In the February issue of GMHTP, I embarked on an exciting project to replace my 2001 Z28's LS1 with a 480-horsepower crate engine from GM Performance Parts. Down at TT Performance in North Jersey, we got the LS1 pulled and started swapping parts onto the big crate in preparation for installation.
However, this is not a direct swap electronically-in order to benefit from the huge airflow and big power/torque numbers of GM's Generation IV engines, we'd have to do some modifications. For those of you unfamiliar with the old-style 24x/new-style 58x reluctor wheel saga, it wasn't long ago that you had limited options for your late-model F-body: you could use the universal GMPP controller and harness for an easy LS3 (or other Gen IV) connection, but your factory gauges wouldn't work. Or you could completely disassemble the bottom end of your new crate engine to swap on a 24x reluctor wheel (compatible with your LS1 PCM) and swap the cam, cam sprocket, and timing cover. That's a lot of work-around eight hours for a very experienced engine guy, and much longer for novices.
Thankfully, the aftermarket has been working feverishly to create adapters to easily mate the LS3 with the older LS1 harness and PCM-allowing for working factory gauges without tearing apart a crate engine! Early planning for this project had me contacting Lingenfelter Performance Engineering-a legendary name in the EFI GM world-for advice on how to proceed with the swap. LPE had done more than its fair share of Gen IV conversions, and informed me that its 58x to 24x Trigger Conversion Module was now in the catalogue and at my disposal. I've been in this business for a long time now, and when undertaking a complex project, the words "conversion" and "module" invariably mean less hassle! LPE also provided more goodies to simplify this swap; I'll show 'em to you in the captions.
I've chosen a dual-disc clutch for this project; this is no slight to the SPEC single-disc in 1SC-YA now, as it has held up admirably to some very aggressive driving and revved ultra-quick with its lightweight options. But there has been some great and some not-so-great reports from dual disc clutch users who street-drive them, and I want to experience a "dual" with this swap to get some first-hand experience. I contacted Ram and after a few conversations, had a Street Dual system with its hydraulics sent my way.
And finally, I mentioned last month that this Z's engine harness is toast-thankfully, Scoggin-Dickey can still get original GM harnesses at a decent price, so I jumped on that and they sent it out. I recommend a new wiring harness any time a major swap is performed on an older or high-mile car, it usually saves electrical headaches down the road. My hardtop is aching to hit the dyno, strip and street, so let's get to it.
 Picking up from last issue,...  Picking up from last issue, my old LS1 had been removed from the cradle, which the TTP staff graciously de-greased, as it was pretty dirty for only 46,000 miles. The LS376/480 was hoisted carefully onto the cradle; the bolts are threaded through the new GM motor mounts, and are torqued to 70 ft-lb. |  I've never owned a dual-disc...  I've never owned a dual-disc clutch, and was looking forward to testing RAM's new Street Dual Disc unit (part No. 90-2100, $1,300). This piece is comprised of an aluminum flywheel, an "easy pedal effort" diaphragm pressure plate, a special floater plate/retainer system, and RAM's 300-series clutch discs. The hard parts combine with the organic material to live behind 900-plus foot-pounds of torque-with very manageable pedal power. It needs an adjustable master, so we used RAM's unit (part No. 78165, $350) and also its new slave setup (part No. 510, $175). |  RAM's new dual-disc clutch...  RAM's new dual-disc clutch is disassembled. Rob marks where all the stands need to go (three composite, three metal are used for this mostly street-driven car for quiet operation-for lots of track action you'll want to use all metal and live with a little more noise). |