Hi, all, welcome to two threads! This one is for my posts only, about my upgrades. I'll do another one for Discussion about these upgrades. To better serve all who care to read about what I'm doing to mine, and don't want to search through many pages to find out what they'd like to know, please post any questions or comments in this Discussion thread here. Thank you!
Eddie FourFather Hill Ariel Atom Performance Upgrade
Hi. My name is Eddie Hill, and I’m a recovering Nitrohaulic. I’ve been Nitro free for 11 years, except for my radio-controlled airplanes. I raced Top Fuel cars and boats for many years, and had my best quarter mile run, 323.74 MPH in 4.520 seconds, and also my last Nitro ride, in 1999. If anyone is interested in reading about my attempt at drag racing, the Los Angeles Times ran this- http://articles.latimes.com/1988-10-28/ ... eddie-hill -a good while ago.
More recently, the National Hot Rod Association had this to say- http://www.division4halloffame.com/?page_id=347
And in May 2009, this- http://www.draglist.com/artman2/publish ... Hill.shtml
I bought my Ariel Atom in 2007, attended the first AtomFest event at Hallett Motor Raceway near Tulsa, Oklahoma, and instantly fell in love with the Atoms and their owners, the road race track and it’s owners, and the thrill of sideways gees!
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Eddie Hill with his Atom at Hallett Motor Raceway, near Tulsa, Oklahoma[/align]
This is my car with me in the right seat receiving some much-needed, and greatly appreciated, instruction from Tim Webb, who is an outstanding individual, as well as a terrific instructor/driver.
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Eddie Hill's Atom with Tim Webb driving/instructing, Eddie as student/passenger, Hallett Motor Raceway, AtomFest Poster[/align]
Since then, I’ve also spent many happy hours at a relatively new track, Eagles Canyon near Decatur, Texas, and it is friendly, well run, and huge fun!
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Eddie Hill and his Atom at Eagles Canyon Raceway, near Decatur, Texas[/align]
The Ariel Atom is probably the most fun of anything I’ve ever enjoyed on the street. (With four wheels, that is- some of the super sport bikes from Honda, Kawasaki, and Yamaha, that we sell, are incredible!) However, the more times I go to Hallett, or to Eagles Canyon Raceway, at Decatur Texas, the less fun it is to drive on the road! Once I found out what the car is capable of doing when properly set up and driven at 10/10ths, it now feels like most street driving is in slow-motion, way less than even half of what the car can do. Still a blast! on the street, but nowhere near the thrill of driving as close to the edge as my driving experience and my instinct of self preservation will allow!
So, after a lifetime of going straight, I’m trying to learn how to turn corners. And having an absolute blast doing it! What I enjoy the most is being able to go faster each time I go to the track, and so I’m always looking for ways to improve my lap times. Most of the improvement since I’ve started, has been the slow elimination of some of my more obvious driver errors. I try to work on that each outing.
My Ariel Atom II is one of the American built ones powered by the Chevy Ecotec 2.0 liter LSJ four cylinder all-aluminum engines factory equipped with a roots-type Eaton M 62 supercharger. Jay Leno has Atom #1, mine is Atom #72. The Atoms are no longer available with Chevy engines, so I’m happy to have not only a very high performance car, but also a very rare one. Not saying these are “collectible”, but I do know for a fact that some high performance cars that are very rare have brought very high sale prices.
In this article I plan to tell about what I’ve done, and what I’m planning to do, to the car, in the search for improved lap times. If this can help other owners, or be of some interest to other gearheads like myself, then that’s a good thing.
Some of the things I’ve done to the engine already:
I’ve installed a very nice sophisticated water/methanol injection system that is very controllable/adjustable, and is happy pumping straight methanol in the current amount of one gallon of methanol used for each 5 gallons of 93 octane gasoline used on track. On the street, hardly any methanol consumption-can’t run it hard enough/long enough under power, to use much.
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[/align]I’ve increased the supercharger speed by using a 2.8 inch pulley on the blower.
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[/align]Two steps colder spark plugs.
I installed the dual-pass endplate on the after cooler/intercooler . This is the stocker-
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[/align]And this is the dual-pass-
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[/align]I mounted and plumbed an aluminum expansion tank with a 22psi pressure cap
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[/align]in place of the original tiny plastic “t” fitting that had the filler cap in it.
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[/align]WaterWetter, instead of antifreeze, in the engine cooling system, as well as in the aftercooler system.
The original exhaust system has been replaced with a much better and freer flowing one, and I have a choice of FlowMaster mufflers for the street, or less restrictive (louder!) ones, for track use. See FlowMaster's ad here-
http://www.flowmastermufflers.com/index.php?page=95
When I run it with no muffler at all, it is easily the loudest car at the track. I love it like that! But I loved the sound of the Top Fuelers, too! Your results may vary. What’s that you said? Would you repeat that, please? (I don’t hear so good anymore)
What I consider the most help to date is the HPTuners computer reader/programmer, and the progress I’ve made in learning to use it. Even though it is taking me a long time to learn to use it, I feel that the progress is good, and I feel that it will only improve with time.
The original ECU was replaced with a Chevy Cobalt one from a used car, to begin the tuning process.
A fellow Atom owner (may I use your name, or your forum name here?) graciously sent me a starter tune to get me in the ballpark with the above modifications, and here is the first dyno result.
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[/align]As you can see, the power takes a dramatic drop at 5800. Before we ran this first dyno, I told the dyno operator that the car felt like it was running into a brick wall just before 6000. After this printout, he said “Man, you weren’t kidding, were you?” It was going WAY RICH at 5800 RPM, much richer than shown here where the Air/Fuel curve hugs the 10 line. The meter was pegged, it couldn’t read any higher!
Although it peaked at 220 HP, it had only about 200 HP, from 5800 through 6900! And on the track, it spends a considerable amount of time in that RPM range. Obviously, we had a LOT of work to do.
So, many tunes and several dyno sessions later, and a total of 22 dyno pulls, after a pretty steep learning curve on the HPTuners equipment, we wound up with this next dyno chart.
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[/align]We were pretty happy with this. It has over 240 WHP from 5800 through 7100, with a VERY driver-friendly horsepower curve that has no reverse curves in it. Peak of about 252 WHP and no sudden surges anywhere to break the tires loose in mid-corner.
An important part of this combination is it’s reliability-NO engine problems in two seasons of track use. The engine has never had the cam cover or the oil pan off, nor has the clutch or transmission (5-speed with Limited Slip Differential-LSD for short) given any trouble whatsoever.
This setup was good for a 1:20.6 minute lap time the first day at the 2009 AtomFest, and that was, at the time, the all-time Atom record.
This next picture, taken right after the record run, shows how serious I got about saving weight to help lap times. I removed the lights, turn signals, the “tea tray’ (rear upper engine cover), and even took the passenger seat out!
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[/align]DP35 later got into the 1:19 zone, and then worked his way down to 1:19.1! And with his inspiration and helpful advice, I have since been able to put three consecutive laps together in the 1:19’s myself, with a best of 1:19.6.
With a goal now of getting into the 1:18’s, I plan to do the following engine work:
Supercharger upgrade from the 1.0 liter M62 Eaton to the 1.3 liter Harrop HTV 1320 LSJ.
CNC porting of the LSJ cylinder head, with better valve springs and retainers.
Install a couple of much more aggressive camshafts with a goal of 8000 RPM rev limit, and good power from 6000 to 8000. If I can do that it will save several time-consuming shifts per lap. As it is now, I have to upshift, and then right after, have to downshift back, on three straightaways.
Forged pistons, probably 9.5 compression.
Lighter and stronger flywheel and clutch assembly, which will save not only total weight of the car, but more importantly, weight that has to rotate and accelerate with the crank shaft, and in every gear.
And I’m thinking more important still, the fact that while shifting up, the rpm will fall to synchronization speed quicker, so time will be saved while shifting. It will also make throttle blipping quicker, and so down shifts will be quicker- not all that important since this is done under braking, anyway, but I like quicker, better. And I have always enjoyed engines more when they rev quickly, even if just for the cool sound!
The engine is out and ready for disassembly-
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