KyleDallas

An interesting little tidbit from the Hemmings article on the Sunray/Yenko 67 L-88 at the Daytona 24 Hour race of 1967... Yenko had a special 2.60:1 rear end ratio, made by Chevrolet Engineering, that pushed his L-88 to 194 mph.

I can't help wondering what type of aerodymanic buffeting was occuring at this speed... I say this for two reasons.
First, I have an article that stated that Junior Johnson had parked his
Stingray at Daytona because of the car's instability at high speed
a few years earlier. Second, I remember the "Flying Front End" feeling
some of my own street cars had when I had them up over 110 mph in the early 80's.

Whatever magic Yenko found was certainly the real deal... he won
GT class in 1968........ in a 1967 L-88...... against the more slippery
C-3 L-88's.

http://www.hemmings.com/mus/stories/...feature12.html

jr9170

I remember reading about that car in the NCRS CORVETTE RESTORER a few years back.I also remember reading in Corvette Fever that the #57 Rebel Racer was clocked at 212 mph on the backstretch at Lemans.

jr9170

BTW,does Richard Prince still own the #8?

joe58

In 1968 the Yenko DX Oil team ran 3 Corvettes 2 1968 L88s and the 67. The 67 Finished 1st in GT class and 10th overall but was driven by Jerry Grant and Dave Morgan.
Don drove one of the 68s which had rear gear oil overheating problems.
There is a well used PR picture of all 3 DX Oil Corvettes on the high bank with the Daytona sign in the backround.

jr9170

Does anyone have that pic of all DX vettes?If so can they post it.

KyleDallas

Here's an excerpt I have on the Rebel Racer:

"Over the years, Corvettes have not done well at the 24 Hours of Le Mans. It's a tough race and most cars don't finish. Until recently, the only Corvette to actually finish the Le Mans race was the Rebel Red big-block, '68 Corvette driven by Bob Johnson and Dave Heinz. The car was owned by Toye English and was built and worked on by his son, Dave. After taking first in GT class at the 24 Hours of Daytona and the 12 Hours of Sebring, the team decided to race the car at Le Mans.

When they arrived at the race, they almost weren't able to race because they did not have an invitation! Luigi Chinetti, an importer of Ferraris, had entered only two cars and agreed to let the team use his third invitation, as long as they repainted the car to look like Chinetti's Ferraris: red with a blue and white stripe, and wearing the N.A.R.T. decal. A small price to pay after going all the way to Le Mans.

The car could not have performed better. For the entire 24 hours all the car needed was a driver change every hour, gas, tires, and oil. On the very long Mulsanne Straight, the car topped out at 210 mph! Only the prototype cars were faster.

The Corvettes were the biggest and heaviest cars in the GT Class, prompting many to ask, "What's in that dinosaur?" Just good, strong, Chevy parts, thanks to Duntov and crew. The car is basically a '68 L88 model. Under the hood, the L88 was balanced and blueprinted. An 850 Holley carb sat on an aluminum high-rise manifold, and header-side exhausts helped crank out over 560 horsepower. The suspension used heavy-duty L88 parts, along with solid suspension bushings, heavy-duty springs, anti-roll bars, and double- adjustable Koni shocks. A standard M22 transmission and heavy-duty Posi unit were used as well as.

Additional body work included factory fender flairs, L88 hood with the cowl-induction, plexi headlight covers, and the factory hardtop. A front spoiler helped keep the front end down on the Mulsanne. The interior had a full compliment of gauges, a bolt-on eight-point roll- cage and a Vega steering wheel. American Torque- Thrust aluminum wheels and Goodyear racing tires gave the car a distinctly American musclecar, tough guy look.

This is exactly what Zora had in mind with his "for racing only" parts program. With the right parts, carefully assembled, the average guy had a chance. Completing the 24 Hours of Le Mans is an amazing achievement for any car, let alone a production car with over-the-counter, bolt-on factory parts. "

KyleDallas

Here is one of the DX Yenko cars in 1967
http://public.fotki.com/scalecentral...y_vette_8.html

Procrastination Racing

Wasn't Jr Johnson's a small block a couple of years earlier?

Talking to Phil Currin several years ago, he said that his '63 coupe had a tendency to lift the rear end. The rear would lift enough that tires would begin to lose traction somewhat. I think he said that was around 150 or so. He had a lot of front air dam, so that helped lift the rear.

My '66 convertible also wanted to lift the front end at Daytona. When you figure that you are actually in a bowl and driving around at speed tends to smash you DOWN into the track, lifting means there is a lot of lift in those bodies.

I did have a front air dam, not nearly as much as I needed, but there was one. It was about 5 inches deep and flared over the front wheels ala Pontiac Trans Am style which also helped hold it down. My top was around 185-190, depending on how you figure it. I only had a 3.08 rear. I had tried to find a 2.73 which would have made life must nicer. Still, taking off with the 427 and the 3.08 was not pleasant and I can't imagine a 2.60 rear. Of course, some of that was the triple disc racing clutch with no spring dampers.

The best way to describe it is for anyone who has drag raced a bike at a drag strip. If you have, then you know how the front end of the bike wants to lift, and you need to basically reach your body out across the handle bars and shove it back down on the ground. Well, that is about how a '66 Sting Ray feels at over 180 at Daytona.

I imagine anything like that for a good ol' boy NASCAR racer must have made them ready to fill their pants. No wonder he parked it.




www.corvettelegends.com/penske.htm
Penske's car, with the exception of the crudely flared fenders, is very stock. It is amazing anyone would run those speeds in that body.

Dave9542

Here's a piece of trivia. I took title to 66 BB Coupe in March 1966 from Roger Penske at Penske McKean Chevy in Philly. Took it back to Roger 3 weeks later with stuff needed fixing. And left it for two weeks. Had to because I was at Annapolis and could not get back quickly. Roger asked to take car home so mechanics wouldn't have chance to rag it. When I picked it up there was about 400 miles on it! I was pissed, principaled and young. Wrote a letter to president, GM. Changed dealers to get stuff fixed Penske's boys had screwed up. Guess he was a busy guy around that time. Mine was probably his driver to the track...or maybe on the track.
Dave

magicv8

I have an air dam on my 66 with the tail 1 inch higher than the front and have run it to 140 in MT with no problems. It feels like any other car at 80mph. I tend to think of all the crabbing about high speed areodynamics as urban legends. I have run triple digits in over 30 states, sometimes for a half hour, and never noticed a problem.

KyleDallas

You need to try 120 plus in a boxy Nova or 70's Pickup ... without airdams or spoilers and stock ride height.

I did 160mph in a 1990 Mustang coupe that had been lowered 1 inch...and had no aerodynamic aids at all..... the faster we went, the more planted the mustang felt... it was a pretty easy way to hit high speed..
But it was a completely different experience than when I had my
1975 Ford Granada 302 running 120mph... the front end had a very light feel that was accentuated with every dip in the road...
the car was tennatively stable... but it wasn't comfortable.. you could
feel control slipping away.

Im sure there are other guys here who had their 60's and 70's
cars up well over 100 and can atest to the front end getting light.

magicv8

No thank you.

I have done that in the 60s at Niagara dragway for a few seconds. The lack of adequate brakes and high speed handling in other 60s cars is why I drive a Corvette.

I stuck the air dam on to keep bugs off the suspension during cross country tours, and I like the look of tail high cars - so I raised the rear of my 1966 20 years ago.

Years later I read that both contribute to high speed stability, so, if that's true, I lucked out in the high speed handling department.

KyleDallas

Unfortunately when I was 16 years old... the old V8 boxes and trucks were the only avenue we had to run speed.... and so that's what we used ...... Big difference between those cars and the club racers I would run a few years later. I hear you on the 60's brakes...

Here's a Grand Sport replica pic... notice how the nose has been
altered to premote aerodynamics.

joe58

this picture is from the Yenko estate sale. It has some water damage
DX Oil sponsored the Yenko Corvette Racing team in 67-68 then DX Oil was bought by Sun Oil who already had the Sunoco race team so Yenko was out of oil money again. Yenko lost Gulf in 1964 when they went with Ford after the Grand Sport program got the axe.

KyleDallas

Joe.... very nice... sell me a copy

jr9170

Joe,that is a great pic...

macdarren

MagicV8,

Might have asked this before but, got a picture of that air dam?


Never Mind I just checked out your web site.....like those aux light too.

Thanks

joe58

found this on my computer. One of the 68 L88s with the Yenko crest on the hood
I think this picture was from an article in Corvette news. They covered Yenko pretty well in the 60s and Don also wrote articles for CN on occasion

jr9170

Joe,another great pic,keep them coming...

63Corvette

My understanding of the reason that Junior Johnson refused to drive the 63 at Daytona....from some of those who were there in 63...is as follows:
In order to check tire wear on the front tires, the inner fiberglass had "doors" cut in them to allow the driver to pull a wire and open the door to see if the front tires were cording. This was because (due to insufficient testing) nobody knew how long the front tires would last Unfortunately it RAINED, and the rain turned to steam, which reduced the in car visibility to ZERO. Then according to witnesses, Junior came into the pits and told Mickey Thompson "If you want this damn thing to be in the race, then YOU drive it".