In Reply to: Call Korman anyway...Nothing to lose! posted by Phaedrus on August 01, 2000 at 13:48:13:
'88 535is Dinan Turbo Final Edition
I would still call Korman. An intercooler is not a big deal to install if you are willing to do some plumbing. Volvo 240 Turbos ran without intercoolers and were extremely reliable, although they did give up some HP that would otherwise be available if an intercooler were used (the 740 Turbos which made another 20-30hp with virtually the same motor and same boost). Low boost turbos do not necessarily require intercoolers, but they don't have the HP potential that intercooled ones do.
The other reason why an E28 535i _could_ get away without an intercooler is that the boost is not only modest (5.5-6.0 psi) but also the compression of the E28 is only 8:1. The relatively low compression combined with modest boost makes detonation very unlikely. Intercooling would _still_ be a good idea...
From the performance perspective, my E28 535i (with 3.46 diff) will take my E34 535i to lunch any day of the week. With a turbo and some appropriate suspension and brake work, the E28 535i will make mincemeat of a stock or sharked E34 M5. The extra weight of the E34 M5 (more than 600 lbs when compared to my '85 535i) and the poor low end grunt of the M5 make it more of a autobahn stormer than a track car.
For my money, a turboed E28 535i would be the ultimate sleeper. Cheap to insure, cheaper parts (none of those $250+ sparkplug wires on an M5), and far more tossable on the track.
Rob's turboed M5 would be better still!