We profess to be all about the aftermarket selection and bringing out the potential in your car that the factory just plain left out, but where are all the posts concerning this topic? From here on out, that’s where our writing will swerve.
It can only start in one place – Isuzu. Yes, it’s a rare marque, and yes, they practically don’t exist today. Stamping out heavy-duty engines for the increasingly dubious corporation known as GM doesn’t count. In its day, however, Isuzu, when not being meddled with, made some great cars. The design and execution, for the most part, rivalled anything else from Japan, given the class and range of offerings.
In particular, a few models stand out, and are worthy of bowing down to every afternoon at 3:00pm. From 1985-1989, the first generation Isuzu Impulse came with turbocharged 2.0-Liter engine that produced 140 Japanese ponies and even more torque. A rather weak non-turbo version was also offered, but we can overlook that discrepancy. In 1988, GM brought in Lotus to design a suspension package, making the ‘88-’89 Turbo Impulses the best of the lot.
This being a singularly rare and unique car, like many Isuzu cars, the existing aftermarket just plain doesn’t exist. That said, if you’re creative and apply some common sense and basic tuning knowledge (as with every car), you can tweak the first-generation Impulse to become even better. Working with a factory turbo gives us a head-start, as a lot of the engineering and fabrication has already been done. Just like any other engine, think airflow — before and after the engine. A cold-air intake (that’s cold, as in cold, not short-ram or any other variation where the intake filter sits in the hot engine compartment) and good 2.5″ catback exhaust will work wonders.
Normally, this is where a good Isuzu specialist will step up to the bat. Back in the day, Isuzuperformance (headed by Bill Luton) was the only place to turn. Due to some unsavory business practices and downright selfishness on the part of Bill & Co., most of the original parts are now unavailable, as they have sold out and gone domestic with their production. As if Cavaliers and Sunfires needed more aftermarket support. Infuriatingly, Isuzu racing parts are still developed and flaunted on their home page, every one of them being “Not For Sale To The General Public”. Now that’s good business, and a good way to aid enthusiasts and customers alike.
The automotive world being what it has been for the past several decades, we here in the U.S. got screwed, as usual, out of the really cool options, such as the “Bella” or “Nero” trim level, the latter of which must have been named after the Roman emporer. Guigiaro penned the curvacious bodywork, which in all likelyhood began to fuel the jealousy that eventually ended in GM killing off Isuzu’s U.S. distribution. You may be able to tell we don’t care for GM that much.
Irmscher, a German tuning company, was involved with some trick bits, including body parts and suspension work . . . naturally available only on Japanese Impulses (called the Isuzu Piazza there). Those parts, incidentally, are even more rare than Isuzu cars themselves, somewhere around the likelihood of hearing Bush admit he screwed up the entire war in Iraq. If you ever find yourself in the enviable position of happening across an Irmscher part for a Piazza/Impulse, do everything in your power short of selling your children to get ahold of it. On second thought, go ahead and sell them–kids are everywhere. We’re talking rare car parts here.
Everywhere else in the world except here, an overboost package with another 40 horses came out in 1985. Fortunately, with a simple manual boost controller and blow-off valve, this can be attained rather easily for yourself. Mind you, dialing in something ridiculous like 30psi will get you perhaps to the end of your driveway in a spectacular cloud of smoke and regret. Stock boost is set at around 7.8, so if you aim for 10 (providing your engine is in good working order), you should be good to go.
Expert advice (to include more than you ever wanted to know about Isuzus, probably more than the Isuzu makers themselves) can be found at www.isuzone.org. For the first-generation Impulse, you want to talk to Soren. Conversely, as on many forums, if you jump in there and ask questions with out Searching yourself first, Robbie (skaterkid) will be talking to you. Be warned.
