Ever drag race your Atlantic?

[Stan Clayton]

I came across these photos again recently and thought you might enjoy them...

Anyway, here's the deal. Back in 2000 we got our Ralt RT-41 painted in a sponsorship deal by a shop in Tucson that was heavily into the import drag scene. Part of the deal was that we'd do some car shows with them to show off the paint (it really was gorgeous!). Well, one day the guy rings us up and says that NOPI are having their big show up at Firebird Int'l Raceway in Phoenix...and would we come make some exhibition runs?

Our long-time crew chief Dave Rich is an old drag racer (so am I...I still have my big-block Mustang) assured me on the phone (I was commander of the US air base in Ecuador at the time) that he had everything under control, so I said yes. Dave ran the show and it all came off without a hitch or any damage except for tearing up the "diaper" a bit.

According to all who were there the crowd loved it, even if the announcer did describe the car as a "Toyota Indy Car"...

My sister-in-law Michelle was in the grandstands and snapped these pics. Enjoy!

[Nicholas Belling]

Very interesting.. traction was very hard to acheive.. after going through the sandbox and softening the rear suspension and springs and airpressures I was able to get a semi decent launch..

But the initial 1/8 mile was a little questionable from a comfort point of view with the deep groves in the track, and low ride height clearances.

Will post some in car video sometime when I get around to it.

[lancer360]

Cool! I know a few F500 guys have gone to the track as a cheap way to play around with tuning clutches. If I ever get my car back together, I'm considering it to get some hands on education with various clutch setups.

[Dragnmorad]

He wants to know what the final MPH was? & if you know what your 60 foot time was?

I have no idea what he is asking but that is what he wants to know LOL

[Stan Clayton]

He wants to know what the final MPH was? & if you know what your 60 foot time was?

I have no idea what he is asking but that is what he wants to know LOL

As you can see in the 3rd photo, the MPH lights were not working in the left lane, but IIRC, his speed was about 130 mph. No info on 60-ft time. Sorry. Stan

[swede9]

In 1989 at the Pro Atlantic Event in Seatlle on Saturday night there was a "run what you brung" drag event. Sandy Dells or maybe someone Sandy was running ran his DB4 with gears for Seattle in it, he made 3 or 4 passes (if I remember) he got down to the 10.5 second range, before being eliminated. The local drag boys enjoyed the whole thing, don't remember what odds were given but a fair amount of money changed hands that night.

[J Leonard]

The Seattle event was the first thing I remembered when I saw Stan's post. I remember his reaction times were terrible.

[jerry freeman]

I thought about doing this to test some areo stuff. It would also be good to compare acceleration times with different gears. I may do that before I change motors this winter to see what I gain with the GSXR I just bought compared to the old '94 CB Honda.
As far as reaction times go they will generally be bad because you are foot brake leaving in the formula car and you use a delay box in a bracket car. you can dial a slow driver in to be within a few thousandths od perfect with those boxes. I wouldn't worry about the reaction times because they don't mean anything in car performance.

Jerry

[Wright D]

But the initial 1/8 mile was a little questionable from a comfort point of view with the deep groves in the track, and low ride height clearances.

Back in my FSAE days we made special push rods for the accel event. We raised our ride over 2.5 inches in the rear and 2 inches in the front. We also put very very soft setup on the back of the car. Took out all the toe, and set the front tires to 35 psi too.

Might be fun to try the same type of set up on your f1000.

[Steve O'Hara]

I saw this thread and thought some of you guys might be interested in a project I started back in 1993 but never really finished. At the time I was running the Toyota Atlantic Pro series and we did standing starts in all of our road and street course races. Starts with the very peaky carbureted Atlantic motors were always a crap shoot with either excess wheel spin or a major stumble being the result too frequently. I had observed form some of the events that a perfectly executed start could buy you several positions on the start so I dove into an off season project between the 92 and 93 seasons and designed a centrifugal clutch based on the same principals as the drag racing and kart racing clutches. To keep costs down in the development stage I used Tilton 5.5" friction discs and floaters and only built the pressure plate assembly from scratch. The clutch was designed to allow engagement speed adjustment externally through the small opening in the bottom of the oil tank/bell housing assembly and the clutch pedal and slave cylinder were employed in the opposite function of a standard clutch.... pressing the clutch pedal would lock the clutch up rather than disengage it.
With the help of some very bright enginnering folks I knew we created a mathematial computer model to estimate the spring rates and lever arm design in order to reduce the "cut and try" methods. The initial test was promising but our model missed by a pretty large margin as we seriously over estimated the clamping pressure needed to harness the HP of the motor. Our second design of the lever arms proved to be almost perfect and the clutch could be adjusted to engage anywhere between 5,500 and 7,500 rpm. In January of 1993 I took the DB4 up to The Streets of Willow and had Willi Oppliger along to wrench on the car. In those days we used a DA system made by Race Log and we went through a series of tests working with different combinations of levers and spring preload in the clutch to manipulate the engagement characteristics. As the testing proceeded we arrived at the conclusion that 6,500 rpm was close to optimum for best standing start accleration and learned that tire temp was a critical factor.... I think some drag racers could have predicted that LOL. At one point in the day I ran a 10 lap session and then came into the pit lane for an adjustment to the car and then executed another practice start that simply astonished me and Willi and several other observers. The car launched much better than any previous or subsequest attempt and upon downloading the data after coming in to the pits the Race Log system showed the car had gone from 0 to 60mph in just under 2 seconds! The launch produced visible wheel spin according to the guys but left only a very slight haze of rubber transfer on the ground for the first 30 to 40 feet. We never duplicated that result but we had it close a few times. In 1993 the first road course event was Long Beach and I used the clutch throughout the weekend and finished 4th.... the highest finishing DB4 amoung the 7 or 8 RT40s. The Players cars of JV and Claude Borbonnais were dominant and ran off, Empringham was 3d not that far ahead.
One intersting and unexpected benefit of the clutch that proved to reduce lap times was that it helped the car turn in much better in the tight hair pin corners. The clutch would effectively disengage on approach to the tight corners and take the engine braking torque out of the diff and the car would roll very free through the entry phase of the corner. In additon, low speed stumble was eliminated completely when getting back on the power.
We ran the clutch at Montreal that year and also at Toronto in 1994... both dnfs for other reasons. I never fully developed the clutch to its true potential as I stopped running the pro series after long Beach in 1994 but I am certain it was and advantage and would have been more so if completely sorted out. My guess is that an Atlantic car set up with that clutch could have run way down in the 9 second bracket but we never had the opportunity to prove it on the track.
Not long after I stopped running, the series abandoned the standing starts and it rendered the project kind of pointless for the Atlanics so I showed the clutch to some of my contacts in the dirt racing world that ran one of the Nations top Midget teams. I made the observation that those dirt races are always screwed up because every wreck leaves several undamaged cars sitting stalled on the track and the push trucks have to come out and re start them. I pointed out that my clutch would allow the cars to come to a complete stop on the track and then just step on the gas and drive away! To get it in the hands of the right people for testing I gave the clutch to my long time friend Tony Maglizzi of L&T Clutches and sadly Tony died of a sudden heart attack before we could get the clutch in a car for testing. In the aftermath of Tony's passing the clutch disappeared and has never showed up since.
Ah, the good old days.... always looking for an advantage!
Steve O'Hara

[bill gillespie]

Steve,

Thanks for a really interesting look at the really smart work done way back when....as an adjunct to your project, I've always wondered why no one has developed a sprague clutch ( similar to the Hegar clutch for shifter karts), or a slipper clutch like the Super Moto and Superbike guys use.

Seems like that would save a lot of wear on the gearbox for left foot braking and sequential, clutchless downshifts.

Lastly Steve....paragraphs, dude!

Best regards,
Bill

[Daryl DeArman]

Steve,

Thanks for the story. I knew of Tony, I was just getting out of karting at the time his clutches entered that scene. Did you ever attend his motor meltdowns out behind Callahan's, near his shop? I have one of his first on VHS somewhere....

[Steve O'Hara]

Quickshoe,

Yep, I went to one of Tony's "Big Bang" shows and there must have been 300 people there! The amazing thing to see was how hard it was to destroy a Mazda Rotary... the damn thing would not blow up it just eventually melted

Steve

[Steve O'Hara]

Bill,

I'm not up to date on the latest clutches used on the bikes but I suspect that the function is very similar to what I built. Another very nice benefit to the clutch was that it made downshifts very easy as long as the revs were allowed to fall down into the 5 to 6K range. At that speed the clutch was closed but would not apply much pressure so there was very little throttle application needed to make the shifts and no chance of locking the rear wheels by grabbing the lower gear too early.... not that I ever made that mistake LOL
Steve

[formulasuper]

Steve, Reading this reminded me a lot, being a ex-F500 racer, of how the F500 clutches work & the benefit they provide. They are one of the reasons they are able to run laps equal to FF times. However the headaches of setting up the CVT's in one of those cars became the reason I left the class!