When it comes to exhaust manifolds, Czarnota said that stock headers work fine, up to 11-second hp levels. They are prone to cracking with the common trouble point being the driver's side header where the runner joins the common tubing. It is quite beneficial to port-match headers to the block, because smooth flow here means better turbo spool up and more power. We had our stock headers welded and after about 300 miles, we detected an exhaust leak. Our plan is to examine the header and then consider what action, if any, we are going to take.
On the intercooler front, we kept it simple at this stage, by using a stock chiller outfitted with a Duttweiler neck. When the intercooled Buicks hit the streets, Kenny Duttweiler was playing around with every aspect of the Turbo Regal. In examining the intercooler, he didn't like the harsh bend the ducting was forced make from the intercooler into the throttle body. On a lark, he decided to run the intercooler backwards and realized improved performance. Knowing that the angle of entrance into the motor was critical he developed a cast, weld-on neck that improved flow into the motor.
During the break-in period, we noticed the engine was running about 200 degrees in the summer heat. This condition could have been a factor during the tuning stages. We planned to run 15 psi of boost, just like the previous set-up to illustrate the efficiency of the Limit Engineering turbo. Czarnota played with the boost setting for kicks and noticed a touch of detonation past 16 psi. While 200 degrees in heat of summer is well within parameters, we hope to turn up the boost in the future. Since we plan to go with a front-mount intercooler, a radiator swap is inevitable. We have a heavy-duty aluminum radiator from Be Cool, which we will install at a later date.
The car is an absolute blast to drive, it moves quicker than a running back with a 350-pound linebacker breathing down his neck. Spool-up is fast and the turbo even sounds trick. In the next installment, we will look at the turbo itself, talk about turbo sizing in general, hit the dyno and the strip, and talk more about the drivability of Project Boneyard Buick.
Balancing ActWhile lining up our 42 lb/hr injectors from RC Engineering, we asked that RC's Russ Collins do a leakdown and balance-and- blueprint job on our stockers. You may remember that we swapped a set of 30 lb/hr injectors in place of the stock 28 pounders and netted a 25-hp gain at the wheels in the August 2000 bolt-on article. This was a shocking increase in power. The chart that RC Engineering provided vividly illustrated why so much improvement was made with a simple swap to a 2-lb/hr larger injector. The printout reveals we had problems with spray patterns, more than just a differential in flow problems. We had one dripping injector and two rated at Fair, while the remaining trio checked in at Good. On the flow side, system balance went from 5.2 percent (which is not terribly bad) to .6 percent, which is phenomenal. Volume was also vividly improved upon with the average jumping from 291 cc/min to 309.4 cc/min. If you have a high-mileage engine and plan to incorporate some power adders, it is wise to invest in a set of balanced and blueprinted injectors so you can realize the maximum power potential while enjoying the best fuel mileage possible.