After the strong normally aspirated baseline had been established, we began our long quest to build the most power possible on pump gas by first using a small Weiand supercharger. This little two-lobe blower made our 355 think it was a 502! Beginning with Test 19 we also installed our first set of aluminum heads too. The Trick Flow Specialties (TFS) castings lowered DM's compression to a more blower-friendly 8.5:1 and gave us some extra breathing room with their large ports. To see how much power the blower would add, we baselined the engine with the TFS heads, Air Gap manifold, Demon carb, and a new COMP Cams NX flat-tappet hydraulic camshaft first (Test 19), then bolted on the blower (Test 20).

Test 19-Unblown:
Max 434 tq, 444 hp
Avg 401 tq, 340 hp
8.5:1 cr, TFS heads (Summit Racing PN TFS-30400013-CNC, 72cc chambers, 195cc runners, 2.02/1.60 valves), Edelbrock RPM Air-Gap manifold, COMP NX274H camshaft (274/292 adv dur, 230/244 dur @ .050, .487/.501 lift, 113 LS). COMP Cams 1.6:1 roller rockers. The lower compression and large camshaft didn't seem to hurt too much. In fact, it had some serious top end pull making 444hp at 6100 rpm. Low-end torque fell off, but we expected that since we were running a big cam combined with very low compression.

Test 20-Weiand blower:
Max 574 tq, 602 hp
Avg 539 tq, 462 hp
Installed the 177ci Weiand Pro-Street mini-blower, Holley HP950 supercharger carb out of the box, 36 degrees total advance, 100-octane unleaded pump gas and a can of octane booster. We offered a warm welcome to Mr. 600hp on this pull!

Right after the blower tests were completed we moved to electronic fuel injection. We heard that Edelbrock was making a new EFI manifold based on its Victor E casting and thought it would be a perfect match for the a F.A.S.T. EFI system we'd wanted to run. But, like always, we had to know how much power the engine would make with a goo-ol' carb first. So we equipped DM with a prototype COMP Cams EFI hydraulic roller camshaft and a Speed Demon 750 carb with corks plugging the fuel injector bosses and made a pull (Test 21).

Test 21-Carb baseline:
Max 430 tq, 474 hp
Avg 397 tq, 330 hp
TFS aluminum heads, Edelbrock Victor EFI manifold, COMP Xtreme Energy EFI prototype HR camshaft (281/288 adv dur, 230/236 dur @ .050, .544/.555 lift w/1.6 rockers, 113 LS). COMP 1.6:1 roller rockers, Speed Demon 750 carb, 36 degrees total advance. When compared to previous normally aspirated Test 19, DM's horsepower went through the roof! Peak jumped by 30 to an outstanding 474hp but torque fell off down low, so the extra power wasn't a freebie. COMP attributes the low-end losses to the more-aggressive ramp profiles on the NX274 hydraulic cam used back in Test 19. The hydraulic roller cam in Test 21 really begins to take over at higher rpm due to its reduced frictional losses.

Test 22-F.A.S.T. EFI w/ 30 lb./hr. injectors @ 50 psi:
Max 431 tq, 480 hp
Avg 400 tq, 332 hp
Installed the EFI system with Accufab throttle body and right away the EFI proved its superiority by bringing low-end torque back up and increasing top-end power to 480hp. Although power dropped slightly in the mid-range, which we think we could've recovered with some more tuning time.

Throughout all this we've learned that no matter how tough you build an engine, there comes a time when it will need to rest. So after Test 22 DM went back into the shop for a complete overhaul by the technicians at Speed-O-Motive and came out equipped with some new bottom-end components ready for battle. The first series of tests following the rebuild were pretty uneventful and mostly confirmed that the rebuild did not cost any power. Besides, we wanted to go in a different direction with this rebuild and test some more low-end power making products because we felt DM was already getting too far out of reach for many. So you'll note that power is way down compare to Tests 21-22.

Test 29-Freshly rebuilt with some new components:
Max 415 tq, 399 hp
Avg 397 tq, 316 hp
Installed World Products Sportsman II angle-plug iron heads (64cc chambers, 200cc runners, 2.02 intake valves, 1.60 exhaust valves) @ 10:1compression, Holley dual-plane intake manifold, HP750 carb, Lunati hydraulic roller cam (215/224 @ .050, 268/279 adv, .489 lift, 112 LS), COMP 1.6:1 roller rockers. Also note: the following tests were done at a different dyno facility, so the results are not quite comparable to previous tests.

Immediately following our less than exciting low-end power building exercise, we got our hands on one of ATI 's Procharger D-1SC centrifugal superchargers, which definitely gave us the "most power on pump gas" yet. For the blower bash our champions of the dyno and wrench, Speed-O-Motive, also dove back into DM's storage locker and pulled out the same old set of TFS aluminum heads we'd ran before. Speed-O also installed a new Crane Cams hydraulic roller with lots of lift and duration and then they topped it all off with an ACCEL GEN VII DFI system for the utmost in tunability. You may also note that compression is up slightly when compared to the other blower tests using the TFS heads, (Tests 19-20). That's because during the rebuild, Speed-O-Motive installed a new set of Lunati flattop pistons with a taller compression height, moving the piston top higher up the bore for a true "zero" deck. Previously, the old pistons were installed about .040-inch below the deck to better simulate what might really be under you hood. But, by this time we wanted to truly optimize everything.

Test 31-Unblown:
Max 424 tq, 466 hp
Avg 393 tq, 333 hp
9.1:1 cr, TFS aluminum heads, Accel Gen VII DFI w/ 55 lb/hr, Crane Cams HR camshaft (240/248 @ .050", 306 /314 adv, .595 lift, 114 LS), COMP 1.6:1 rockers. Left the blower belt and induction plumbing off to baseline DM without any boost.

Test 32-ATI blower:
Max 613 tq, 697 hp
Avg 545 tq, 471 hp
Installed ATI Procharger D-1SC centrifugal supercharger with 4.25" pulley and got 697hp and 613 lb-ft of torque, all on 91-octane pump gas.

Right after the blower test we moved back to making power the old-fashioned way, on the motor, and got this little beast up to some pretty big power figures.

Test 34-Vic Jr. heads, COMP XR280R cam:
Max 441 tq, 504 hp
Avg 404 tq, 359 hp
Next we tried Edelbrock's Victor Jr. heads @ 10:1cr, (64cc chambers, 215cc runners, 2.08" intake valves, 1.60" exhaust valves), with a Vic Jr. manifold and one of COMP's Xtreme Energy Street Roller camshafts (242/248 @ .050, 280/286 adv, .600/.606 lift w/ COMP 1.6:1 rockers, 110 LS), and a 650cfm Mighty Demon 650 carb. The results were 504hp and 441 lb-ft tq!

Test 35-Total Seal rings:
Max 453 tq, 497 hp
Avg 413 tq, 366 hp
This one was all about sealing. Total Seals' gapless top rings were installed and power and torque was increased up to 6,000 rpm. Average figures also climbed as well and some more tuning time probably would have gained us back the top-end power we lost.

The last tests got us thinking that bigger could truly be better. So, after acquiring an Edelbrock Super Victor manifold with an even larger COMP roller, we went back to see if we could break the 550hp barrier. Well...DM certainly made more power than it did the month before, but the results were a far cry from spectacular. After swapping the cam, intake, and carburetor, we saw an 11hp peak increase and 2 lb-ft of extra peak torque. While we're certainly not putting it down, for the time, effort, and expense of the swap the results were not worth it in our minds. All that means is that we've pretty much hit the wall with the current parts combination and just like on the street, throwing bigger parts at it won't make it go any faster. So we're rethinking our strategy and planning some cool stuff for DM's future. We're confident we'll see close to 600 N.A. horsepower soon, and still on pump gas too. One thing we know is that it won't be easy. But, it'll sure be fun!

Test 36-Super Vic, COMP XR286R cam:
Max 455 tq, 508 hp
Avg 420 tq, 365 hp
Swapped Edelbrock Super Victor manifold and COMP XR286R solid roller camshaft (248/254 @ .050, 286/292 adv, .606/.612 lift w/ COMP 1.6:1 rockers, 110 LS), Holley HP1000 carb, 38 degrees advance.