Originally Posted by lsc224
That's awesome Craig....What do you have under the hood of that RX7?
Street port (mild compared to what the PR
folks do) four port 13B, Holley 650DP (modified....), Racing Beat manifold, custom manifold spacer to convert to open plenum, full RB exhaust, RB aluminum flywheel, clutch and pp. Dual MSD 6AL's, direct fire/wasted spark to the leading spark plugs, trailing fired through distributor. 13.54@102mph
Shortblock cost $350 in parts to build. 1984 rotors and eccentric shaft, 1982ish side housings, 1976-78(?) rotor housings. Five apex seals at the minimum spec, one well below.
The motor was built just to run long enough to be the guinea pig for the future turbo setup. After minimal NA tuning it ran pretty well considering the quality of the parts. After severe abuse and shifting (and sometimes launching) at 9300rpms (made great power after 9500 but just felt bad spinning it that high with less than stock parts) one of the apex seals cracked. The turbo setup was never installed.
Could have rebuilt the motor within a couple of days but was demoralized. Sold all the turbo bits and parted the car out. Lost all self respect and bought a POS salvage title miata.
Not that anyone asked but there are two things I'm happy with. My stock 84 GSL-SE, 207k miles on the stock engine, tons of Racing Beat bolt ons and the ignition setup above - ran a 14.38@93mph.
With a stock S4 (1986) 13B installed and the same setup as above, car lightened to 2420lbs going down the track - ran a 13.96@97mph.
First night down the track in the miata gave a 17.02@80mph. Painful!