheeldriven record and given the right conditions there's no reason to suppose that the Herbrt car won't go very quickly indeed. If Mother Nature plays hardball.

"It's a pity we didn't start the project three years earlier, before the salt went bad," says Chet ruefully. "The car has so much potential to break Al's 432 best, even somewhere like El Mirage. But that would be too dangerous. If Clayton had any chute Problems there, he'd probably iust keep on going!

"Back in '54 we broke the 10-mile record at Bonneville and we had two, three miles run-up at each end. We had a 15-mile course that year. Now, even on a short course, I think we can break the record. The tyres, the transmission and bearing problems, they're all sorted. No matter how bad the course is this year, I reckon we can break it. The car's now on 26 in M&Hs and it was built to do 500 on 30 in tyres, so with our current gear ratio we're probably good for 450/460. The way the salt is, I'll be happy just to break the record."

Opinions vary just how bad Bonneville's problem is. A recent visit there brought the shocking realisation that where one used to feel as if one was driving across a snowbed on interstate 80, it now feels more like the Black Rock Desert. Instead of pure white, the edges of the flats are muddy yellow. It was like visiting an old flame and discovering that she was starting to go bald. Some say the flats' great days are limited, that too much potash has been extracted to allow the salt to go through its annual self-healing, self-generating process. Others are more optimistic. Time will tell, hopefully before it's too late and the Great Salt Scandal proves irreversible. "I'll tell you what," says Chet, "it's a drag race now, with the short course."

And drag racing, lest we forget, is what Herbert and the Steens have been doing rather well for many decades.

DAVID TREMAYNE, 1995


Mach 1 Club Home Page


About this site

Supersonic Race Update Mach 1 Club ThrustSSC Shop
Sponsored by This site best viewed with Microsoft Internet Explorer 3
Digital msie artewisdom

© SSC Programme Ltd, 1997