I agree - the 2.2/2.5 turbo motor was stout. Still have my first one:
I've prepped, raced, modded, and sold many MANY more in my day. The 2.2/2.5 motor was forged internals from the factory, and the reason many of them died is, people didn't know how to behave with a turbo. Key is idle it down for at least 2 minutes after a hard run, to get fresh (cool) oil and coolant through the turbo center section and keep hot oil from 'coking' (turning to dry carbon - basically charcoal) the bearings.
My car above has been returned to stock because I don't race 'em anymore (and it's one of 26 built in this model and color combo), but back in the day I removed the small Mitsu turbocharger and replaced with a 60-trim Garrett; added an intercooler; added Mopar Performance +60 injectors and an adjustable fuel pressure regulator. It still has the manual boost controller and the boost and air/fuel gauges from back then. With stock injectors, I have enough fuel to safely run 18psi (back in its racing days, I was running 30+). The biggest thing was keeping the headgaskets in, and the way to do that was: get a good machinist to deck the head F-L-A-T, without upping compression too much. Get the Mopar Performance 006 (I think; it's been a while) or 007 headgasket - the difference being cross-drilled cooling passages or no - and put it together with 11mm ARP head studs. 30psi, all day long, never pop another gasket unless something else failed (like an injector). And my personal car still has the factory clutch in the A568 Getrag manual transmission.
My car is about the pinnacle of the 8V cars - big disc brakes all around; fat sway bars; performance valving in the shocks and struts; quick ratio steering rack. They handle amazingly well, and with the advent of the intermediate shaft driveline (three driveshafts - a center shaft going to the right halfshaft - instead of a short left shaft and a looong right shaft) went a long way to eliminating the torque steer, and factory my car was rated at 152hp and 210 lb-ft. Not bad for 7psi boost in a 2.5L four banger.
The true best were the 91/92 R/T cars - Spirit and Daytona - that had the 16v Lotus cylinder head. 225hp stock, paired with the same chassis refinements and transmission my car has. I've had a couple of those, but parts are getting really scarce for them now with virtually no aftermarket support...I have 8v heads stacked like firewood as spares, but only had one spare 16v head, so I sold my R/T a few years back to a buddy who had a stack of spares. Another one I sold recently (to help fund my Charger, actually - and to make a garage space for it!) was this one:
My 1989 Shelby CSX-VNT, one of 15 built, 48k miles, and autographed by Carroll himself in 2001. Carroll Shelby loved these little turbocars and built them for Chrysler in 1986 (Shelby GLH-S, based on the Omni), 1987 (Shelby Charger GLHS, and Shelby CSX based on the Shadow), 1988 (Shelby CSX-T, a Shadow sold to Thrifty rent-a-car much like the old GT350H cars), and 1989 (the CSX-VNT, and the Dakota - he was the first to put a V8 in the Dakota body, before Chrysler had done it). All his cars were "numbered" - mine was #135 of 500 built, and 1 of 15 with both options (wide 225 series Gatorback tires, and Recaro racing seats). Industry firsts - Variable Nozzle Turbocharger, which is now pretty common mostly in diesels; and Fiberide plastic composite road wheels. Not aluminum wheels...
plastic. This car handled like it was on rails. Further upgraded springs and struts, steering ratios, brakes and calipers, Shelby intercooled them all and upped the boost from Chrysler stock and the VNT boost hit RIGHT NOW when you put your foot in it! All were 5 speed manuals (getrag A555 units), and they are a HOOT to drive.
If you find one, grab it. They're a blast. Bulletproof it with head studs and a good gasket, and idle it down after a hard run....and you'll be good forever. Great fuel economy to boot (if you can keep out of the boost!).
The GN/GNX? Was pretty damn awesome back in the day, and I'm not surprised the money they're bringing now. I drove a GNX new and WOW - but I couldn't talk dad into it. He stuck with his Cutlasses.
