Total, Absolute, Wretched Excess
That's about all you can say about the quad turbo, 442ci big-block race engine 31-year-old Mike Moran's famed, street-legal Camaro. Dreamed up with his partner in crime, EFI-wiz John Meaney, Moran's four-huffer is one of those pieces that requires a lengthy, 360-degree study to truly appreciate, though most people will never get to see it that way.
Why's that? Because this tentacle-strewn monster is built to shoehorn into the engine bay of a '95 Chevy Camaro Pro Street car. But you won't have to skulk around Moran's pits at the next street legal drag race to catch a glimpse of this modern marvel, just sit down and learn all about it right here. Better read fast, however, as the street legal groups are likely to ban this thing as quick as they see it!
As wild as it may look, Meaney and Moran, both from the Detroit area, seem to think this quad-turbo big-block is not that over the top. "Well, John (Meaney) and I were sitting around one night talking about engine technology and what kind of engine packages haven't been tried and this is what we came up with (see sidebar...). We just felt if two turbos worked good, then four would work even better-especially on a big engine like this one."
Unfortunately, they didn't get to run this engine on the dyno until just after our deadline, so look for performance figures next month. Moran isn't worried, "Actually, peak power isn't a major concern with this engine setup. We know from experience the turbo engines are easier on parts than the nitrous engines and being able to finish races is worth a bunch when you race in a heads-up class like Pro Street. So if we can get the airflow and fuel distribution figured out, we should be alright."
Beyond dreaming this engine package up with his buddy EFI-guru John Meany, Mike Moran figu
TURBOS VS. NITROUS
Moran has raced nitrous'd cars for years, but it's not hard to see his logic in running a turbo car. He said, "Not long ago, the rules for street car racing had the turbo cars weighing less than the nitrous cars for the same cubic inches, so guys started experimenting with turbocharged engines. A couple of years ago, the turbo guys wouldn't have been able to make the reliable power they do today because the electronic controls didn't exist. But thanks to John Meaney, who created the aftermarket Fel-Pro electronic engine control module, these turbo cars can be tuned to the ninth degree. "The only problem to the turbo development has been that as the turbo cars got faster, the sanctioning bodies made them weigh the same as the nitrous'd cars. The turbo engine is more repeatable. It is not as violent in the way it builds combustion pressure as compared to a nitrous engine. Because of this, the turbo engine is easier on parts, sparing piston ring lands, bearings, and such.
While the parts might last longer, that doesn't mean they are off the shelf. Moran is a technology geek, which is good because he builds race and street engines for a large array of applications through his engine building company, Moran Motorsports. The Camaro is his testbed to refine or throw out various pieces and theories. Because of this, the Quad Turbo engine is loaded with neat stuff. While they won't give us the particular dimensions. Meaney said, "this is a GM DRCE-based turbo engine that'll rev almost 10,000 rpm--you figure it out." So, we said that's a giant bore, a relatively short stroke, and a long rod. Meaney answered, "You're on the right path...." Check out the details we could get...
A NO-GASKET ENGINE?
This engine doesn't have a single gasket in it anywhere. Says Moran, "I haven't had good luck with gaskets in either the nitrous or turbo engines, so this engine is machined for O-rings at every mating surface. Cutting those grooves everywhere adds to the initial cost of building the engine, but I believe it's worth it. Without gaskets, I can pull the engine apart quickly, service it and get it back together without worrying about whether the gasket surfaces were cleaned off and siliconed properly to seal the engine back up." Moran has his machinist create a CNC program for each O-ring, so replicating the grooves on customer engines can be done quickly and efficiently.
Probably the wildest O-ring in the engine is the silver-plated, nitrogen-filled, aluminum tube O-ring used to seal the combustion chambers. These O-rings are similar to technology used in Meaney's BB/A turbo drag race engine and come from England. Moran has them custom-built for his application and feels they are the future. "We run peak combustion pressures that are right at the limit of a solid copper gasket," Mike says. The nitrogen in the O-rings expands as the engine gets hot and does a great job sealing the head to the block no matter what the pressure. About the only negative we've have seen is when they're cold, they bleed off a little combustion pressure. But we don't race when the engine is cold, so I consider them a great solution."
Intake and Packaging
Since this engine has four turbochargers, there is a lot of air to force down into the intake tract. Moran is trying some reverse technology to fill the cylinders, "Obviously, we wanted an unrestricted, even flow of air into the engine, but also wanted to keep the hood as low as possible. To do this, we just looked at airflow systems that work in tight spaces--and what I saw were exhaust headers. Our intake looks similar to an exhaust because I took the basic design of a tubular exhaust header, reversed the airflow, and starting making changes to optimize the flow. We don't know if it'll work as well in real life as it looked in testing, but at least we're trying something different.
It's important to package all of the systems in the car before pulling it on the dyno. To squeeze the lower turbos between the block and the front suspension, Moran mounted the turbo just above the lower A-arm of the front suspension. To make sure the turbo wouldn't interfere with the suspension movement, Moran set the A-arm at full bump first. While doing this on a car that sees a lot of street miles would not be recommended, this "street" car doesn't see a lot of highway miles.
Of the entire turbocharging setup, the laggard in technology seems to be the wastegate, and Moran knows this. "On each side of the engine, We have tied the two turbo pressure tubes to one Turbonetics wastegate in an effort to create a "semi-closed-loop" wastegate system. Since the wastegates are simple, spring-tension popoff valves, they act independently of anything else in the turbo system, which creates a variable in controlling the engine. For now, until they try electronic wastegates, hopefully tying the two turbos together will keep the pressures even throughout the intake tract.
Currently the team is investigating electronic wastegates with linear actuators for closed-loop boost control. This is serious stuff.
In the last decade, domed pistons have gone the way of the dinosaur but the victorious dished piston continues to be refined. The latest technology is pistons with a sculpted dish, like the JE Pistons V-dish examples that Moran prefers. Since he uses a custom combustion chamber design, he starts the process of ordering his pistons by creating a 'plug' using an old piston and some port mold epoxy. This plug is used by JE to create a piston dish that directs the force of the combustion towards the center of the chamber. This theory focuses the power created by the combustion pressure to provide maximum effort on the piston, thus creating more power at the crankshaft with the same amount of combustion pressure. Look for ultra-stout GRP connecting rods in this combo.
Moran focuses a lot of thought on maximizing the use of the combustion pressure in each cylinder. As he says, "Any pressure not pushing that piston down the bore is making me look bad, so I'm going to do what I can to get it working for me." Because of that, he has worked with Speed-Pro to develop a 'L-shaped' top ring and a self-locating, low-tension oil control ring. These Speed-Pro "Hell Fire" heat-treated ductile iron rings require a stepped ring land be cut in the piston, but Moran thinks the extra work and cost is worth it. "The Hell Fire ring allows me to use the combustion pressure trying to get around the piston to push the top ring up against the bore, creating a tight seal. If we used piston gas ports to push the ring out against the bore, some of the combustion pressure would be wasted to create that seal.
Moran also likes using the lowest tension oil-ring pack possible, but he says, "A problem I've encountered with low tension oil ring packs has been the expander ring overlapping itself while in the bore. To avoid this, Speed-Pro designed an expander that accepts a centerwire to lock the expander into place. Ever since I switched to that, the problem has disappeared.
Moran was a turbo-guy long before racing a nitrous-ingesting Pro Streeter, so he's got some experience on what works and what doesn't. "I raced turbo cars ever since the '80s, so I know little things like adding a 'ice screen' inside the intercooler. When running these turbo cars, we pack the intercooler with a lot of ice and a little water before each run to maximize the amount of heat pulled from the intake air. If a mesh screen isn't installed on the front of the exchanger (which Wheel to Wheel's Dan Van Auken did) when he fabbed up the tanks on this intercooler, the ice will eventually smash the fins flat and reduce the ability of the exchanger to cool the air.
"Also, it seems to make sense to mount the backpressure blowoffs on the Spearco intercooler tanks. These blowoffs are needed to avoid bending the blades on the turbos when at the end of a run I lift off the throttle. The resulting pressure spike could easily frag a turbo, but by allowing the pressure to vent through the blowoffs, this problem is avoided.
Cylinder Heads from the professor
Most people would have zero access to cylinder heads from an engine god like Warren Johnson. But, Meaney and Moran have a mutual friend in Jeff Pearley, Kurt Johnson's crewchief, who arranged access for a set of DRCE big-block cylinder heads, CNC-prepared by WJ. While runner volume is a proprietary figure, we do know the heads have a small cross-section and feature very high velocity. Meaney says, "The Professor is very interested in this technology we're working with here.
The Bottom End
The Winberg crank comes with the counterweights machined in a aerodynamic shape to slice through the oil with a minimum of parasitic power loss and to minimize the amount of oil swinging around the crank and mains. Oil control is a must in Moran's book, so he has a Moroso dry-sump pump sucking four stages from a Moroso oil pan along with a Product Engineering vacuum pump pulling air from the crankcase--a system he calls the Moran/Moroso 4 1/2 stage Dry Sump Oiling System. These systems work in concert to create a staggering 20 inches of vacuum inside the engine. Testing has shown the more vacuum, the less oil is inside the engine (in either liquid or vapor form) and the less parasitic loss to whipping the oil around. As any racer knows, reducing the weight of a car is like making horsepower, so Moran is happy to be running this just introduced Eschelmans carbon fiber dry sump oil tank. It weighs less than half of an aluminum oil tank!
This sparse of oil inside the engine means precautions need to be taken to insure metal on metal contact doesn't create a failure. Some of these insurance measures include having the billet aluminum GRP rods bronze bushed at the little end and coating the thrust surfaces of the pistons with a Swain low-friction, moly-based coating.
Reducing weight in the valvetrain is another passion for Moran. To achieve that, he uses Jesel steel shell/aluminum body roller lifters and Ferrea titanium valves that have the head "tuliped"-or machined down to create a dish. The valvesprings are titanium, along with the retainers. Manton's triangulated pushrods minimize flex, which is important when hoisting valves against the backpressure of four raging turbos. By keeping the valvetrain as light as possible, Moran believes he improves reliability while being able to run nearly 9,000 rpm through the lights.
Moran had been breaking camshafts in the past, so he switch to a custom Crane grind made from a 55mm billet, from a diesel application. The cam also goes through a heat treatment, but it's coated with copper right before. "It's a lot of money to run this type of stuff, but since I've gone to the 55mm cam, I have eliminated the camshaft breakage problems."
Since the cam is the mechanical brain of an internal combustion engine, it's no surprise Moran is tight lipped about his cam specs. But here's what he will say, "In general, I think people use a camshaft with too little duration on these turbo engines. I...I'm not going to say any more than that." Ah, once a street racer, always a street racer.
Plumbing: Air, Oil, Coolant, Etc.
The air, oil and coolant plumbing required on a turbo engine, especially a quad-turbo engine, is daunting. Beyond the cost of having someone build the exhaust and intake tubing, finding the people that can visualize where everything should go to get it all to fit in a tight location and then build it to handle the rigors of drag racing is difficult. For help on this, Moran called on some metal wizards, Dan VanAuken and his crew at Wheel to Wheel in Warren, Michigan, to do the cutting and welding. We got a chance to watch over a few weeks (!) as this system came together and can tell you this process challenges even the most talented fabricators. The results are absolutely amazing in how right everything looks, though, which is a true sign of quality workmanship.
On The Dyno
The boys had some issues in getting to the dyno, but once they did, they found some interesting results. Check the numbers on the dyno chart and you'll see that it made similar power to that of an all-out, 632-inch racing engine on nitrous, but did so at only 24 to 25 pounds of boost. They found the exhaust side of the turbo housing to be too large. Once replaced, Meaney says that they should get 35 pounds of boost and could make as much as 2,800 hp! That should be soon, too. They'd like to thank Turbonetics and Garrett for all the tech support on this project and express special thanks to Infineon Technologies, who you normally see funding high-end Indy car and road car projects (in terms of microcontrollers and such), for the funding to make this project possible.
BEYOND THE TURBOS
The original four-turbo concept came from California's Rick "Speed" Lefever, a Banks Engineering fabricator who was contemplating using a similar setup on his Pro Mod Mercedes. John Meaney used that idea and combined it with a chance meeting with Doug Milliken, from Honeywell's Garrett Turbo division. Milliken watched Meaney's record-holding BB/A Dodge Avenger ripping up the Comp Eliminator qualifying sheet at Pomona a few years back and offered some engineering support with the likes of smaller, exotic Indy car turbochargers, modified for drag racing.
On an Indy car, these super-lightweight compressors (with magnesium housings and turbines built from thin-wall stainless-steel investment castings) made high volume at a low pressure (tailored around a boost-limit rule and pop-off valve) via more clearance in the wheel housing interface. With tightened clearances for drag racing, they make crazy boost while maintaining sufficient airflow. Killer turbos like this allow for the four turbo setup to work amazingly, but you could still make the concept work with available turbos--the tough part is packaging and plumbing.
Meaney likes this setup, and these for four reasons: Durability, as typical, 6-inch turbos often lose thrust bearings under 30 to 40 pounds of boost; Spool time, as it's common knowledge that smaller turbos have less lag; Weight, as two typical Y-2000 Turbonetics turbos (like Bob Reiger runs on his '57) weight about 35 to 40 pounds each-these weight 8 pounds; and Airflow, as these turbos from 20 pounds more per minute than typical turbos of the same size. Look for Moran to run a twin Turbonetics setup if the sanctioning bodies don't let him run the quad setup--it's still a brutal, race-winning setup.
Here's the problem--you can't get them and probably can't afford them. Remember that small turbos are easier to find. Could a racer at least gain an advantage with available stuff from Turbonetics or Innovative Turbo? Yes, but not as great. A bright point is that smaller turbos are easier to find and less expensive than big ones! --Cameron Evans
|DYNOMETER RESULTS |
|RPM ||Power (hp) ||Torque (lb-ft) ||Boost (psi) |
|5,500 ||1,168 ||1,115 ||24 |
|6,000 ||1,364 ||1,194 ||24 |
|6,500 ||1,554 ||1,256 ||24 |
|7,000 ||1,731 ||1,299 ||24 |
|7,500 ||1,926 ||1,349 ||25 |
|8,000 ||2,002 ||1,313 ||25 |
|8,500 ||2,083 ||1,287 ||25 |
|9,000 ||2,139 ||1,248 ||25 |
|9,500 ||2,105 ||1,164 ||25 |
Since these are "street" cars, they must have mufflers. Flowmaster built these specificall
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The advantage of having a computer-controlled engine is it can read how each cylinder is p