It's no secret that the formula to build a fast turbo Honda has pretty much stabilized. The technology has matured and gains are starting to become incremental. Just about any import event will have all of the Quick Class qualifiers in the 10s and at least three or four in the 9s. The technology has matured just about as we predicted in our "State of Honda Tuning" article back in the July '99 issue. Now, You can now just about pick up the phone and order yourself a 9-second Honda, just as if you were ordering a (very expensive) pizza.
There is a new class heating up where innovation is ripe and the technology is changing quickly. It is the naturally aspirated all-motor class where things are the most interesting; records are being swapped on a race-by-race basis. This is an engine builder's paradise; it is an all-in-the-engine, no power-adding crutches, mano-a-mano challenge to extract power from thin, breathable air. Because the crutch of the boost controller does not exist here, every bit of power helps and the tuners strive to eke out every advantage possible.
Surprisingly, these all-motor cars are getting pretty consistently in the 11s and a few are, unbelievably, dipping into the 10s where they could, on some weekends, qualify mid-pack for the turbocharged Quick Class!
How do these cars do it? What is inside these engines? What does the future hold? We are going to look at the insides of a few of the class leading cars. This is very secret stuff. We had to do some late-night sneaking around with our digital miniature spy camera, buy drinks to loosen tongues and take other devious measures to get these secrets, but get them we did, all for the sake of getting the inside scoop.
First, let's get right to the nuts and bolts, what is inside these high-revving, speed-shifting, high strung monsters? To find out, we dug into two of the leading naturally aspirated engine builders on the import drag racing circuit today, R&D Racing and Automotive Engine Breathing Sysystems (AEBS). These two builders both field fast, record-holding and race-winning machines. Both engine builders build their engines with dramatically different theories and viewpoints. Both, it turns out, are damn fast and are fierce competitors. Strangely enough, both engines seem to match the personalities of their creators.
R&D RacingLet's first look at the engines of R&D Racing. To many of our readers, R&D may ring a bell as one of our favorite dyno facilities, where quite a bit of our own research takes place. What some of you don't know is that R&D is one hell of an engine building and development shop with turbocharged customers like Russ Matusovich and Rodger Scalise. R&D is also a hotbed of naturally aspirated Honda engine development and, as of this writing, R&D holds the record for the fastest all-motor run to date, a blistering 10.73 at 129.8 mph in the CRX owned and driven by Jeremy Lookofsky.
R&D also leads the way with SOHC D-series engine development with Bisi Ezerioha's world's fastest all-motor SOHC CRX, which runs an 11.40 at 121 mph.
What is in R&D's secret engines and what makes them tick? That's what we wanted to know. We first got to look at the guts of Jeremy Lookofsky's and Bisi Ezerioha's record-winning engines when we were at R&D doing some testing on one of our project cars. After a lot of nagging and prodding, we finally got R&D's Darren SanAngelo to admit what the pieces were and whom they were for. SanAngelo's motors adhere to the no-replacement-for-displacement school of thought. They are big. Unbelievably big. So big, that if some of the engineers at Honda could see what was going on with their marvelously designed engines, they would probably say that it was either impossible or just die of a cardiac arrest on the spot.
R&D's racing engines also push the limits of thermal efficiency, fuel science and combustion stability with sky-high compression ratios, higher than we have ever seen successfully run in any sort of racing before. The results of this approach are engines that are tractable, with lots of torque and broad, useable powerbands, sort of like the quiet, soft-spoken SanAngelo himself. These characteristics also are passed onto R&D's awesome, detuned street motors that deliver supercharged horsepower with naturally aspirated reliability.
Let's first take a look inside of Jeremy Lookofsky's world's fastest all-motor H22. Looking at Lookofsky's motor, we can see the custom R&D crank. R&D is having its own forged crank blanks made from 4340 forgings. 4340 is a tough, high-nickel chrome-moly alloy, which is considerably stronger that the stock steel crank. The unique forging is pretty cool, as it allows better alignment of the grain structure within the crank, assuring that it will be plenty strong. R&D is making the crank blank with lots of extra meat around the rod journals to allow for generous stroking of the crank during final finish machining, if so desired.
R&D's own rods are used here, available in either H or I beam pattern. The rods are cut from 4340 forgings and feature 220,000 psi H11 tool steel rod bolts. Like the crank, R&D has commissioned that its forging dies be made to the company's spec, so these rods are lighter than your typical aftermarket rod. The prices for the R&D rods are pretty reasonable when compared with typical racing custom billet pieces.
The block is fitted with R&D's ductile iron sleeves, which allows a big oversize piston to be used. Although the stroke, bore and rod length are secret, Lookofsky's motor packs a whooping 2600cc of displacement. That is 400cc more than stock! The bore surfaces are finely finished so the low-tension rings can seat and seal quickly.
All of the main cap and head bolts are replaced with ARP studs to maintain a higher clamp load for better head gasket sealing and for additional strength for the bottom end. The block is fully deburred, all press-in oil passages plugs are replaced with screw-in plugs and the block is notched at the base of the cylinder bores for rod clearance needed with the big stroke.
R&D low-silicon pistons are hand-massaged to an incredible, unheard of 16:1 compression ratio, requiring the use of very high octane racing gas. Conventional wisdom says that compression ratios of above 14:1 are in the zone of diminishing returns, as combustion stability becomes an issue at this point. Somehow, the guys at R&D have figured a way to keep the fire lit with this hard squeeze. The pistons are aggressively gas-ported in an effort to maintain ring seal at the astronomical piston speeds seen with the long strokes, small rod ratios and high revs these engines see.
The pistons are fitted with Speed Pro piston rings. These lightweight, low inertia, low-tension rings are important to maintain good ring seal while avoiding ring flutter at the engine's ultra-fast piston speeds. In addition to gas-porting, the pistons also feature a gas trap between the number one and number two piston ring. Lightweight, full-floating H11 tool steel tapered pins hold the pistons to the rods.
When questioned about piston speed issues, SanAngelo stated that the engines still produce good top end power. This says loads about Honda's excellent port design and volumes about the head-work. Although SanAngelo isn't talking about these specs, we figure that these motors must run pretty low rod to stroke ratios, which makes port flow even more critical, especially at high rpm.
SanAngelo disconnects the balance shafts in the block on race engines, but for street and endurance engines he leaves them in for improved oil pump life.
The R&D cylinder head is pretty straightforward with slightly larger stainless steel valves with tuliped and undercut stems. Valve guides are stock and the porting is a clean, straightforward line-of-sight job. A narrow, but otherwise conventional 45 degree seat, three-angle valve job is used. The combustion chamber is CNC'ed and polished with minor unshrouding around the valves, nothing crazy here, just good straightforward work.
The heads are fitted with double valve springs and titanium retainers. An R&D cam with 0.480-inches of lift and 310 degrees of duration moves the valves. The cams are timed with adjustable timing gears to a secret, unspecified lobe centerline. These cams are, without a doubt, critical to the engine's ability to produce power to the usable 9200 rpm redline.
The engine is fitted with R&D's custom designed, stainless-steel, four-into-one headers, which feature a stepped primary diameter and a merged collector. A TWM manifold handles induction chores with dual 48mm sidedraft throttle bodies fired by a Speed Pro engine management system. The spark is provided by an MSD ignition system.
How much power do these parts get you? Lookofsky's record-setting engine pumps out 260 hp to the wheels at 8800 rpm with over 200 lb-ft of torque! The powerband is broad, wide and flat, with an equally flat torque curve; not your typical peaky Honda powerband at all
SanAngelo is proud to point out that this engine can be detuned for pump gas and lower-rpm driving and still put out 220 wheel hp and 180 lb-ft of torque. These are about the same numbers we would expect from a supercharged H22. Can you say project car, anyone?
SanAngelo also recommended keeping the engine below 2,400cc when building for heavy nitrous oxide use or turbocharging. The reduced displacement leaves more cylinder wall for increased strength. Can you imagine a 2.4-liter turbo H22?