ACCEL Gen 7 System - 1988 Pontiac Firebird - Magnum Returns

Our 396-cid Third-Gen makes big progress at the dragstrip thanks to DFI's new Gen 7 and professional tuning by Second Street Speed

Johnny Hunkins Jan 1, 2003 0 Comment(s)

Step By Step

Exhibit A: The 396 cubic-inch small-block in our 1988 Firebird project car, which was built by Strope Speed Shop. This naturally-aspirated 11:1 mill packs a stock, clearanced, .030-over block, splayed billet main caps, Cola forged crank, Lunati Pro Mod rods, Lunati custom forged pistons, CNC-ported AFR 190 aluminum heads, a Comp Cams hydraulic roller cam, Comp Cams valvetrain, ACCEL SuperRam intake, and SLP ceramic-coated 1 3/4-inch shorty headers. On an engine dyno with a Holley 750-cfm carb and 300-36 intake, this mild "smogger" 396 made 481 hp at 5800 rpm and 485 lb.-ft. at 4200 rpm. In fuel-injected trim using the stock ECM it made just 226 rear wheel hp--around 290 flywheel hp. Something--or a combination of things--was very wrong. As we would eventually discover, the factory computer and the restrictive factory air ducting were the culprits.

The factory ECM was not the primary problem, it was the programming. GM has always guarded and continues to guard its programming with encryption, making repair, diagnosis and recalibration extremely difficult. Even if you have access to one of the many calibration programs and an EPROM burner/eraser, the iterative process of tuning for maximum performance and acceptable driveability can take years in extreme cases. If you're one of the few who has more time than money--or lots of time and lots of money--this may be a viable option for you, but it sure wasn't for us.

It's long overdue, but we finally got everything to come together in the engine room of our long-term third-gen project car, Magnum TPI. We'll let the photos tell most of the story, but if you want to bone up on the first three parts of our 396 stroker build up, we suggest you reference the September 2001, November 2001 and January 2002 issues (see "Pumping Up," parts 1, 2 & 3, respectively). Here, we're dealing strictly with the engine management portion of the project, but we still need to acknowledge the contributions of Lunati (rods, pistons, bearings, rings, oil pump), Cola (forged crank), AFR (cylinder heads), Comp Cams (cam, valvetrain), ACCEL (SuperRam intake, throttle body), Evans Cooling (cooling system), Be-Cool (cooling fans), Royal Purple (lubricants), and Strope Speed Shop (engine assembly and installation).

The big news here is DFI's new Gen 7 engine management system. It offers the sophistication and flexibility of Detroit's most advanced engine control systems combined with the programming ease of a Windows-based program. This ease of programming is significant, because to make max power in a street engine like our 396, it's just not practical, or even possible, with 14-year-old electronics. Not only is the Gen 7 a performance breakthrough--incorporating the latest in wide-band 02 technology--but as you'll see, it's got a scandalously low price too. (For more on the DFI Gen 7, check out "Better By Design" in the October 2002 issue.)

The other big breakthrough is Fast Track Performance's jumper wiring harness. This piece allows our factory ECM to control all emission functions just as it did when our car rolled off the assembly line--and it can for you too, provided all your smog gear still exists and operates properly. Essentially, Fast Track's harness allows an aftermarket computer such as the DFI to run the engine while the OEM computer runs the smog gear. It's an elegant solution to a difficult problem, especially for street-legal cars in smog-controlled states like California and New Jersey.

The final piece of the puzzle was finding a qualified engine management installation center like Second Street Speed to do the dyno tuning. These guys know how to make cars run and have some of the fastest EFI cars on the east coast running out of their shop. When Magnum TPI finally came under the gentle electronic tutelage of Second Street's Bill Hunsberger, we knew we were seeing the light at the end of the tunnel.

As you'll see, Hunsberger got us hooked up, dialed in and tuned up with Second Street's vast array of gear, including its wide-band monitor, CDS data acquisition and Dynojet chassis dyno. It also offers complete engine building services, a state-of-the-art SuperFlow 1020 flowbench and a SuperFlow engine dyno equipped for fuel injection, so if you've got a truly hairy GM-powered street car in need of attention, give Second Street a call--they can handle it.

We did uncover some expected airflow limitations which cut substantially into our power, but at least we can hang a real number on it and get it fixed for our next trip to the track. Even with the restriction of the factory air intake ductwork and MAF housing, we managed a respectable 12.30/109.4 in the summer heat at full weight. As demonstrated by the Second Street dyno, there's another 30 rearwheel horsepower waiting for us with a proper inlet tract, so we are definitely within reach of running 11s on pump gas with catalytic converters and a smog-legal tune. Check out the accompanying photo captions for the entire story.

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