The A/F gauge readings on the GN were off a point (10.5 A/F) due to a buildup of tetraethyl lead from the leaded race fuel we mix with 93-octane unleaded pump gas (future use of unleaded race gas or meth injection is needed). On our first pass we were pleased to learn the A/F was at a near perfect 11.5 (according to the wideband O2 sensor on their Mustang dynamometer). Matt Hauffe has been handling driving and tuning duties to the Turbo Regal right from the beginning of Turbo Buick Basics. Big kudos to Turbo Tweak after considering we still have only 42 lb injectors, up to this point the GN has never ran stronger!Īn appointment was made at our favorite local dyno tuning shop, Tune Time Performance in Toms River, New Jersey.
#Scanmaster buick full#
On the dyno we'll tune the full boost A/F to be in the safe zone of 11.5 to 11.9:1. Now we observed a safe A/F in the mid-10's at full boost and WOT. With the old chip the A/F at WOT (according to the GN's A/F gauge) was a risky 12.1 to 12.4 at 20-21 psi boost. After swapping chips, a test-drive revealed a smoother, more responsive running engine, quicker spool-up along with a now perfect A/F (14.7 to 15.1) at idle. In the meantime, we'll keep a close eye on the A/F gauge. Since it's programmable, we'll be able to add or reduce timing and change the fuel mixture (richer/leaner) for a safe air/fuel mixture. Also the old chip was set-up for 15-17psi while the new one is 20-22psi boost. This new chip will increase the ignition timing from the old chip's 19/17-degrees to 23/20-degrees at full boost. TT burned us a chip for our latest combo (62 mm turbo, ported heads, roller cam, larger intercooler neck) with additional timing and fuel mixture for using 100 to 105 octane fuel. We ordered it for a 50/50 race gas/pump gas mix. Next we installed the new custom chip from Turbo Tweak. This time the EGR block-off plate we installed blew-out its gasket causing a vacuum leak and turbo lag.
![scanmaster buick scanmaster buick](http://www.turbotweakstore.com/v/vspfiles/photos/1007-Buick-2.jpg)
Then, during a test ride, after setting the Cam Positioning Sensor (CPS) timing, another EGR leak (there was also an EGR leak in Part 7) came back to haunt us.
#Scanmaster buick install#
We later found out the timing issue was because we didn't install the cam positioning sensor properly (it was 180-degrees out) when we swapped to the forged short-block in Part 7. Full boost (20-21psi) didn't develop until we were over 100-feet downtrack causing the GN to run disappointingly low to mid 12's (we were expecting to go mid 11's). At the starting line while power-braking for our holeshot, we couldn't even build more than 3-psi of boost. Unbeknown to us, the timing (ignition and injector pulse) was way off, causing terrible turbo lag. (Note: never take a Turbo Buick to the track without knowing your car can't even do a 5-psi powerbrake burnout.) Quickly, we learned the importance of proper tuning and preparation before running a Turbo Buick at the strip. Well, we made it back to Atco, but we went ill prepared and were nonetheless disappointed. In the last episode (September, 2011) we promised we'd take our buddy Tim Cairone's '87 Buick GN back to Atco Dragway to strip-test its latest combination.